Tropical Storm Jerry

Post Tropical Storm Jerry Track 1700 Hours September 25 2019
Post Tropical Storm Jerry Track 1700 Hours September 25 2019

Tropical Storm Jerry Satellite 1100 Hours September 24 2019Tropical Storm Jerry – NWS National Hurricane Center Miami FL 500 PM AST Wed Sep 25, 2019

Multiple scatterometer passes over Jerry (see Wednesday video below) indicate that the cyclone no longer has sustained tropical-storm-force winds. Therefore Jerry is now a remnant low, and the Bermuda Weather Service has discontinued the Tropical Storm Warning for Bermuda. However, wind gusts to tropical storm force are still possible on the island during the next few hours, especially at elevated observing sites.

Based on the scatterometer data, the current intensity is estimated to be 30 kt. The low-cloud swirl is becoming less well-defined, and since the system will continue moving through a hostile environment of strong shear and dry mid-level air, steady weakening is likely. The cyclone should dissipate in 2-3 days. The NHC intensity the forecast is close to the latest intensity model consensus.

The system is moving east-northeastward at a slightly faster clip, or 070/10 kt. A gradual turn to the east and east-southeast is forecast as the cyclone moves along the southern edge of the band of mid-latitude westerlies, and then turns to the right along the northeastern periphery of a subtropical anticyclone before dissipating.

This is the last advisory on Jerry.

FORECAST POSITIONS AND MAX WINDS

INIT  25/2100Z 32.2N  65.6W   30 KT  35 MPH - Low (ENE St George's, Bermuda)
 12H  26/0600Z 32.8N  63.8W   30 KT  35 MPH - Low (ENE St George's, Bermuda)
 24H  26/1800Z 33.7N  61.5W   25 KT  30 MPH - Low (ENE St George's, Bermuda)
 36H  27/0600Z 34.7N  59.0W   25 KT  30 MPH - Low (ENE St George's, Bermuda)
 48H  27/1800Z 35.0N  56.5W   20 KT  25 MPH - Low (ENE St George's, Bermuda)
 72H  28/1800Z...DISSIPATED

NWS National Hurricane Center Miami FL 1100 AM AST Wed Sep 25, 2019

Jerry remains devoid of deep convection in an environment of dry mid-level air and strong westerly shear. Data from a new scatterometer pass indicate that the maximum winds are no more than 35 kt, and even that value could be generous. The system should remain in a hostile environment for the next few days, and simulated satellite imagery from the global models suggest that no significant deep convection will redevelop within it. Therefore the official intensity forecast calls for the cyclone to gradually spin down over the next 2-3 days. The NHC intensity forecast is just slightly below the model consensus.

The cyclone has turned toward the east-northeast with some increase in forward speed, and the initial motion estimate is 060/8 kt. Jerry should continue to move east-northeastward, to the south of the main belt of mid-latitude westerlies, for the next day or two. Later in the forecast period, the weak cyclone is expected to turn east-southeastward along the northeastern periphery of a subtropical high-pressure area, and dissipate. The official track forecast continues to follow the NOAA corrected consensus guidance rather closely.

Key Messages:

  • 1. Tropical-storm-force winds are expected on Bermuda later today. Large swells are also expected to affect the coast of Bermuda during the next few days. These swells could cause life-threatening rip currents. See products issued by the Bermuda Weather Service for more information.
FORECAST POSITIONS AND MAX WINDS

INIT  25/1500Z 32.0N  66.8W   35 KT  40 MPH - Tropical Storm (WSW St George's, Bermuda)
 12H  26/0000Z 32.6N  65.1W   35 KT  40 MPH - Tropical Storm (WNW St George's, Bermuda)
 24H  26/1200Z 33.4N  62.9W   30 KT  35 MPH - Tropical Depression (ENE St George's, Bermuda)
 36H  27/0000Z 34.3N  60.4W   25 KT  30 MPH - Low (ENE St George's, Bermuda)
 48H  27/1200Z 34.9N  58.0W   25 KT  30 MPH - Low (ENE St George's, Bermuda)
 72H  28/1200Z 33.8N  54.5W   20 KT  25 MPH - Low (ENE St George's, Bermuda)
 96H  29/1200Z...DISSIPATED

NWS National Hurricane Center Miami FL 500 AM AST Wed Sep 25, 2019

Jerry has lacked organized deep convection since around 1500 UTC yesterday. It is therefore now designated as a post-tropical cyclone. However, a Tropical Storm Warning remains in effect for Bermuda and advisories will continue to be issued on Jerry until it no longer poses any threat to the island.

An Air Force Reserve Hurricane Hunter aircraft continued to fly through Jerry after the last advisory. The plane reported that Jerry’s wind field has become quite asymmetric, with no tropical-storm-force winds in the western half of the cyclone. That said, on its last pass through the southeast quadrant of the cyclone the plane reported max flight-level winds of 55 kt at 925 mb and believable SFMR winds of 40 kt. The intensity of Jerry is therefore maintained at 40 kt for this advisory. With no deep convection to sustain it, the cyclone should gradually spin down during the next few days. The dynamical models indicate that Jerry will dissipate in about 4 days and the NHC forecast does as well.

A mid-latitude trough to the north has caused Jerry to turn northeastward, and the initial motion estimate is 055/6 kt. The models are in good agreement that the post-tropical low will continue generally northeastward today and tomorrow, steered by the low-level southwesterly flow. On this track, the cyclone will pass very near Bermuda later today. The models are in excellent agreement on the track of Jerry, and only small adjustments were made to the previous NHC track forecast. Key Messages: 1. Tropical-storm-force winds are expected on Bermuda later today. Large swells are also expected to affect the coast of Bermuda during the next few days. These swells could cause life-threatening rip currents. See products issued by the Bermuda Weather Service for more information.

FORECAST POSITIONS AND MAX WINDS

INIT  25/0900Z 31.8N  67.9W   40 KT  45 MPH - Tropical Storm (WSW St George's, Bermuda)
 12H  25/1800Z 32.3N  66.5W   35 KT  40 MPH - Tropical Storm (WNW St George's, Bermuda)
 24H  26/0600Z 33.0N  64.2W   35 KT  40 MPH - Tropical Storm (ESE St George's, Bermuda)
 36H  26/1800Z 33.9N  61.7W   30 KT  35 MPH - Tropical Depression (WNW St George's, Bermuda)
 48H  27/0600Z 34.6N  59.3W   25 KT  30 MPH - Low (WNW St George's, Bermuda)
 72H  28/0600Z 34.0N  55.5W   20 KT  25 MPH - Low (ENE St George's, Bermuda)
 96H  29/0600Z...DISSIPATED

NWS National Hurricane Center Miami FL 1100 PM AST Tue Sep 24, 2019

Dry air and shear have continued to take a toll on Jerry, and the cyclone has been devoid of deep convection for about 12 hours. An Air Force reconnaissance aircraft that has been in the storm this evening measured peak flight-level winds of 43 kt, and SFMR winds of 34 to 36 kt. The aircraft has not sampled the entire circulation yet, so the initial intensity has been lowered, perhaps conservatively, to 40 kt. Increasing shear and dry air that is being entrained into the circulation from the west are likely to continue to contribute to Jerry’s gradual spin down over the next couple of days. If deep convection does not return overnight, Jerry could become a post-tropical cyclone as early as tomorrow morning. Regardless of the status of the system, it still has the potential to bring tropical-storm-force winds to Bermuda and advisories would continue as long as the Tropical Storm Warning is needed for that island. The global models completely dissipate Jerry in a little more than 3 days, and so does the new NHC forecast.

Jerry has turned northeastward but continues to move very slowly, or 025/4 kt. The cyclone should pick up its pace tonight and Wednesday as a broad trough passes to the north and the system gets caught within the southern edge of the mid-latitude westerlies. As Jerry get increasingly weaker it is forecast to again slow down and turn southeastward before dissipation occurs. The official track forecast is not very different than the previous advisory and is closest to the TCVN multi-model consensus.

Key Messages:

  • 1. Tropical-storm-force winds are expected on Bermuda beginning on Wednesday. Large swells are also expected to affect the coast of Bermuda during the next few days. These swells could cause life-threatening rip currents. See products issued by Bermuda Weather Service for more information.
FORECAST POSITIONS AND MAX WINDS

INIT  25/0300Z 31.4N  68.7W   40 KT  45 MPH - Tropical Storm (WSW St George's, Bermuda)
 12H  25/1200Z 32.2N  67.3W   35 KT  40 MPH - Tropical Storm (WSW St George's, Bermuda)
 24H  26/0000Z 33.0N  64.9W   35 KT  40 MPH - Tropical Storm (WNW St George's, Bermuda)
 36H  26/1200Z 33.8N  62.3W   30 KT  35 MPH - Tropical Depression (ENE St George's, Bermuda)
 48H  27/0000Z 34.4N  59.9W   25 KT  30 MPH - Tropical Depression (ENE St George's, Bermuda)
 72H  28/0000Z 34.0N  56.5W   20 KT  25 MPH - Low (ENE St George's, Bermuda)
 96H  29/0000Z...DISSIPATED

NWS National Hurricane Center Miami FL 500 PM AST Tue Sep 24, 2019

Jerry no longer looks like either a tropical or a subtropical cyclone, since it lacks deep convection within a couple of hundred miles of the center. This is likely due to a combination of strong shear and drier air. The advisory intensity of 45 kt is based on SFMR-observed surface winds from earlier Hurricane Hunter observations. Another Hurricane Hunter plane is scheduled to investigate Jerry in a few hours, and given the lack of convection, will likely find a weaker cyclone. The numerical guidance indicates that strong shear and increasingly drier air will affect Jerry over the next few days. Therefore, additional weakening is likely, and the system will probably become a remnant low in 72 hours or less, and completely dissipate by the end of the period. This is also shown by the global models.

Jerry has moved quite slowly today, and the estimated initial motion is just east of northward, or 010/5 kt. Jerry should pass through a weakness in the subtropical ridge tonight. A broad mid-latitude trough to the north of the cyclone should soon cause the system to turn toward the northeast with an increase in forward speed. Later in the period, the cyclone should turn south of east while moving around the northeastern periphery of a subtropical ridge. The official track forecast is close to the previous one, and leans toward the corrected consensus model guidance.

Key Messages:

  • 1. Tropical-storm-force winds are expected on Bermuda by early Wednesday. Large swells are also expected to affect the coast of Bermuda during the next few days. These swells could cause life-threatening rip currents. See products issued by Bermuda Weather Service for more information.
FORECAST POSITIONS AND MAX WINDS

INIT  24/2100Z 31.1N  69.0W   45 KT  50 MPH - Tropical Storm (WSW St George's, Bermuda)
 12H  25/0600Z 31.9N  67.9W   40 KT  45 MPH - Tropical Storm (WSW St George's, Bermuda)
 24H  25/1800Z 32.9N  65.6W   35 KT  40 MPH - Tropical Storm (WNW St George's, Bermuda)
 36H  26/0600Z 33.7N  62.8W   35 KT  40 MPH - Tropical Storm (ENE St George's, Bermuda)
 48H  26/1800Z 34.4N  60.1W   25 KT  30 MPH - Tropical Depression (ENE St George's, Bermuda)
 72H  27/1800Z 34.5N  56.5W   20 KT  25 MPH - Low (ENE St George's, Bermuda)
 96H  28/1800Z 33.0N  54.0W   20

NWS National Hurricane Center Miami FL 1100 AM AST Tue Sep 24, 2019

Jerry’s interaction with an upper-level trough has resulted in a system that is less tropical in appearance, with a lack of central convection and most of the heavier showers displaced to the west and well southeast of the center. In fact, the cyclone looks somewhat subtropical at this time. For simplicity, however, we will continue to carry Jerry as a tropical storm. Flight-level winds from an Air Force Reserve Unit Hurricane Hunter plane still support an intensity of 50 kt. Jerry will be encountering an increasingly unfavorable environment during the next few days, with the ambient air mass becoming drier and vertical shear becoming stronger. The official intensity forecast calls for continued weakening and degeneration to a remnant low later in the forecast period. This is similar to the consensus of the model guidance.

Based on fixes from the Hurricane Hunters, the center has moved a little to the left of previous estimates, and the initial motion estimate is 350/6 kt. There are no significant changes to the track forecast philosophy, however. Over the next couple of days Jerry should turn northeastward and then east-northeastward in the flow to the south of a broad mid-latitude trough. Later in the period, the weakening cyclone should move eastward to east-southeastward on the northeast side of a subtropical anticyclone. The official track forecast is close to the previous one and in general agreement with the corrected multi-model consensus guidance.

Key Messages:

  • 1. Tropical-storm-force winds are expected on Bermuda by tonight or early Wednesday. Large swells are also expected to affect the coast of Bermuda during the next few days. These swells could cause life-threatening rip currents. See products issued by the Bermuda Weather Service for more information.
FORECAST POSITIONS AND MAX WINDS

INIT  24/1500Z 30.8N  69.3W   50 KT  60 MPH - Tropical Storm (WSW St George's, Bermuda)
 12H  25/0000Z 31.7N  68.5W   45 KT  50 MPH - Tropical Storm (WSW St George's, Bermuda)
 24H  25/1200Z 32.6N  66.7W   40 KT  45 MPH - Tropical Storm (WNW St George's, Bermuda)
 36H  26/0000Z 33.5N  64.2W   35 KT  40 MPH - Tropical Storm (ENE St George's, Bermuda)
 48H  26/1200Z 34.2N  61.5W   30 KT  35 MPH - Tropical Depression (ENE St George's, Bermuda)
 72H  27/1200Z 35.0N  57.4W   25 KT  30 MPH - Low (ENE St George's, Bermuda)
 96H  28/1200Z 34.5N  54.0W   25 KT  30 MPH - Low (ENE St George's, Bermuda)
120H  29/1200Z...DISSIPATED

NWS National Hurricane Center Miami FL 500 PM AST Mon Sep 23, 2019

The low-level center of Jerry became fully exposed to the west of the convection earlier today. Later, however, new convection formed near or just north of the center. The storm continues to be affected by strong westerly shear associated with a sharp upper-level trough over the southwestern Atlantic. The current intensity estimate remains 55 kt, which is consistent with data from an earlier ASCAT overpass. The dynamical guidance shows only a brief relaxation of the shear over the next several days, and the ambient air mass becomes quite dry in 3 to 5 days. Therefore, slow but steady weakening is forecast. This is close to the latest simple and corrected intensity model consensus predictions.

Jerry has slowed its forward speed today and the motion is now just 5 kt toward the north-northwest. The tropical cyclone should continue to move through a weakness in the subtropical ridge tonight and then turn toward the north and northeast under the influence of a mid-tropospheric trough moving off the northeast U.S. coast. In 2 to 4 days, Jerry is expected to move just north of east while embedded in the nearly zonal flow. By the end of the forecast period, some of the models now show a slightly south of east motion as the cyclone moves along the northeast periphery of a subtropical anticyclone. The official track forecast is slower than the previous one, especially during the latter part of the period. This is fairly close to the latest corrected consensus guidance, HCCA.

Key Messages:

  • 1. Tropical-storm-force winds are expected on Bermuda by late Tuesday. Large swells are also expected to affect the coast of Bermuda during the next few days. These swells could cause life-threatening rip currents. See products issued by Bermuda Weather Service for more information.
FORECAST POSITIONS AND MAX WINDS

INIT  23/2100Z 28.4N  68.3W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 12H  24/0600Z 29.6N  68.6W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 24H  24/1800Z 30.9N  68.4W   50 KT  60 MPH - Tropical Storm (WSW St George's, Bermuda)
 36H  25/0600Z 32.1N  66.8W   50 KT  60 MPH - Tropical Storm (WSW St George's, Bermuda)
 48H  25/1800Z 33.3N  64.0W   45 KT  50 MPH - Tropical Storm (ENE St George's, Bermuda)
 72H  26/1800Z 35.0N  58.0W   45 KT  50 MPH - Tropical Storm (ENE St George's, Bermuda)
 96H  27/1800Z 36.0N  53.5W   40 KT  45 MPH - Tropical Storm (ENE St George's, Bermuda)
120H  28/1800Z 35.0N  50.0W   35 KT  40 MPH - Tropical Storm (ENE St George's, Bermuda)

NWS National Hurricane Center Miami FL 1100 AM AST Mon Sep 23, 2019

Strong shear associated with an upper-level trough off the southeast U.S. coast continues to affect Jerry, and the low-level center is exposed to the west-southwest of the main convective mass. Observations from an Air Force Reserve Unit Hurricane Hunter aircraft indicated that the intensity remains near 55 kt. However, if the current sheared state persists, then a weakening trend is likely to commence soon. For now, the official forecast will only show a very slow weakening over the next few days. This prediction is somewhat higher than the intensity model consensus. It should be noted that experience has shown that tropical cyclones at subtropical latitudes tend to be more resilient to shear than those in the deep tropics.

Jerry has slowed its forward speed and is now moving north-northwestward at around 6 kt. The storm will continue passing through a break in the subtropical ridge through tonight. On Tuesday, a trough moving off the northeast U.S. coast will cause Jerry to turn northward. Within a couple of days, the trough should steer the tropical cyclone northeastward at a faster forward speed. In days 3-5, Jerry should move east-northeastward to eastward while embedded in the southern portion of the mid-latitude westerlies. The official track forecast is similar to the previous one and close to the model consensus.

Key Messages:

  • 1. Tropical-storm-force winds are expected on Bermuda by late Tuesday. Large swells are also expected to affect the coast of Bermuda during the next few days. These swells could cause life-threatening rip currents. See products issued by Bermuda Weather Service for more information.
FORECAST POSITIONS AND MAX WINDS

INIT  23/1500Z 28.1N  68.0W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 12H  24/0000Z 29.2N  68.3W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 24H  24/1200Z 30.4N  68.4W   50 KT  60 MPH - Tropical Storm (WSW St George's, Bermuda)
 36H  25/0000Z 31.8N  67.3W   50 KT  60 MPH - Tropical Storm (WSW St George's, Bermuda)
 48H  25/1200Z 33.3N  65.0W   50 KT  60 MPH - Tropical Storm (WNW St George's, Bermuda)
 72H  26/1200Z 35.8N  58.5W   45 KT  50 MPH - Tropical Storm (ENE St George's, Bermuda)
 96H  27/1200Z 37.0N  53.5W   45 KT  50 MPH - Tropical Storm (ENE St George's, Bermuda)
120H  28/1200Z 37.0N  48.0W   35 KT  40 MPH - Tropical Storm (ESE New York City, NY)

NWS National Hurricane Center Miami FL 500 PM AST Sun Sep 22, 2019

Jerry continues to struggle to become better organized in an environment of moderate westerly vertical shear. The low-level center is near the western side of the main area of deep convection, and the overall cloud pattern remains rather ragged-looking. Flight-level, SFMR-observed, and Doppler wind data from a NOAA Hurricane Hunter aircraft indicate that the intensity remains near 55 kt. The dynamical guidance shows that the shear will remain rather strong throughout much of the forecast period, so the official forecast shows little change in strength for the next couple of days followed by gradual weakening. This is a little above the intensity model consensus.Tropical Storm Jerry Tropical Force Wind Probability September 22 2019

The motion is still north-northwestward or 345/8 kt. Jerry continues to move through a weakness in the subtropical ridge. In a couple of days, a mid-latitude trough moving off the northeast U.S. coast should cause the storm to turn north-northeastward to northeastward with a gradual increase in forward speed in the latter part of the forecast period, Jerry is likely to move east-northeastward at a faster speed, following the mid-level westerly flow. The official forecast is a bit slower than the previous one and leans toward the corrected dynamical model consensus, HCCA.

Key Messages:

  • 1. The risk of tropical-storm-force winds on Bermuda is increasing, with Jerry forecast to pass near the island Tuesday night and Wednesday. It is too soon to determine what impacts the system may have on Bermuda, but interests there should monitor the progress of Jerry. A Tropical Storm Watch could be issued tonight for Bermuda.
FORECAST POSITIONS AND MAX WINDS

INIT  22/2100Z 26.7N  66.9W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 12H  23/0600Z 27.7N  67.4W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 24H  23/1800Z 29.0N  67.9W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 36H  24/0600Z 30.4N  68.3W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 48H  24/1800Z 31.8N  67.8W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 72H  25/1800Z 34.4N  63.5W   50 KT  60 MPH - Tropical Storm (ENE St George's, Bermuda)
 96H  26/1800Z 37.0N  56.5W   50 KT  60 MPH - Tropical Storm (ENE Virginia Beach, VA)
120H  27/1800Z 38.5N  50.5W   45 KT  50 MPH - Tropical Storm (ESE St. John's, Newfoundland)

NWS National Hurricane Center Miami FL 1100 AM AST Sun Sep 22, 2019

Jerry is not well organized on satellite images, with a ragged-looking CDO and limited banding features over the eastern semicircle. Reports from an Air Force Hurricane Hunter aircraft indicate a slight fall in central pressure but the maximum winds remain near 55 kt. The storm is under the influence of westerly shear, and the numerical guidance does not indicate that this shear will relax during the forecast period. Therefore, only slight strengthening is allowed for in the official forecast. This is a little above most of the model guidance.

Jerry continues to move north-northwestward, or 340/9 kt, through a weakness in the subtropical ridge. A mid-tropospheric trough moving off the northeast U.S. coast in a couple of days should cause the cyclone to turn north-northeastward to northeastward with some acceleration later in the forecast period. The official track forecast is close to the previous one and is also similar to the corrected consensus model guidance.

Key Messages:

  • 1. The risk of tropical-storm-force winds on Bermuda is increasing, with Jerry forecast to pass near the island Tuesday and Wednesday. It is too soon to determine what impacts the system may have on Bermuda, but interests there should monitor the progress of Jerry. A Tropical Storm Watch could be issued later today for Bermuda.
FORECAST POSITIONS AND MAX WINDS

INIT  22/1500Z 25.7N  66.6W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 12H  23/0000Z 26.9N  67.3W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 24H  23/1200Z 28.2N  67.7W   60 KT  70 MPH - Tropical Storm (WSW St George's, Bermuda)
 36H  24/0000Z 29.5N  67.9W   60 KT  70 MPH - Tropical Storm (WSW St George's, Bermuda)
 48H  24/1200Z 31.0N  68.0W   60 KT  70 MPH - Tropical Storm (WSW St George's, Bermuda)
 72H  25/1200Z 35.0N  63.5W   55 KT  65 MPH - Tropical Storm (ENE St George's, Bermuda)
 96H  26/1200Z 40.0N  54.5W   50 KT  60 MPH - Tropical Storm (ENE New York City, NY)
120H  27/1200Z 45.0N  45.0W   45 KT  50 MPH - Tropical Storm (ESE St. John's, Newfoundland )

NWS National Hurricane Center Miami FL 1100 PM AST Sat Sep 21, 2019

Jerry’s center is still exposed to the northwest of the bulk of the deep convection, although a new burst of thunderstorms is just now developing just to the southeast of the center. With no significant change to the storm’s structure, the initial intensity is held at 55 kt, which matches a blend of final-T and CI numbers from TAFB and SAB. UW-CIMSS is depicting 15-20 kt of westerly shear over Jerry at the moment, although the analysis suggests that the cyclone could sneak into a slightly lower-shear environment during the next 12-24 hours.

After that time, however, Jerry is expected to interact with a mid- to upper-level trough, putting the system under counterbalancing influences of strong shear but stronger divergence aloft. Because of these conditions, only small fluctuations in intensity are expected during the next 4 days or so. Jerry will be bumping up against a baroclinic zone while interacting with the trough, and it’s likely that extratropical transition will at least commence while this system is over the western Atlantic. At this point, however, that transition is not expected to be completed before the end of the 5-day forecast period.

The initial motion is northwestward, or 325/13 kt. Jerry is still expected to continue recurving around the subtropical ridge, interact with the western Atlantic trough in about 48 hours, and then become embedded in the mid-latitude westerlies from day 3 onward. Except for a slight westward kink in the track between 48-72, resulting from Jerry’s expected interaction with the trough, little change in the NHC track forecast was required from the previous one.

Key Messages:

  • 1. The risk of tropical-storm-force winds on Bermuda is increasing, with Jerry forecast to pass near the island Tuesday and Wednesday. It is too soon to determine what impacts the system may have on Bermuda, but interests there should monitor the progress of Jerry.
FORECAST POSITIONS AND MAX WINDS

INIT  22/0300Z 24.1N  66.3W   55 KT  65 MPH - Tropical Storm (WNW San Juan, Puerto Rico)
 12H  22/1200Z 25.4N  67.1W   55 KT  65 MPH - Tropical Storm (WNW San Juan, Puerto Rico)
 24H  23/0000Z 26.7N  67.8W   60 KT  70 MPH - Tropical Storm (WSW St George's, Bermuda)
 36H  23/1200Z 28.0N  68.0W   60 KT  70 MPH - Tropical Storm (WSW St George's, Bermuda)
 48H  24/0000Z 29.4N  68.0W   60 KT  70 MPH - Tropical Storm (WSW St George's, Bermuda)
 72H  25/0000Z 32.6N  66.2W   55 KT  65 MPH - Tropical Storm (WNW St George's, Bermuda)
 96H  26/0000Z 36.8N  60.2W   55 KT  65 MPH - Tropical Storm (ENE St George's, Bermuda)
120H  27/0000Z 40.8N  54.0W   50 KT  60 MPH - Tropical Storm (ESE Provincetown, MA)

NWS National Hurricane Center Miami FL 500 PM AST Sat Sep 21, 2019

Jerry has become quite disorganized this afternoon. The low-level center is exposed to the northwest of a small area of persistent deep convection. The NOAA G-IV aircraft, which is flying a research mission in and around the tropical storm, measured a minimum pressure of 1004 mb with 17 kt of wind, implying that the minimum pressure of Jerry has increased since this morning. However, ASCAT data from a couple hours after an Air Force Reserve hurricane hunter plane completed its mission into Jerry showed that the maximum winds were still 50-55 kt. The max winds are therefore conservatively held at 55 kt for this advisory.Tropical Storm Jerry Wind Probability 1400 Hours September 21 2019

Only minor adjustments were made to the NHC intensity forecast, and users should not focus on the 5 kt difference between a tropical storm and hurricane, especially at 72 h and beyond. Based on Jerry’s disheveled appearance, significant strengthening does not seem imminent. That said, the HWRF and HMON forecast that the cyclone will quickly restrengthen tonight or tomorrow and become a hurricane again. If the shear decreases during the next 24 hours, that is possible, however, SHIPS diagnostics suggest that will not happen. The NHC forecast instead follows the statistical guidance and keeps Jerry in a more-or-less steady state through day 5. The cyclone is still forecast to be near hurricane strength when it moves near Bermuda next week, and there is still a distinct possibility that Jerry will re-gain hurricane strength at some point during the next 5 days.

All of the models still show Jerry turning northward later today or on Sunday toward a break in the subtropical ridge, and then turning northeastward ahead of an approaching mid-latitude trough. This track will bring Jerry close to Bermuda by late Tuesday or early Wednesday. The model spread has increased a little since the last advisory, but confidence in this scenario is still high. The NHC track forecast has been adjusted only slightly to the west and remains near the multi-model consensus through day 5.

Key Messages:

  • 1. Jerry is forecast to be near hurricane strength when it moves near Bermuda late Tuesday or early Wednesday. It is too soon to determine what impacts the system may have on the island but interests there should monitor the progress of Jerry.
FORECAST POSITIONS AND MAX WINDS

INIT  21/2100Z 23.0N  65.8W   55 KT  65 MPH - Tropical Storm (ENE San Juan, Puerto Rico)
 12H  22/0600Z 24.3N  66.9W   55 KT  65 MPH - Tropical Storm (WNW San Juan, Puerto Rico)
 24H  22/1800Z 25.8N  67.6W   60 KT  70 MPH - Tropical Storm (WNW San Juan, Puerto Rico)
 36H  23/0600Z 27.0N  67.8W   60 KT  70 MPH - Tropical Storm (WSW St George's, Bermuda)
 48H  23/1800Z 28.5N  67.8W   60 KT  70 MPH - Tropical Storm (WSW St George's, Bermuda)
 72H  24/1800Z 31.5N  66.5W   60 KT  70 MPH - Tropical Storm (WSW St George's, Bermuda)
 96H  25/1800Z 35.5N  61.5W   60 KT  70 MPH - Tropical Storm (ENE St George's, Bermuda)
120H  26/1800Z 40.0N  56.0W   60 KT  70 MPH - Tropical Storm (ENE St George's, Bermuda)

NWS National Hurricane Center Miami FL 1100 AM AST Sat Sep 21, 2019

An Air Force Reserve hurricane hunter plane has investigated Jerry this morning and found that the tropical storm has become quite disorganized. The highest flight-level winds reported by the plane at the 700 mb level were 59 kt, which supports holding the intensity at 55 kt. The highest reliable SFMR winds were lower and the minimum pressure estimated from the plane data was 999 mb, so its possible that Jerry’s winds are actually a little lower.

Jerry is still moving northwestward, with an initial motion of 315/12 kt. The track guidance is still in very good agreement on the forecast track for the tropical storm, and only small changes were made to the track forecast. Jerry should continue northwestward today and then turn northward on Sunday toward a break in the subtropical ridge. By late Monday or Tuesday, Jerry should turn northeastward and begin to accelerate in that direction ahead of an approaching mid-latitude trough, likely passing near Bermuda late Tuesday or early Wednesday. The track guidance is still tightly clustered, especially for the first 72 h of the forecast, and the NHC forecast is near the consensus throughout the 5-day period.

Because Jerry is not well organized at the moment, no strengthening is expected in the short term. The NHC forecast now calls for little change in Jerry’s intensity for the next couple days, and I can’t rule out that additional weakening could occur later today or tomorrow. Most of the guidance suggests that restrengthening could then occur once Jerry turns northeastward ahead of the aforementioned mid-latitude trough, perhaps in part due to baroclinic forcing. Jerry is still forecast to become a hurricane again before the end of the forecast period, but the NHC forecast is now on the high side of the guidance, a little above the consensus.

Key Messages:

  • 1. Jerry is forecast to be near hurricane strength when it moves near Bermuda late Tuesday or early Wednesday. It is too soon to determine what impacts the system may have on the island but interests there should monitor the progress of Jerry.
FORECAST POSITIONS AND MAX WINDS

INIT  21/1500Z 22.0N  65.0W   55 KT  65 MPH - Tropical Storm (ENE San Juan, Puerto Rico)
 12H  22/0000Z 23.3N  66.0W   55 KT  65 MPH - Tropical Storm (ENE San Juan, Puerto Rico)
 24H  22/1200Z 25.0N  66.9W   55 KT  65 MPH - Tropical Storm (WNW San Juan, Puerto Rico)
 36H  23/0000Z 26.4N  67.1W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 48H  23/1200Z 27.8N  67.1W   55 KT  65 MPH - Tropical Storm (WSW St George's, Bermuda)
 72H  24/1200Z 30.6N  66.3W   60 KT  70 MPH - Tropical Storm (WSW St George's, Bermuda)
 96H  25/1200Z 34.5N  62.0W   65 KT  75 MPH - Category 1 (ESE St George's, Bermuda)
120H  26/1200Z 38.5N  57.5W   65 KT  75 MPH - Category 1 (ESE Atlantic City NJ)

NWS National Hurricane Center Miami FL 1100 AM AST Fri Sep 20, 2019

Data from both NOAA and Air Force Reserve Hurricane Hunter aircraft indicate that Jerry is weakening quickly, and radar images from NOAA show no sign of the eyewall reported on the last mission. Maximum flight-level winds on the mission were about 78 kt, with SFMR values near 70 kt, and the central pressure has risen about 10 mb overnight. These observations also agree with the latest satellite imagery that shows a less organized cyclone, with the center on the far northwestern edge of a distorted central dense overcast. A blend of all these data gives an initial wind speed estimate of 75 kt.Hurricane Jerry Tropical Force Wind Probability 09-20-2019

Jerry is moving about the same as before, west-northwestward at 15 kt. The hurricane should gradually bend to the right and slow down during the next few days while the cyclone is steered around the western periphery of a weakening subtropical ridge. The guidance is tightly packed on the forecast through Monday, and little change was made to the previous NHC prediction. At longer range, a mid-latitude trough interaction should turn the hurricane northward and northeastward, but the models are really struggling on how quickly this occurs. While yesterday much of the guidance had Jerry accelerating ahead of the trough, today’s models have slowed everything down as the trough looks like it could weaken before fully recurving the cyclone. The new track forecast is considerably slower than the last one beyond 72 hours, about as much as continuity allows, and later forecasts could slow Jerry down even more.

Northwesterly shear is forecast to persist near Jerry for the next day or two, and some weakening is expected. The intensity forecast is reduced from the previous one, and could be a bit too high in the short term given recent trends. In a few days, the aforementioned trough interaction is anticipated, but it is next to impossible to know at this lead time whether the trough will weaken or strengthen the cyclone, so no forecast change is made. It is a little tempting to raise the intensity by the end, given the recent weaker mid-latitude trough in the models, but there’s just too much track uncertainty to mess with the intensity forecast at this time.

Key Messages:

  • 1. Although the core of Jerry is expected to move north of the northern Leeward Islands, heavy rainfall and flash floods are possible there today.
FORECAST POSITIONS AND MAX WINDS

INIT  20/1500Z 18.8N  60.3W   75 KT  85 MPH - Category 1 (ENE Codrington, Barbuda)
 12H  21/0000Z 19.6N  62.4W   70 KT  80 MPH - Category 1 (ENE Philipsburg, Saint Martin)
 24H  21/1200Z 20.9N  64.7W   65 KT  75 MPH - Category 1 (WNW The Settlement, BVI)
 36H  22/0000Z 22.3N  66.6W   60 KT  70 MPH - Tropical Storm (WNW San Juan, Puerto Rico)
 48H  22/1200Z 23.6N  68.0W   60 KT  70 MPH - Tropical Storm (ENE Cockburn Town, Turks and Caicos Islands)
 72H  23/1200Z 26.5N  69.0W   65 KT  75 MPH - Category 1 (ENE Cockburn Town, Turks and Caicos Islands)
 96H  24/1200Z 29.0N  67.5W   65 KT  75 MPH - Category 1 (WSW St George's, Bermuda)
120H  25/1200Z 33.0N  64.0W   65 KT  75 MPH - Category 1 (ENE St George's, Bermuda)

NWS National Hurricane Center Miami FL 500 AM AST Fri Sep 20, 2019

Jerry appears to have stopped strengthening for now. The last reports from the Air Force Hurricane Hunters indicated that the minimum pressure had risen slightly, and the satellite appearance has become a little more ragged during the past several hours. Radar images sent from the aircraft showed a well-defined inner core, but there are no hints of an eye in geostationary satellite images. The initial intensity is held at 90 kt based on the earlier aircraft data. Both the Air Force and NOAA Hurricane Hunters will be investigating Jerry later today, and that data should provide a better assessment of its intensity and structure.

Jerry continues to move west-northwestward at a relatively quick pace of 14 kt. This motion is expected to continue for about another 24 hours as the cyclone is steered by a subtropical ridge to its northeast. The ridge is expected to weaken and slide eastward late this weekend in response to an eastward-moving trough over the north Atlantic. This change in the steering pattern should cause Jerry to slow down and gradually turn to the northwest and then the north late this weekend and early next week. A faster north- northeastward motion is anticipated toward the end of the forecast period as another trough approaches the system. The models remain in very good agreement on the hurricane passing well to the north of the northern Leeward Island and Puerto Rico late today and Saturday and possibly moving near Bermuda in a little more than 4 days. The only notable change this cycle is a slower northward motion from days 3 to 5 to be in better agreement with the latest models.

The intensity forecast is a bit more challenging. The global models show a relatively favorable upper-level wind pattern over Jerry during the next couple of days, but there is also a significant amount of dry air around the cyclone. Although the shear could increase early next week, some of the models show Jerry deepening, likely due to baroclinic effects due to the nearby trough. There is a very large spread in the intensity guidance ranging from SHIPS and LGEM showing little change in strength to pronounced weakening shown by HMON during the forecast period. The NHC intensity forecast is between those extremes and lies a little above the consensus aids.

Key Messages:

  • 1. Although the core of Jerry is expected to move north of the northern Leeward Islands, heavy rainfall and flash floods are possible there today.
FORECAST POSITIONS AND MAX WINDS

INIT  20/0900Z 18.4N  58.7W   90 KT 105 MPH - Category 2 (ENE Codrington, Barbuda)
 12H  20/1800Z 19.1N  60.8W   85 KT 100 MPH - Category 2 (ENE Philipsburg, Saint Martin)
 24H  21/0600Z 20.4N  63.3W   80 KT  90 MPH - Category 1 (ENE The Settlement, BVI)
 36H  21/1800Z 21.8N  65.4W   75 KT  85 MPH - Category 1 (ENE San Juan, Puerto Rico)
 48H  22/0600Z 23.2N  67.1W   70 KT  80 MPH - Category 1 (WNW San Juan,  Puerto Rico)
 72H  23/0600Z 26.1N  68.4W   65 KT  75 MPH - Category 1 (ESE Elbow Cay, Bahamas)
 96H  24/0600Z 29.4N  66.8W   65 KT  75 MPH - Category 1 (WSW St George's, Bermuda)
120H  25/0600Z 34.6N  63.0W   65 KT  75 MPH - Category 1 (ENE St George's, Bermuda)

NWS National Hurricane Center Miami FL 1100 AM AST Thu Sep 19, 2019

Satellite images indicate that the center of Jerry) is on the northwestern side of the central dense overcast near a very deep convective burst. An Air Force recon plane just flew through the center and found a central pressure of 988 mb and SFMR values near 65 kt. These data support making Jerry the 4th hurricane of the 2019 Atlantic hurricane season with an initial wind speed of 65 kt.

Jerry has the potential to further strengthen today, but an increase in northwesterly shear related to an upper-level ridge is anticipated overnight. This change in shear will likely arrest the development of Jerry and start a slow weakening trend sometime tomorrow. In 3 or 4 days, Jerry could enter a more conducive environment for strengthening, but there is a pretty large spread in the shear forecast near the cyclone at this time, related to the positioning of Jerry relative to the ridge. Since the environmental uncertainty at long range is so high, little change has been made to the previous forecast.

The initial motion is estimated to be west-northwestward, or 295/14 kt. The track forecast has remained rather consistent during the past several cycles, taking Jerry just north of the Leeward Islands during the first couple of days due to seemingly reliable steering flow from the subtropical ridge to the north. The track is a little trickier beyond that time due to some dependence on the strength of Jerry, with a stronger system, likely moving a bit longer toward the west-northwest, similar to the latest ECMWF/HWRF forecast. Regardless, the cyclone should eventually turn northward and northeastward by day 5 due to a substantial break in the subtropical ridge. The track forecast puts slightly greater weight on those stronger solutions, and the official track forecast is a little left of the various consensus aids and not too far from the last NHC prediction.

Key Messages:

  • 1. Although the core of Jerry is expected to pass north of the northern Leeward Islands, tropical-storm-force winds and locally heavy rainfall are possible, and tropical storm watches are in effect.
FORECAST POSITIONS AND MAX WINDS

INIT  19/1500Z 16.8N  54.4W   65 KT  75 MPH - Category 1 (ESE St. John’s, Antigua and Barbuda)
 12H  20/0000Z 17.5N  56.5W   75 KT  85 MPH - Category 1 (ENE Codrington, Barbuda)
 24H  20/1200Z 18.5N  59.3W   75 KT  85 MPH - Category 1 (ENE Codrington, Barbuda)
 36H  21/0000Z 19.5N  62.1W   70 KT  80 MPH - Category 1 (ENE Philipsburg, Saint Martin)
 48H  21/1200Z 20.7N  64.8W   65 KT  75 MPH - Category 1 (ENE San Juan, Puerto Rico)
 72H  22/1200Z 23.5N  68.6W   60 KT  70 MPH - Tropical Storm (ENE Cockburn Town, Turks and Caicos Islands)
 96H  23/1200Z 26.5N  70.0W   65 KT  75 MPH - Category 1 (ESE Elbow Cay, Bahamas)
120H  24/1200Z 30.5N  67.0W   65 KT  75 MPH - Tropical Storm (WSW St George's, Bermuda)

NWS National Hurricane Center Miami FL 500 AM AST Thu Sep 19, 2019

A fortuitous 0531 UTC AMSR2 microwave overpass indicated that Jerry’s inner core has significantly become better organized this morning. The image revealed a nearly enclosed banding eye feature with the curved band wrapping around the eastern portion of the cyclone. Based on the much-improved cloud pattern and a blend of the subjective and objective satellite intensity estimates, the initial intensity is increased to 60 kt for this advisory.

Jerry is expected to strengthen further in the short term and become a hurricane later today. Afterward, the statistical-dynamical intensity models show some moderate northwesterly shear impinging on the northern half of the cyclone, which should arrest the early period intensification. Beyond the 48 hour period, a majority of the large-scale models indicate increasing westerly vertical shear as Jerry moves northwest of an upper anti-cyclone situated to the north of Hispaniola. Therefore, a weakening trend is expected through the remaining portion of the forecast. The NHC forecast is slightly below the previous advisory after the 48 hour period, but above the HFIP HCCA and IVCN consensus models, and as well as the HWRF.Tropical Storm Jerry Tropical Force Wind Probability 09-19-2019

The initial motion is estimated to be west-northwestward, or 290/14 kt. There are no significant changes to the forecast track philosophy. The cyclone is forecast to be steered by the southeasterly flow generated by a subtropical ridge to the northeast of Jerry through the 48 hour period. Around day 3, Jerry is likely to turn northwest to the north-northwest, in response to growing weakness in the aforementioned mid-tropospheric ridge along 70-75W longitude. The official track forecast is based on a blend of the various consensus aids.

Key Messages:

  • 1. Jerry is expected to become a hurricane before it moves close to the northern Leeward Islands Friday. Although the core of Jerry is currently expected to pass north of the islands, tropical-storm-force winds and locally heavy rainfall are possible, and tropical storm watches have been issued for a portion of this area.
FORECAST POSITIONS AND MAX WINDS

INIT  19/0900Z 16.0N  53.2W   60 KT  70 MPH - Tropical Storm (ESE Sainte-Anne, Guadeloupe)
 12H  19/1800Z 16.8N  55.2W   70 KT  80 MPH - Category 1 (ESE Sainte-Anne, Guadeloupe)
 24H  20/0600Z 17.8N  57.9W   70 KT  80 MPH - Category 1 (ESE Gustavia, Saint Barthélemy)
 36H  20/1800Z 18.9N  60.9W   65 KT  75 MPH - Category 1 (ENE Philipsburg, Saint Martin)
 48H  21/0600Z 20.1N  63.7W   65 KT  75 MPH - Category 1 (ENE San Juan, Puerto Rico)
 72H  22/0600Z 22.9N  68.2W   60 KT  70 MPH - Tropical Storm (ENE Cockburn Town, Turks and Caicos)
 96H  23/0600Z 26.0N  70.0W   65 KT  75 MPH - Category 1 (ENE Arthur's Town, Bahamas )
120H  24/0600Z 29.5N  68.5W   65 KT  75 MPH - Category 1 (WSW St George's, Bermuda)

NWS National Hurricane Center Miami FL 1100 PM AST Wed Sep 18, 2019

Jerry is gradually becoming better organized, with a small circular CDO and some banding features over its northwestern quadrant. Although the storm has some modest upper-level outflow, there is evidence of west-northwesterly winds undercutting the system just below the outflow layer. An upper-level cyclone is located a few hundred miles to the northwest of Jerry, as confirmed by synoptic surveillance observations taken recently by the NOAA G-IV jet. However, the global models suggest that this feature should remain far enough to the north of the tropical cyclone so that its shearing influence will be minimal in the short term. The current intensity estimate is 55 kt based on Dvorak classifications from TAFB and SAB. Since the environment is likely to be modestly conducive during the next day or so, strengthening is predicted for the next 24 hours. Thereafter, the dynamical guidance shows some increase in shear, which should result in a leveling off of Jerry’s intensity. Later in the forecast period, the global models predict a significant increase in shear, so some weakening is likely. The official intensity forecast is close to the multi-model consensus.

The storm remains on track with the motion continuing around 290/13 kt. There are no important changes to the track forecast from the previous advisory. Jerry should move along the southwestern periphery of a subtropical ridge over the next couple of days. In 3-5 days, the tropical cyclone is likely to turn northwest, north-northwest, and eventually north following a weakness in the ridge near 70-75W longitude. The official track forecast is close to the latest corrected multi-model consensus guidance. Key Messages: 1. Jerry is expected to become a hurricane before it moves close to the northern Leeward Islands Friday. Although the core of Jerry is currently expected to pass north of the islands, tropical-storm-force winds and locally heavy rainfall are possible, and tropical storm watches have been issued for a portion of this area.

FORECAST POSITIONS AND MAX WINDS

INIT  19/0300Z 15.4N  51.8W   55 KT  65 MPH - Tropical Storm (ESE Roseau, Dominica)
 12H  19/1200Z 16.2N  53.9W   65 KT  75 MPH - Category 1 (ESE Sainte-Anne, Guadeloupe)
 24H  20/0000Z 17.3N  56.7W   75 KT  85 MPH - Category 1 (ESE Codrington, Barbuda)
 36H  20/1200Z 18.5N  59.7W   75 KT  85 MPH - Category 1 (ENE Codrington, Barbuda)
 48H  21/0000Z 19.7N  62.7W   75 KT  85 MPH - Category 1 (ENE Philipsburg, Saint Martin)
 72H  22/0000Z 22.4N  67.3W   70 KT  80 MPH - Category 1 (WNW San Juan, Puerto Rico)
 96H  23/0000Z 25.7N  70.0W   65 KT  75 MPH - Category 1 (ENE Cockburn Town, Turks and Caicos )
120H  24/0000Z 29.0N  69.0W   65 KT  75 MPH - Category 1 (WSW St George's, Bermuda)

NWS National Hurricane Center Miami FL 1100 AM AST Wed Sep 18, 2019

Satellite images indicate that Jerry continues to become better organized, with a large curved band wrapping around the center. While microwave data does not show an inner core yet, the overall satellite presentation has improved during the past several hours. The initial wind speed is set to 45 kt, which closely matches almost all of the available Dvorak estimates and a just-arrived ASCAT-C scatterometer pass.

Further intensification of Jerry is expected during the next day or two as the cyclone moves over very warm waters within light shear. While this type of environment could support even more strengthening than forecast, there is some substantial dry air around the cyclone, which is forecast to limit the intensification rates for now. This forecast leans heavier on the regional hurricane models HWRF, HMON and COAMPS-TC, which all show a weaker cyclone than the statistical/dynamical LGEM and SHIPS models. Most of the guidance shows increasing shear in a couple of days, and the shear could become somewhat strong by next week. While little change in strength is indicated beyond Friday, this usually doesn’t happen in reality, and further changes will be necessary as the environmental factors become more clear.

The initial motion continues to be west-northwestward, or 290/12 kt. The subtropical ridge to the north should steer Jerry at a faster forward speed for the next couple of days. Afterward, a northwest to north-northwestward turn, influenced by a weakness in the aforementioned ridge left behind by Humberto, is expected. The NHC track forecast is basically an update from the previous advisory and lies on the left side of the guidance suite, nearest the ECMWF model and the corrected-consensus forecasts.

Key Messages:

  • 1. Jerry is expected to strengthen and be a hurricane when it moves near the northern Leeward Islands Friday, although it is too soon to determine the direct impacts to the islands. Interests there should ensure they have their hurricane plan in place and monitor the progress of this system. Watches could be issued for a portion of this area this afternoon or evening.
FORECAST POSITIONS AND MAX WINDS

INIT  18/1500Z 14.6N  49.2W   45 KT  50 MPH - Tropical Storm (ENE Le Vauclin, Martinique)
 12H  19/0000Z 15.3N  51.0W   55 KT  65 MPH - Tropical Storm (ESE Roseau, Dominica)
 24H  19/1200Z 16.3N  53.7W   60 KT  70 MPH - Tropical Storm (ENE La Désirade, Guadeloupe)
 36H  20/0000Z 17.3N  56.5W   65 KT  75 MPH - Category 1 (ESE St. John’s, Antigua and Barbuda)
 48H  20/1200Z 18.4N  59.5W   65 KT  75 MPH - Category 1 (ENE Grand Case, Saint Martin)
 72H  21/1200Z 20.5N  65.3W   65 KT  75 MPH - Category 1 (ENE San Juan, Puerto Rico,)
 96H  22/1200Z 23.3N  69.1W   65 KT  75 MPH - Category 1 (ENE Cockburn Town, Turks and Caicos Islands)
120H  23/1200Z 26.5N  70.5W   60 KT  70 MPH - Tropical Storm (ESE Elbow Cay, Bahamas)

NWS National Hurricane Center Miami FL 500 AM AST Wed Sep 18, 2019

Tropical Storm Jerry Enhanced BD-curve infrared imagery and a 0431 UTC AMSR2 microwave pass indicate that the cyclone has become better organized during the past several hours. Although the surface center is still situated near the northeastern edge of the convective mass, the deep convection has expanded in the form of curve bands in the south portion of the cyclone. Based on the increased subjective and objective satellite intensity estimates, and the improved microwave presentation, the initial intensity is raised to 40 kt making the system the tenth named storm of the season.

Even though the shear is low and the sea surface temperatures are warm, GOES-16 sounder data and the GFS/ECMWF SHIPS intensity models indicate that the environment surrounding the cyclone is still a little dry and stable. Therefore, only gradual intensification is forecast. The shear is forecast to increase after 24 hours or so, to the point where it should slow, or halt development, and this is reflected in the official forecast. It should be noted that the forecast still calls for the cyclone to become a hurricane as it approaches the northern Leeward Islands.

The initial motion is estimated to be west-northwestward, or 290/11 kt, within the low to mid-tropospheric steering flow produced by a subtropical ridge to the north of the tropical storm. This general motion is expected to continue during the next 3 to 4 days. Afterward, a northwest to north-northwestward turn, influenced by a growing weakness in the aforementioned ridge, is expected. The NHC track forecast is basically an update from the previous advisory and lies in the middle of the guidance suite, and hedged toward the HCCA multi-model consensus.

Key Messages:

  • 1. Jerry is expected to strengthen and be a hurricane when its moves near the northern Leeward Islands Friday, although it is too soon to determine if there will be any direct impacts in the islands. Interests there should ensure they have their hurricane plan in place and monitor the progress of this system.
FORECAST POSITIONS AND MAX WINDS

INIT  18/0900Z 14.1N  47.7W   40 KT  45 MPH - Tropical Storm (ESE Gros Islet, Saint Lucia)
 12H  18/1800Z 14.8N  49.4W   45 KT  50 MPH - Tropical Storm (ESE Sainte-Anne, Martinique)
 24H  19/0600Z 15.7N  52.0W   55 KT  65 MPH - Tropical Storm (ENE Roseau, Dominica)
 36H  19/1800Z 16.8N  54.9W   60 KT  70 MPH - Tropical Storm (ESE St. John’s, Antigua and Barbuda)
 48H  20/0600Z 17.9N  57.9W   65 KT  75 MPH - Category 1 (ENE Barbuda, Antigua and Barbuda)
 72H  21/0600Z 20.2N  64.2W   65 KT  75 MPH - Category 1 (N The Settlement. British Virgin Islands)
 96H  22/0600Z 22.8N  68.6W   65 KT  75 MPH - Category 1 (ENE Cockburn Town, Turks and Caicos Islands)
120H  23/0600Z 25.6N  70.2W   65 KT  75 MPH - Category 1 (WNW Cockburn Town, Turks and Caicos Islands)

NWS National Hurricane Center Miami FL 1100 PM AST Tue Sep 17, 2019

Convection associated with Tropical Depression Ten  has increased and become better organized since the last advisory, and various subjective and objective satellite intensity estimates are now in the 35-40 kt range. However, just-received ASCAT-C data indicates that, despite this increase in organization, the surface winds have not yet reached 35 kt. Based on this, the cyclone remains a 30 kt depression for this advisory.

The initial motion is now 285/9. The cyclone is to the south of a low- to the mid-level ridge, and this feature should steer the system generally west-northwestward with an increase in forward speed during the next 3-4 days. Near the end of the forecast period, the cyclone should approach a weakness in the ridge and turn more northwestward. The track guidance is in generally good agreement with this scenario, with the GFS near the northern edge of the guidance and the HWRF remaining near the southern edge. The new forecast track lies a little to the south of the center of the guidance envelope in best agreement with the HCCA corrected consensus model.

The depression should be in an environment of light shear and over warm water for the next 24-36 h, which should allow steady strengthening during that time. The shear is forecast to increase after 36 h to the point where it may at least slow development, and this is reflected in slight changes from the previous forecast. The new intensity forecast is near the intensity consensus through 48 h, and then is above the consensus from 72-120 h. It should be noted that the forecast still calls for the cyclone to become a hurricane as it approaches the northern Leeward Islands.

Key Messages:

  • 1. The depression is expected to strengthen and be a hurricane when its moves near the northern Leeward Islands Thursday night and Friday, although it is too soon to determine if there will be any direct impacts in the islands. Interests there should ensure they have their hurricane plan in place and monitor the progress of this system.
FORECAST POSITIONS AND MAX WINDS

INIT  18/0300Z 13.7N  46.7W   30 KT  35 MPH - Tropical Depression (ESE Gros Islet, Saint Lucia)
 12H  18/1200Z 14.4N  48.2W   35 KT  40 MPH - Tropical Storm (ESE Sainte-Anne, Martinique)
 24H  19/0000Z 15.3N  50.4W   45 KT  50 MPH - Tropical Storm (ESE Good Hope, Dominica)
 36H  19/1200Z 16.2N  53.0W   50 KT  60 MPH - Tropical Storm (ESE La Désirade, Guadeloupe)
 48H  20/0000Z 17.3N  56.0W   55 KT  65 MPH - Tropical Storm (ESE St. John’s, Antigua and Barbuda)
 72H  21/0000Z 19.5N  62.0W   65 KT  75 MPH - Category 1 (ESE Philipsburg, Saint Martin)
 96H  22/0000Z 21.5N  67.0W   70 KT  80 MPH - Category 1 (N San Juan, Puerto Rico)
120H  23/0000Z 24.5N  70.5W   75 KT  85 MPH - Category 1 (WNW Cockburn Town, Turks and Caicos Islands)

NWS National Hurricane Center Miami FL 1100 AM AST Tue Sep 17, 2019

Deep convection associated with the area of low pressure over the central Atlantic has become more persistent and better organized this morning. Data T-numbers from both SAB and TAFB are 2.0 on the Dvorak scale, therefore advisories are being initiated on a tropical depression. The initial intensity is set at 30 kt, in line with the satellite estimates. The depression is forecast to move over gradually increasing sea surface temperatures within a favorable upper-level environment. The only negative factor for intensification appears to be some nearby dry air, but with low shear conditions expected, so steady strengthening is forecast during the next several days. The NHC forecast calls for the depression to become a tropical storm later today, and attain hurricane status within 72 hours. The NHC intensity forecast is in good agreement with the SHIPS and LGEM statistical models.

Since the depression is still in the development phase, the initial motion is a somewhat uncertain 295/10 kt. A strong deep-layer ridge to the north of the cyclone should steer the depression generally west-northwestward at a faster forward speed during the next few days. The track guidance is in relatively good agreement through 72 hours, and brings the cyclone near the northern Leeward Islands in about 3 days. By late in the period, the cyclone is expected to reach the western periphery of the ridge, and there is increasing spread among the guidance. The global model ensemble means are along the right side of the envelope while the HWRF and UKMET are along the left side.

FORECAST POSITIONS AND MAX WINDS

INIT  17/1500Z 12.9N  44.9W   30 KT  35 MPH - Tropical Depression (WSW Pie Corner, Barbados)
 12H  18/0000Z 13.8N  46.1W   35 KT  40 MPH - Tropical Storm (WSW Pie Corner, Barbados)
 24H  18/1200Z 14.7N  47.9W   40 KT  45 MPH - Tropical Storm (WSW Sainte-Anne, Martinique)
 36H  19/0000Z 15.5N  50.2W   45 KT  50 MPH - Tropical Storm (WSW Saint-Louis, Guadeloupe)
 48H  19/1200Z 16.3N  52.9W   55 KT  65 MPH - Tropical Storm (WSW St. John’s, Antigua and Barbuda)
 72H  20/1200Z 18.2N  59.2W   65 KT  75 MPH - Category 1 (WNW St. John’s, Antigua and Barbuda)
 96H  21/1200Z 20.2N  64.7W   75 KT  85 MPH - Category 1 (ENe San Juan, Puerto Rico)
120H  22/1200Z 22.5N  69.0W   80 KT  90 MPH - Category 1 (WNW Cockburn Town, Turks and Caicos Islands)

NWS National Hurricane Center Miami FL 800 AM EDT Tue Sep 17 2019

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

The National Hurricane Center is issuing advisories on Hurricane Humberto, located more than 500 miles west of Bermuda.

A small low-pressure system is located about 1000 miles east of The Lesser Antilles. The associated shower and thunderstorm activity has increased and become a little better organized this morning, and conditions are expected to be conducive for the formation of a tropical depression during the next day or so while the system moves slowly northwestward to west-northwestward.

* 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 Mon Sep 16, 2019

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

The National Hurricane Center is issuing advisories on Hurricane Humberto located less than 700 miles west-southwest of Bermuda.

A small low-pressure system located about 1200 miles east of The Lesser Antilles continues to produce disorganized showers and thunderstorms. Environmental conditions are expected to be conducive for the formation of a tropical depression during the next day or so while the system moves slowly northwestward to west-northwestward.

* Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high…90 percent.

NWS National Hurricane Center Miami FL 200 PM EDT Mon Sep 16, 2019

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

The National Hurricane Center is issuing advisories on Hurricane Humberto located less than 700 miles west-southwest of Bermuda.

A well-defined small low-pressure system located about 1200 miles east of the Lesser Antilles continues to produce disorganized showers and thunderstorms. However, environmental conditions are expected to be conducive for the formation of a tropical depression during the next day or so while the system moves slowly northwestward to west-northwestward.

* Formation chance through 48 hours…high…70 percent. * Formation chance through 5 days…high...90 percent.

NWS National Hurricane Center Miami FL 800 AM EDT Mon Sep 16, 2019

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

The National Hurricane Center is issuing advisories on Hurricane Humberto, located more than 700 miles west-southwest of Bermuda.

Showers and thunderstorms have increased this morning in association with a small low-pressure system located over the central tropical Atlantic. Satellite data also indicate that the low has become better defined, and environmental conditions are expected to be conducive for the formation of a tropical depression during the next couple of days while the system moves slowly northwestward to west-northwestward.

* 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 Sun Sep 15, 2019

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

The National Hurricane Center is issuing advisories on Tropical Storm Humberto, located about 200 miles north of the northwestern The Bahamas.

A small low-pressure system is producing an elongated area of disorganized showers and thunderstorms over the central tropical Atlantic. Slow development is anticipated during the next day or two, but environmental conditions are forecast to become more conducive for development by the middle of the week, and a tropical depression is likely to form by the end of the week while the system moves slowly west-northwestward to northwestward.

* Formation chance through 48 hours…low…30 percent. * Formation chance through 5 days…high…80 percent.

NWS National Hurricane Center Miami FL 800 AM EDT Sun Sep 15, 2019

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

The National Hurricane Center is issuing advisories on Tropical Storm Humberto, located more than 100 miles north of the northwestern Bahamas.

An elongated area of disturbed weather is located over the central tropical Atlantic. Shower activity remains disorganized and only slow development, if any, is anticipated during the next day or two. However, environmental conditions are forecast to become more conducive for gradual development through the middle of the week, and a tropical depression is likely to form by the end of the week while the system moves slowly westward or west-northwestward.

* Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…high...70 percent.

NWS National Hurricane Center Miami FL 800 PM EDT Sat Sep 14, 2019

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

The National Hurricane Center is issuing advisories on Tropical Storm Humberto, centered just northeast of the northwestern Bahamas.

An elongated area of disturbed weather is located over the central tropical Atlantic. This disturbance is currently disorganized and only slow development, if any, is anticipated during the next day or two. Conditions are then forecast to be conducive for gradual development through the middle of next week and a tropical depression could form while the system moves slowly westward or west-northwestward.

* Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…medium...60 percent.

NWS National Hurricane Center Miami FL 200 PM EDT Sat Sep 14, 2019

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

The National Hurricane Center is issuing advisories on Tropical Storm Humberto, centered just east-northeast of the northwestern The Bahamas.

An elongated area of disturbed weather is located about 750 miles southwest of the Cabo Verde Islands. The gradual development of this system is possible during the next several days, and a tropical depression could form by the middle of next week while it moves westward across 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 800 AM EDT Sat Sep 14, 2019

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

The National Hurricane Center is issuing advisories on Tropical Storm Humberto, centered just east of the northwestern Bahamas.

An elongated area of disturbed weather is located about 650 miles southwest of the Cabo Verde Islands. The gradual development of this system is possible during the next several days, and a tropical depression could form early next week while it moves westward across 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 PM EDT Fri Sep 13, 2019

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

The National Hurricane Center is issuing advisories on Potential Tropical Cyclone Nine, centered over the central Bahamas. This system is gradually becoming better organized, and if this trend continues, a tropical depression or tropical storm may develop later this afternoon or evening as the system drifts northwestward.

A tropical wave located about midway between the Cabo Verde Islands and the Lesser Antilles is producing a large but disorganized area of cloudiness and showers. Conditions are expected to become more conducive for development in a couple of days, and a tropical depression could form early next week while the system moves westward across the tropical Atlantic and approaches the eastern Caribbean Sea.

* Formation chance through 48 hours…low…20 percent. * Formation chance through 5 days…medium…50 percent.

NWS National Hurricane Center Miami FL 800 AM EDT Fri Sep 13, 2019

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

The National Hurricane Center is issuing advisories on Potential Tropical Cyclone Nine, centered over the central Bahamas.

1. A tropical wave located midway between the Cabo Verde Islands and the Lesser Antilles is producing a large but disorganized area of cloudiness and showers. Conditions are expected to become more conducive for development in a couple days, and a tropical depression could form early next week while the system moves westward across the tropical Atlantic.

* Formation chance through 48 hours…low…10 percent. * Formation chance through 5 days…medium...50 percent.

NWS National Hurricane Center Miami FL 800 PM EDT Thu Sep 12, 2019

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

The National Hurricane Center is issuing advisories on Potential Tropical Cyclone Nine.

A tropical wave located several hundred miles west of the Cabo Verde Islands is currently producing limited and disorganized shower activity. Conditions are expected to become more conducive for development in a couple of days, and a tropical depression could form early next week while the system moves quickly westward across the 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 200 PM EDT Thu Sep 12, 2019

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

A tropical wave located several hundred miles west of the Cabo Verde Islands is producing disorganized showers and thunderstorms. Conditions appear conducive for development, and a tropical depression could form early next week while the system moves westward over the 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 Thu Sep 12 2019

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

A tropical wave located several hundred miles west of the Cabo Verde Islands is producing disorganized showers and thunderstorms. Conditions appear conducive for development, and a tropical depression could form early next week while the system moves westward over the tropical Atlantic.

* Formation chance through 48 hours…low…near 0 percent. * Formation chance through 5 days…medium…40 percent.

If this storm system is named, it will be Tropical Storm Jerry.

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