Tropical Storm Laura

Tropical Depression Laura Track 2200 Hours August 27 2020
Tropical Depression Laura Track 2200 Hours August 27 2020

Tropical Storm Laura Wind Speed FieldTropical Storm LauraNWS National Hurricane Center Miami FL1000 PM CDT Thu Aug 27, 2020 (see final video below)

Laura has continued to spin down after being over land for nearly a day. Surface observations no longer support tropical storm intensity, and therefore the system is being downgraded to a tropical depression. The cyclone should become a post-tropical low within a couple of days, and then transform into an extratropical cyclone while moving off the U.S. east coast. The official forecast shows some restrengthening in 2-4 days due to baroclinic processes. However, by the end of the forecast period, the system should be absorbed by a larger extratropical cyclone to the east of the Canadian Maritimes.

Laura continues to move north-northeastward or at about 015/13 kt. A turn toward the northeast and east-northeast with increasing forward speed is likely while the cyclone becomes embedded in the stronger westerly flow. The official track forecast follows the latest dynamical model consensus. There is a continued threat of flooding from Laura for the next couple of days.

This is the last NHC advisory on Laura.

Key Messages:

  • 1. Additional rainfall will continue to lead to flash flooding along small streams, urban areas, roadways, and minor to moderate river flooding across portions of Louisiana, Mississippi and Arkansas. The heavy rainfall threat and flash and urban flooding potential will spread northeastward into the middle-Mississippi, lower Ohio and Tennessee Valleys, and Mid-Atlantic States Friday and Saturday.
  • 2. A few tornadoes remain possible this evening across eastern Arkansas, western Tennessee, northern Mississippi, and the Missouri Bootheel. The risk for a few tornadoes is expected to redevelop Friday afternoon into the evening across parts of the Mid-South and Tennessee Valley regions.
FORECAST POSITIONS AND MAX WINDS

INIT  28/0300Z 35.1N  92.0W   30 KT  35 MPH - Depression (WNW  Beebe, AR)
 12H  28/1200Z 36.3N  91.0W   30 KT  35 MPH - Depression (WNW  Pocahontas, AR)
 24H  29/0000Z 37.3N  87.8W   25 KT  30 MPH - Depression (ESE  Providence, KY)
 36H  29/1200Z 38.0N  82.3W   25 KT  30 MPH - Post Tropical (WSW Harts, WV)
 48H  30/0000Z 38.5N  75.5W   25 KT  30 MPH - Post Tropical (ESE Laurel, DE)
 60H  30/1200Z 41.5N  67.5W   35 KT  40 MPH - Post Tropical (ESE Boston, MA)
 72H  31/0000Z 44.0N  60.5W   45 KT  50 MPH - Post Tropical (ESE Lunenburg, Canada)
 96H  01/0000Z 48.0N  52.0W   40 KT  45 MPH - Post Tropical (ENE St. John's, Canada)
120H  02/0000Z...DISSIPATED

NWS National Hurricane Center Miami FL 400 PM CDT Thu Aug 27, 2020 

Laura has continued to weaken this afternoon. The satellite and radar presentation of the tropical cyclone has continued to degrade, and the center has now moved into southern Arkansas. The initial intensity has been reduced to 45 kt, and is based on a blend of surface observations, Doppler radar data, and typical over land tropical cyclone filling rates. Sustained tropical storm force winds have been observed in northern Louisiana, and wind gusts to nearly 50 kt were reported in southern Arkansas earlier this afternoon.

Laura will continue to rapidly weaken during the next 6-12 hours, and it is expected to become a tropical depression either this evening or overnight. The extratropical remnants could strengthen over the western Atlantic early next week, and the track and intensity forecast for that time is based on guidance from the NOAA Ocean Prediction Center.

The tropical storm has turned north-northeastward or 015/13 kt. The cyclone is forecast to turn northeastward, and then east- northeastward as it becomes embedded within the mid-latitude westerlies on Friday. This motion will take Laura or its remnants across the central Appalachians and to the Mid-Atlantic states on Saturday. After that time, the system should accelerate east-northeastward to northeastward over the western Atlantic. The updated NHC track forecast remains similar to the previous advisory and is close to the various consensus models.

Key Messages:

  • 1. Tropical storm-force winds, especially in gusts, will continue near the center of Laura over portions of extreme northern Louisiana and Arkansas this evening.
  • 2. Flash flooding along small streams, urban areas, and roadways will continue across portions of Louisiana, Mississippi and Arkansas. Additional rainfall will also lead to minor to moderate freshwater river flooding. The heavy rainfall threat and flash and urban flooding potential will spread northeastward into the middle-Mississippi, lower Ohio and Tennessee Valleys, and Mid-Atlantic States Friday and Saturday.
  • 3. A few tornadoes are possible this evening across central and eastern Arkansas into Mississippi. The risk for a few tornadoes should redevelop Friday afternoon and evening across parts of the Mid-South and Tennessee Valley regions.
FORECAST POSITIONS AND MAX WINDS

INIT  27/2100Z 33.4N  92.8W   45 KT  50 MPH - Tropical Storm (WNW  Louann, AR)
 12H  28/0600Z 35.3N  91.7W   30 KT  35 MPH - Depression (ENE Searcy, AR)
 24H  28/1800Z 36.7N  89.3W   25 KT  30 MPH - Depression (WSW Pinhook, MO)
 36H  29/0600Z 37.4N  85.1W   25 KT  30 MPH - Post Tropical (ESE Merrimac, KY)
 48H  29/1800Z 38.2N  78.6W   25 KT  30 MPH - Post Tropical (WSW Boonesville, VA)
 60H  30/0600Z 39.6N  70.9W   35 KT  40 MPH - Post Tropical (ENE Atlantic City, NJ)
 72H  30/1800Z 43.1N  63.4W   45 KT  50 MPH - Post Tropical (ESE Shelburne, Canada)
 96H  31/1800Z 48.8N  50.7W   45 KT  50 MPH - Post Tropical (ENE St. John's, Canada)
120H  01/1800Z...DISSIPATED

NWS National Hurricane Center Miami FL  1000 AM CDT Thu Aug 27, 2020 

Laura has continued to move inland over west-central Louisiana this morning. Satellite and radar imagery has shown a gradual filling of the eye, and a reduction in Doppler velocities in the northeastern eyewall. The initial intensity is set at 65 kt, based on a reduction of the Doppler velocities and the typical filling rate of inland hurricanes. The highest wind gusts at official observing sites within the past few hours has been at Alexandria, Louisiana, where a gust to 75 kt has been reported.

The hurricane is moving slightly east of due north or 005/14 kt. A general northward motion should continue through this evening as the hurricane moves around the western portion of a mid-level ridge over the southeastern United States. Laura should turn northeastward overnight while it moves across Arkansas and becomes embedded within the mid-latitude westerlies. A faster east-northeastward motion is forecast by late Friday, which will bring Laura or its remnants across the central Appalachians and to the Mid-Atlantic states on Saturday. After that time, the system is expected to accelerate east-northeastward to northeastward over the western Atlantic.

Laura will continue to rapidly weaken today while it moves farther inland. The cyclone will become a tropical storm this afternoon and is expected to weaken to a tropical depression tonight or early Friday. Although Laura is weakening, strong wind gusts are likely to spread over northern Louisiana and Arkansas into this evening. The UKMET and ECMWF models continue show the extratropical remnants of Laura strengthening somewhat over the western Atlantic, and the NHC forecast continues to depict the system as a gale-force low at days 3-5. An alternate scenario is for the system to be absorbed by a frontal boundary over the western Atlantic before the end of the forecast period. The extratropical portion of the forecast is based on guidance from the NOAA Ocean Prediction Center.

Key Messages:

  • 1. Dangerous storm surge will result in elevated water levels for the next few hours along the Gulf Coast from Sabine Pass, Texas, to Port Fourchon, Louisiana. In some areas where surge penetrated far inland, flood waters will not fully recede for several days.
  • 2. Damaging winds will continue near the center of Laura over portions of northern Louisiana and Arkansas today and this evening.
  • 3. Widespread flash flooding along small streams, urban areas, and roadways will continue across portions of Louisiana, Mississippi, and Arkansas. Additional rainfall will also lead to minor to moderate freshwater river flooding. The heavy rainfall threat and flash and urban flooding potential will spread northeastward into the middle-Mississippi, lower Ohio and Tennessee Valleys, and Mid-Atlantic States Friday and Saturday.
FORECAST POSITIONS AND MAX WINDS

INIT  27/1500Z 31.9N  93.1W   65 KT  75 MPH - Category 1 (ESE  Campti, LA)
 12H  28/0000Z 33.9N  92.7W   40 KT  45 MPH - Tropical Storm (WNW  Holly Springs, AR)
 24H  28/1200Z 35.8N  91.2W   30 KT  35 MPH - Depression (WSW Swifton, AR)
 36H  29/0000Z 37.0N  87.7W   25 KT  30 MPH - Depression (ENE Cerulean, KY)
 48H  29/1200Z 38.0N  82.1W   25 KT  30 MPH - Post Tropical (ESE  Harts, WV)
 60H  30/0000Z 38.7N  74.9W   30 KT  35 MPH - Post Tropical (ESE Cape May, NJ)
 72H  30/1200Z 41.8N  66.7W   45 KT  50 MPH - Post Tropical (ESE Boston, MA)
 96H  31/1200Z 50.0N  53.5W   45 KT  50 MPH - Post Tropical (ESE Joe Batts Arm, Canada)
120H  01/1200Z 53.5N  43.0W   45 KT  50 MPH - Post Tropical (ESE Greenland)

NWS National Hurricane Center Miami FL 1000 PM CDT Wed Aug 26, 2020

Extremely dangerous Laura has the signature of a classic hurricane on satellite images, with a well-defined eye surrounded by very deep convection. There is little evidence of shear, and the upper-level outflow pattern is extremely well defined, while the cyclone is over sea surface temperatures near 30 deg C. Observations from both NOAA and Air Force Hurricane Hunter aircraft show that Laura continued to strengthen during the evening. Using a blend of adjusted flight-level and SFMR-observed surface winds, the intensity estimate is 130 kt for this advisory. Since there is now little time remaining for the system over water, no significant change in intensity is anticipated until the center crosses the coastline. Laura will weaken rapidly after it begins to move over land, but destructive winds should spread well inland, more than 100 miles, along its path. Later in the forecast period, the ECMWF and U.K. Met. Office global models indicate some baroclinic re-intensification as the remnants of Laura move off the U.S. East coast, and this is reflected in the NHC forecast.

Laura has begun to turn northward as it moves around the western side of a subtropical high pressure area, and the initial motion is about 340/13 kt. The track forecast is essentially unchanged from the previous advisories. The cyclone should move through a weakness in the ridge and turn to the northeast over the next day or two. Then the system should accelerate toward the east-northeast while embedded in the westerlies. The official track forecast remains close to both the simple and the corrected dynamical model consensus predictions, TVCA and HCCA.

Laura is a large hurricane, and users are reminded to not focus on the precise track forecast since wind, storm surge, and rainfall hazards extend far from the center.

Key Messages:

  • 1. Unsurvivable storm surge with large and destructive waves will cause catastrophic damage from Sea Rim State Park, Texas, to Intracoastal City, Louisiana, including Calcasieu and Sabine Lakes. This surge could penetrate up to 40 miles inland from the immediate coastline, and flood waters will not fully recede for several days after the storm.
  • 2. Hurricane-force winds are expected tonight in portions of the hurricane warning area, with catastrophic wind damage expected where Laura’s eyewall moves onshore. Hurricane-force winds and widespread damaging wind gusts will spread well inland into portions of extreme eastern Texas and western Louisiana early Thursday.
  • 3. Widespread flash flooding along small streams, urban areas, and roadways is expected to begin overnight tonight into Thursday from far eastern Texas into Louisiana and Arkansas. This will also lead to minor to moderate freshwater river flooding. The heavy rainfall threat and flash and urban flooding potential will spread northeastward into the middle-Mississippi, lower Ohio, and Tennessee Valleys Friday night and Saturday.
FORECAST POSITIONS AND MAX WINDS

INIT  27/0300Z 29.0N  93.2W  130 KT 150 MPH - Category 4 (ESE Port Arthur, TX)
 12H  27/1200Z 31.0N  93.7W   95 KT 110 MPH - Category 2 (ENE Wiergate, TX)
 24H  28/0000Z 33.8N  92.9W   50 KT  60 MPH - Tropical Storm (ENE  Chidester, AR)
 36H  28/1200Z 35.6N  91.5W   35 KT  40 MPH - Tropical Storm (WNW Thida, AR)
 48H  29/0000Z 36.8N  88.2W   25 KT  30 MPH - Depression (WNW  Aurora, K)
 60H  29/1200Z 37.5N  82.7W   25 KT  30 MPH - Depression (ENE  McDowell, KY)
 72H  30/0000Z 38.5N  75.5W   30 KT  35 MPH - Low (ENE Delmar, DE)
 96H  31/0000Z 45.0N  60.0W   45 KT  50 MPH - Low (ENE) Sherbrooke, Canada)
120H  01/0000Z 52.0N  46.0W   45 KT  50 MPH - Low (ENE St, John's, Canada)

NWS National Hurricane Center Miami FL 400 PM CDT Wed Aug 26, 2020

Laura has continued to rapidly strengthen today with recent visible satellite imagery revealing a very distinct 25 nautical- mile-wide eye embedded in a symmetric central dense overcast. The upper-level outflow has also become well established in all quadrants. An Air Force Reserve hurricane hunter aircraft that is still investigating the hurricane has reported peak 700-mb flight-level winds of 136 kt and SFMR winds of 121 kt in the northeast eyewall. These data support an initial intensity of 125 kt, which is an increase of 55 kt over the past 24 hours. The minimum pressure has fallen to around 947 mb. The well-defined eye is now within range of the NWS Lake Charles WSR-88D radar, and hourly Tropical Cyclone Updates began at 1900 UTC (2 PM CDT) and will continue through landfall and beyond overnight.

Hurricane Laura Peak Storm Surge
Hurricane Laura Peak Storm Surge

Laura still has about 12 hours remaining over the warm waters of the northwest Gulf of Mexico waters, but increasing southwesterly shear around the time of landfall and the possibility of an eyewall replacement could result in some fluctuations in intensity this evening, but Laura is expected to remain an extremely dangerous category 4 hurricane through landfall tonight. Although rapid weakening is expected on Thursday as Laura moves inland, the hurricane is expected to bring a swath of damaging winds well inland over western Louisiana and extreme eastern Texas. The cyclone or its remnants are forecast to move off Mid-Atlantic coast over the weekend and there remains some possibility that Laura will re-intensify as a tropical cyclone offshore of the United States east before it merges with a frontal boundary later in the forecast period.

Recent satellite and aircraft fixes show that Laura is moving northwestward at about 13 kt. Laura is nearing the western extent of a mid-level ridge that is located over the southeastern United States. The hurricane should turn north-northwestward this evening and northward on Thursday between the ridge and a weak trough over the south-central United States. By Friday the cyclone should turn northeastward and then east-northeastward as it becomes embedded in the mid-latitude westerlies. The track model guidance continues to be in good agreement through 72, but there are some forward speed differences thereafter. The new NHC track is very close to the previous advisory and is near the middle of the guidance envelope.

Laura is a large hurricane and users are reminded to not focus on the precise track forecast since wind, storm surge, and rainfall hazards extend far from the center.

Key Messages:

  • 1. Unsurvivable storm surge with large and destructive waves will cause catastrophic damage from Sea Rim State Park, Texas, to Intracoastal City, Louisiana, including Calcasieu and Sabine Lakes. This surge could penetrate up to 40 miles inland from the immediate coastline, and flood waters will not fully recede for several days after the storm.
  • 2. Hurricane-force winds are expected tonight in portions of the hurricane warning area, with catastrophic wind damage expected where Laura’s eyewall moves onshore. Hurricane-force winds and widespread damaging wind gusts will spread well inland into portions of extreme eastern Texas and western Louisiana early Thursday.
  • 3. Widespread flash flooding along small streams, urban areas, and roadways is expected to begin this afternoon into Thursday from far eastern Texas into Louisiana and Arkansas. This will also lead to minor to moderate freshwater river flooding. The heavy rainfall threat and flash and urban flooding potential will spread northeastward into the middle-Mississippi, lower Ohio, and Tennessee Valleys Friday night and Saturday.
FORECAST POSITIONS AND MAX WINDS

INIT  26/2100Z 27.9N  92.8W  125 KT 145 MPH - Category 4 (ESE Galveston, TX)
 12H  27/0600Z 29.7N  93.6W  130 KT 150 MPH - Category 4 (WSW Holly Beach, LA)
 24H  27/1800Z 32.5N  93.5W   60 KT  70 MPH - Tropical Storm (ESE Haughton, LA)
 36H  28/0600Z 34.8N  92.7W   35 KT  40 MPH - Tropical Storm (ENE  Paron, AR)
 48H  28/1800Z 36.5N  90.1W   25 KT  30 MPH - Depression (WNW Campbell, MO)
 60H  29/0600Z 37.3N  85.6W   25 KT  30 MPH - Depression (WSW Gabe, KY)
 72H  29/1800Z 38.0N  79.0W   30 KT  35 MPH - Low (ESE Stuarts Draft, VA)
 96H  30/1800Z 43.2N  64.0W   45 KT  50 MPH - Low (ESE Clark's Harbour, Canada)
120H  31/1800Z 51.0N  49.0W   45 KT  50 MPH - Low (ENE St. John's, Canada)

NWS National Hurricane Center Miami FL 1000 AM CDT Wed Aug 26, 2020 

Corrected 24-h status in forecast table to inland.

Laura has become a very powerful hurricane this morning. The satellite presentation has continued to improve with the eye becoming better defined, and cloud tops colder than -70C in the surrounding ring of deep convection. Both NOAA and Air Force hurricane hunter aircraft have provided valuable data this morning. The NOAA P-3 aircraft reported a peak flight-level wind of 125 kt at 8000 ft, and a peak SFMR wind of 104 kt, while the Air Force crew has observed peak 700-mb flight-level winds of 121 kt and peak SFMR winds of 104 kt. The lastest minimum pressure estimated from aircraft data is 956 mb, indicating a pressure drop of 27 mb over the past 12 hours. Based on the aircraft data, the initial wind speed was increased to 100 kt on the 1200 UTC intermediate advisory, and is now set at 110 kt based on the latest flight-level and SFMR winds.

Laura is likely to continue strengthening today while it moves over warm waters of the northwestern Gulf of Mexico and the vertical wind shear remains low. Laura’s intensity could level-off by this evening due to the possibility of an eyewall replacement cycle and the expected increase in shear around the time of landfall. Even if the rate of strengthening eases, Laura is expected to be an extremely powerful category 4 hurricane when it reaches the northwestern Gulf coast. After landfall, rapid weakening will occur, but Laura will bring a swath of damaging winds well inland over western Louisiana and eastern Texas. The UKMET and ECMWF models suggest that there is some chance that Laura re-intensifies as a tropical cyclone off the mid-Atlantic coast, but given the uncertainties at that time range the forecast continues to show it as a post-tropical cyclone at days 4 and 5.

Laura is moving northwestward at about 13 kt. A gradual turn toward the north-northwest and north are expected within the next 12-18 hours as the hurricane moves around the western portion of a mid- level ridge that extends from the western Atlantic into the southeastern United States. This motion will bring the center of Laura onshore in southwestern Louisiana or extreme eastern Texas tonight. By Thursday night, Laura is forecast to turn northeastward, and then east-northeastward on Friday as it becomes embedded in the mid-latitude westerlies. The dynamical track models are in good agreement, and little adjustment to the previous NHC forecast track was required.

Laura is a large hurricane and users are reminded to not focus on the precise track forecast since wind, storm surge, and rainfall hazards extend far from the center.

Key Messages:

  • 1. Unsurvivable storm surge with large and destructive waves will cause catastrophic damage from Sea Rim State Park, Texas, to Intracoastal City, Louisiana, including Calcasieu and Sabine Lakes. This surge could penetrate up to 30 miles inland from the immediate coastline. Only a few hours remain to protect life and property and all actions should be rushed to completion.
  • 2. Hurricane-force winds are expected tonight in portions of the hurricane warning area from San Luis Pass, Texas, to west of Morgan City, Louisiana, with catastrophic wind damage expected where Laura’s eyewall makes landfall. Hurricane-force winds and widespread damaging wind gusts will spread well inland across portions of eastern Texas and western Louisiana early Thursday.
  • 3. Widespread flash flooding along small streams, urban areas, and roadways is expected to begin this afternoon into Thursday from far eastern Texas, across Louisiana and Arkansas. This will also lead to minor to isolated moderate freshwater river flooding. The heavy rainfall threat and localized flash and urban flooding potential will spread northeastward into the middle-Mississippi, lower Ohio and Tennessee Valleys Friday night and Saturday.
FORECAST POSITIONS AND MAX WINDS

INIT  26/1500Z 27.0N  92.0W  110 KT 125 MPH - Category 3 (WSW Galveston, TX)
 12H  27/0000Z 28.5N  93.2W  125 KT 145 MPH - Category 4 (WSW Galveston, TX)
 24H  27/1200Z 31.0N  93.8W   75 KT  85 MPH - Category 1 (WNW  Farrsville, TX)
 36H  28/0000Z 33.7N  93.5W   40 KT  45 MPH - Tropical torm (ENE Perrytown, AR)
 48H  28/1200Z 35.8N  92.2W   25 KT  30 MPH - Depression (ENE  Turkey Creek, AR)
 60H  29/0000Z 37.2N  89.1W   25 KT  30 MPH - Depression (ENE Olmsted, IL)
 72H  29/1200Z 37.6N  83.9W   25 KT  30 MPH - Depression (ENE  Alumbaugh, KY)
 96H  30/1200Z 40.0N  70.0W   40 KT  45 MPH - Post Tropical (ESE New York City, NY)
120H  31/1200Z 48.0N  55.0W   45 KT  50 MPH - Post Tropical (ENE Rencontre East, Canada)

NWS National Hurricane Center Miami FL 1000 PM CDT Tue Aug 25, 2020 

Laura’s cloud pattern is becoming better organized on satellite images, with a banding feature over the eastern portion of the circulation and an expanding central dense overcast with cloud tops of -80C or colder. The upper-level outflow is becoming better established over the northwestern quadrant. Flight-level and SFMR-observed surface winds from NOAA and Air Force Hurricane Hunter aircraft indicate that the maximum winds have increased to near 80 kt, and the central pressure is falling. The hurricane is expected to remain over SSTs near 30 deg C until it nears the coast, with only moderate vertical shear. The SHIPS Rapid Intensification Index shows a significant probability for a 25-30 kt increase in strength during the next 24 hours, and this is reflected in the official forecast. This is also between the simple and corrected intensity model consensus predictions. Laura will weaken rapidly after landfall, but it will likely bring hurricane-force winds well inland over extreme western Louisiana and eastern Texas.

Hurricane Laura Rainfall Totals
Hurricane Laura Rainfall Totals

Aircraft and satellite fixes show a continued west-northwestward track with an initial motion estimate near 300/15 kt. The track forecast reasoning has not changed. The hurricane should gradually turn toward the northwest and north over the next day or two as it moves around the western periphery of a mid-level high and into a weakness into the subtropical ridge. Later in the forecast period the cyclone should turn toward the east-northeast and move with increasing forward speed while embedded within the westerlies. The official track forecast is very similar to the previous one and also very close to the simple and corrected consensus track model predictions.

Users are again reminded not to focus on the exact details of the track or intensity forecasts as the average NHC track error at 36 h is around 60 miles and the average intensity error is close to 10 mph. In addition, wind, storm surge, and rainfall hazards will extend far from the center.

Key Messages:

  • 1. There is a danger of life-threatening storm surge with large and dangerous waves producing potentially catastrophic damage from San Luis Pass, Texas, to the Mouth of the Mississippi River, including areas inside the Port Arthur Hurricane Flood Protection system. This surge could penetrate up to 30 miles inland from the immediate coastline in southwestern Louisiana and far southeastern Texas. Actions to protect life and property should be rushed to completion, as water levels will begin to rise on Wednesday.
  • 2. Hurricane-force winds are expected Wednesday night in the warning area from San Luis Pass, Texas, to west of Morgan City, Louisiana, and the strongest winds associated with Laura’s eyewall will occur somewhere within this area. Hurricane-force winds and widespread damaging wind gusts are also expected to spread well inland into portions of eastern Texas and western Louisiana early Thursday.
  • 3. Widespread flash flooding along small streams, urban areas, and roadways is expected to begin Wednesday night into Thursday across far eastern Texas, Louisiana, and Arkansas. This will also lead to minor to isolated moderate river flooding. The heavy rainfall threat and localized flash and urban flooding potential will spread northeastward into the middle-Mississippi, lower Ohio and Tennessee Valleys Friday night and Saturday.
FORECAST POSITIONS AND MAX WINDS

INIT  26/0300Z 25.2N  89.5W   80 KT  90 MPH - Category 1 (WNW Cancun, Mexico)
 12H  26/1200Z 26.5N  91.4W   95 KT 110 MPH - Category 2 (ESE Galveston, TX)
 24H  27/0000Z 28.7N  93.1W  105 KT 120 MPH - Category 3 (ESE Cameron, TX)
 36H  27/1200Z 31.2N  93.8W   70 KT  80 MPH - Category 1 (WNW  Fairmount, TX)
 48H  28/0000Z 33.7N  93.6W   40 KT  45 MPH - Tropical Storm (ESE  Hope, AR)
 60H  28/1200Z 36.0N  92.3W   30 KT  35 MPH - Depression (ESE Big Flat, AR)
 72H  29/0000Z 37.2N  89.5W   25 KT  30 MPH - Depression (ESE Scott City, MO )
 96H  30/0000Z 38.0N  78.0W   30 KT  35 MPH - Depression (ESE Louisa, VA)
120H  31/0000Z 42.0N  65.0W   35 KT  40 MPH - Tropical Storm (ESE Boston, MA)

NWS National Hurricane Center Miami FL 400 PM CDT Tue Aug 25, 2020 

Satellite imagery shows some changes in the convective pattern of Laura since the last advisory. The ragged central dense overcast seen earlier has been replaced by a curved convective band that wraps almost all the way around a cloud-filled banding-type eve. One possible reason for this change is that the imagery also suggests a tongue of dry air is trying to entrain into the cyclone just west of the central convection. Aircraft data received after the last advisory did not show any fall in the central pressure, but did have high enough flight-level and SFMR winds to justify nudging the initial intensity up to 70 kt.

The initial motion is now west-northwestward or 300/15 kt. There is no change in the forecast philosophy since the last advisory. The hurricane is currently on the south side of a large-deep layer ridge over the southeastern United States, and it is moving toward a break in the ridge caused by mid- to -upper-level troughing over Texas and the southern Great Plains. The current and forecast synoptic pattern should steer Laura west-northwestward this evening, followed by a turn toward the northwest tonight and toward the north by Wednesday night and Thursday. This will result in the hurricane making landfall in the area of southwestern Louisiana or the upper Texas coast late Wednesday night or Thursday morning. The new forecast track has a slight eastward nudge during the first 12-24 h, but the landfall position is almost unchanged from that of the previous forecast. It should the be noted that the current forecast track lies to the east of the ECMWF and UKMET models, so it is still possible that the forecast track could nudge westward in later advisories. After landfall, Laura is expected to recurve into the westerlies and move eastward through the Tennessee Valley and the mid-Atlantic States before reaching the Atlantic in about 120 h.Hurricane Laura Flash Flood Risk

All indications are that the hurricane should steadily to rapidly intensify during the next 24 h, with the only negative factor being the possibility of more dry air entrainment. The intensity forecast will go with the scenario that the dry air will not significantly hinder strengthening. The global models are in good agreement that Laura will encounter increasing southwesterly shear in the last 6-12 h before landfall, so the intensity forecast shows slower strengthening during that time. With all that said, the landfall intensity of 100 kt is unchanged from the previous advisory. After landfall, Laura should weaken through the 96 h point, followed by re-intensification through baroclinic energy as the cyclone becomes extratropical.

Users are again reminded not to focus on the exact details of the track or intensity forecasts as the average NHC track error at 36 h is around 60 miles and the average intensity error is close to 10 mph. In addition, wind, storm surge, and rainfall hazards will extend far from the center.

Key Messages:

  • 1. There is a danger of life-threatening storm surge with large and dangerous waves producing potentially catastrophic damage from San Luis Pass, Texas, to the Mouth of the Mississippi River, including areas inside the Port Arthur Hurricane Flood Protection system. This surge could penetrate up to 30 miles inland from the immediate coastline in southwestern Louisiana and far southeastern Texas. Actions to protect life and property should be rushed to completion this evening, as water levels will begin to rise on Wednesday.
  • 2. Hurricane-force winds are expected Wednesday night in the warning area from San Luis Pass, Texas, to west of Morgan City, Louisiana, and the strongest winds associated with Laura’s eyewall will occur somewhere within this area. Hurricane-force winds and widespread damaging wind gusts are also expected to spread well inland into portions of eastern Texas and western Louisiana early Thursday.
  • 3. The threat of widespread flash and urban flooding along with small streams overflowing their banks will increase due to heavy rainfall Wednesday night into Thursday from far eastern Texas, across Louisiana, and Arkansas. This will also result in minor to isolated moderate river flooding. The heavy rainfall threat will spread northeastward into the middle-Mississippi, lower Ohio and Tennessee Valleys Friday night and Saturday.
FORECAST POSITIONS AND MAX WINDS

INIT  25/2100Z 24.7N  88.3W   70 KT  80 MPH - Category 1 (WNW Key West, FL)
 12H  26/0600Z 25.7N  90.3W   85 KT 100 MPH - Category 2 (ESE Brownsville, TX)
 24H  26/1800Z 27.5N  92.4W   95 KT 110 MPH - Category 2 (ESE Galveston, TX)
 36H  27/0600Z 29.7N  93.8W  100 KT 115 MPH - Category 3 (WSW May's Beach, LA)
 48H  27/1800Z 32.2N  93.9W   65 KT  75 MPH - Category 1 (ENE Keachi, LA)
 60H  28/0600Z 34.7N  93.3W   40 KT  45 MPH - Tropical Storm (ESE  Mt Tabor, AR)
 72H  28/1800Z 36.5N  90.9W   30 KT  35 MPH - Depression (ESE  Poynor, MO)
 96H  29/1800Z 38.5N  80.5W   25 KT  30 MPH - Depression (ESE  Erbacon, WV)
120H  30/1800Z 42.0N  66.5W   40 KT  45 MPH - Low (ESE Boston, MA)

NWS National Hurricane Center Miami FL 1000 AM CDT Tue Aug 25, 202

Satellite imagery shows that Laura has become a little better organized since it crossed western Cuba, and it now has a central dense overcast and some outer banding in the southern quadrant. Reports from Air Force Reserve and NOAA Hurricane Hunter aircraft included SFMR winds of near 65 kt, 700-mb flight-level winds as high as 77 kt, and a central pressure near 990 mb. Based on these data, Laura has been upgraded to a hurricane with an initial intensity of 65 kt. The initial motion is west-northwestward or 290/14 kt.

The hurricane is currently on the south side of a large-deep layer ridge over the southeastern United States, and it is moving toward a break in the ridge caused by mid- to -upper-level troughing over Texas and the southern Great Plains. The current and forecast synoptic pattern should steer Laura west-northwestward today followed by a turn toward the northwest tonight and toward the north by Wednesday night and Thursday. This will result in the hurricane making landfall in the area of southwestern Louisiana or the upper Texas coast late Wednesday night or Thursday morning. The new forecast track before landfall has been nudged a little to the west of the previous track in response to a westward nudge in the guidance. However, it still lies a little east of the consensus models at the time of landfall. After landfall, Laura is expected to recurve into the westerlies and move eastward through the Tennessee Valley and the mid-Atlantic States.

Hurricane Laura Estimated Rainfall Prediction
Hurricane Laura Estimated Rainfall Prediction

The hurricane currently looks a little ragged, with little or no convection outside of the central dense overcast and the southern quadrant banding. This may be due to dry air in the vicinity and some light northerly shear. Conditions appear generally favorable for strengthening during the next 36 h, and the new intensity forecast calls for Laura to become a major hurricane during this time. The global model are in good agreement that the hurricane should encounter increasing shear in the last 12 h before landfall, although the potential impacts on the landfall intensity are unclear. After landfall, Laura should weaken through the 96 h point. After that, some re-intensification is expected as the storm becomes extratropical. Users are again reminded not to focus on the exact details of the track or intensity forecasts as the average NHC track error at 48 h is around 80 miles and the average intensity error is close to 15 mph. In addition, wind, storm surge, and rainfall hazards will extend far from the center.

Key Messages:

  • 1. Laura is forecast to reach the northwestern Gulf Coast at or near major hurricane intensity Wednesday night. Do not focus on the details of the official forecast given the typical uncertainty in NHC’s track and intensity predictions. Storm surge, wind, and rainfall hazards will extend well away from Laura’s center along the Gulf Coast.
  • 2. There is the danger of life-threatening storm surge accompanied by large and dangerous waves from San Luis Pass, Texas, to the Mouth of the Mississippi River, including areas inside the Port Arthur Hurricane Flood Protection system. A Storm Surge Warning is in effect and residents should follow any advice given by local officials. Actions to protect life and property should be rushed to completion today, as water levels will begin to rise Wednesday.
  • 3. Hurricane conditions are expected by Wednesday evening in the area from San Luis Pass, Texas, to west of Morgan City, Louisiana, and a Hurricane Warning is in effect. Tropical storm conditions are expected to begin in the warning area Wednesday afternoon.
  • 4. The threat of widespread flash and urban flooding along with small streams overflowing their banks will be increasing Wednesday night into Thursday from far eastern Texas, across Louisiana, and Arkansas. This will also lead to minor to isolated moderate river flooding. The heavy rainfall threat will spread northeastward into the middle-Mississippi, lower Ohio,
FORECAST POSITIONS AND MAX WINDS

INIT  25/1500Z 23.7N  87.0W   65 KT  75 MPH - Category 1 (WNW Cancun, Mexico)
 12H  26/0000Z 24.6N  89.2W   75 KT  85 MPH - Category 1 (ENE Merida, Mexico)
 24H  26/1200Z 26.0N  91.5W   90 KT 105 MPH - Category 2 (ESE Brownsville, TX)
 36H  27/0000Z 28.0N  93.3W  100 KT 115 MPH - Category 3 (ESE Galveston, TX)
 48H  27/1200Z 30.5N  93.9W   80 KT  90 MPH - Category 1 (ESE Buna, TX)
 60H  28/0000Z 33.1N  93.6W   45 KT  50 MPH - Tropical Storm (ENE  Bradley, AA)
 72H  28/1200Z 35.2N  92.1W   30 KT  35 MPH - Depression (WSW Mt Vernon, AR)
 96H  29/1200Z 37.5N  83.5W   25 KT  30 MPH - Low (WSW Guerrant, KY)
120H  30/1200Z 40.5N  69.5W   40 KT  45 MPH - Low (ESE Nantucket, MA)

NWS National Hurricane Center Miami FL 1100 PM EDT Mon Aug 24, 2020

Tropical Storm Laura made landfall on the Pinar del Rio province in western Cuba around 0000 UTC with maximum winds of about 55 kt. Around that time, a wind gust of 56 kt was reported in Havana. Since then the storm has moved across western Cuba and is now coming off the island and over the extreme southeastern Gulf of Mexico. Radar data from Cuba and satellite images indicate that the storm has become better organized with deep convection beginning to wrap around the center with persistent thunderstorms on the south side. Data from the NOAA and Air Force Hurricane Hunters indicate that the pressure has fallen to 996 mb and that the winds are around 55 kt.

Laura continues to move fairly steadily to the west-northwest with the latest initial motion estimated to be 290/17 kt. The track forecast reasoning is generally unchanged from previous discussions. Laura should continue to move west-northwestward at about the same forward speed through Tuesday as it remains in the flow on the southwest side of the Atlantic subtropical ridge. By early Wednesday, Laura will likely slow down and turn northwestward and then northward as it moves into a break in the ridge, caused by a weak trough over the south-central U.S. This motion should cause the system to make landfall in either southwestern Louisiana or the Upper Texas coast Wednesday night or early Thursday. After landfall, Laura is forecast to continue moving northward before turning eastward on Friday as it becomes embedded in the mid-latitude westerlies. Although the global models are in relatively good agreement, there remains some spread in the ensemble members, especially in the ECMWF. Therefore, confidence in the track forecast is still not high. The NHC track forecast is slightly to the left of the previous one, trending toward the latest consensus aids.

The storm is starting to pull away from the western portion of Cuba, and it should be over the warm Gulf of Mexico waters for about 2 days. Since Laura will have a notable amount of time over waters with high oceanic heat while moving through a low wind shear and high moisture air mass, significant strengthening seems quite likely until the storm makes landfall. The intensity models all show Laura making landfall as a hurricane, but there are differences on exactly how strong it will be. The NHC intensity forecast continues to stay near the consensus aids, which usually perform best, and Laura could be near major hurricane strengthen when it reaches the coast.

Users are again reminded not to focus on the exact details of the track or intensity forecasts as the average NHC track error at 48 h is around 80 miles and the average intensity error is close to 15 mph. In addition, wind, storm surge, and rainfall hazards will extend far from the center.

Key Messages:

  • 1. Laura is forecast to reach the northwestern Gulf Coast as a hurricane late Wednesday and early Thursday. Do not focus on the details of the official forecast given the typical uncertainty in NHC’s 2 to 3 day track and intensity predictions. In addition, storm surge, wind, and rainfall hazards will extend well away from Laura’s center along the Gulf Coast.
  • 2. There is a risk of life-threatening storm surge from San Luis Pass, Texas, to Ocean Springs, Mississippi, within the next 48 hours, and a storm surge watch is in effect for these areas outside of the southeast Louisiana Hurricane and Storm Damage Risk Reduction System. Residents in these areas should follow any advice given by local officials.
  • 3. Hurricane conditions are possible by late Wednesday from Port Bolivar, Texas, to west of Morgan City, Louisiana, with tropical storm conditions possible by Wednesday afternoon, and a hurricane watch is in effect. Additional hurricane watches may be needed farther south along the Texas coast if the track forecast shifts toward the south and west tonight and Tuesday.
  • 4. Tropical storm conditions and heavy rainfall are expected across central and western Cuba for several more hours. These rains could cause mudslides and life-threatening flash and urban flooding.
ORECAST POSITIONS AND MAX WINDS

INIT  25/0300Z 22.7N  84.0W   55 KT  65 MPH - Tropical Storm (WSW Cayo Jutias, Cuba)
 12H  25/1200Z 23.7N  86.3W   65 KT  75 MPH - Category 1 (WNW Las Tumbas, Cuba)
 24H  26/0000Z 25.2N  89.1W   75 KT  85 MPH - Category 1 (WSW Naples, FL)
 36H  26/1200Z 26.8N  91.6W   85 KT 100 MPH - Category 1 (ESE Corpus Christi, TX)
 48H  27/0000Z 28.8N  93.0W   95 KT 110 MPH - Category 2 (ESE Galveston, TX)
 60H  27/1200Z 31.3N  93.6W   65 KT  75 MPH - Category 1 (ESE  Clare, LA)
 72H  28/0000Z 33.8N  93.0W   40 KT  45 MPH - Tropical Storm (ENE Chidester, AR)
 96H  29/0000Z 36.7N  89.1W   25 KT  30 MPH - Low (WSW Columbus, KY)
120H  30/0000Z 36.9N  77.1W   25 KT  30 MPH - Low (WSW Wakefield, VA)

NWS National Hurricane Center Miami FL 500 PM EDT Mon Aug 24, 2020 

The satellite presentation of the tropical storm has improved somewhat with deep convection remaining over the center, and an increase in banding over the southeastern portion of the circulation. Earlier aircraft and scatterometer data, however, indicated that there has been little change in strength today, and the initial intensity remains 50 kt. These observations have shown the the stronger winds are located in the convective band well east and southeast of the center, and that the system currently lacks an inner core. This is likely the reason that Laura has not been able to strengthen while it has moved over water today. The aircraft also reported a fairly stable minimum pressure of 1001-1003 mb during its mission this morning and early afternoon.

The intensity forecast philosophy remains the same as the previous advisory. Once Laura moves over the southeastern Gulf of Mexico tonight, a combination of warm sea surface temperatures and low vertical wind shear should allow for steady strengthening. The latest iterations of the global and regional hurricane models continue to show significant deepening while Laura traverses the Gulf of Mexico, and a period or rapid strengthening is possible once an inner core is able to organize. The statistical guidance is again on the lower side of the intensity forecast envelope while the HWRF and CTCI models bringing Laura to major hurricane strength. The NHC intensity forecast is again between these solutions and is close to the consensus aids.

The initial motion estimate is 290/16 kt. A deep-layer ridge over the western Atlantic is expected to build westward during the next day or so. By early Wednesday, a mid- to upper-level trough over the south-central United States is forecast to erode the western portion of the ridge, which should cause Laura to turn northwestward and then northward toward the northwestern Gulf coast. After landfall, Laura or its remnants are expected to become embedded in the mid-latitude westerlies and recurve over the eastern U.S. on days 4 and 5. The latest runs of the dynamical models are in a little better agreement, but the 1200 UTC ECMWF ensemble mean is located considerably left of its deterministic run, indicating that uncertainty regarding the track forecast remains. Users are again reminded to not to focus on the exact details of the track or intensity forecasts as the average NHC track error at 60 h is around 90 miles and the average intensity error is close to 15 mph. In addition, wind, storm surge, and rainfall hazards will extend far from the center.

The new NHC forecast necessitates the issuance of storm surge and hurricane watches for portions of the U.S. Gulf Coast.

Key Messages:

  • 1. Laura is forecast to reach the northwestern Gulf Coast as a hurricane late Wednesday and early Thursday. Do not focus on the details of the official forecast given the typical uncertainty in NHC’s 2 to 3 day track and intensity predictions. In addition, storm surge, wind, and rainfall hazards will extend well away from Laura’s center along the Gulf Coast.
  • 2. There is a risk of life-threatening storm surge from San Luis Pass, Texas, to Ocean Springs, Mississippi, within the next 48 hours, and a storm surge watch has been issued for these areas outside of the southeast Louisiana Hurricane and Storm Damage Risk Reduction System. Residents in these areas should follow any advice given by local officials.
  • 3. Hurricane conditions are possible by late Wednesday from Port Bolivar, Texas, to west of Morgan City, Louisiana, with tropical storm conditions possible by Wednesday afternoon, and a hurricane watch has been issued. Additional hurricane watches may be needed farther south along the Texas coast if the track forecast shifts toward the south and west tonight and Tuesday.
  • 4. Tropical storm conditions and heavy rainfall are expected across central and western Cuba through tonight. These rains could cause mudslides and life-threatening flash and urban flooding.
FORECAST POSITIONS AND MAX WINDS

INIT  24/2100Z 21.7N  82.2W   50 KT  60 MPH - Tropical Storm (ESE Cayo Campos, Cuba)
 12H  25/0600Z 22.7N  84.5W   50 KT  60 MPH - Tropical Storm (WNW Dimas, Cuba)
 24H  25/1800Z 24.2N  87.4W   60 KT  70 MPH - Tropical Storm (ENE Cancun, Mexico)
 36H  26/0600Z 25.7N  90.0W   75 KT  85 MPH - Category 1 (ESE Brownsville, Texas)
 48H  26/1800Z 27.5N  92.0W   85 KT 100 MPH - Category 1 (ESE Galveston, Texas)
 60H  27/0600Z 29.8N  93.1W   90 KT 105 MPH - Category 2 (ENE Creole, Louisiana)
 72H  27/1800Z 32.5N  93.0W   45 KT  50 MPH - Tropical Storm (ESE Mt Lebanon, Louisiana)
 96H  28/1800Z 36.1N  90.0W   25 KT  30 MPH - Depression (ENE Rives, Missouri)
120H  29/1800Z 36.5N  80.5W   25 KT  30 MPH - Low (WNW Westfield, NC)

NWS National Hurricane Center Miami FL 1100 AM EDT Mon Aug 24, 2020 

Laura’s satellite presentation has degraded somewhat since yesterday, however, there has been a recent increase in convection near the center, and a large band over the southern periphery of the circulation. It appears that the combination of land interaction, moderate northerly shear, and some dry air has caused the change in structure. NOAA and Air Force reconnaissance aircraft have reported several believable SFMR winds in the 45-50 kt range and a minimum pressure of around 1002 kt. Based on these observations, the initial wind speed has been set at 50 kt.

Laura is forecast to pass over the very warm water of the extreme northwestern Caribbean Sea just south of the coast of Cuba today, and some modest strengthening is possible before the center moves over the western portion of Cuba this evening. Laura is then forecast to emerge over the southeastern Gulf of Mexico overnight where a combination of warm sea surface temperatures and a favorable upper-level environment are expected to allow for steady strengthening. Given the very conducive upper-level wind pattern depicted by the global models, a period of rapid strengthening is possible once Laura re-organizes an inner core after its passage over western Cuba. The regional hurricane models remain quite bullish on intensification, and the GFS and UKMET models indicate significant deepening while Laura moves over the Gulf of Mexico. The statistical guidance is not as aggressive, and the NHC forecast is in good agreement with the intensity consensus aids which lie between the higher solutions of the regional models and the SHIPS and LGEM guidance.

Laura has been moving on a steady west-northwestward track over the past day or so, and the initial motion estimate is 285/17 kt. The deep-layer ridge over the western Atlantic is forecast to build westward over the eastern Gulf of Mexico during the next day or so, and this should keep Laura on a west-northwestward heading through Tuesday. After that time, a mid- to upper-level trough over the south-central United States should produce a break in the ridge over the western Gulf of Mexico.

Laura should turn northwestward Tuesday night in response to the break in the ridge, and the storm is expected to reach the northwestern Gulf coast Wednesday night. The cyclone should become embedded within the mid-latitude westerlies by day 4, and Laura or its remnants should recurve to the northeast and east-northeast by the end of the period. Although the track guidance is in somewhat better agreement today, there remains some cross-track spread by day 3, with the UKMET showing landfall well southwest of the official forecast. The NHC track is close to the various consensus aids and leans toward the typically reliable GFS and ECMWF models.

Users are again reminded to not to focus on the exact details of the track or intensity forecasts as the average NHC track error at 72 h is around 100 miles and the average intensity error is around 15 mph (13 kt). In addition, wind, storm surge, and rainfall hazards will extend far from the center.

Key Messages:

  • 1. Tropical storm conditions are expected across much of Cuba today. Heavy rainfall is likely across Cuba and Jamaica today, and these rains could cause mudslides and life-threatening flash and urban flooding. Tropical storm conditions are expected in the Dry Tortugas, and the Middle and Lower Florida Keys later today.
  • 2. There is an increasing risk of dangerous storm surge, wind, and rainfall impacts from the upper Texas coast through the north- central Gulf Coast beginning on Wednesday. Interests in these areas should monitor the progress of Laura and ensure they have their hurricane plan in place, as storm surge and hurricane watches will likely be issued later today.
FORECAST POSITIONS AND MAX WINDS

INIT  24/1500Z 21.2N  80.6W   50 KT  60 MPH - Tropical Storm (WSW Playa Ancon, Cuba)
 12H  25/0000Z 22.2N  82.9W   55 KT  65 MPH - Tropical Storm (WNW Islas de Mangles, Cuba)
 24H  25/1200Z 23.6N  86.0W   60 KT  70 MPH - Tropical Storm (WNW Las Tumbas, Cuba)
 36H  26/0000Z 25.2N  88.8W   70 KT  80 MPH - Category 1 (WSW Naples, Florida)
 48H  26/1200Z 26.8N  91.1W   80 KT  90 MPH - Category 1 (WSW Galveston, Texas)
 60H  27/0000Z 28.7N  92.8W   90 KT 105 MPH - Category 2 (ESE Port Authur, Texas)
 72H  27/1200Z 31.2N  93.3W   65 KT  75 MPH - Category 1 (ESE Anacoco, Louisiana)
 96H  28/1200Z 36.0N  90.9W   30 KT  35 MPH - Depression (ESE Walnut Ridge, Arkansas)
120H  29/1200Z 37.5N  81.0W   25 KT  30 MPH - Low (WNW Lerona, West Virginia)

NWS National Hurricane Center Miami FL 1100 PM EDT Sun Aug 23, 2020

Radar data from Cuba and satellite images indicate that Laura continues to gradually become better organized. Convection is quite deep on the south side of the circulation, and rainfall is likely very heavy over portions of eastern Cuba and Jamaica. A surface observation from Guantanamo Bay, Cuba, measured sustained winds of 52 kt with a wind gust to 63 kt a few hours ago. Based on this observation and the system’s improved structure, the initial intensity is nudged up to 55 kt.

Laura continues to move swiftly to the west-northwest on the south side of a strong subtropical ridge, with the initial motion estimated to be 285/18 kt. The subtropical high is expected to expand westward during the next couple of days, and that should keep Laura moving fairly quickly to the west-northwest near or over Cuba through Monday and then across the south-central Gulf of Mexico on Tuesday. The models suggest that a gradual turn to the northwest is likely by early Wednesday as the storm nears the western side of the ridge, followed by a northward motion after that. The details of the northwest and north turn are quite important when trying to figure out where the core of Laura is going to make landfall. However, at this time there is still a notable spread in the models and their ensemble members, meaning that it is still unclear exactly where the worst weather conditions will occur. The NHC track forecast is little changed from earlier and near the consensus aids. This forecast shows landfall along the northern Gulf coast in about 3 days.

The tropical storm is expected to move very near or over the entire island of Cuba through Monday, and the interaction with the island should limit strengthening during that time. However, significant intensification is expected when the storm moves over the Gulf of Mexico due to a combination of favorable conditions of low wind shear, high moisture, and warm SSTs. The NHC intensity forecast is largely an update of the previous one and lies near the middle of the guidance envelope. Although not explicitly forecast, Laura could threaten the northwestern Gulf coast near major hurricane strength.

Users are again reminded to not to focus on the exact details of the track or intensity forecast as the average NHC track error at 72 h is around 100 miles and the average intensity error is around 15 mph (13 kt). In addition, winds, storm surge, and rainfall hazards will extend far from the center.

Key Messages:

  • 1. Tropical storm conditions are expected across much of Cuba through Monday. Heavy rainfall is likely across Cuba and Jamaica through Monday and these rains could cause mudslides and life-threatening flash and urban flooding. Tropical storm conditions are expected in the Dry Tortugas on Monday.
  • 2. Tropical storm conditions are possible over the Middle and Lower Florida Keys on Monday.
  • 3. While the details of the long-range track and intensity forecasts remain uncertain, Laura is forecast to strengthen over the Gulf of Mexico and there is an increasing risk of dangerous storm surge, wind, and rainfall impacts along portions of the U.S. Gulf Coast by the middle of the week. This could result in a prolonged period of hazardous weather for areas that are likely to be affected by Marco. Interests along the Gulf Coast should monitor the progress of Laura and Marco and updates to the forecast during the next couple of days.
FORECAST POSITIONS AND MAX WINDS

INIT  24/0300Z 20.1N  76.6W   55 KT  65 MPH - Tropical Storm (WNW Uvero, Cuba)
 12H  24/1200Z 21.1N  79.4W   55 KT  65 MPH - Tropical Storm (Jardines de la Reina, Cuba)
 24H  25/0000Z 22.5N  82.6W   60 KT  70 MPH - Tropical Storm (WSW La Palma, Cuba)
 36H  25/1200Z 23.8N  85.7W   65 KT  75 MPH - Category 1 (WNW Havana, Cuba)
 48H  26/0000Z 25.3N  88.5W   70 KT  80 MPH - Category 1 (WSW Naples, FL)
 60H  26/1200Z 27.1N  90.9W   80 KT  90 MPH - Category 1 (ESE Galveston, TX)
 72H  27/0000Z 29.2N  92.4W   90 KT 105 MPH - Category 2 (ESE Pecan Island, LA)
 96H  28/0000Z 34.2N  90.9W   40 KT  45 MPH - Tropical Storm (ESE Mellwood, MS)
120H  29/0000Z 37.4N  83.7W   25 KT  30 MPH - Depression (WSW Ricetown, KY)

NWS National Hurricane Center Miami FL 500 PM EDT Sun Aug 23, 2020 

Satellite imagery and radar data from eastern Cuba show that the center of Laura has been moving over water between Haiti and eastern Cuba this afternoon. There has been a recent uptick in convection near the center and the radar imagery has shown an increase in banding. An Air Force reconnaissance aircraft investigating Laura this afternoon has reported a minimum pressure that has fallen to around 1000 mb, and winds to support an intensity of 50 kt. The plane very recently found a small area of stronger flight-level winds, but these winds may be associated with mesocyclone, and not representative of the large scale circulation. Laura continues to move briskly west-northwestward or 285/18 kt. The track forecast reasoning remains the same as the previous advisory. Laura should continue to move west-northwestward to the south of a deep-layer ridge that is forecast to build westward across Florida and the eastern Gulf of Mexico during the next day or two. The track guidance has continued to edge southward for the portion of the forecast near Cuba, and the NHC forecast has again been moved in that direction. Laura should continue moving west-northwestward over the southeastern Gulf on Tuesday, but a turn toward the northwest is expected Tuesday night as the cyclone nears the western portion of the ridge. A northwestward to north-northwestward motion should then continue around the western portion of the ridge until the cyclone reaches the northwestern Gulf coast. The latest run of the ECMWF has shifted significantly eastward, however its ensemble mean and many of the stronger ensemble members remain farther west as a stronger cyclone is likely to be steered more westward by the deep-layer ridge. The GFS, UKMET, and HWRF remain close to the previous NHC track, so little change was made to the official forecast was made after 48 hours. The intensity forecast during the next 24 hours is highly dependent on the track and the amount of interaction Laura has with Cuba. If the storm stays along the southern coast or just offshore, the environment of warm water and low vertical wind shear could allow for some slight strengthening, but little overall change in intensity is indicated during the next 24 hours. After the center clears western Cuba, the upper-level wind pattern is predicted to quite favorable while the storm traverses the warm waters of the Gulf of Mexico. The GFS, UKMET, and regional hurricane models all indicate significant deepening, and the NHC intensity forecast has been adjusted slightly upward. Although not explicitly shown, Laura could threaten the northwestern Gulf coast near major hurricane strength. Users are again reminded to not to focus on the exact details of the track or intensity forecast at the longer range as winds, storm surge, and rainfall hazards will extend far from the center.

Key Messages:

  • 1. Tropical storm conditions are expected across portions of the Haiti, the southeastern Bahamas, and Cuba through Monday. Heavy rainfall is likely across Haiti, Cuba, and Jamaica through Monday and these rains could cause mudslides and life-threatening flash and urban flooding.
  • 2. Tropical storm conditions are possible over the Middle and Lower Florida Keys and the Dry Tortugas on Monday.
  • 3. While the details of the long-range track and intensity forecasts remain uncertain, Laura is forecast to strengthen over the Gulf of Mexico and there is an increasing risk of dangerous storm surge, wind, and rainfall impacts along portions of the U.S. Gulf Coast by the middle of the week. This could result in a prolonged period of hazardous weather for areas that are likely to be affected by Marco. Interests along the Gulf Coast should monitor the progress of Laura and Marco and updates to the forecast during the next few days.
FORECAST POSITIONS AND MAX WINDS

INIT  23/2100Z 19.5N  75.2W   50 KT  60 MPH - Tropical Storm (ESE Guantanamo, Cuba)
 12H  24/0600Z 20.6N  78.3W   50 KT  60 MPH - Tropical Storm (ESE Santa Cruz del Sur, Cuba)
 24H  24/1800Z 21.8N  81.7W   50 KT  60 MPH - Tropical Storm (ESE Traviesa, Cuba)
 36H  25/0600Z 23.3N  84.9W   55 KT  65 MPH - Tropical Storm (ENE Las Tumbas, Cuba)
 48H  25/1800Z 24.7N  87.7W   60 KT  70 MPH - Tropical Storm (WNW Key west, FL)
 60H  26/0600Z 26.1N  90.2W   75 KT  85 MPH - Category 1 (WNW Mérida, MX)
 72H  26/1800Z 28.0N  92.5W   90 KT 105 MPH - Category 2 (S Pecan Island, LA)
 96H  27/1800Z 32.7N  93.5W   45 KT  50 MPH - Tropical Storm (ENE Princeton, LA)
120H  28/1800Z 37.0N  88.0W   25 KT  30 MPH - Depression (WNW  Confederate, Kentucky)

NWS National Hurricane Center Miami FL 500 AM EDT Sun Aug 23, 2020 

Laura has maintained an impressive convective pattern despite the center being located over extreme south-central Dominican Republic. Numerous cloud tops of -85C to -90C have been noted over the Barahona peninsula, an indication that extremely heavy rainfall has been occurring there. The center of Laura passed over or very near Santo Domingo around 0430Z based on a noticeable wind shift that was measured at the international airport. Laura’s outflow pattern has also continue to improve in all quadrants. The initial intensity of 40 kt is based on earlier scatterometer and aircraft data, along with surface observations along the north coast of the Dominican Republic.

Laura has continued to move west-northwestward and the initial motion estimate is now 285/16 kt. There has been a significant westward shift in the latest NHC model guidance, which appears to be due to most of the global models taking the center of Laura farther south over central or southern Hispaniola rather than emerging it off the north coast of Haiti like the GFS is and has been forecasting. Given that the most intense convection has persisted along the southern coast of Hispaniola, that is where the most likely area that a low-level and/or mid-level circulation is most probable to develop or persist. As a result, the new NHC track forecast favors a more southerly and westerly track solution similar to the preponderance of the track guidance. However, the new forecast track has not been shifted as far to the left as the consensus models in the event that the models shift back to the north. However, the latter scenario is appearing less likely based observed satellite trends since the previous advisory.

Little if any significant change in strength is expected due to Laura moving pretty much down the spine of Hispaniola and Cuba during the the next 36 hours, with the strongest wind likely remaining over water in the northeast quadrant where the pressure gradient will be the tightest between the cyclone and the Bermuda High. By 48 hours and continuing until landfall, Laura is forecast to remain in a low shear and very favorable upper-level outflow environment while passing of extremely warm SSTs near 31C. This should allow for significant strengthening to occur once the cyclone regains a decent inner core after exiting Cuba. The new NHC intensity forecast is a blend of the intensity forecasts by the GFS and ECMWF global models and the corrected consensus models HCCA and FSSE.

Key Messages:

  • 1. Tropical storm conditions are expected across portions of the Dominican Republic and Haiti, the Turks and Caicos, the southeastern Bahamas, and Cuba through Monday. Heavy rainfall is likely across these areas and could cause mudslides and flash and urban flooding.
  • 2. Tropical storm conditions are possible the central Bahamas and Andros Island tonight and Monday, and in the Florida Keys on Monday.
  • 3. The details of the long-range track and intensity forecasts remain uncertain since Laura is forecast to move near or over portions of the Greater Antilles through Monday. However, Laura is forecast to strengthen over the Gulf of Mexico and could bring storm surge, rainfall, and wind impacts to portions of the U.S. Gulf Coast by the middle of next week. This could result in a prolonged period of hazardous weather for areas that are likely to be affected by Tropical Storm Marco earlier in the week. Interests there should monitor the progress of Laura and Marco and updates to the forecast during the next few days.
FORECAST POSITIONS AND MAX WINDS

INIT  23/0900Z 18.8N  70.9W   40 KT  45 MPH - Tropical Storm (WNW  Las Lagunas, DR)
 12H  23/1800Z 19.8N  73.7W   40 KT  45 MPH - Tropical Storm (WSW Jean-Rabel, Haiti)
 24H  24/0600Z 20.9N  77.5W   40 KT  45 MPH - Tropical Storm (WSW Colombia, Cuba)
 36H  24/1800Z 22.2N  81.1W   40 KT  45 MPH - Tropical Storm (ESE PLaya Larga, Cuba)
 48H  25/0600Z 23.5N  84.2W   45 KT  50 MPH - Tropical Storm (WNW Harlem, Cuba)
 60H  25/1800Z 24.9N  87.0W   60 KT  70 MPH - Tropical Storm (WSW Key West Fl)
 72H  26/0600Z 26.4N  89.4W   75 KT  85 MPH - Category 1 (ESE Port Eads, LA)
 96H  27/0600Z 29.9N  92.5W   85 KT 100 MPH - Category 2 (ESE  Gueydan, LA)
120H  28/0600Z 35.0N  91.4W   30 KT  35 MPH - Depression (WSW  Little Dixie, Arkansas)

NWS National Hurricane Center Miami FL 1100 PM AST Sat Aug 22, 2020 

Laura is now located near the eastern portion of the Dominican Republic, and it is producing a large area of showers and thunderstorms over much of Hispaniola and adjacent areas. The NOAA Hurricane Hunters have been flying in the tropical storm this evening and have found winds to support maintaining the initial intensity of 45 kt. Dropsonde data from the aircraft suggests that the pressure has fallen a little to 1003 mb, and that the center is still quite elongated. Laura is moving west-northwestward at 14 kt. The track forecast reasoning is generally unchanged from earlier. A subtropical high pressure system is expected to build westward during the next few days, which should continue to steer Laura generally west-northwestward at a fairly quick pace. This track should take the storm across Hispaniola tonight and early Sunday and then across Cuba late Sunday and Monday. Laura is then expected to emerge over the eastern Gulf of Mexico, where it will likely turn northwestward and slow down some as it reaches the western side of the ridge. The models are in fair agreement that Laura will generally follow a similar path to Marco when it nears the northern Gulf coast in 3 to 4 days. There has been little change in the guidance this cycle, and the NHC track forecast is largely an update of the previous one. This forecast is near the typically reliable TVCA and HCCA consensus aids. Since the tropical storm is expected to track across the mountainous islands of Hispaniola and Cuba during the next 36 to 48 hours, little change in intensity seems like a good bet during that time period. However, after the storm pulls away from the islands and moves over the warm Gulf of Mexico waters while being in low wind shear and high moisture conditions, strengthening seems very likely. Most of the better-performing intensity models show Laura making landfall along the U.S. northern Gulf coast as a hurricane in about 4 days. The NHC intensity forecast is slightly higher than the previous one, and it lies roughly near the middle of the guidance suite.

Key Messages:

  • 1. Tropical storm conditions are expected to continue across portions of the U.S. Virgin Islands and Puerto Rico for a few more hours. Tropical storm conditions are also expected across portions of the Dominican Republic and Haiti, the Turks and Caicos, the southeastern Bahamas, and central and eastern Cuba through Sunday. Heavy rainfall is likely across these areas and could cause mudslides and flash and urban flooding through Sunday, with widespread river flooding possible in Puerto Rico.
  • 2. Tropical storm conditions are possible over portions of central and western Cuba, the central Bahamas and Andros Island Sunday night and Monday, and in the Florida Keys on Monday.
  • 3. The details of the long-range track and intensity forecasts remain uncertain since Laura is forecast to move near or over portions of the Greater Antilles through Monday. However, Laura is forecast to strengthen over the Gulf of Mexico and could bring storm surge, rainfall, and wind impacts to portions of the U.S. Gulf Coast by the middle of next week. This could result in a prolonged period of hazardous weather for areas that are likely to be affected by Tropical Storm Marco earlier in the week. Interests there should monitor the progress of Laura and Marco and updates to the forecast during the next few days.
FORECAST POSITIONS AND MAX WINDS

INIT  23/0300Z 18.3N  69.6W   45 KT  50 MPH - Tropical Storm (WSW Isla de Mona, Puerto Rico)
 12H  23/1200Z 19.3N  72.3W   45 KT  50 MPH - Tropical Storm (WNW Debaucne, Haiti)
 24H  24/0000Z 20.6N  76.0W   45 KT  50 MPH - Tropical Storm (WSW Barajagua, Cuba)
 36H  24/1200Z 22.1N  79.6W   45 KT  50 MPH - Tropical Storm (WSW Potrón, Cuba)
 48H  25/0000Z 23.4N  83.0W   50 KT  60 MPH - Tropical Storm (WNW Havana, Cuba)
 60H  25/1200Z 24.7N  85.8W   60 KT  70 MPH - Tropical Storm (WNW Key West, FL)
 72H  26/0000Z 26.2N  88.0W   75 KT  85 MPH - Category 1 (WNW Naples, FL)
 96H  27/0000Z 29.8N  91.2W   80 KT  90 MPH - Category 1 (ENE Morgan City, LA)
120H  28/0000Z 34.7N  89.6W   30 KT  35 MPH - Depression (ENE  Chulahoma, MS)

NWS National Hurricane Center Miami FL 500 PM AST Sat Aug 22, 2020

A couple of hours ago an observing site on the southeast coast of Puerto Rico, Las Mareas, reported sustained winds of 52 kt. These winds were apparently associated with a mesocyclone embedded within the larger-scale circulation and not representative of the intensity of the tropical storm. Scatterometer data and WSR-88D Doppler velocities from San Juan support an intensity of 45 kt. Since the center should be moving over land for the next 48 hours or so, no additional intensification is anticipated until Monday night when the center moves over the southeastern Gulf of Mexico.

Over warm waters, with anticipated weak vertical shear, and anticyclonic flow aloft, Laura will likely strengthen into a hurricane before it reaches the northern Gulf of Mexico coast. The NHC intensity forecast is close to the multi-model consensus, but given the possibility of a favorable upper-air environment over the Gulf, this forecast could be conservative. At this time it does not seem likely that Marco, which is forecast to make landfall on the north-central Gulf coast a day or two earlier than Laura, should have much of an influence on the latter system.

Center locations from earlier scatterometer data, low-cloud motions, and Dvorak fixes from both TAFB and SAB, give a motion of about 280/16 kt. Laura should move west-northwestward along the southern side of a mid-tropospheric anticyclone centered near the southeastern U.S. coast through 72 hours. Then, the cyclone is expected to turn northwestward to northward on the western side of the high. The official track forecast is on the right side of the track guidance suite.

Given the predicted track and wind radii, a Tropical Storm Watch has been issued for the Florida Keys and the Dry Tortugas.

Key Messages:

  • 1. Tropical storm conditions are expected to continue across portions of the U.S. Virgin Islands and Puerto Rico through this evening. Tropical storm conditions are also expected across portions of the Dominican Republic and Haiti, the Turks and Caicos, the southeastern Bahamas, and central and eastern Cuba through Sunday. Heavy rainfall is likely across these areas and could cause mudslides and flash and urban flooding through Sunday, with widespread river flooding possible in Puerto Rico.
  • 2. Tropical storm conditions are possible over portions of the central Bahamas and Andros Island Sunday night and Monday, and in the Florida Keys on Monday.
  • 3. The details of the long-range track and intensity forecasts remain uncertain since Laura is forecast to move near or over portions of the Greater Antilles through Monday. However, Laura is forecast to strengthen over the Gulf of Mexico and could bring storm surge, rainfall, and wind impacts to portions of the U.S. Gulf Coast by the middle of next week. This could result in a prolonged period of hazardous weather for areas that are likely to be affected by Tropical Storm Marco earlier in the week. Interests there should monitor the progress of Laura and Marco and updates to the forecast during the next few days.
FORECAST POSITIONS AND MAX WINDS

INIT  22/2100Z 18.0N  68.1W   45 KT  50 MPH - Tropical Storm (WSW Isla de Mona, Puerto Rico)
 12H  23/0600Z 18.9N  70.6W   45 KT  50 MPH - Tropical Storm (ESE Tireo, DR)
 24H  23/1800Z 20.1N  74.3W   45 KT  50 MPH - Tropical Storm (ENE Punta Caleta, Cuba)
 36H  24/0600Z 21.6N  78.1W   45 KT  50 MPH - Tropical Storm (ENE Florida, Cuba)
 48H  24/1800Z 23.0N  81.6W   45 KT  50 MPH - Tropical Storm (WSW Matanzas, Cuba)
 60H  25/0600Z 24.3N  84.5W   55 KT  65 MPH - Tropical Storm (WSW Key West, FL)
 72H  25/1800Z 25.7N  87.3W   65 KT  75 MPH - Category 1 (WSW Naples, FL)
 96H  26/1800Z 29.0N  90.7W   75 KT  85 MPH - Category 1 (WSW Cocodrie, LA)
120H  27/1800Z 33.0N  91.0W   30 KT  35 MPH - Depression (WNW Grace, MS)

\NWS National Hurricane Center Miami FL 500 AM AST Sat Aug 22, 2020

Corrected status at 96 and 120 h Surface observations and Doppler radar data from Puerto Rico indicate that the center of Laura is currently over the Virgin Islands, eastern Puerto Rico, and the adjacent Caribbean waters. Overall, the system has become a little better organized since the last advisory, with strong convection forming not far from the center to the east and southeast and a somewhat better defined circulation. However, the central area of light winds is quite large, and there is evidence of several vorticity centers rotating around the mean storm center. Earlier scatterometer data suggested that the maximum winds had decreased to 35 kt, and that is the initial intensity for this advisory.

The initial motion is a somewhat uncertain 280/18. There is no change in the track forecast philosophy, as a subtropical ridge over the central and western Atlantic is expected to expand westward, causing Laura to move quickly west-northwestward for the next 3 days or so. After that, the storm should turn northwestward toward the western edge of the ridge over the northern Gulf coast. While the dynamical models are in good agreement with the general scenario, there is an unusual amount of cross track spread. The track guidance is spread from the Florida Keys to the western end of Cuba as the storm enters the Gulf of Mexico, and the models have potential landfall locations along the Gulf coast from the Florida Panhandle to the middle Texas coast. One complicating factor is the potential for interaction with Tropical Storm Marco, although at this time the model guidance suggests the storms will stay far enough apart to prevent direct interaction. The new forecast track is similar to the previous track through 72 hr, then it is shifted a bit to the west after that time. The new track lies near the various consensus models.

Laura is moving into an environment of light shear, and combined with the somewhat improved organization it suggests the storm should strengthen. However, the forecast track takes the center over Hispaniola and then down the length of Cuba, which should at least slow any intensification. This is reflected in the new intensity forecast which shows slow strengthening. Over the Gulf of Mexico, warm water and a likely favorable shear environment should allow Laura to become a hurricane, a scenario now supported by much of the guidance.

Key Messages:

  • 1. Tropical storm conditions are expected across portions of the northern Leeward Islands, the Virgin Islands, and Puerto Rico through today. Tropical storm conditions are also expected along the northern coasts of the Dominican Republic and Haiti, and the Turks and Caicos and southeastern Bahamas Saturday into Sunday. Heavy rainfall is likely across these areas beginning and could cause mudslides and flash and urban flooding through Sunday.
  • 2. Tropical storm conditions are possible over portions of the central Bahamas Sunday night, as well as portions of eastern and central Cuba Sunday and Sunday night. 3. The details of the long-range track and intensity forecasts remain more uncertain than usual since Laura is forecast to move near or over portions of the Greater Antilles through Monday. However, Laura could bring storm surge, rainfall, and wind impacts to portions of Cuba, the Bahamas, and Florida early next week and the northern U.S. Gulf Coast by the middle of next week. Interests there should monitor the progress of Laura and updates to the forecast during the next few days.
FORECAST POSITIONS AND MAX WINDS

INIT  22/0900Z 17.6N  65.5W   35 KT  40 MPH - Tropical Storm (WSW Guayama, Puerto Rico)
 12H  22/1800Z 18.2N  67.7W   40 KT  45 MPH - Tropical Storm (ESE Isla de Mona, Puerto Rico)
 24H  23/0600Z 19.1N  71.0W   40 KT  45 MPH - Tropical Storm (WSW Manabao, DR)
 36H  23/1800Z 20.3N  74.6W   45 KT  50 MPH - Tropical Storm (WSW Baracoa)
 48H  24/0600Z 21.6N  78.3W   45 KT  50 MPH - Tropical Storm (WNW Havana, Cuba)
 60H  24/1800Z 23.1N  81.8W   45 KT  50 MPH - Tropical Storm (ESE Matanzas, Cuba)
 72H  25/0600Z 24.6N  84.7W   55 KT  65 MPH - Tropical Storm (WSW Key West, FL)
 96H  26/0600Z 27.5N  89.5W   75 KT  85 MPH - Category 1 (ESE New Orleans, LA)

NWS National Hurricane Center Miami FL 1100 PM AST Fri Aug 21, 2020 

Laura remains quite disorganized this evening. Although satellite and radar images show a fair amount of deep convection over and to the east of the northern Leeward Islands, NOAA Hurricane Hunter data and surface observations indicate that the low-level center is located well to the west of the main area of deep convection. This asymmetric structure indicates that Laura is still not vertically aligned due to at least moderate wind shear. The initial intensity is held at a possibly generous 40 kt, and most of the strongest winds are well north and east of the center.

The steering pattern for Laura appears to be very well established. A subtropical ridge over the central and western Atlantic is expected to expand westward, and that should cause Laura to move west-northwestward at a fairly quick pace during the next few days. This should take the storm across Puerto Rico on Saturday, near Hispaniola Saturday night, and close to or over Cuba on Sunday and Monday. By early next week, Laura should approach the western end of the ridge and that should cause the storm to slow down and turn toward the northwest over the eastern and central Gulf of Mexico. Even though the steering pattern is well established, there are still chances of center reformations, which could cause small but important track changes. The NHC track forecast has been adjusted a little to the south of the previous one to account for the more southern initial position and westward motion. Near the end of the period, Laura’s track could also be influenced by Tropical Storm Marco, which is also forecast to be over the Gulf of Mexico, however the details of that interaction are highly uncertain at this time.

Although the storm’s structure is quite ragged at the moment, some of the models do show Laura becoming better organized this weekend and early next week due to a decrease in wind shear and very warm waters. However, there is significant uncertainty on how much the circulation will interact with the rugged islands of Hispaniola and Cuba. If the storm is able to stay north of those islands, some notable strengthening is possible as depicted by the HWRF and HMON models. However, if the storm moves over the islands, it might not strengthen at all until it passes through that area. The bottom line is the intensity forecast is very track dependent, which makes it more uncertain than normal. Given that the new track shows more land interaction, this forecast shows less strengthening in the short term, but is largely unchanged at the longer forecast times.

Key Messages:

  • 1. Tropical storm conditions are expected across portions of the northern Leeward Islands, the Virgin Islands, and Puerto Rico through Saturday. Tropical storm conditions are also expected along the northern coasts of the Dominican Republic and Haiti, and the Turks and Caicos and southeastern Bahamas Saturday into Sunday. Heavy rainfall is likely across these areas beginning and could cause mudslides and flash and urban flooding through Sunday.
  • 2. Tropical storm conditions are possible over portions of the central Bahamas Sunday night.
  • 3. The details of the long-range track and intensity forecasts remain more uncertain than usual since Laura is forecast to move near or over portions of the Greater Antilles through Monday. However, Laura could bring storm surge, rainfall, and wind impacts to portions of Cuba, the Bahamas, and Florida early next week and the northern U.S. Gulf Coast by the middle of next week. Interests there should monitor the progress of Laura and updates to the forecast during the next few days.
FORECAST POSITIONS AND MAX WINDS

INIT  22/0300Z 17.0N  63.5W   40 KT  45 MPH - Tropical Storm (Charlestown St Kitts & Nevis)
 12H  22/1200Z 17.6N  65.9W   40 KT  45 MPH - Tropical Storm (ESE San Juan, Puerto Rico )
 24H  23/0000Z 18.4N  69.3W   40 KT  45 MPH - Tropical Storm (ESE San Pedro De Macoris, DR)
 36H  23/1200Z 19.5N  72.8W   40 KT  45 MPH - Tropical Storm (WNW Gonaïves, Haiti)
 48H  24/0000Z 20.8N  76.4W   45 KT  50 MPH - Tropical Storm (WNW Cacocum, Cuba)
 60H  24/1200Z 22.1N  80.1W   45 KT  50 MPH - Tropical Storm (WNE El Nicho, Cuba)
 72H  25/0000Z 23.8N  83.3W   55 KT  65 MPH - Tropical Storm (WNW Havana, Cuba)
 96H  26/0000Z 26.5N  87.7W   65 KT  75 MPH - Caegory 1 (ESE New Orleans, LA)
120H  27/0000Z 29.2N  90.2W   65 KT  75 MPH - Caegory 1 (WSW Leeville, LA)

NWS National Hurricane Center Miami FL 1100 AM AST Fri Aug 21, 2020  

A NOAA Hurricane Hunter aircraft has been investigating the system this morning and found that the maximum winds have increased to near 40 kt, and therefore the cyclone is being named. The Hurricane Hunters also found that the center of the storm is located somewhat to the south of previous estimates. The system is better organized than it was yesterday, but still lacks well-defined banding features. However, some upper-level outflow is now noted over the southern portion of the circulation. The official forecast calls for some slow strengthening during the next couple of days, but the intensity forecast is quite uncertain and depends on how much interaction with land will occur. For now, we will assume that the northern part of the circulation will remain over water so that the system will not be too disrupted by Hispaniola and Cuba. The official intensity forecast remains close to the model consensus except at days 4 and 5 where it is a little lower due to these uncertainties.

With the repositioning of the center, the motion is very uncertain but is estimated to be 270/16 kt. Laura is expected to move mainly west-northwestward on the south side of a subtropical high pressure system over the next couple of days. Later in the forecast period, the tropical cyclone should turn toward the northwest as it moves around the western periphery of the high. The official track forecast has been adjusted to the south of the previous one and is on the northern side of the guidance suite.

Tropical storm warnings have been issued for the northern Leeward Islands, Puerto Rico, and the Virgin Islands.

Key Messages:

  • 1. Tropical storm conditions are expected across portions of the northern Leeward Islands, the Virgin Islands, and Puerto Rico today through Saturday, and Tropical Storm Warnings are in effect. Heavy rainfall is likely across this area beginning today and could cause mudslides and flash and urban flooding through Sunday.
  • 2. Tropical storm conditions are possible along the northern coasts of the Dominican Republic and Haiti, the southeastern Bahamas, and the Turks and Caicos islands Saturday and Sunday, and Tropical Storm Watches are in effect.
  • 3. The details of the long-range track and intensity forecasts remain more uncertain than usual since Laura is forecast to move near or over portions of the Greater Antilles through Monday. However, Laura could bring storm surge, rainfall, and wind impacts to portions of Cuba, the Bahamas, and Florida early next week and the northeast U.S. Gulf Coast by the middle of next week. Interests there should monitor the progress of Laura and updates to the forecast over the next few days.
FORECAST POSITIONS AND MAX WINDS

INIT  21/1500Z 17.0N  60.2W   40 KT  45 MPH - Tropical Storm (St John's, A and B)
 12H  22/0000Z 17.4N  62.7W   40 KT  45 MPH - Tropical Storm (WNE Cayon, A and B)
 24H  22/1200Z 18.3N  66.0W   45 KT  50 MPH - Tropical Storm (Trujillo Alto, Puerto Rico)
 36H  23/0000Z 19.2N  69.5W   45 KT  50 MPH - Tropical Storm (Los Róbalos, DR)
 48H  23/1200Z 20.2N  73.4W   45 KT  50 MPH - Tropical Storm (Pointe Quest, Haiti)
 60H  24/0000Z 21.6N  77.1W   50 KT  60 MPH - Tropical Storm (La Boca, Cuba)
 72H  24/1200Z 23.2N  80.7W   55 KT  65 MPH - Tropical Storm (Cayo Cabezos Island, Cuba)
 96H  25/1200Z 26.5N  85.5W   65 KT  75 MPH - Category 1 (WSW Fort Myers, FL)
120H  26/1200Z 29.5N  87.5W   65 KT  75 MPH - Category 1 (WSW Gulf Shores, AL)

NWS National Hurricane Center Miami FL 1100 PM AST Thu Aug 20, 2020

A NOAA Hurricane Hunter aircraft has been flying all around the circulation of the depression this evening, providing valuable information on the low-level structure. The strongest winds are primarily northeast of the center, with an elongated surface circulation and a mid-level swirl near the southern end. While the plane couldn’t locate a definite center, there’s enough uncertainty and curvatu+re in the plane’s wind field data to hold onto the system as 30-kt tropical depression for now. Another mission should be in the area around 1200 UTC. A late-arriving scatterometer pass confirms both the disorganization of the cyclone and the maximum winds.

The initial motion continues about the same as before, 290/19. A strong subtropical ridge over the western Atlantic should remain north of the depression during the next few days, steering the cyclone at a fast pace to the west-northwest. After the weekend, the ridge weakens some over the eastern Gulf of Mexico, leading to depression probably turning more to the northwest. The guidance has trended to the south and west after 24 hours tonight, led by the GFS and HWRF models. I’m not inclined to make significant changes since the models are about to ingest the information from the reconnaissance mission, plus the initial disorganization of the center, but the new track is still adjusted slightly to the south and west, north of much of the guidance.

The depression should be moving through mixed conditions over the next few days. While the water is very warm, GFS forecasts show that there is significant mid-level shear that could continue to mix in nearby dry air toward the center. This shear will probably relax late this weekend or early next week, but there is very poor agreement on how much shear remains and the timing of this event. In addition, a track any farther south would result in potentially mountainous land interaction, which also increases the intensity forecast uncertainty. No significant changes were made to the previous wind speed forecast, and the overall confidence in both the track and intensity forecasts remain lower than normal.

Key Messages:

  • 1. Tropical storm conditions are possible across portions of the northern Leeward Islands, the Virgin Islands, and Puerto Rico Friday night and Saturday, and Tropical Storm Watches have been issued for some of these islands. Heavy rainfall is likely across this area beginning late Friday and could cause mudslides and flash and urban flooding through Sunday.
  • 2. The details of the long-range track and intensity forecasts are more uncertain than usual since the system could move over portions of the Greater Antilles this weekend. However, this system could bring some storm surge, rainfall and wind impacts to portions of Hispaniola, Cuba, the Bahamas, and Florida this weekend and early next week. Interests there should monitor this system’s progress and updates to the forecast over the next few days.
FORECAST POSITIONS AND MAX WINDS

INIT  21/0300Z 17.3N  56.4W   30 KT  35 MPH - Depression (ESE Basse-Terre, Guadeloupe)
 12H  21/1200Z 17.9N  59.1W   30 KT  35 MPH - Depression (ESE Basse-Terre, Guadeloupe)
 24H  22/0000Z 18.6N  62.4W   35 KT  40 MPH - Tropical Storm (ENE Codrington, Barbuda)
 36H  22/1200Z 19.4N  65.7W   40 KT  45 MPH - Tropical Storm (ENE The Settlement, BVI)
 48H  23/0000Z 20.3N  69.2W   45 KT  50 MPH - Tropical Storm (WNW San Juan, Puerto Rico)
 60H  23/1200Z 21.3N  72.8W   50 KT  60 MPH - Tropical Storm (ESE Balfour Town, TACI)
 72H  24/0000Z 22.6N  76.4W   55 KT  65 MPH - Tropical Storm (WNW Duncan Town, Bahamas)
 96H  25/0000Z 26.0N  82.5W   65 KT  75 MPH - Category 1 (WSW Naples, FL)
120H  26/0000Z 29.0N  85.5W   65 KT  75 MPH - Category 1 (WSW Apalachicola, FL)

NWS National Hurricane Center Miami FL 500 PM AST Thu Aug 20, 2020 

Recent late afternoon visible satellite imagery has shown evidence of a low-level swirl that is racing away from the persistent area of deep convection. It is unclear if that is the only center of circulation or a swirl rotating around the broader circulation. The initial position for this advisory is a compromise between the earlier estimated center location and the swirl seen in satellite imagery. The initial intensity has been held at 30 kt, based on the earlier ASCAT data.

The initial motion estimate is a somewhat uncertain 290/18 kt. The cyclone is located south of a subtropical ridge that is forecast to build westward over the western Atlantic through early next week. This ridge should steer the system west-northwestward over the next several days, and the suite of dynamical track models continue to be agreement on this overall scenario. The lastest NHC track foreast is similar to the previous advisory and again lies between the HFIP corrected consensus and the TVCA multi-model consensus. It should be noted that since the system is still lacking in organization, there could be some center reformations that result in some shifts in the track forecast.

Although the depression has changed little in strength since it formed yesterday, the overall environment ahead of the system favors gradual strengthening. The cyclone is forecast to remain over warm water and in an area of light to moderate vertical wind shear. Most of the guidance suggests a little more favorable upper-level wind pattern once the system is north of the Greater Antilles, but a track farther south would result in more land interaction, which increases the intensity forecast uncertainty. The updated NHC intensity forecast shows a slightly slower rate of strengthening over the next couple of days, but is unchanged at the latter periods. The overall confidence in both the track and intensity forecasts remain lower than normal.

Key Messages:

  • 1. Tropical storm conditions are possible across portions of the northern Leeward Islands, the Virgin Islands, and Puerto Rico Friday night and Saturday, and Tropical Storm Watches have been issued for some of these islands. Heavy rainfall is likely across this area beginning late Friday and could cause mudslides and flash and urban flooding through Sunday.
  • 2. The details of the long-range track and intensity forecasts are more uncertain than usual since the system could move over portions of the Greater Antilles this weekend. However, this system could bring some storm surge, rainfall and wind impacts to portions of Hispaniola, Cuba, the Bahamas, and Florida this weekend and early next week. Interests there should monitor this system’s progress and updates to the forecast over the next few days.
FORECAST POSITIONS AND MAX WINDS

INIT  20/2100Z 16.7N  53.9W   30 KT  35 MPH - Depression (ESE Basse-Terre, Guadeloupe)
 12H  21/0600Z 17.5N  57.2W   30 KT  35 MPH - Depression (ESE Basse-Terre, Guadeloupe)
 24H  21/1800Z 18.3N  60.5W   35 KT  40 MPH - Tropical Storm (ENE Codrington, Barbuda)
 36H  22/0600Z 19.1N  63.5W   40 KT  45 MPH - Tropical Storm (ENE The Settlement, BVI)
 48H  22/1800Z 20.0N  66.7W   45 KT  50 MPH - Tropical Storm (WNW San Juan, Puerto Rico)
 60H  23/0600Z 20.9N  70.4W   50 KT  60 MPH - Tropical Storm (ESE Balfour Town, TACI)
 72H  23/1800Z 22.2N  74.1W   60 KT  70 MPH - Tropical Storm (ESE Acklins, Bahamas)
 96H  24/1800Z 25.1N  80.4W   65 KT  75 MPH - Category 1 (ENE Key Largo, FL)
120H  25/1800Z 28.3N  84.2W   65 KT  75 MPH - Category 1 (WNW Clearwater, FL)

NWS National Hurricane Center Miami FL 1100 AM AST Thu Aug 20, 2020

The organization of the depression has not changed much overnight or this morning. An area of convection has persisted near the estimated center, with some banding noted over the northwestern portion of the circulation. An earlier SSMIS overpass was very helpful in locating the center of what appears to be a small circulation. A very recent ASCAT overpass has also revealed a small circulation that is weak on the southeastern side, but with winds near tropical storm strength to the north of the center. The ASCAT data along with subjective Dvorak classification from TAFB and SAB support maintaining the 30-kt initial intensity.

The depression continues to move briskly west-northwestward or 290/18 kt. The track forecast philosophy has not changed from before. A subtropical ridge over the central Atlantic is forecast to build westward and strengthen over the next several days. This pattern is expected to keep the cyclone on a west-northwestward heading throughout the forecast period. The dynamical models continue to agree on this overall scenario, but there some differences in both forward speed and how close it gets to the Greater Antilles. In general, the models that indicate a stronger cyclone favor a more northern track, while those which depicted a weaker system are along the southern and faster side of the envelope. The latest consensus aids are little north of the previous track, and the new NHC forecast lies between the HFIP corrected consensus and the TVCA multi-model consensus. This is slightly north of the previous advisory, and not far from the GFS ensemble mean.

The environment consisting of light to moderate vertical wind shear is expected to allow for gradual strengthening over the next few days, and the NHC forecast calls for the system to become a tropical storm later today or tonight. The upper-level wind pattern is expected to remain favorable in the latter portion of the forecast period, and if there is minimal land interaction, a faster rate of strengthening is possible at that time. The NHC intensity foreast now shows the system becoming a hurricane by 96 hours, but it is a little lower than the consensus aids at days 4 and 5 due to uncertainty in how much the system will interact with the Greater Antilles.

Key Messages:

  • 1. Tropical storm conditions are possible across portions of the northern Leeward Islands by Friday night, and Tropical Storm Watches have been issued for some of these islands. Heavy rainfall is likely across this area beginning late Friday.
  • 2. There is a risk of tropical storm conditions in the Virgin Islands and Puerto Rico Friday night and Saturday and Tropical Storm Watches could be required for these islands later today. Interests there should closely monitor the progress of this system.
  • 3. The details of the long-range track and intensity forecasts are more uncertain than usual since the system could move over portions of the Greater Antilles this weekend. However, this system could bring some storm surge, rainfall and wind impacts to portions of Hispaniola, Cuba, the Bahamas, and Florida this weekend and early next week. Interests there should monitor this system’s progress and updates to the forecast over the next few days.
FORECAST POSITIONS AND MAX WINDS

INIT  20/1500Z 16.0N  52.0W   30 KT  35 MPH - Depression (ESE Basse-Terre, Guadeloupe)
 12H  21/0000Z 17.0N  54.7W   35 KT  40 MPH - Tropical Storm (ENE St John's, A and B)
 24H  21/1200Z 18.0N  58.3W   40 KT  45 MPH - Tropical Storm (ENE St John's, A and B)
 36H  22/0000Z 18.9N  61.6W   45 KT  50 MPH - Tropical Storm (ENE Philipsburg,Sint Maarten)
 48H  22/1200Z 19.6N  64.7W   50 KT  60 MPH - Tropical Storm (ENE San Juan, Puerto Rico)
 60H  23/0000Z 20.4N  68.1W   55 KT  65 MPH - Tropical Storm (ENE Punta Cana, Dom R)
 72H  23/1200Z 21.5N  71.8W   60 KT  70 MPH - Tropical Storm (WSW Cockburn Harbor, Turks)
 96H  24/1200Z 24.0N  78.6W   65 KT  75 MPH - Category 1 (WNW Congo Town, Bahamas)
120H  25/1200Z 27.0N  83.4W   65 KT  75 MPH - Category 1 (WSW Venice, FL)

NWS National Hurricane Center Miami FL 1100 PM AST Wed Aug 19, 2020 

The low-pressure system that NHC has been monitoring over the central tropical Atlantic has now developed a well-defined center of circulation and maintained enough organized deep convection to be classified as a tropical depression, the thirteenth cyclone of the 2020 Atlantic hurricane season. The depression already has some banding features on its north and west sides as evident in geostationary satellite and microwave images. The initial intensity is set at 30 kt based on ASCAT data from around 0100 UTC and a T2.0/30 kt Dvorak classifications from TAFB.

The depression has been moving fairly quickly to the west-northwest, with the latest initial motion estimated to be 295/17 kt. It should be noted that the initial motion is somewhat uncertain given that the system has only recently formed. A subtropical ridge currently over the central Atlantic is expected to build westward during the next several days and should be the primary steering feature for the depression through the forecast period. This pattern should keep the depression on a fairly quick west-northwest track during the next several days, taking the cyclone near the northern Leeward Islands by Friday night and near the Greater Antilles and southeastern Bahamas this weekend. The models are in fairly good agreement, but there is some north-south spread with the GFS being on the southern side of the guidance envelope and the ECMWF on the northern end. The NHC track forecast lies down the middle of the guidance suite.

The environmental conditions appear generally favorable for the depression to strengthen, with the wind shear expected to remain relatively low while the system moves over warm SSTs and remains in a moist airmass. These conditions should promote gradual strengthening and it seems quite likely that the cyclone will be a tropical storm when it moves near or north of the northern Leeward Islands in a couple of days. The bigger question is how much interaction will there be with the Greater Antilles. If the depression moves on the south side of the guidance envelope, further strengthening would be limited due to land interaction. Conversely, if the system gains more latitude and moves north of these highly topographic islands, it could have the opportunity for more significant intensification. The NHC intensity forecast, which is of low confidence, is roughly near the middle of the guidance envelope.

Key Messages:

  • 1. Tropical storm conditions are possible across portions of the northern Leeward Islands by Friday night, and Tropical Storm Watches have been issued for some of these islands. Heavy rainfall is likely across this area beginning late Friday.
  • 2. There is a risk of tropical storm conditions in the Virgin Islands and Puerto Rico Friday night and Saturday and Tropical Storm Watches could be required for these islands tomorrow. Interests there should closely monitor the progress of this system.
  • 3. The details of the long-range track and intensity forecasts are more uncertain than usual since the system could move over portions of the Greater Antilles this weekend. However, this system could bring some rainfall and wind impacts to portions of Hispaniola, Cuba, the Bahamas, and Florida this weekend and early next week. Interests there should monitor this system’s progress and updates to the forecast over the next few days.
FORECAST POSITIONS AND MAX WINDS

INIT  20/0300Z 14.6N  47.9W   30 KT  35 MPH - Depression (ESE Bridgetown, Barbados)
 12H  20/1200Z 16.1N  50.8W   30 KT  35 MPH - Depression (ESE Basse-Terre, Guadeloupe)
 24H  21/0000Z 17.4N  54.6W   35 KT  40 MPH - Tropical Storm (ESE St John's, A and B)
 36H  21/1200Z 18.4N  58.4W   40 KT  45 MPH - Tropical Storm (ENE St John's, A and B)
 48H  22/0000Z 19.1N  62.1W   45 KT  50 MPH - Tropical Storm (ENE Philipsburg,Sint Maarten)
 60H  22/1200Z 19.9N  65.9W   50 KT  60 MPH - Tropical Storm (WNW San Juan, Puerto Rico)
 72H  23/0000Z 20.8N  69.7W   55 KT  65 MPH - Tropical Storm (Cockburn Town, Turks Caicos)
 96H  24/0000Z 22.9N  76.7W   60 KT  70 MPH - Tropical Storm (WNW Moss Town, Bahamas)
120H  25/0000Z 26.2N  82.2W   60 KT  70 MPH - Tropical Storm (WSW North Naples, FL)

NWS National Hurricane Center Miami FL 800 PM EDT Wed Aug 19, 2020 

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

  • 1. A tropical wave and accompanying broad area of low pressure is producing a concentrated area of showers and thunderstorms over the central Caribbean Sea. This system is gradually becoming better organized, and a tropical depression is likely to form in a couple of days when the system reaches the northwestern Caribbean Sea. This low pressure area is moving westward, and interests in Honduras and the Yucatan Peninsula should closely monitor its progress. Regardless of development, this disturbance will likely produce heavy rains across a large portion of Central America and southeastern Mexico late this week and this weekend. * Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…80 percent.
  • 2. Satellite images indicate that the low-pressure system located about 850 miles east of the Windward Islands is gradually becoming better defined. In addition, the associated showers and thunderstorms are showing signs of organization, and a tropical depression could be forming. The system is expected to move generally west-northwestward at 15 to 20 mph, and interests in the northern Leeward Islands should closely monitor its progress as tropical storm watches could be required as early as this evening. * Formation chance through 48 hours…high…90 percent. * Formation chance through 5 days…high...90 percent.
  • 3. A tropical wave over western Africa is producing disorganized showers and thunderstorms. This wave is expected to move over the far eastern tropical Atlantic on Friday, and some slow development is possible through the weekend while it moves west-northwestward at 15 to 20 mph across the eastern tropical Atlantic. * Formation chance through 48 hours…low…10 percent.

NWS National Hurricane Center Miami FL 200 PM EDT Wed Aug 19, 2020 

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

  • 1. Showers and thunderstorms have become more concentrated today in association with a tropical wave currently located over the central Caribbean Sea. Some gradual development of this system is possible over next day or so while it moves westward at about 15 to 20 mph across the central Caribbean Sea. After that time, the wave is forecast to move more slowly west-northwestward, and a tropical depression is likely to form later this week when the system reaches the northwestern Caribbean Sea. * Formation chance through 48 hours…medium…60 percent. * Formation chance through 5 days…high…80 percent.
  • 2. An elongated area of low pressure, located about 1000 miles east of the Windward Islands continues to produce a concentrated area of showers and thunderstorms. Although recent satellite-derived wind data indicates that the low is not well-defined, environmental conditions are conducive for further development, and a tropical depression is expected to form during the next day or two while the system moves generally west-northwestward at 15 to 20 mph across the central and western portions of the tropical Atlantic. Interests in the Lesser Antilles should monitor the progress of this system. * Formation chance through 48 hours…high…90 percent. * Formation chance through 5 days…high…90 percent.
  • 3. A large area of showers and thunderstorms, located over Guinea and Sierra-Leone, Africa, is associated with a vigorous tropical wave. Environmental conditions are expected to be conducive for some development of this system while the wave enters the extreme eastern Atlantic on Friday. By early next week, however, conditions are forecast to become less favorable for tropical cyclone formation while it moves west-northwestward at 15 to 20 mph toward the central tropical Atlantic. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low...30 percent.

NWS National Hurricane Center Miami FL 800 AM EDT Wed Aug 19, 2020

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

  • 1. A tropical wave located over the eastern Caribbean Sea is producing disorganized showers and thunderstorms, along with gusty winds in these thunderstorms. Some gradual development of this system is possible over next day or so while it moves westward at about 15 to 20 mph across the central Caribbean Sea. After that time, the wave is forecast to move more slowly west-northwestward, and a tropical depression is likely to form late this week or this weekend when the system reaches the northwestern Caribbean Sea. * Formation chance through 48 hours…medium…40 percent. * Formation chance through 5 days…high…80 percent.
  • 2. An elongated area of low pressure, located a little over 1000 miles east of the Windward Islands continues to produce a concentrated area of showers and thunderstorms mainly on the west side of the disturbance. Environmental conditions are conducive for further development, and a tropical depression is expected to form during the next day or two while the system moves generally west-northwestward at 15 to 20 mph across the central and western portions of the tropical Atlantic. * Formation chance through 48 hours…high…90 percent. * Formation chance through 5 days…high…90 percent.
  • 3. A large area of showers and thunderstorms, located over Guinea and Sierra-Leone, Africa, is associated with a vigorous tropical wave. Environmental conditions are expected to be marginally conducive for some development of this system while the wave enters the extreme eastern Atlantic on Friday. By early next week, however, conditions are forecast to become less favorable for tropical cyclone formation while it moves west-northwestward at 15 to 20 mph toward the central tropical Atlantic. * Formation chance through 48 hours…low…near 0 percent.

NWS National Hurricane Center Miami FL 800 PM EDT Tue Aug 18, 2020

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

  • 1. A tropical wave located over the eastern Caribbean Sea is producing a large area of cloudiness and disorganized thunderstorms, along with strong gusty winds on the north side of the disturbance. Significant development of this system is unlikely during the next day or so while it moves quickly westward at about 20 mph across the eastern and central Caribbean Sea. After that time, however, the wave is forecast to move more slowly west-northwestward, and a tropical depression is likely to form late this week or this weekend when the system reaches the northwestern Caribbean Sea. * Formation chance through 48 hours…medium…40 percent. * Formation chance through 5 days…high…80 percent.
  • 2. A broad and elongated area of low pressure located about 1000 miles west-southwest of the Cabo Verde Islands continues to produce a concentrated area of showers and thunderstorms on the west side of the disturbance. Environmental conditions are conducive for further development, and a tropical depression is expected to form during the next day or two while the system moves generally west- northwestward at 15 to 20 mph across the central and western portions of the tropical Atlantic. * Formation chance through 48 hours…high…90 percent. * Formation chance through 5 days…high…90 percent.

NWS Weather Prediction Center College Park MD 200 PM EDT Tue Aug 18, 2020 

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

  • 1. A tropical wave over the eastern Caribbean Sea continues to produce an area of disorganized thunderstorms and gusty winds. This wave is moving quickly westward at about 20 mph and significant development is unlikely while it moves across the eastern and central Caribbean Sea during the next day or two. After that time, however, the wave is forecast to slow down, and a tropical depression will likely form late this week or this weekend when it reaches the northwestern Caribbean Sea. * Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…high…70 percent.
  • 2. An area of low pressure located about 1300 miles east of the Lesser Antilles is producing a concentrated area of showers and thunderstorms. Environmental conditions are conducive for development, and a tropical depression is expected to form within the next couple of days while the system moves west-northwestward at 15 to 20 mph across the central and western portions of the tropical Atlantic. Interests in the Lesser Antilles should monitor the progres of this system. * Formation chance through 48 hours…high…80 percent. * Formation chance through 5 days…high…90 percent.

NWS National Hurricane Center Miami FL 800 AM EDT Tue Aug 18, 2020 

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

  • 1. A tropical wave over the eastern Caribbean Sea is producing an area of disorganized thunderstorms and gusty winds. Significant development of this system is unlikely during the next couple of days while it moves quickly westward at about 20 mph across the eastern and central Caribbean Sea. After that time, however, the wave is forecast to move more slowly westward, and a tropical depression could form late this week or this weekend when it reaches the northwestern Caribbean Sea. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium…60 percent.
  • 2. A broad area of low pressure located about 900 miles west-southwest of the Cabo Verde Islands is producing a concentrated area of showers and thunderstorms. Environmental conditions are conducive for further development, and a tropical depression is likely to form within the next couple of days while the system moves westward to west-northwestward at 15 to 20 mph across the central and western portions of the tropical Atlantic. * Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…90 percent.

NWS National Hurricane Center Miami FL 200 AM EDT Tue Aug 18, 2020 

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

  • 1. Disorganized showers and thunderstorms continue in association with a tropical wave located over the eastern Caribbean Sea. This disturbance is moving westward at about 20 mph, and is forecast to continue to move quickly westward over the eastern and central Caribbean Sea during the next couple of days, which is likely to limit significant development. After that time, however, the system is forecast to move more slowly westward across the western Caribbean, where upper-level winds could become more conducive for the development of a tropical depression during the latter part of this week. Regardless of development, locally heavy rainfall and gusty winds are expected over portions of the Windward and southern Leeward Islands this morning. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium…60 percent.
  • 2. A broad area of low pressure located a little over 700 miles west-southwest of the Cabo Verde Islands is producing a concentrated area of showers and thunderstorms displaced to the west of an elongated surface circulation. Environmental conditions are conducive for further development, and a tropical depression is likely to form within the next day or two while the system moves westward to west-northwestward at 15 to 20 mph across the central and western portions of the tropical Atlantic. * Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…90 percent.

NWS National Hurricane Center Miami FL 800 PM EDT Mon Aug 17, 2020 

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

  • 1. A tropical wave near the Windward Islands continues to produce a large area of disorganized showers and thunderstorms. This disturbance is moving westward at about 20 mph, and is expected to continue to move quickly westward over the eastern and central Caribbean Sea during the next couple of days, which is likely to limit significant development. After that time, however, the system is forecast to move more slowly westward across the western Caribbean, where upper-level winds could become more conducive for the development of a tropical depression during the latter part of this week. Regardless of development, locally heavy rainfall and gusty winds are expected over portions of the Windward and southern Leeward Islands through Tuesday morning. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium…60 percent.
  • 2. Satellite images indicate that a broad area of low pressure located about 700 miles west-southwest of the Cabo Verde Islands has become better organized since yesterday, with increasing banding features near the center. Environmental conditions are conducive for further development, and a tropical depression is likely to form within a couple days while the system moves westward to west-northwestward at 15 to 20 mph across the central and western portions of the tropical Atlantic. * Formation chance through 48 hours…medium…60 percent. * Formation chance through 5 days…high…90 percent.

NWS National Hurricane Center Miami FL 200 PM EDT Mon Aug 17, 2020

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

  • 1. A tropical wave approaching the Windward Islands is producing a large area of disorganized shower and thunderstorm activity. This disturbance is moving westward at about 20 mph, and is expected to continue to move quickly westward over the eastern and central Caribbean Sea during the next couple of days, which is likely to limit significant development. After that time, however, the system is expected to move more slowly westward across the western Caribbean, where upper-level winds could become more conducive for the development of a tropical depression during the latter part of this week. Regardless of development, locally heavy rainfall and gusty winds are expected over portions of the Windward and southern Leeward Islands through Tuesday morning. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium…50 percent.
  • 2. A tropical wave over the eastern tropical Atlantic is forecast to interact with another disturbance located several hundred miles southwest of the Cabo Verde Islands within the next day or two. This interaction is expected to lead to the formation of a broad area of low pressure, and conditions are forecast to be conducive for the development of a tropical depression during the middle-to-latter part of this week while the system moves westward to west- northwestward at 15 to 20 mph across the central and western portions of the tropical Atlantic. * Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…high…70 percent.

NWS National Hurricane Center Miami FL 800 AM EDT Mon Aug 17, 2020

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

  • 1. A fast-moving tropical wave located a couple of hundred miles east of the Windward Islands continues to produce disorganized shower and thunderstorm activity. This disturbance is expected to move westward at about 20 mph during the next few days, and that fast forward speed is likely to limit significant development while the system approaches the Windward and southern Leeward Islands today, and moves across the eastern and central Caribbean Sea on Tuesday and Wednesday. After that time, however, the system is expected to move more slowly westward across the western Caribbean Sea, where upper-level winds could become more conducive for the development of a tropical depression during the latter part of this week. Regardless of development, locally heavy rainfall and gusty winds are expected over portions of the Windward and southern Leeward Islands beginning today through Tuesday morning. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium…50 percent.
  • 2. Another tropical wave located over the eastern tropical Atlantic to the south-southwest of the Cabo Verde Islands is producing disorganized cloudiness and showers. The wave is forecast to move westward to west-northwestward at 15 to 20 mph during the next few days, and environmental conditions are expected to become more conducive for the development of a tropical depression during the middle-to-latter part of this week while the system moves across the central and western portions of the tropical Atlantic. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium…60 percent.

NWS National Hurricane Center Miami FL 200 AM EDT Mon Aug 17, 2020

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

  • 1. A fast-moving tropical wave located about 400 miles east of the Windward Islands continues to produce disorganized shower and thunderstorm activity. This disturbance is expected to move westward at about 20 mph during the next few days, and that fast forward speed is likely to limit significant development while the system approaches the Windward and southern Leeward Islands today, and moves across the eastern and central Caribbean Sea on Tuesday and Wednesday. After that time, however, the system is expected to move more slowly westward across the western Caribbean Sea, where upper-level winds could become more conducive for the development of a tropical depression during the latter part of this week. Regardless of development, locally heavy rainfall and gusty winds are expected over portions of the Windward and southern Leeward Islands beginning this evening through Tuesday morning. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium…50 percent.
  • 2. Another tropical wave located over the far eastern tropical Atlantic well to the south-southeast of the Cabo Verde Islands is producing a large area of cloudiness and disorganized showers. The wave is forecast to move westward to west-northwestward at 15 to 20 mph during the next few days, and environmental conditions are expected to become more conducive for the development of a tropical depression during the middle-to-latter part of this week while the system moves across the central tropical Atlantic. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…medium…60 percent.

NWS National Hurricane Center Miami FL 800 PM EDT Sun Aug 16, 2020

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center has issued the last advisory on Post-Tropical Cyclone Josephine, located a couple of hundred miles north of San Juan, Puerto Rico.

  • 1. Shower and thunderstorm activity has continued to increase in association with a fast-moving tropical wave located about 500 miles east of the Windward Islands. This disturbance is expected to move westward at about 20 mph during the next few days, and that fast forward speed is likely to limit significant development while the system approaches the Windward and southern Leeward Islands on Monday, and moves across the eastern Caribbean Sea on Tuesday. After that time, however, the system is expected to move more slowly westward across the central and western Caribbean Sea, where upper-level winds could become more conducive for the development of a tropical depression during the middle-to-latter part of this week. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium...50 percent.
  • 2. Another tropical wave located over the far eastern tropical Atlantic well to the southeast of the Cabo Verde Islands is producing a large area of cloudiness and disorganized showers. The wave is forecast to move westward at 15 to 20 mph during the next few days, and environmental conditions are expected to become more conducive for the development of a tropical depression during the middle-to- latter part of this week while the system moves across the central tropical Atlantic. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…50 percent.

NWS National Hurricane Center Miami FL 200 PM EDT Sun Aug 16, 2020

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical Depression Josephine, located a couple of hundred miles north-northeast of San Juan, Puerto Rico.

  • 1. Shower and thunderstorm activity has increased in association with a fast-moving tropical wave located about 700 miles east of the Windward Islands. This system is expected to move westward at about 20 mph during the next few days, and that fast speed is likely to limit significant development while the system approaches the Windward and southern Leeward Islands Monday, and moves across the eastern Caribbean Sea on Tuesday. After that time, the system is expected to move more slowly westward across the central and western Caribbean Sea, and upper-level winds could be conducive for development during the middle to latter part of this week. * Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium…40 percent.
  • 2. Another tropical wave located over the far eastern tropical Atlantic is producing a large area of cloudiness and showers. This wave is forecast to move westward at 15 to 20 mph during the next few days, and some development will be possible by the middle to latter part of the week as environmental conditions become more conducive while the system is over the central tropical Atlantic. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium...40 percent.

NWS National Hurricane Center Miami FL 800 AM EDT Sun Aug 16, 2020

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical Storm Josephine, located a couple of hundred miles northeast of San Juan, Puerto Rico. The National Hurricane Center has issued the last advisory on Post-Tropical Cyclone Kyle, located several hundred miles southwest of Cape Race, Newfoundland.

  • 1. A fast-moving tropical wave located about 850 miles east of the Windward Islands is producing a small area of disorganized showers and thunderstorms. This system is expected to move westward at about 20 mph during the next few days, and that fast speed is likely to limit development while the system approaches the Windward and southern Leeward Islands today and Monday and moves across the eastern Caribbean Sea on Tuesday. After that time, the system is expected to move more slowly westward across the central and western Caribbean Sea, and upper-level winds could be conducive for development during the middle to latter part of this week. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…low…30 percent.
  • 2. Another tropical wave located just west of the coast of Africa is producing a large area of cloudiness and showers. This wave is forecast to move westward at 15 to 20 mph during the next few days, and some development will be possible by the middle to latter part of the week as environmental conditions become more conducive while the system is over the central tropical Atlantic. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 200 AM EDT Sun Aug 16, 2020

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical Storm Josephine, located just over a hundred miles north-northeast of the northern Leeward Islands, and on Tropical Storm Kyle, located several hundred miles southwest of Cape Race, Newfoundland.

  • 1. A fast-moving tropical wave located over the central tropical Atlantic several hundred miles east of the Windward Islands is producing a small area of disorganized showers and thunderstorms. This system is expected to move westward at about 20 mph during the next few days, and that fast speed is likely to limit development while the system approaches the Windward and southern Leeward Islands today and Monday and moves across the eastern Caribbean Sea on Tuesday. After that time, the system is expected to move more slowly westward across the central and western Caribbean Sea, and upper-level winds could be conducive for development during the middle to latter part of this week. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…low…30 percent.
  • 2. Another tropical wave moving off the coast of Africa is producing a large area of cloudiness and showers. This wave is forecast to move westward at 15 to 20 mph during the next few days, and some development will be possible by the middle to latter part of the week as environmental conditions become more conducive while the system is over the central tropical Atlantic. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…20 percent.

NWS National Hurricane Center Miami FL 800 PM EDT Sat Aug 15, 2020

For the North Atlantic…Caribbean Sea and the Gulf of Mexico:

The National Hurricane Center is issuing advisories on Tropical Storm Josephine, located over the tropical Atlantic Ocean a few hundred miles northeast of the northern Leeward Islands, and on Tropical Storm Kyle, located several hundred miles southeast of the New England states of the United States.

  • 1. A westward-moving tropical wave located over the central tropical Atlantic several hundred miles east of the Windward Islands is currently producing limited shower and thunderstorm activity. However, upper-level winds are expected to become a little more conducive for development by the middle of next week as the disturbance approaches the central and southern Lesser Antilles and moves into the eastern Caribbean Sea. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…low…20 percent.

If this system is named, it will become Tropical Storm Laura.

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Video: RAW: Drone view of damage from Hurricane Laura in Texas