ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM
 
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
 
NNNN