Tropical Storm Zeta

Post Tropical Storm Zeta Track 1700 Hours October 29 2020
Post Tropical Storm Zeta Track 1700 Hours October 29 2020

Tropical Storm Zeta Wind Speed FieldTropical Storm Zeta – NWS National Hurricane Center Miami FL 500 PM EDT Thu Oct 29, 2020 (see 5 pm video below)

Zeta lost tropical characteristics and was declared post-tropical a few hours ago. The surface pressure field has become elongated with the center now embedded within a frontal zone over the Mid-Atlantic states. The maximum sustained winds are still estimated to be 45 kt, based on an observation received from northeastern North Carolina a few hours ago, and winds have been increasing at marine sites located just off the Mid-Atlantic coast.

Zeta is zooming toward the east-northeast (060/48 kt), and its center is just about to move off the Delmarva Peninsula over the western Atlantic waters. This motion should continue for the next day or so since Zeta is embedded within fast westerly flow ahead of a strong mid-level trough.

Some baroclinic re-intensification is expected over the next day or so while Zeta moves farther out over the western Atlantic, and the 12-hour forecast intensity is based on the GFS and ECMWF global models. Zeta’s center is expected to dissipate within the frontal zone by 24 hours, with another strong low pressure area likely to develop and move toward the north Atlantic over the next several days. The forecast wind radii are based on guidance from the Ocean Prediction Center.

This is the last advisory issued on Zeta.

KEY MESSAGES:

  • 1. Strong wind gusts are still possible over portions of extreme eastern North Carolina, southeastern Virginia, and the southern Delmarva Peninsula during the next couple of hours.
  • 2. Through this evening, the last of the heavy rainfall along the track of Zeta is expected over the Mid-Atlantic. This rainfall may lead to flash, urban, small stream, and isolated minor river flooding.
FORECAST POSITIONS AND MAX WINDS

INIT  29/2100Z 38.8N  75.3W   45 KT  50 MPH - Post Tropical (ENE Milton, Delaware)
 12H  30/0600Z 41.0N  66.1W   50 KT  60 MPH - Post Tropical (ESE Boston,  Massachusetts)
 24H  30/1800Z...DISSIPATED

NWS National Hurricane Center Miami FL 1100 AM EDT Thu Oct 29, 2020 

Zeta continues to move rapidly over land, and its maximum sustained winds are estimated to be near 45 kt over the southeastern quadrant, with thew highest winds occuring over elevated locations. The wind gust factor continues to be higher than usual due to the interaction with land. Zeta continues to accelerate northeastward and is now moving near 055/42 kt. The cyclone should accelerate some more ahead of a strong 500-mb trough moving into the eastern United States over the next day or so. The official track forecast is in reasonable agreement with the global model predictions.

The pressure pattern of Zeta is becoming distorted, and starting to take on an extratropical appearance as the cyclone begins to interact with a nearby frontal system. By this afternoon, the global models indicate that the system will become a frontal low and thus extratropical. Some short-term baroclinic strengthening is possible over the western Atlantic, but the guidance suggests that the system will become absorbed into the frontal zone in 36 hours or so.

KEY MESSAGES:

  • 1. Strong, damaging wind gusts, which could cause tree damage and power outages, will continue to spread eastward across portions of the Carolinas and southeastern Virginia through this afternoon due to Zeta’s fast forward speed.
  • 2. Through today, heavy rainfall is expected near and in advance of Zeta from portions of the Ohio Valley, into the central Appalachians and Mid-Atlantic. This rainfall may lead to flash, urban, small stream, and isolated minor river flooding.
FORECAST POSITIONS AND MAX WINDS

INIT  29/1500Z 36.5N  81.5W   45 KT  50 MPH - Tropical Storm (ENE Lansing, North Carolina)
 12H  30/0000Z 39.4N  73.1W   50 KT  60 MPH - Post Tropical (ENE Atlantic City, NJ)
 24H  30/1200Z 42.0N  60.0W   50 KT  60 MPH - Post Tropical (ESE Shelburne, NS Canada)
 36H  31/0000Z...DISSIPATED

NWS National Hurricane Center Miami FL 1000 PM CDT Wed Oct 28, 2020 

The center of Zeta made landfall on the Louisiana coast south of Cocodrie at about 4 pm CDT with maximum sustained winds of about 95 kt. Since then, the hurricane has raced across southeastern Louisiana and is now over southeastern Mississippi. While the sustained winds have been coming down, the satellite presentation is actually not very degraded for a system that has been over land for this long, and there have been reports of 100-mph wind gusts during the past couple of hours. The initial wind speed is set to 70 kt on the basis of radar velocities and the decay-SHIPS model.

The hurricane is accelerating tonight toward the northeast or 040/27 kt. While Zeta should continue to weaken due to land effects, strong gusty winds are likely to occur near and east of the center due to the cyclone moving rapidly northeastward, allowing these strong winds to spread well inland. Little change was made to the intensity forecast. Zeta should become extratropical and merge with a front before moving off the Mid-Atlantic coast, eventually merging with a frontal boundary in a couple of days. The official track forecast most closely follows a blend of the model consensus and the GFS, and is faster than the last NHC track.

Note that the wind gust factor for this hurricane is higher than typical for a tropical cyclone, and that is reflected in the Forecast/Advisory product.

KEY MESSAGES:

  • 1. A dangerous storm surge is continuing along portions of the Mississippi and Alabama coastline and will gradually subside in the early morning hours on Thursday.
  • 2. Dangerous hurricane conditions expected to continue for the next few hours near and along the Mississippi and Alabama coastlines. Tropical storm conditions will also continue for portions of the Tropical Storm Warning area along the Alabama and far western Florida Panhandle coasts.
  • 3. Strong, damaging wind gusts, which could cause tree damage and power outages, will spread well inland across portions of southeastern Mississippi, Alabama, northern Georgia, the Carolinas, and southeastern Virginia overnight and Thursday due to Zeta’s fast forward speed. Wind gusts could be especially severe across the southern Appalachian Mountains on Thursday.
  • 4. Through Thursday, heavy rainfall is expected from portions of the central U.S. Gulf Coast into the Mid-Mississippi Valley, Ohio Valley, southern to central Appalachians, and Mid-Atlantic States near and in advance of Zeta. This rainfall will lead to flash, urban, small stream, and minor river flooding.
FORECAST POSITIONS AND MAX WINDS

INIT  29/0300Z 31.5N  88.7W   70 KT  80 MPH - Category 1 (WSW Clara, MS)
 12H  29/1200Z 35.5N  83.5W   45 KT  50 MPH - Tropical Storm (WNW 
 24H  30/0000Z 39.5N  73.0W   45 KT  50 MPH - Post Tropical (ENE Atlantic City, NJ)
 36H  30/1200Z 42.5N  59.0W   45 KT  50 MPH - Post Tropical (ESE Shelburne, NS Canada)
 48H  31/0000Z...DISSIPATED

NWS National Hurricane Center Miami FL 400 PM CDT Wed Oct 28, 2020 

The center of Zeta is in the Terrebone Bay area of Louisiana and is making landfall near Cocodrie. Somewhat surprisingly, Zeta has rapidly intensified this afternoon. Although the hurricane has been moving over marginally warm SSTs and relatively low heat content waters, it has intensified from 80 kt to 95 kt in about 6 hours. It is possible that this intensification can be at least partly attributable to a conducive interaction with with an upper-level trough located a few hundred miles to the west-northwest of Zeta. The 95-kt intensity estimate for Zeta is based on a blend of flight-level, SFMR and dropsonde winds from an Air Force Reserve Hurricane Hunter aircraft.

Since the center will either be interacting with land or moving over land from this point, a weakening trend should begin tonight. The official intensity forecast is close to the Decay-SHIPS guidance, which should handle the exponential decay of wind seed for tropical cyclones moving over land. In 24 hours or so, the global models depict the system as being embedded in a front while it approaches the United States east coast. Thus the official forecast shows an extratropical cyclone at that point and beyond. After 48 hours, the models show the low becoming elongated and absorbed into the frontal zone. Zeta has turned toward the north-northeast and the forward speed is increasing, with the motion now 025/21 kt. The cyclone should accelerate north-northeastward ahead of a 500-mb trough through tonight. The system should then move even faster toward the northeast, ahead of the trough, and across the southeastern and eastern United States on Thursday. Post-tropical Zeta should move east-northeastward, in the mid-level westerlies, into the Atlantic Friday morning. The official track forecast follows the correct model consensus, HCCA, rather closely.

Given Zeta’s acceleration after landfall, strong winds are likely to spread well inland over the southeastern U.S. overnight and early Thursday.

KEY MESSAGES:

  • 1. A life-threatening storm surge is beginning along portions of the northern Gulf Coast, with the highest inundation expected to occur somewhere between Port Fourchon, Louisiana, and Dauphin Island, Alabama, especially along the Mississippi coast. Overtopping of local, non-federal levee systems is possible within southeastern Louisiana outside of the Hurricane and Storm Damage Risk Reduction System.
  • 2. Extremely dangerous hurricane conditions are spreading across portions of the Hurricane Warning area along the southeastern Louisiana coast and will spread to the Mississippi coast this evening. Tropical storm conditions will spread into portions of the Tropical Storm Warning area along the Alabama and far western Florida Panhandle coasts in the next few hours.
  • 3. Strong, damaging wind gusts, which could cause tree damage and power outages, will spread well inland across portions of southeastern Mississippi, Alabama, northern Georgia, the Carolinas, and southeastern Virginia tonight and Thursday due to Zeta’s fast forward speed. Wind gusts could be especially severe across the southern Appalachian Mountains on Thursday.
  • 4. Through Thursday, heavy rainfall is expected from portions of the central U.S. Gulf Coast into the Mid-Mississippi Valley, Ohio Valley, southern to central Appalachians, and Mid-Atlantic States near and in advance of Zeta. This rainfall will lead to flash, urban, small stream, and minor river flooding.
FORECAST POSITIONS AND MAX WINDS

INIT  28/2100Z 29.2N  90.6W   95 KT 110 MPH - Category 2 (WSW Dulac, Louisiana)
 12H  29/0600Z 32.8N  87.0W   55 KT  65 MPH - Tropical Storm (WNW Maplesville, Alabama)
 24H  29/1800Z 37.5N  78.8W   40 KT  45 MPH - Post Tropical (ESE Gladstone, Virginia)
 36H  30/0600Z 41.0N  68.0W   45 KT  50 MPH - Post Tropical (ESE Nantucket, Massachusetts)
 48H  30/1800Z 44.0N  57.0W   45 KT  50 MPH - Post Tropical (ESE Glace Bay, NS Canada)
 60H  31/0600Z...DISSIPATED

NWS National Hurricane Center Miami FL 1000 AM CDT Wed Oct 28, 2020 

Zeta has a well-organized cloud pattern on satellite images, and the eye has been fairly well-defined. Strong upper-level outflow is evident over the northern semicircle of the hurricane. Reports from Air Force and NOAA Hurricane Hunter aircraft indicate that the system had continued to strengthen over the past few hours. Peak 700-mb flight level winds were 89 kt, which equates to a maximum surface wind of about 80 kt, and The central pressure has fallen to 976 mb. Zeta still has a few hours to intensify before it begins to move over the cooler waters of the northern Gulf of Mexico, and southwesterly shear is likely to increase by the time the center reaches the coast. Even if a little weakening begins later today, however, Zeta should maintain hurricane strength through landfall. The official intensity forecast is near the high end of the model guidance. In 36 hours or so, the global models clearly depict the system as a frontal wave approaching the United States east coast so the official forecast shows an extratropical cyclone at that point and beyond. After 48 hours, the models show the low becoming elongated and absorbed into the frontal zone.

The hurricane has turned northward and is now moving at around 010/16 kt. A strong 500-mb trough moving into Texas will continue to move eastward during the next 36-48 hours. The flow ahead of this trough will cause Zeta to accelerate north-northeastward and move inland along the central Gulf Coast in 6-12 hours. On Thursday, the cyclone will then move northeastward on the east side of the trough, at an even faster pace, over the southeastern United States. By early Friday, the system should move east- northeastward in the westerlies and into the western Atlantic as an extratropical cyclone. The official track forecast is close to the previous one and generally follows the dynamical model consensus.

Given Zeta’s acceleration near and after landfall, strong winds are likely to spread well inland over the southeastern U.S. this evening and early Thursday.

KEY MESSAGES:

  • 1. A life-threatening storm surge is expected along portions of the northern Gulf Coast beginning later today, with the highest inundation occurring between Port Fourchon, Louisiana, and Dauphin Island, Alabama. Residents in the Storm Surge Warning area should follow any advice given by local officials. Overtopping of local, non-federal levee systems is possible within southeastern Louisiana outside of the Hurricane and Storm Damage Risk Reduction System.
  • 2. Hurricane conditions are expected this afternoon and evening within portions of the Hurricane Warning area along the southeastern Louisiana and Mississippi coasts. Tropical storm conditions are expected within portions of the Tropical Storm Warning area along the Alabama and far western Florida Panhandle coasts.
  • 3. Strong, damaging wind gusts, which could cause tree damage and power outages, will spread well inland across portions of southeastern Mississippi, Alabama, northern Georgia, the Carolinas, and southeastern Virginia tonight and Thursday due to Zeta’s fast forward speed. Wind gusts could be especially severe across the southern Appalachian Mountains on Thursday.
  • 4. Through Thursday, heavy rainfall is expected from portions of the central U.S. Gulf Coast into the Mid-Mississippi Valley, Ohio Valley, southern to central Appalachians, and Mid-Atlantic States near and in advance of Zeta. This rainfall will lead to flash, urban, small stream, and minor river flooding.
FORECAST POSITIONS AND MAX WINDS

INIT  28/1500Z 26.9N  91.7W   80 KT  90 MPH - Category 1 (WSW Galveston,TX)
 12H  29/0000Z 30.1N  89.9W   80 KT  90 MPH - Category 1 (WNW New Orleans,LA )
 24H  29/1200Z 35.3N  83.9W   40 KT  45 MPH - Tropical Storm (WSW )
 36H  30/0000Z 39.1N  74.2W   40 KT  45 MPH - Post Tropical (ESE Sea Isle City, NJ)
 48H  30/1200Z 41.5N  63.0W   40 KT  45 MPH - Post Tropical (ESE Boston, MA)
 60H  31/0000Z...DISSIPATED

NWS National Hurricane Center Miami FL 1000 PM CDT Tue Oct 27, 2020

Satellite images show that Zeta is becoming better organized tonight with a ragged eye feature now present, plenty of deep convection and a more symmetric appearance. The Air Force Reserve Hurricane Hunter aircraft has found increasing winds on this flight, recently recording peak flight-level winds of 65 kt and a minimum pressure of around 990 mb. The initial wind speed is raised to 60 kt on the basis of the wind data.

The improving cloud pattern of Zeta is usually one that favors intensification in the short term. In addition, microwave data from a couple hours ago indicated that a 37 GHz low-level ring was present, which also can be a harbinger of strengthening, and sometimes that strengthening is on the rapid side. Since the storm remains over warm water with fairly light shear, the NHC forecast still anticipates Zeta regaining hurricane intensity within the next 6 hours and making a second landfall as a hurricane. The new NHC forecast is a little higher than the previous one, remaining on the high side of the guidance. After landfall, Zeta is likely to become an extratropical cyclone while it approaches the eastern United States in a couple of days, and become absorbed by the same frontal system.

Zeta is moving northwestward a little faster tonight (325/13 kt). The storm is expected to turn northward and move along the western side of a mid-level anticyclone centered east of Florida through Wednesday morning. A deep cold low (responsible for the southern Plains ice storm) approaching from the west will cause Zeta to sharply accelerate north-northeastward and move inland along the southeastern Louisiana coast Wednesday afternoon. The cyclone should continue to accelerate ahead of the trough and move over the southeastern and eastern U.S. through Thursday. Similar to the last forecast, the official track forecast was moved slightly westward during the first 24 hours, not too dissimilar from a consensus of the latest GFS, UKMET and ECMWF forecasts.

Given Zeta’s acceleration near landfall, strong winds are likely to spread well inland along the northern Gulf coast Wednesday night.

KEY MESSAGES:

  • 1. A life-threatening storm surge is expected along portions of the northern Gulf Coast by late Wednesday, with the highest inundation occurring somewhere between the Mouth of the Pearl River and Dauphin Island, Alabama. Residents in the Storm Surge Warning area should follow any advice given by local officials.
  • 2. Hurricane conditions are expected Wednesday afternoon within portions of the Hurricane Warning area between Morgan City, Louisiana, and the Mississippi/Alabama border. Damaging winds, especially in gusts, will spread well inland across portions of southeast Mississippi and southern Alabama Wednesday night due to Zeta’s fast forward speed.
  • 3. Localized heavy rainfall from Zeta will continue tonight in portions of the Yucatan Peninsula of Mexico and western Cuba where additional flash flooding is possible in urban areas. Between tonight and Thursday, heavy rainfall is expected from portions of the central U.S. Gulf Coast into the Ohio Valley and Mid-Atlantic States near and in advance of Zeta. This rainfall will lead to flash, urban, small stream, and minor river flooding.
FORECAST POSITIONS AND MAX WINDS

INIT  28/0300Z 23.8N  91.2W   60 KT  70 MPH - Tropical Storm (ENE Tampico, Mexico)
 12H  28/1200Z 26.0N  91.7W   75 KT  85 MPH - Category 1 (ESE Brownsville, Texas)
 24H  29/0000Z 30.2N  89.7W   65 KT  75 MPH - Category 1 (WSW White Kitchen, Louisiana)
 36H  29/1200Z 35.0N  84.5W   30 KT  35 MPH - Depression (ESE Grassy Creek, Tennessee)
 48H  30/0000Z 39.5N  74.5W   40 KT  45 MPH - Post Tropical (WSW Port Republic, New Jersey)
 60H  30/1200Z...DISSIPATED

NWS National Hurricane Center Miami FL 400 PM CDT Tue Oct 27, 2020

Visible satellite images show that the low-level center of the storm is slightly displaced to the north of the main area of deep convection. Since the organization of the tropical cyclone has not yet improved, the current intensity is held at 55 kt, which is a blend of subjective and objective Dvorak estimates. Zeta should move over warm waters and through a moist, low-shear environment through tomorrow morning, so strengthening is anticipated, and the cyclone is likely to regain hurricane intensity within the next 6-12 hours. The NHC intensity forecast is on the high side of the model guidance suite. Zeta is expected to interact with a frontal zone and become an extratropical cyclone as it approaches the eastern United States in a couple of days. After moving off the U.S. east coast, the system is forecast to become absorbed by the same frontal system.

Zeta continues to move northwestward, or at about 310/12 kt. The expected large-scale steering flow evolution remains about the same as before. Zeta is expected to turn northward and move along the western side of a mid-level anticyclone centered east of Florida through Wednesday morning. Then, a vigorous 500-mb shortwave trough approaching from the west should cause Zeta to accelerate north- northeastward and move inland along the central Gulf Coast by late Wednesday. The cyclone should continue to accelerate ahead of the trough and move over the southeastern and eastern U.S. through Thursday. The official track forecast was nudged just slightly westward in 24 to 36 hours to be in better agreement with the latest GFS and ECMWF explicit model fields.

Given Zeta’s acceleration near landfall, strong winds are likely to spread well inland along the northern Gulf coast Wednesday night.

KEY MESSAGES:

  • 1. A life-threatening storm surge is expected along portions of the northern Gulf Coast by late Wednesday, with the highest inundation occurring somewhere between the Mouth of the Pearl River and Dauphin Island, Alabama. Residents in the Storm Surge Warning area should follow any advice given by local officials.
  • 2. Hurricane conditions are expected by late Wednesday within portions of the Hurricane Warning area between Morgan City, Louisiana, and the Mississippi/Alabama border. Damaging winds, especially in gusts, will spread well inland across portions of southeast Mississippi and southern Alabama Wednesday night due to Zeta’s fast forward speed.
  • 3. Localized heavy rainfall from Zeta will continue tonight in portions of the Yucatan Peninsula of Mexico and western Cuba where additional flash flooding is possible in urban areas. Tonight through Thursday heavy rainfall is expected from portions of the central U.S. Gulf Coast into the Ohio Valley and Mid-Atlantic States. This rainfall will lead to flash, urban, small stream, and minor river flooding.
FORECAST POSITIONS AND MAX WINDS

INIT  27/2100Z 22.7N  90.3W   55 KT  65 MPH - Tropical Storm (WNW Progreso, Mexico)
 12H  28/0600Z 24.5N  91.3W   70 KT  80 MPH - Category 1 (ESE Brownsville, Texas)
 24H  28/1800Z 27.9N  91.0W   70 KT  80 MPH - Category 1 (WSW New Orleans, Louisiana)
 36H  29/0600Z 32.4N  87.8W   45 KT  50 MPH - Tropical Storm (WNW Providence, Alabama)
 48H  29/1800Z 37.2N  81.3W   30 KT  35 MPH - Post Tropical (WSW Bluefield, Virginia)
 60H  30/0600Z 40.0N  70.5W   40 KT  45 MPH - Post Tropical (ESE New York City, New York)
 72H  30/1800Z...DISSIPATED

NWS National Hurricane Center Miami FL 1000 AM CDT Tue Oct 27, 2020 

High-resolution GOES-16 visible satellite images indicate that the center of Zeta has moved just offshore of the northern coast of Yucatan. Based on Air Force and NOAA aircraft observations a little while ago, after the cyclone’s interaction with the Yucatan, the maximum winds had decreased to near 55 kt. The cloud pattern of the storm is well organized, with a small Central Dense Overcast and numerous banding features. Given this, Zeta is likely to restrengthen as it moves over the warm waters of the southern Gulf of Mexico and in a low-shear environment today through tomorrow morning. When the cyclone nears the northern Gulf Coast in 30-36 hours, decreasing oceanic heat content and possibly stronger shear will likely halt the intensification process. The official intensity forecast shows slight weakening near landfall, but Zeta is likely to be at or near hurricane strength when it crosses the coastline. The NHC intensity forecast is close to the model consensus and a blend of the LGEM and Decay-SHIPS guidance.

The storm continues its generally northwestward motion, or at around 305/12 kt. Zeta will move northwestward to northward around the southwestern and western periphery of a mid-level high pressure area centered east of Florida for the next 24 hours or so. Then, a strong 500-mb shortwave trough approaching from the west should cause Zeta to accelerate north-northeastward to northeastward by late Wednesday and Thursday. This will bring Zeta across the north-central Gulf coast late Wednesday and over the southeastern United States on Thursday. Aside from some speed differences, the track models are in good agreement and have shown good run-to-run consistency. The official track forecast is about the same as the previous one and close to the model consensus.

Given Zeta’s acceleration near landfall, strong winds are likely to spread well inland along the northern Gulf coast Wednesday night.

KEY MESSAGES:

  • 1. A life-threatening storm surge is expected along portions of the northern Gulf Coast by late Wednesday, with the highest inundation occurring somewhere between the Mouth of the Pearl River and Dauphin Island, Alabama. Residents in the Storm Surge Warning area should follow any advice given by local officials.
  • 2. Hurricane conditions are expected by late Wednesday within portions of the Hurricane Warning area between Morgan City, Louisiana, and the Mississippi/Alabama border. Damaging winds, especially in gusts, will spread well inland across portions of southeast Mississippi and southern Alabama Wednesday night due to Zetas fast forward speed.
  • 3. Between tonight and Thursday, heavy rainfall is expected from portions of the central U.S. Gulf Coast into the Ohio Valley and Mid-Atlantic States near and in advance of Zeta. This rainfall will lead to flash, urban, small stream, and minor river flooding.
  • 4. Tropical storm conditions will continue in portions of the northern Yucatan Peninsula of Mexico during the next few hours. Heavy rainfall is expected across the Yucatan Peninsula, the Cayman Islands, and western Cuba today, which will lead to flash flooding in urban areas.
FORECAST POSITIONS AND MAX WINDS

INIT  27/1500Z 21.6N  89.5W   55 KT  65 MPH - Tropical Storm (WNW Progreso, Mexico) 
 12H  28/0000Z 23.1N  90.9W   70 KT  80 MPH - Category 1 (ENE Tampico, Mexico)
 24H  28/1200Z 25.7N  91.6W   75 KT  85 MPH - Category 1 (ESE Brownsville, Texas)
 36H  29/0000Z 29.3N  89.9W   70 KT  80 MPH - Category 1 (ENE Isle Grande Terre, Louisiana)
 48H  29/1200Z 34.2N  85.2W   30 KT  35 MPH - Depression (ENE Six Mile, Georgia)
 60H  30/0000Z 38.5N  76.5W   30 KT  35 MPH - Depression (ESE Prince Frederick, Maryland)
 72H  30/1200Z 41.0N  66.0W   45 KT  50 MPH - Post Tropical (ESE Nantucket, Massachusetts)
 96H  31/1200Z...DISSIPATED

NWS National Hurricane Center Miami FL 1000 PM CDT Mon Oct 26, 2020

Satellite images are showing that convection has been increasing near Zeta tonight, with cold cold tops to at least -93C, and occasional hints of a warm spot related to the early-stages of an eye beneath the clouds. Yet, the NOAA Hurricane Hunter aircraft mission found that Zeta has basically been steady state in terms of maximum winds and pressures, with peak SFMR values hovering between 65-70 kt and dropsonde data showing central pressures of about 982 mb. The data did show that the area of hurricane-force winds has grown, about 40 n mi in the eastern semicircle, and it is possible that the worst of this hurricane will be after the center makes landfall. The initial wind speed is kept at 70 kt on this advisory.

The hurricane is running out of time to get much stronger before landfall during the next couple of hours, but some increase in intensity is possible. Zeta should spend less than 12 hours over land as it crosses Yucatan, but that’s enough time to probably drop it below hurricane strength early tomorrow. However, environmental conditions are unseasonably conducive for intensification so late in the year in the southern and central Gulf of Mexico, with fairly light shear and warm waters during the next 24 to 36 hours. The peak intensity forecast is raised slightly after considering those factors, and some models like the HWRF or ECMWF even suggest it could get a little stronger. As the hurricane nears the northern Gulf Coast, it is likely to encounter stronger shear and cooler waters, so some weakening is anticipated, but Zeta is still expected to be at or near hurricane intensity at landfall. The NHC intensity forecast is generally similar to the previous one, lying above the model consensus.

Zeta continues to move on a generally northwestward track, or about 305/11 kt. The hurricane should move around the southwestern and western periphery of a mid-level subtropical high centered just east of Florida. Thereafter, a potent shortwave trough approaching from the Desert Southwest and Texas is likely to cause the cyclone to accelerate north-northeastward to northeastward on Wednesday and move over the southeastern and eastern United States. Model guidance is in very good agreement, with only some minor differences, and the new forecast is close to the previous one and the models consensus. The system should move off the Mid-Atlantic U.S. coast and become an extratropical cyclone within 3 days, and dissipate soon thereafter.

KEY MESSAGES:

  • 1. Hurricane conditions and dangerous storm surge are expected to continue in portions of the northern Yucatan Peninsula of Mexico through early Tuesday. Heavy rainfall is expected across the Yucatan Peninsula, the Cayman Islands, and western Cuba through Tuesday, which could lead to flash flooding in urban areas.
  • 2. Hurricane conditions and life-threatening storm surge are possible along portions of the northern Gulf Coast on Wednesday, and Storm Surge and Hurricane Watches are in effect. Residents in the watch areas should follow any advice given by local officials.
  • 3. Between Tuesday night and Thursday, heavy rainfall is expected from portions of the central Gulf Coast into the southern Appalachians and Mid-Atlantic States near and in advance of Zeta. This rainfall will lead to flash, urban, small stream, and minor river flooding.
FORECAST POSITIONS AND MAX WINDS

INIT  27/0300Z 20.2N  87.1W   70 KT  80 MPH - Category 1 (WSW Cozumel, Mexico)
 12H  27/1200Z 21.3N  88.8W   60 KT  70 MPH - Tropical Storm (ENE Dzonot, Mexico)
 24H  28/0000Z 23.1N  90.7W   65 KT  75 MPH - Category 1 (WNW Progreso, Mexico)
 36H  28/1200Z 25.6N  91.6W   75 KT  85 MPH - Category 1 (ESE Brownsville, Texas)
 48H  29/0000Z 29.1N  90.1W   65 KT  75 MPH - Category 1 (ESE Port Fourchon, Louisiana)
 60H  29/1200Z 33.8N  85.7W   35 KT  40 MPH - Tropical Storm (Shelton Lakes, Alabama)
 72H  30/0000Z 38.5N  76.5W   45 KT  50 MPH - Post Tropical (ESE Prince Frederick, Maryland)
 96H  31/0000Z...DISSIPATED

NWS National Hurricane Center Miami FL 400 PM CDT Mon Oct 26, 2020

The cloud pattern of Zeta became better organized today, with deep convection forming over and around the center and some banding features developing. The Air Force Reserve Hurricane Hunters recently found surface winds to near 70 kt over the inner northeastern quadrant of the circulation and a central pressure of around 981 mb, signifying that the system had become a hurricane. Given the increased organization over very warm waters, some additional strengthening is possible before the center crosses the east coast of the Yucatan Peninsula this evening. Some weakening should occur while Zeta interacts with land tonight and early Tuesday. Once the center moves into the southern Gulf of Mexico tomorrow, atmospheric and oceanic conditions are conducive for some re-strengthening. When Zeta moves over the northern Gulf of Mexico later on Wednesday, cooler shelf waters and some increase in southwesterly shear should halt the intensification process, with some weakening possible by the time the center reaches the northern Gulf Coast, but Zeta is still expected to be at or near hurricane intensity at landfall. The NHC intensity forecast is similar to the previous one and is near or above the model consensus.

The hurricane continues to move on a generally northwestward track, or at about 305/10 kt. There are basically no changes to the track forecast reasoning, or to the forecast itself. For the next couple of days, Zeta should move around the southwestern and western periphery of a mid-level high pressure area centered just east of Florida. Thereafter, a shortwave trough approaching from the west is likely to cause the cyclone to accelerate north-northeastward to northeastward and move over the southeastern and eastern United States. The system should move off the northeast U.S. coast and become an extratropical cyclone within the next 4 days. The guidance has come into better agreement since yesterday, and the official track forecast is very close to the corrected model consensus, HCCA. Storm Surge, Hurricane, and Tropical Storm Watches have been issued for a portion of the northern U.S. Gulf Coast.

KEY MESSAGES:

  • 1. Hurricane conditions and dangerous storm surge are expected in portions of the northern Yucatan Peninsula of Mexico this evening through early Tuesday. Through Tuesday, heavy rainfall is expected across the Yucatan Peninsula, the Cayman Islands, and central to western Cuba, which could lead to flash flooding in urban areas.
  • 2. Hurricane conditions and life-threatening storm surge are possible along portions of the northern Gulf Coast on Wednesday, and Storm Surge and Hurricane Watches are in effect. Residents in the watch areas should follow any advice given by local officials.
  • 3. Between Tuesday night and Thursday, heavy rainfall is expected from portions of the central Gulf Coast into the southern Appalachians and Mid-Atlantic States near and in advance of Zeta. This rainfall will lead to flash, urban, small stream, and minor river flooding.
FORECAST POSITIONS AND MAX WINDS

INIT  26/2100Z 19.5N  86.0W   70 KT  80 MPH - Category 1 (ESE Cozumel, Mexico)
 12H  27/0600Z 20.5N  87.7W   75 KT  85 MPH - Category 1 (ENE Coba, Mexico)
 24H  27/1800Z 22.1N  89.9W   65 KT  75 MPH - Category 1 (WNW Progreso, Mexico)
 36H  28/0600Z 24.2N  91.4W   70 KT  80 MPH - Category 1 (ESE Corpus Christi, TX)
 48H  28/1800Z 26.8N  91.4W   70 KT  80 MPH - Category 1 (ESE Galveston, TX)
 60H  29/0600Z 30.8N  88.9W   60 KT  70 MPH - Tropical Storm (ENE Ramsey Springs, MS)
 72H  29/1800Z 35.0N  83.5W   30 KT  35 MPH - Depression (ENE Tate City, GA)
 96H  30/1800Z 42.0N  68.0W   35 KT  40 MPH - Post Tropical (ESE Provincetown,MA)
120H  31/1800Z...DISSIPATED

NWS National Hurricane Center Miami FL 1000 AM CDT Mon Oct 26, 2020 

After a significant strengthening episode early this morning, Zeta appears to have changed little in intensity recently. High spatial and temporal resolution GOES-16 visible satellite images indicate that the low-level center of the storm is located near the northwestern edge of the main area of vigorous deep convection. The current intensity estimate is held at 60 kt which is the average of recent Dvorak estimates from TAFB and SAB. An Air Force Reserve Hurricane Hunter aircraft is scheduled to investigate Zeta in a few hours, and should provide a better estimate of the strength of the storm.

Zeta is moving northwestward, or about 305/9 kt. A mid-level high pressure area centered just east of Florida should steer the tropical cyclone on a continued northwestward heading for the next day or so, taking center over the northern part of the Yucatan Peninsula. By around 48 hours, Zeta is expected to turn northward over the Gulf along the western side of the high. Afterward, a shortwave trough moving into the southern Plains should induce a turn toward the north-northeast and take the center inland over the southern United States. The system should then move fairly quickly northeastward across the eastern U.S. and emerge into the Atlantic by day 4. The official track forecast has been adjusted a bit to the west of the previous one but not quite as far west as the corrected model consensus.

Zeta is apparently experiencing some north-northwesterly shear given the displacement of the low-level center from the convection. However, this shear is expected to abate very soon, and the cyclone is likely to strengthen into a hurricane before reaching the northeastern Yucatan Peninsula. Some weakening should occur while Zeta interacts with land during the next 12 to 24 hours. The atmospheric and oceanic environment should be somewhat conducive while the system moves over the southern Gulf of Mexico in a day or two, and the official forecast shows some re-strengthening in 24-36 hours. Later in the forecast period, when Zeta approaches the northern Gulf Coast, cooler shelf waters and some increase in southwesterly shear could cause some weakening. The official intensity forecast is similar to the previous ones and shows Zeta still near hurricane strength at landfall along the northern Gulf of Mexico coast, which is near or above most of the model guidance. Zeta is likely to become an extratropical cyclone when it emerges into the Atlantic, and be absorbed by a frontal system around the end of the forecast period.

Given the timing of the track and the forecast wind radii, watches will likely be required for a portion of the northern Gulf Coast later today.

KEY MESSAGES:

  • 1. Hurricane conditions and dangerous storm surge are expected in portions of the northern Yucatan Peninsula of Mexico tonight and early Tuesday. Tropical storm conditions could occur over extreme western Cuba beginning later today.
  • 2. Through Tuesday, heavy rainfall is expected from Zeta across the Yucatan Peninsula of Mexico, the Cayman Islands, and central to western Cuba. This rainfall may lead to flash flooding in urban areas. Between Tuesday night and Thursday, heavy rainfall is expected from portions of the central U.S. Gulf Coast into the southern Appalachians, and Mid-Atlantic States near and in advance of Zeta. This rainfall will lead to flash, urban, small stream, and minor river flooding.
  • 3. Zeta is forecast to be at or near hurricane strength when it approaches the northern Gulf Coast on Wednesday, and there is an increasing risk of dangerous storm surge, wind, and rainfall impacts from Louisiana to the Florida Panhandle. Residents in these areas should monitor the progress of Zeta, as Hurricane and Storm Surge watches will likely be issued later today.
FORECAST POSITIONS AND MAX WINDS

INIT  26/1500Z 19.1N  85.3W   60 KT  70 MPH - Tropical Storm (ESE Cozumel, Mexico)
 12H  27/0000Z 20.1N  86.7W   75 KT  85 MPH - Category 1 (ESE Cozumel, Mexico)
 24H  27/1200Z 21.5N  88.8W   65 KT  75 MPH - Category 1 (WNW Dzilam de Bravo Mun, Mexico )
 36H  28/0000Z 23.3N  90.8W   70 KT  80 MPH - Category 1 (ENE Tampico, Mexico)
 48H  28/1200Z 25.7N  91.8W   70 KT  80 MPH - Category 1 (ESE Brownsville, Texas)
 60H  29/0000Z 28.9N  90.7W   65 KT  75 MPH - Category 1 (WSW Grand Isle, Louisiana)
 72H  29/1200Z 33.0N  87.0W   35 KT  40 MPH - Tropical Storm (ENE Centreville, Alabama)
 96H  30/1200Z 40.0N  73.0W   35 KT  40 MPH - Post Tropical (ENE New York City, New York)
120H  31/1200Z...DISSIPATED

NWS National Hurricane Center Miami FL 1100 PM EDT Sun Oct 25, 2020

The tropical storm continues to produce deep convection on its south side, with the low-level center estimated to be near the northern edge of the thunderstorms. The last pass from the NOAA Hurricane Hunters a few hours ago indicated that the minimum pressure had fallen to 997 mb, and since the storm appears better organized than before the initial intensity is nudged up to 50 kt. This intensity estimate is slightly above the latest Dvorak numbers. The NOAA Hurricane Hunters are planning to be in Zeta again overnight and that data will be helpful in assessing the storm’s intensity and structure.

Zeta has not moved much during the past several hours, and the initial motion is a very slow north-northwest drift. As ridging begins to build over and near Florida, Zeta is forecast to move faster to the northwest overnight and Monday, and that should take the center of the cyclone near or over the northeastern portion of the Yucatan Peninsula in about 24 hours. The ridge is then expected to shift eastward over the western Atlantic on Tuesday and Wednesday as a large and quite powerful mid- to upper-level low moves eastward across the southwest and south-central United States. This change in the steering pattern should cause Zeta to accelerate northward toward the northern Gulf Coast, and likely make landfall there on Wednesday. The models remain in poor agreement on the details of the evolution of the steering pattern and consequently, there is about a 300 n mi spread in the landfall locations from the various models, which currently spans the region from the far western Florida panhandle to western Louisiana. The NHC track forecast is a little west of the previous one trending toward the middle of the guidance envelope. Based on the poor model agreement, the confidence in the track forecast is lower than normal. It is hoped that data being collected by the NOAA Gulfstream jet flying around Zeta and special NWS weather balloon launches will help the models come into better agreement on the future track of Zeta soon.

Given the low wind shear conditions, moist air mass, and high oceanic heat content over the northwestern Caribbean, steady strengthening seems likely until Zeta reaches the Yucatan Peninsula by late Monday. The cyclone is expected to be a hurricane at landfall in Mexico, and the new forecast shows a slightly higher intensity there based on the new models and favorable conditions. The models differ on how long the core of Zeta will be inland over the Yucatan, but in general, it seems likely that significant weakening won’t occur given the storm’s expected increasing forward speed. The overall environmental conditions are anticipated to remain generally favorable while Zeta moves across the southern Gulf of Mexico, but there should be an increase in shear when it reaches the central Gulf and the cyclone will then be moving over the cooler shelf waters over the northern Gulf. The combination of the stronger shear and cooler waters should cause Zeta to level off in strength and perhaps weaken slightly before the U.S. landfall. The intensity models are in fair agreement, and the NHC forecast lies near the HCCA and IVCN consensus models.

KEY MESSAGES:

  • 1. Hurricane conditions and storm surge are expected in portions of the northern Yucatan Peninsula of Mexico Monday night and early Tuesday. Tropical storm conditions could occur over extreme western Cuba on Monday.
  • 2. Through Wednesday, heavy rainfall is expected from Zeta across portions of central and western Cuba, the Cayman Islands, Jamaica, the northeast Yucatan peninsula of Mexico, southern Florida and the Keys. This rainfall could lead to flash flooding in urban areas.
  • 3. Zeta is forecast to be at or near hurricane strength when it approaches the northern Gulf Coast on Wednesday, and there is an increasing risk of storm surge, rainfall, and wind impacts from Louisiana to the Florida Panhandle. Residents in these areas should monitor the progress of Zeta and updates to the forecast.
FORECAST POSITIONS AND MAX WINDS

INIT  26/0300Z 18.1N  83.8W   50 KT  60 MPH - Tropical Storm (ESE Xcalak, Mexico)
 12H  26/1200Z 18.9N  84.7W   60 KT  70 MPH - Tropical Storm (ENE Mahahual, Mexico)
 24H  27/0000Z 20.2N  86.5W   75 KT  85 MPH - Category 1 (ESE Cozumel, Mexico)
 36H  27/1200Z 21.8N  88.6W   65 KT  75 MPH - Category 1 (WNW Río Lagartos, Mexico)
 48H  28/0000Z 24.0N  90.4W   65 KT  75 MPH - Category 1 (ESE Brownsville, Texas)
 60H  28/1200Z 27.1N  91.1W   65 KT  75 MPH - Category 1 (ESE Galveston, Texas)
 72H  29/0000Z 31.1N  89.6W   50 KT  60 MPH - Tropical Storm (WNW Baxterville, Mississippi)
 96H  30/0000Z 38.7N  78.8W   30 KT  35 MPH - Post Tropical (WSW Forestville, Virginia)
120H  31/0000Z...DISSIPATED

NWS National Hurricane Center Miami FL 500 PM  EDT Sun Oct 25, 2020

Although the overall cloud pattern of Zeta is still not very well organized, with a lack of distinct banding features, it continues to generate very intense deep convection mainly over the southeastern portion of the circulation. Moreover, in spite of its ragged appearance, the storm has strengthened today. Reports from a NOAA Hurricane Hunter aircraft investigating the system this afternoon indicate that, based on adjusted flight-level and SFMR-observed surface winds, the intensity has increased to near 45 kt and the central pressure has fallen to 999 mb. Since the storm will be moving over the high oceanic heat content of the northwestern Caribbean Sea and in a moist environment with low vertical shear through Monday, strengthening is forecast and Zeta will likely become a hurricane before it nears the Yucatan Peninsula in a day or so. After Zeta moves into the Gulf of Mexico, southwesterly shear is likely to increase and oceanic heat content below the cyclone will diminish, especially when the system approaches the northern Gulf coast on Wednesday. Therefore, no strengthening is forecast in 2-3 days and Zeta could be weakening by the time it reaches the northern Gulf coast. However, the intensity forecast is still subject to significant uncertainty.

The center has been meandering this afternoon, and apparently has reformed nearer to the deep convection over the southeastern quadrant. Since this is not considered representative of larger-scale motion, the system is still considered to be quasi-stationary at this time. However, the track guidance is in agreement that Zeta will move northwestward over the next 1-2 days, passing near or over the Yucatan Peninsula. Thereafter, the cyclone is likely to turn north-northwestward to northward while it moves on the western side of a mid-tropospheric anticyclone near Florida. A turn toward the north-northeast is expected when Zeta nears the northern Gulf coast, due to an approaching shortwave trough. The track guidance has more than the usual amount of spread at the 72-hour time frame, with the ECMWF and the GFS predictions being about 300 miles apart near the northern Gulf coast. The official forecast track lies between these 2 solutions, and is similar to the previous NHC track. However, given the inherent uncertainties, one should not focus on the exact forecast track.

Based on the new intensity forecast, the government of Mexico has issued a Hurricane Warning for a portion of the Yucatan peninsula.

KEY MESSAGES:

  • 1. Hurricane conditions and storm surge are expected in portions of the northern Yucatan Peninsula of Mexico Monday night and early Tuesday. Tropical storm conditions could occur over extreme western Cuba on Monday.
  • 2. Through Wednesday, heavy rainfall is expected from Zeta across portions of central and western Cuba, the Cayman Islands, Jamaica, the northeast Yucatan peninsula of Mexico, southern Florida and the Keys. This rainfall may lead to flash flooding in urban areas.
  • 3. Zeta is forecast to be at or just below hurricane strength when it approaches the northern Gulf Coast on Wednesday, and there is an increasing risk of storm surge, rainfall, and wind impacts from Louisiana to the Florida Panhandle. Residents in these areas should monitor the progress of Zeta and updates to the forecast.
FORECAST POSITIONS AND MAX WINDS

INIT  25/2100Z 17.7N  83.4W   45 KT  50 MPH - Tropical Storm (ENE Coxen Hole, Honduras)
 12H  26/0600Z 18.7N  84.3W   55 KT  65 MPH - Tropical Storm (ESE Mahahual, Mexico)
 24H  26/1800Z 19.7N  85.7W   65 KT  75 MPH - Category 1 (ESE Cozumel, Mexico)
 36H  27/0600Z 21.1N  87.6W   65 KT  75 MPH - Category 1 (WNW Kantunilkín, Mexico)
 48H  27/1800Z 23.2N  89.6W   65 KT  75 MPH - Category 1 (ENE Tampico, Mexico)
 60H  28/0600Z 25.7N  90.8W   65 KT  75 MPH - Category 1 (ESE Brownsville, Texas)
 72H  28/1800Z 29.4N  90.3W   60 KT  70 MPH - Tropical Storm (WSW New Orleans,  Louisiana)
 96H  29/1800Z 37.0N  83.0W   25 KT  30 MPH - Depression (WNW Cumberland, Kentucky)

NWS National Hurricane Center Miami FL 1100 AM EDT Sun Oct 25, 2020

Although the cloud pattern of the storm is not well-organized and somewhat elongated zonally, the system is producing very vigorous deep convection, particularly over the southern portion of the circulation. Cirrus cloud motions show that the upper-level outflow is well-defined. The current intensity estimate remains at 35 kt in agreement with Dvorak values from both TAFB and SAB, and pending another Hurricane Hunter mission into the system this afternoon.

The center is difficult to locate at this time, and the best estimate for motion is quasi-stationary. A high pressure area developing near Florida should induce a general northwestward motion over the next couple of days. Later, a shortwave trough approaching from the west is likely to cause Zeta to turn northward and north-northeastward while it nears the northern Gulf Coast in 72-84 hours. The official track forecast lies between the GFS solution which is farther east and the ECMWF prediction which lies farther south and west.

Given the favorable upper-level outflow pattern and very high oceanic heat content over the northwestern Caribbean, strengthening is likely until the center moves near or over the Yucatan Peninsula late tomorrow. Zeta should be near or at hurricane strength when it approaches the Yucatan. The official intensity forecast for the next 36 hours is close to the model consensus. After Zeta moves into the central Gulf of Mexico, increasing southwesterly shear and diminishing oceanic heat content are expected to prevent strengthening. The NHC intensity forecast over the Gulf is above the latest model consensus. Although not explicitly shown in the official forecast, the unfavorable atmospheric and oceanic conditions over the northern Gulf of Mexico could cause Zeta to weaken by the time the center nears the northern Gulf coast. However, users are reminded that these intensity forecasts are subject to uncertainty.

KEY MESSAGES:

  • 1. Tropical storm conditions are expected in portions of the northern Yucatan Peninsula of Mexico Monday night and early Tuesday, with hurricane conditions possible. Tropical storm conditions could occur over extreme western Cuba on Monday.
  • 2. Through Wednesday, heavy rainfall is expected from Zeta across portions of central and western Cuba, the Cayman Islands, Jamaica, the northeast Yucatan peninsula of Mexico, southern Florida and the Keys. This rainfall may lead to flash flooding in urban areas.
  • 3. Zeta could be at or just below hurricane strength when it approaches the northern Gulf Coast on Wednesday, and could bring storm surge, rainfall, and wind impacts to areas from Louisiana to the Florida Panhandle. Residents in these areas should monitor the progress of Zeta and updates to the forecast.
FORECAST POSITIONS AND MAX WINDS

INIT  25/1500Z 17.8N  83.8W   35 KT  40 MPH - Tropical Storm (ENE Belize City, Belize)
 12H  26/0000Z 18.4N  84.1W   40 KT  45 MPH - Tropical Storm (ESE Chetumal, Mexico)
 24H  26/1200Z 19.2N  85.1W   50 KT  60 MPH - Tropical Storm (ESE Tulum, Mexico)
 36H  27/0000Z 20.3N  86.7W   60 KT  70 MPH - Tropical Storm (ESE Cozumel, Mexico)
 48H  27/1200Z 21.9N  88.7W   65 KT  75 MPH - Category 1 (WNW Río Lagartos, Mexico)
 60H  28/0000Z 24.0N  90.3W   65 KT  75 MPH - Category 1 (ESE Brownsville, Texas)
 72H  28/1200Z 27.0N  90.5W   65 KT  75 MPH - Category 1 (WSW Grand Isle, Louisiana)
 96H  29/1200Z 35.0N  85.5W   25 KT  30 MPH = Low (WNW Whiteside, Tennessee)
120H  30/1200Z...DISSIPATED

NWS National Hurricane Center Miami FL 1100 PM EDT Sat Oct 24, 2020

Deep convection has increased during the past few hours south of the estimated low-level position based on aircraft data from just after the release of the previous advisory. In fact, geostationary imagery suggests that the low-level center could be trying to reform closer to the deep convection. The initial intensity is set to 30 kt based on the latest Dvorak estimate from SAB. Another NOAA Hurricane Hunter aircraft will investigate the system overnight and provide additional data on the cyclone’s structure and intensity.

As noted above, the depression hasn’t moved much, and the system currently appears to be stationary. Satellite imagery and upper-air data show a shortwave trough moving through the southeastern United States, which has weakened the steering flow around the cyclone. As the shortwave moves eastward, the subtropical ridge will expand westward to the north of the tropical cyclone by Monday, which should result in a steadier west-northeastward motion. After that time, a powerful mid/upper-level low is forecast to eject out of the southwestern U.S., which will weaken the ridge and cause the tropical cyclone to turn northward and northeastward as it approaches the northern Gulf Coast. The global models are not in good agreement on the details of the timing of the eastward movement of the upper-low. While this isn’t unusual, it results in significant differences in when and where the tropical cyclone turns and exactly where it crosses the Gulf Coast next week, with model solutions ranging from Louisiana to the Florida Panhandle. The new NHC track forecast lies near the middle of the guidance envelope between the HCCA and the TVCA multi-model consensus. However, given the current lack of motion of the system and the large model spread late in the period, the details of the track forecast are more uncertain than usual.

If the cyclone’s low- and mid-level circulations can become better aligned, the environment for the next 2 to 3 days appears conducive for steady intensification, with low shear and SSTs of near 30C in the northwestern Caribbean and above 28C in the southern Gulf. After 72 hours, the shear is expected to increase while the cyclone moves over cooler SSTs near the northern Gulf Coast, which should result in weakening before the center moves inland. The new NHC intensity forecast is a bit higher than the previous one through about 60 hours, and is a blend of the latest intensity consensus aids and HCCA. While the current NHC forecast indicates that the system should weaken below hurricane strength before landfall, users are reminded that strong tropical storms can still produce significant storm surge, rainfall, and wind impacts along the northern Gulf Coast. The cyclone should be absorbed into a frontal system by the end of the forecast period.

KEY MESSAGES:

  • 1. The depression is forecast to strengthen to a tropical storm by Sunday and tropical storm conditions are expected in extreme western Cuba on Monday. Tropical storm conditions are possible in the northern Yucatan Peninsula of Mexico Monday night and early Tuesday.
  • 2. Through Wednesday, heavy rainfall is expected across portions of central and western Cuba, the Cayman Islands, Jamaica, the northeast Yucatan peninsula of Mexico, southern Florida and the Florida Keys. This rainfall may lead to flash flooding in urban areas.
  • 3. The system is forecast to approach the northern Gulf Coast as a tropical storm on Wednesday, and could bring storm surge, rainfall, and wind impacts to areas from Louisiana to the Florida Panhandle. Residents in these areas should monitor the progress of the depression and updates to the forecast.
FORECAST POSITIONS AND MAX WINDS

INIT  25/0300Z 18.9N  83.1W   30 KT  35 MPH - Depression (WSW George Town, Grand Cayman)
 12H  25/1200Z 19.2N  83.3W   35 KT  40 MPH - Tropical Storm (WSW West Bay, Grand Cayman)
 24H  26/0000Z 20.0N  83.7W   40 KT  45 MPH - Tropical Storm (ESE Tulum, Mexico)
 36H  26/1200Z 20.7N  84.9W   50 KT  60 MPH - Tropical Storm (ENE Playa del Carmen, Mexico)
 48H  27/0000Z 21.7N  86.6W   55 KT  65 MPH - Tropical Storm (ENE Isla Contoy, Mexico)
 60H  27/1200Z 23.2N  88.6W   65 KT  75 MPH - Category 1 (ENE Progreso, Mexico)
 72H  28/0000Z 25.4N  90.3W   65 KT  75 MPH - Category 1 (ESE Brownsville, Texas)
 96H  29/0000Z 31.5N  89.5W   40 KT  45 MPH - Tropical Storm (WNW Sanford, Mississipp)
120H  30/0000Z...ABSORBED

NWS National Hurricane Center Miami FL 500 PM EDT Sat Oct 24, 2020

Satellite imagery and NOAA Hurricane Hunter aircraft data indicate that the broad area of low pressure that NHC has been following for the past couple of days has consolidated enough to be considered a tropical depression. GOES-16 1-minute data shows the center pretty clearly, with a new area of convection close by, and a minimum pressure of 1005 mb was reported by the aircraft in that area. The surface winds were generally fairly light within about a degree of the center, but data from the plane supports a 25-kt initial intensity.

The tropical depression hasn’t been moving much, but recently it has started at least drifting toward the north-northwest. A shortwave trough moving across the southeastern United States should keep the cyclone in a rather weak steering pattern during the next day or so, with only a northwest drift anticipated. Mid-level ridging should build over the northern Gulf of Mexico on Monday, forcing the depression to move faster to the west-northwest toward the Yucatan Peninsula or Channel. The ridge shouldn’t last too long, however, with a substantial upper-level low forecast to eject out of the southwestern United States in a few days, causing the tropical cyclone to sharply turn to the north and northeast on Wednesday. The guidance isn’t in very good agreement, and these types of trough ejection scenarios can have significant timing differences. At this time, the NHC track forecast leans a little more on the global models than the regional hurricane models, and is just west of the model consensus.

While the large-scale shear is fairly light at the moment, the low- and mid-level circulations of the depression are not well-aligned. Thus, it might take some time for the system to strengthen despite low shear and very warm waters. In a day or two, the depression will likely have a structure that supports a faster rate of strengthening, and the intensification rate is increased while the cyclone is near the Yucatan. Although the forecast shows the system reaching hurricane strength in the southern Gulf of Mexico, this is rather uncertain given the potential land interaction and only a narrow area of favorable upper-level winds. A combination of cooler shelf waters and increasing shear will likely weaken the cyclone below hurricane strength as it approaches the northern Gulf Coast. However, strong tropical storms can still produce significant storm surge, rainfall, and wind impacts, and residents in this region will yet again need to monitor another tropical cyclone moving northward across the Gulf.

KEY MESSAGES:

  • 1. The depression is forecast to strengthen to a tropical storm Sunday and could bring tropical storm conditions to extreme western Cuba on Monday, where a Tropical Storm Watch is in effect. There is also a risk of tropical storm conditions in the northern Yucatan Peninsula of Mexico Monday night and Tuesday.
  • 2. Through Wednesday, heavy rainfall is expected across portions of central and western Cuba, the Cayman Islands, Jamaica, the northeast Yucatan peninsula of Mexico, southern Florida and the Keys. This rainfall may lead to flash flooding in urban areas.
  • 3. The system is forecast to approach the northern Gulf Coast as a tropical storm on Wednesday, and could bring storm surge, rainfall, and wind impacts to areas from Louisiana to the Florida Panhandle. Residents in these areas should monitor the progress of the depression and updates to the forecast.
FORECAST POSITIONS AND MAX WINDS

INIT  24/2100Z 18.7N  83.0W   25 KT  30 MPH - Depression (WSW George Town, Grand Cayman)
 12H  25/0600Z 19.0N  83.2W   30 KT  35 MPH - Depression (WSW George Town, Grand Cayman)
 24H  25/1800Z 19.5N  83.5W   35 KT  40 MPH - Tropical Storm (WNW West Bay, Grand Cayman)
 36H  26/0600Z 20.1N  84.2W   40 KT  45 MPH - Tropical Storm (ESE Cozumel, Mexico)
 48H  26/1800Z 20.9N  85.6W   45 KT  50 MPH - Tropical Storm (ESE Cancún, Mexico)
 60H  27/0600Z 22.0N  87.5W   55 KT  65 MPH - Tropical Storm (WNW Holbox, Mexico)
 72H  27/1800Z 23.4N  89.4W   65 KT  75 MPH - Category 1 (ENE Progreso, Mexico)
 96H  28/1800Z 27.5N  91.0W   55 KT  65 MPH - Tropical Storm (WSW Grand Isle, LA )
120H  29/1800Z 35.5N  84.5W   25 KT  30 MPH - Post Tropical (ESE Niota, TN)

NWS National Hurricane Center Miami FL 200 PM EDT Sat Oct 24, 2020

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

The National Hurricane Center is issuing advisories on Hurricane Epsilon, located over the west-central Atlantic Ocean.

  • 1. Satellite, radar and surface data indicate that an area of low pressure located about 125 miles west-southwest of Grand Cayman Island continues to become better organized, and if current trends continue, advisories will be initiated on a tropical depression this afternoon or evening. Environmental conditions are conducive for further development while the low drifts toward the north and northwest this weekend. The system could move near western Cuba on Monday and move across the southern Gulf of Mexico or the northeastern portion of the Yucatan Peninsula on Tuesday. Interests in western Cuba and the Yucatan Peninsula should monitor the progress of this low. A NOAA Hurricane Hunter reconnaissance aircraft is en route to investigate the disturbance this afternoon. Regardless of development, locally heavy rainfall will be possible over portions of the Cayman Islands, Jamaica, Cuba, and northeastern Yucatan through early next week. * Formation chance through 48 hours…high…near 100 percent. * Formation chance through 5 days…high…near 100 percent.

NWS National Hurricane Center Miami FL 800 AM EDT Sat Oct 24, 2020

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

The National Hurricane Center is issuing advisories on Hurricane Epsilon, located over the west-central Atlantic Ocean.

  • 1. Satellite, radar and surface data indicate that a broad area of low pressure located just southwest of Grand Cayman Island is gradually becoming better organized, with a better defined wind circulation, increasing thunderstorm activity and falling surface pressures since yesterday. Environmental conditions are conducive for further development, and a tropical depression is expected to form within the next day or so while the low drifts toward the north and northwest. The system could move near western Cuba on Monday and move slowly across the southeastern Gulf of Mexico by Tuesday. Interests in western Cuba, the Florida Keys, and the Yucatan Peninsula should monitor the progress of this disturbance. A NOAA Hurricane Hunter reconnaissance aircraft is scheduled to investigate the disturbance this afternoon. Regardless of development, locally heavy rainfall will be possible over portions of the Cayman Islands, Jamaica and Cuba through early next week. * Formation chance through 48 hours…high…90 percent. * Formation chance through 5 days…high…90 percent.

NWS National Hurricane Center Miami FL 800 PM EDT Fri Oct 23, 2020

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

The National Hurricane Center is issuing advisories on Hurricane Epsilon, located over the west-central Atlantic a couple of hundred miles northeast of Bermuda.

  • 1. Satellite images and surface observations indicate that the broad area of low pressure located just west of Grand Cayman Island continues to show signs of organization. Environmental conditions appear conducive for further development, and a tropical depression will likely form during the next day or two while the low drifts toward the northwest. The system could move near western Cuba by Sunday and move slowly across the southeastern Gulf of Mexico by early next week. Interests in western Cuba, the Florida Keys, and southern Florida should monitor the progress of this disturbance. Regardless of development, locally heavy rainfall will be possible over portions of the Cayman Islands, Jamaica, Cuba, southern Florida, the Florida Keys, and the northwestern Bahamas through the weekend. * Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…70 percent.

NWS National Hurricane Center Miami FL 200 PM EDT Fri Oct 23, 2020

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

The National Hurricane Center is issuing advisories on Hurricane Epsilon, located over the west-central Atlantic a couple of hundred miles northeast of Bermuda.

  • 1. Satellite images and radar data indicate that the broad area of low pressure located just west of Grand Cayman Island is gradually becoming better defined. Environmental conditions appear conducive for further development, and a tropical depression will likely form during the next day or two while the low drifts toward the northwest. The system could move near western Cuba by Sunday and move slowly across the southeastern Gulf of Mexico by early next week. Interests in western Cuba, the Florida Keys, and southern Florida should monitor the progress of this disturbance. Regardless of development, locally heavy rainfall will be possible over portions of the Cayman Islands, Jamaica, Cuba, southern Florida, the Florida Keys, and the northwestern Bahamas through the weekend. * Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…70 percent.

NWS National Hurricane Center Miami FL 800 AM EDT Fri Oct 23, 2020

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

The National Hurricane Center is issuing advisories on Hurricane Epsilon, located over the west-central Atlantic a couple of hundred miles northeast of Bermuda.

  • 1. A broad area of low pressure located near Grand Cayman Island is producing a large area of showers and thunderstorms mainly east and south of the center. This system has become much better organized since yesterday, and a tropical depression could form during the next couple of days while the low moves slowly toward the northwest. This system is now anticipated to move near western Cuba this weekend and move slowly across the southeastern Gulf of Mexico by early next week. Regardless of development, locally heavy rainfall will be possible over portions of the Cayman Islands, Cuba, southern Florida and the Keys, and the northwestern Bahamas through the weekend. * Formation chance through 48 hours…medium…50 percent. * Formation chance through 5 days…medium...60 percent.

NWS National Hurricane Center Miami FL 200 AM EDT Fri Oct 23, 2020

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

The National Hurricane Center is issuing advisories on Hurricane Epsilon, located over the west-central Atlantic about 200 miles east of Bermuda.

  • 1. A broad trough of low pressure, located over the western Caribbean Sea, is producing a large area of showers and thunderstorms mainly east of the trough. Surface observations, satellite-derived surface wind data, and radar data indicate that a low pressure system has developed along the trough axis just south of Grand Cayman Island. Some gradual development of the low is possible during the next few days while it moves northwestward to northward across western or central Cuba on Saturday, then turning northward to northeastward across the southeastern Gulf of Mexico, Straits of Florida, and the central Bahamas on Sunday. Regardless of development, locally heavy rainfall will be possible over portions of the Cayman Islands, Cuba, South Florida, and the Bahamas through early next week. * Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…medium…40 percent.

NWS National Hurricane Center Miami FL 800 PM EDT Thu Oct 22, 2020

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

The National Hurricane Center is issuing advisories on Hurricane Epsilon, located over the west-central Atlantic a couple hundred miles east of Bermuda.

  • 1. A trough of low pressure, located over the western Caribbean Sea, is producing an area of disorganized showers and thunderstorms which extends near Jamaica, the Cayman Islands, portions of Cuba, and the Windward Passage. Some slow development of this system is possible during the next few days while it moves northeastward near western or central Cuba, the Straits of Florida and the central Bahamas through the weekend. Regardless of development, locally heavy rainfall is possible over portions of Cuba, South Florida, and the Bahamas through early next week. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…low...30 percent.

NWS National Hurricane Center Miami FL 200 PM EDT Thu Oct 22, 2020

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

The National Hurricane Center is issuing advisories on Hurricane Epsilon, located over the west-central Atlantic a couple hundred miles east-southeast of Bermuda.

  • 1. A trough of low pressure located over the western Caribbean Sea is producing a large area of disorganized showers and thunderstorms which primarily extend near Jamaica, the Cayman Islands, and Cuba. Some slow development of this system is possible during the next few days while it moves northeastward near western or central Cuba, the Straits of Florida and the Bahamas through the weekend. Regardless of development, locally heavy rainfall is possible over portions of Cuba, South Florida, and the Bahamas through early next week. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 800 AM EDT Thu Oct 22, 2020

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

The National Hurricane Center is issuing advisories on Hurricane Epsilon, located over the west-central Atlantic a few hundred miles southeast of Bermuda.

  • 1. A trough of low pressure located over the western Caribbean Sea is producing a large area of disorganized showers and thunderstorms which primarily extend near Jamaica, the Cayman Islands, and Cuba. Some slow development of this system is possible during the next few days while it moves northeastward near western or central Cuba, the Straits of Florida and the Bahamas through the weekend. Regardless of development, locally heavy rainfall is possible over portions of Cuba, South Florida, and the Bahamas through early next week. * Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…low…30 percent.

NWS National Hurricane Center Miami FL 200 AM EDT Thu Oct 22, 2020

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

The National Hurricane Center is issuing advisories on Hurricane Epsilon, located over the west-central Atlantic a few hundred miles southeast of Bermuda.

  • 1. A trough of low pressure located over the western Caribbean Sea is producing a large area of disorganized showers and thunderstorms which primarily extend near Jamaica, the Cayman Islands, and Cuba. Development of this system is unlikely to occur during the next few days as it passes near western Cuba and moves over the Straits of Florida. By late this weekend or early next week, however, some slow development is possible while the system moves generally northeastward from near the northwestern Bahamas toward the western Atlantic. Regardless of development, locally heavy rainfall is possible over portions of Cuba, South Florida, and the Bahamas through early next week. * 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 Wed Oct 21, 2020

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

The National Hurricane Center is issuing advisories on Hurricane Epsilon, located over the central Atlantic a few hundred miles east-southeast of Bermuda.

  • 1. A trough of low pressure located over the western Caribbean Sea is producing a large area of disorganized showers and thunderstorms. Development of this system is unlikely to occur during the next few days as it passes near western or central Cuba, and moves over the Straits of Florida. By late weekend or early next week, however, some slow development of this system is possible while it moves generally northeastward near the central Bahamas. Regardless of development, locally heavy rainfall is possible over portions of Cuba, South Florida, and the Bahamas through early next week. * Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…low…20 percent.

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

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Video: 6 dead, millions without power as Zeta batters Southeast