*******Note that forecasts and outlooks in this post are NOT the official forecast from the National Hurricane Center (NHC). They are my own detailed views on the Atlantic tropics based on current observations and latest computer model runs. As such do not make decisions based on my posts...consult news media...watches and warnings from your local weather office...and any evacuation orders issued by local governments to make the most informed and best decisions. Visit the NHC website hurricanes.gov (hurricanes dot gov) for the latest watches/warnings and official forecasts on active tropical cyclones.*********
...UPDATE...MONDAY NOVEMBER 11 2024 2:46 PM EDT...
The surface and upper air charts valid for November 3 have been added below.
...UPDATE...MONDAY NOVEMBER 4 2024 10:08 AM EDT...
Satellite image of Patty as of 0000Z early today as it produced enough thunderstorms to transition to a fully tropical system:
The following additional events have occurred in the Atlantic tropics as of this morning:
(1) In the northeastern Atlantic to the east of the Azores... Patty produced enough persistent thunderstorm activity to be upgraded to a fully tropical storm at 4 AM EDT... and was estimated to pack 40 mph maximum sustained winds while centered at 38.2N-18W. As of 10 AM EDT satellite pictures showed the thunderstorm activity had already dissipated and the surface swirl had become elongated to suggest a surface trough instead of a closed low... and the NHC downgraded Patty to a remnant trough located near 38.5N-16.2W.
(2) In the central Caribbean... potential tropical cyclone eighteen (tagged as area of interest #44 in this blog post) was upgraded to tropical depression eighteen at 10 AM EDT after aircraft recon spotted a well-defined surface center. The surface center was located at 15.2N-76.9W... and was located on the west edge of spiral thunderstorm bands and mid-level center located along 75.5W longitude. This system continues to move north toward Jamaica as previously forecasted.
...UPDATE… SUNDAY NOVEMBER 3 2024 6:40 PM EDT...
The following changes have occurred in the Atlantic tropics since the update from earlier today:
(1) The NHC has begun to issue advisories… containing specific track and intensity forecasts… on area of interest #44 under the header of potential tropical cyclone eighteen. This is allowing for the issuance of Tropical Storm warnings for Jamaica and a hurricane watch for the Cayman Islands as of this writing.
(2) As of 1 PM EDT earlier this afternoon… the NHC added the possible day-5 northeastern Caribbean islands tropical disturbance into their tropical weather outlook. This new area of interest will be tagged #48 in my next update on the Atlantic tropics… as it will be the forty-eighth such area of interest tracked on this site this year.
...SUNDAY NOVEMBER 3 2024 12:30 PM EDT...
The Atlantic tropics remain busy for early November with the following areas of interest in progress:
(1) See area of interest #44 and #47 sections below for information on a pair of disturbances covering much of the Caribbean region. Area of interest #44 is expected to become a tropical cyclone soon… bringing impacts to Jamaica… Haiti… Cuba… the Cayman Islands… and possibly south Florida in the days ahead.
(2) See Patty section below for an update on the subtropical storm that moved through the Azores on Saturday
In addition yet another tropical disturbance could develop near or over the northeastern Caribbean Islands within the next five days as follows. The southwest part of upper trough that recently entered the North Atlantic from eastern Canada is likely to become cut-off upper vorticity that dives south toward the islands due to the force of the currently developing eastern US upper ridge. If the cut-off upper vorticity becomes amplified enough to produce a pocket of low shear and focused upper divergence on its east side... it could trigger a tropical disturbance over or near the northeastern Caribbean Islands in the days ahead… will add an area of interest for this situation in future updates if necessary.
SUBTROPICAL STORM PATTY… Recent visible satellite image of Subtropical Storm Patty as of 1540Z:
Special update #111A (https://www.infohurricanes.com/post/my-2024-atlantic-hurricane-season-birdseye-view-post-111a-special-update) covered the formation of Subtropical Storm Patty as it moved east across the Azores on Saturday. Impacts in the western and central Azores have ended… and any remaining coastal surf affecting the eastern Azores should dwindle as the small subtropical cyclone continues east and away. While becoming wedged against the southwest side of the British Isles deep-layer ridge… the overhead upper vortex has become an NW/SE tilted upper trough. It appears the northward turn of Patty has been delayed while caught in the upper westerlies on the back side of the upper trough… and my updated track forecast is adjusted accordingly… but note an eventual north turn is expected just offshore of Portugal and northwestern Spain as the tilted upper trough and Patty eventually move around the British Isles ridge. A combination of westerly shear imparted by the aforementioned upper westerly flow… which has leaned the remainder showers east of the swirl center… and lack of overhead upper divergence has caused Patty to weaken faster than previously forecasted despite the updated track keeping it over 20 deg C waters where it previously developed. Therefore Patty should be a remnant low by 24 hours. As such I plan this to be my final statement on Patty on this blog.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
0 Hr Position (1200Z Nov 3)... 45 mph maximum sustained wind subtropical storm centered just east of the eastern Azores at 37.5N-24.3W
IOH 24 Hr Forecast (1200Z Nov 4)... Remnant low centered in the northeast Atlantic at 38.5N-15W
*****National Hurricane Center (hurricanes.gov) official forecast as of 10 AM EDT*************************
2-Day Position (1200Z Nov 5)… 30 mph maximum sustained wind dissipating remnant low centered just offshore of northern Portugal at 40.8N-10.5W
AREA OF INTEREST #44... Recent visible satellite image of the southern Caribbean tropical low as of 1540Z:
Increasingly organized thunderstorm activity has developed today within the east side of the tropical low in the south-central Caribbean… due to supportive divergence on the southeast side of upper vorticity currently parked over eastern Cuba. A warm core upper ridge is currently developing over the eastern US… and this upper ridge will help amplify the the upper vorticity into an upper vortex... with the vortex also retrograding westward and away with time under the influence of the new upper ridge. This will allow wind shear to drop... and it is almost certain now that a tropical cyclone will form soon within the organizing thunderstorms within the east side of the tropical low. Therefore I have begun a tropical cyclone formation forecast with a specific track and intensity forecast.
In the next 24 hours a north-northeast to north turn toward Jamaica is expected due to the combination of the surface ridge weakness associated with the Dominican Republic surface trough (area of interest #47)… the cyclonic flow associated with the remainder western portion of the tropical low… and the steering provided by the retrograding upper vortex to the west. The track deflects to a more west and less north angle after 24 hours once this system bumps into a sprawling surface ridge currently building over the eastern US… taking this system in the environment of the Cayman Islands and Cuba. Note after 72 hours the models are split on the long-range track which will be influenced by the current eastern US surface and upper ridges as they move offshore… and a pair of upper troughs ejecting from western North America. The divergence zone of the first of the two troughs will generate a narrow ridge weakness in the vicinity of the US east coast while its convergence zone produces a new long-range surface ridge over the eastern US. Noting the narrow ridge weakness closes quickly as the first of the two troughs lifts northeastward and away due to the strength of the offshore-moving upper ridge. Despite this some of the models have this system turn north across the eastern Gulf of Mexico… into Florida and the vicinity of the southeast US coast while turning into the narrow weakness… then stalling this system as the weakness closes which traps it in between the old offshore moving surface ridge and new eastern US surface ridge. Other models have this system continue generally west across the Gulf of Mexico under the influence of the new eastern US surface ridge. My current long range forecast is similar to today’s 0600Z GFS which splits the difference between the two extremes.
Forecasting this system to steadily intensify into a top-end category 1 hurricane through 60 hours as the shear is allowed to relax with the westward-retrogression of the aforementioned Cuba area upper vortex. Weakening is then shown after 60 hours once the remains of the upper vortex are slung northeast back toward this system and by the first of the two ejecting upper troughs from western North America… which re-increased the wind shear. Around 120 hours… on my current forecast track… there is some opportunity for the westerly shear to relax as a warm core upper ridge builds over the central Gulf of Mexico in the warm southerly flow ahead of the western/central US frontal system to be generated by the second of the two upper troughs ejecting from western North America. However with my 5-day position being at the northeast side of the building upper ridge… I currently forecast more weakening in the 4 to 5 day window.
The following is the currently expected timing of tropical cyclone conditions (gusty winds with damage potential… coastal surf… and heavy rainfall):
(1) High chance of tropical storm force conditions… Jamaica and southwestern Haiti… by tomorrow afternoon and evening
(2) High chance of tropical storm to hurricane force conditions… Cuba and the Cayman Islands… by Tuesday further east and Wednesday further west
(3) Interests across the Florida Keys and peninsula should be aware of possible tropical storm conditions by Wednesday and beyond… as the long-range track is uncertain and maybe adjusted toward the area in future updates. Note on the current track shown below the north side of this system would overspread far south Florida and the Keys with tropical storm conditions by Wednesday.
******Infohurricanes.com forecast. Visit hurricanes.gov (hurricanes dot gov) for official forecast***********
0 Hr Position (1200Z Nov 3)... Tropical low centered in the southern Caribbean at 13N-77W
IOH 24 Hr Forecast (1200Z Nov 4)... 45 mph maximum sustained wind tropical storm centered southeast of Jamaica at 16N-75W
IOH 48 Hr Forecast (1200Z Nov 5)… 75 mph maximum sustained wind hurricane centered southwest of eastern Cuba at 19N-78.2W
IOH 72 Hr Forecast (1200Z Nov 6)... 85 mph maximum sustained wind hurricane centered on the south coast of western Cuba at 22.5N-82W
IOH 96 Hr Forecast (1200Z Nov 7)... 65 mph maximum sustained wind tropical storm centered in the southeastern Gulf of Mexico at 25N-85W
IOH 120 Hr Forecast (1200Z Nov 8)… 50 mph maximum sustained wind tropical storm centered offshore of southeastern Louisiana at 27.5N-89W
*****National Hurricane Center (hurricanes.gov) official outlook as of 7 AM EDT*************************
Formation chance through 48 hours… 90%
Formation chance through 7 days… 90%
AREA OF INTEREST #47... The surface trough of low pressure that is making landfall in the Dominican Republic no longer has development potential due to increasing land interaction and suppressing upper convergence occurring under the northwest quadrant of the upper vortex parked over Puerto Rico. Within the next day or so currently expecting the surface trough to become absorbed by the north side of area of interest #44 as it continues across Haiti and eastern Cuba. The NHC continues to assign a 10% chance of tropical cyclone as of this writing… currently expecting a downgrade to 0% soon and then cancellation from the NHC outlook altogether. Therefore this is my planned final statement on this area of interest on this blog.
…COMPUTER MODEL SUMMARY...
Source...Florida State University Experimental Forecast Tropical Cyclone Genesis Potential Fields (http://moe.met.fsu.edu/tcgengifs/).
0000Z (Nov 3) CMC Model Run...
**For Subtropical Storm Patty… after passing through the Azores the remnant circulation dissipates offshore of NW Spain at 78 hours
**For area of interest #44... tropical low swings north into Jamaica through 48 hours while absorbing area of interest #47… after moving NW across central and western Cuba becomes a tropical cyclone over the Florida Keys at 78 hours… tropical cyclone turns north and makes landfall over the far NW Florida peninsula coast at 102 hours… while moving into wares offshore of SE US weakens to a shared and stalled surface trough thru 138 hours… the fading surface trough retrogrades west back toward NE Florida coast thru 168 hours
**For area of interest #47... westward-moving surface low becomes increasingly defined over the southeastern Bahamas and vicinity through 24 hours and becomes absorbed by area of interest #44 while it moves into eastern Cuba at 48 hours
0000Z (Nov 3) ECMWF Model Run...
**For Subtropical Storm Patty… after passing through the Azores the remnant circulation dissipates just offshore of NW Spain at 78 hours
**For area of interest #44... becomes a large sized tropical depression centered just SW of western Jamaica at 54 hours while absorbing AOI #47… strengthens to a tropical storm over the Cayman Islands at 72 hours… tropical storm moves NW into western Cuba at 90 hours… while continuing NW in the SE Gulf of Mexico becomes a hurricane centered near 25N-85W at 108 hours… afterwards continues WNW across the remainder of the Gulf of Mexico and into coastal Texas through 168 hours while weakening to a tropical storm then remnant surface trough
**For area of interest #47... westward-moving surface low becomes increasingly defined over the southeastern Bahamas and vicinity through 30 hours and becomes absorbed by area of interest #44 while it moves into central Cuba at 54 hours
**Southwest side of surface frontal system and upper trough currently over the North Atlantic leaves behind upper vorticity that dives south toward the NE Caribbean Islands… divergence zone of the upper vorticity produces surface low near 23N-52.5W at 60 hours… the surface low weakens to a trough while moving WSW into the NE Caribbean Islands at 114 hours… redevelops into a surface low east of the SE Bahamas at 132 hours… continues west across the SE Bahamas and into eastern Cuba through 168 hours
0600Z (Nov 3) GFS Model Run...
**For Subtropical Storm Patty… after passing through the Azores the remnant circulation dissipates just offshore of NW Spain at 78 hours
**For area of interest #44... tropical cyclone formation suggested just southeast of Jamaica at 30 hours… quickly strengthens to a high-end tropical storm while moving NW into Jamaica at 45 hours and passed between the Cayman Islands and Cuba at hurricane strength through 60 hours… the hurricane makes landfall in western Cuba at 72 hours… the center of the hurricane passes just west of Key West Florida at 81 hours… the hurricane turns north into the NE Gulf of Mexico through 108 hours… through 144 hours turns WNW into the AL/MS border while weakening to a tropical storm… subsequently frontal system approaching from the central US swings the inland remnant low NE across AL where it loses identity in the NE corner of AL at 156 hours
**Through 57 hours southwest side of surface frontal system and upper trough currently over the North Atlantic leaves behind upper vorticity that dives south toward the NE Caribbean Islands while at the same time the divergence zone of the south-diving base of the upper trough produces a sheared tropical low near 22N-49W… subsequently moves WSW where it transitions into a broad surface trough along 54W longitude supported by the divergence zone of the NE Caribbean Islands upper vorticity by 90 hours… the upper vorticity evolves into a westward-retrograding vortex with the surface trough continuing west and evolving into a subtropical cyclone centered NE of Puerto Rico and supported by the NE divergence zone of the vortex by 114 hours… while passing just north of the upper vortex the subtropical cyclone becomes fully tropical and moves WNW into the central Bahamas by 168 hours
0600Z (Nov 3) NAVGEM Model Run...
**For Subtropical Storm Patty… after passing through the Azores the remnant circulation dissipates just offshore of NW Spain at 60 hours
**For area of interest #44... thru 36 hours while moving NNW into the SW coast of Jamaica tropical cyclone formation suggested… the strengthening tropical cyclone continues NW across the eastern Cayman Islands between 48 and 54 hours and then across western Cuba thru 66 hours… tropical cyclone then curves north across the eastern Gulf of Mexico and makes landfall on the Big Bend region of the eastern Florida panhandle at 108 hours… subsequently curves more east into waters offshore of the SE US through 150 hours… the tropical cyclone then drifts very slowly west at this location through 168 hours
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