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WTNT42 KNHC 171434

TCDAT2

 

Potential Tropical Cyclone Twenty-Two Discussion Number   4

NWS National Hurricane Center Miami FL       AL222023

1000 AM EST Fri Nov 17 2023

 

First-light visible satellite images indicate that the disturbance 

is still a surface trough of low pressure with nearly all of the 

deep convection to the east of the trough axis streaming northward 

across Jamaica, Haiti, and eastern Cuba.  Surface pressures remain 

low--about 1004 mb--but the center of circulation is ill defined.  

Maximum winds are still estimated to be 30 kt, primarily within the 

deep convection.



The system appears to be accelerating northeastward with an initial 

motion of 045/12 kt.  A continued northeastward acceleration is 

anticipated during the next day or two as the disturbance moves 

ahead of a mid-level trough moving across Florida and the far 

northwestern Caribbean Sea.  With the circulation being so broad, 

however, global model wind fields suggest the system may jump 

discontinuously rather than move seamlessly across the Greater 

Antilles during the next 24 hours.  The NHC track forecast favors 

the faster model solutions and is generally a blend of the previous 

forecast with the latest GFS solution.

 

The prospects for the disturbance to become a tropical cyclone 

appear to be decreasing.  The system is already battling strong 

southwesterly shear and mid-level dry air, and none of the global 

models any longer depicts the development of a well-defined 

circulation.  The new NHC forecast therefore keeps the system as a 

disturbance through tonight, with some possibility (albeit 

decreasing) of the system becoming a tropical depression or 

tropical storm after it passes the mountainous terrain of Jamaica 

and southeastern Cuba.  In whatever form the system emerges over 

the western Atlantic over the weekend, it is likely to become 

extratropical or merge with a front over the weekend.



Despite the decreasing chance of tropical cyclone formation, there 

is high confidence that heavy rainfall and flooding will remain a 

distinct and serious threat across Jamaica, southeastern Cuba, and 

Hispaniola.  Additional rainfall amounts of 4 to 8 inches, with 

isolated areas as high as 16 inches, are forecast in these areas 

and are likely to produce life-threatening flash flooding and 

mudslides.

 

 

KEY MESSAGES:

 

1.  Potential Tropical Cyclone Twenty-Two could produce tropical 

storm conditions, especially in areas of heavy rainfall, across 

Jamaica, southeastern Cuba, Haiti, the southeastern Bahamas, and the 

Turks and Caicos Islands through Saturday, and tropical storm 

watches are in effect for these areas.

 

2.  Heavy rains will impact portions of Jamaica, southeastern Cuba, 

and southern Hispaniola through Sunday.  This rainfall is likely to 

produce flash flooding, along with mudslides in areas of higher 

terrain.  Lighter amounts across the southeastern Bahamas as well 

as the Turks and Caicos Islands may lead to flash flooding in urban 

areas.

 

 

FORECAST POSITIONS AND MAX WINDS

 

INIT  17/1500Z 17.5N  79.1W   30 KT  35 MPH...POTENTIAL TROP CYCLONE

 12H  18/0000Z 19.3N  76.8W   30 KT  35 MPH...POTENTIAL TROP CYCLONE

 24H  18/1200Z 21.9N  73.3W   35 KT  40 MPH...TROPICAL STORM

 36H  19/0000Z 25.2N  68.9W   35 KT  40 MPH

 48H  19/1200Z 28.3N  64.8W   40 KT  45 MPH...POST-TROP/EXTRATROP

 60H  20/0000Z 31.8N  61.0W   40 KT  45 MPH...POST-TROP/EXTRATROP

 72H  20/1200Z...ABSORBED BY A FRONT

 

$$

Forecaster Berg