Potential Tropical Cyclone Twenty-Two Discussion Number 1
NWS National Hurricane Center Miami FL AL222023
400 PM EST Thu Nov 16 2023

NHC has been monitoring the development of a broad area of low
pressure over the western Caribbean Sea during the past several
days. Satellite images and recent data from an Air Force Reserve
Hurricane Hunter aircraft indicate that the low has a closed but
broad circulation, and there is no evidence yet of a well-defined
center. Elongated bands of deep convection extend over much of
the eastern part of the circulation and are streaming northward
toward portions of the Greater Antilles. Since the system is
forecast to become a tropical storm, and there is a risk of
tropical-storm-force winds across portions of the Greater Antilles,
southeastern Bahamas, and Turks and Caicos Islands during the next
couple of days, advisories are being initiated on Potential Tropical
Cyclone Twenty-Two.

The initial motion is uncertain since the system does not yet have
a well-defined center, but the overall cloud system appears to be
moving generally north-northeastward, or 015/8 kt. The disturbance
is forecast to turn northeastward by tonight due to a broad
mid-level trough located over Florida and the adjacent waters. A
continued northeastward motion with increasing forward speed is
then expected through the weekend as the system becomes
increasingly picked up by the trough. Although there is a bit
uncertainty in the forecast track since there is not yet a center
to track, the model guidance is in generally good agreement on this
scenario. The NHC track forecast blends the latest TVCA and HCCA
consensus aids.

The system's broad nature, increasing southerly shear, and nearby
dry air suggest that it likely won't strengthen much. That said,
the disturbance could become a tropical depression or tropical storm
tonight or on Friday if the circulation can contract enough for a
well-defined center to form. Conditions should be sufficiently
conducive to allow for modest strengthening, and the NHC intensity
forecast is just below the IVCN and HCCA consensus aids. Most
global model fields indicate the cyclone should become extratropical
over the western Atlantic in about 3 days, and then become absorbed
by a front by day 5.

The most significant hazard from this system is likely to be heavy
rainfall, especially in areas of higher terrain, across portions of
Jamaica, southeastern Cuba, and Hispaniola.


KEY MESSAGES:

1. Potential Tropical Cyclone Twenty-Two is forecast to become a
tropical storm on Friday. Tropical storm conditions are possible
across Jamaica, southeastern Cuba, Haiti, the southeastern Bahamas,
and the Turks and Caicos Islands through Saturday, and tropical
storm watches are now in effect for these areas.

2. Heavy rains will affect portions of Panama, Costa Rica, Jamaica,
southeastern Cuba, and Hispaniola through Monday morning. This
rainfall is likely to produce flash flooding, along with mudslides
in areas of higher terrain.


FORECAST POSITIONS AND MAX WINDS

INIT 16/2100Z 15.2N 81.5W 30 KT 35 MPH...POTENTIAL TROP CYCLONE
12H 17/0600Z 15.7N 80.8W 30 KT 35 MPH...TROPICAL DEPRESSION
24H 17/1800Z 17.0N 79.0W 35 KT 40 MPH
36H 18/0600Z 19.2N 76.6W 40 KT 45 MPH
48H 18/1800Z 21.9N 73.3W 45 KT 50 MPH
60H 19/0600Z 25.3N 69.0W 45 KT 50 MPH
72H 19/1800Z 29.4N 64.5W 45 KT 50 MPH...POST-TROP/EXTRATROP
96H 20/1800Z 38.0N 54.1W 45 KT 50 MPH...POST-TROP/EXTRATROP
120H 21/1800Z...DISSIPATED

$$
Forecaster Berg