Potential Tropical Cyclone Nine Forecast Discussion

000
WTNT44 KNHC 231500
TCDAT4

Potential Tropical Cyclone Nine Discussion Number   1
NWS National Hurricane Center Miami FL       AL092024
1100 AM EDT Mon Sep 23 2024

A broad area of low pressure over the northwestern Caribbean Sea
continues to produce disorganized showers and thunderstorms. While
some mid-level rotation is evident in visible satellite images,
surface observations and visible satellite images suggest the
low-level circulation remains broad and farther to the southwest.
Nonetheless, the system has a high chance of tropical cyclone
formation during the next day or two, and it is likely to bring
tropical storm conditions to land areas within the next 36 to 
48 hours. Therefore, the NHC is initiating Potential Tropical 
Cyclone advisories for this disturbance.

The initial motion is quite uncertain given the current lack of 
organization, but the best estimate is northward at about 5 kt. A 
gradual turn toward the northwest is expected during the next day or 
so, with the center passing through the Yucatan Channel and into the 
southern Gulf of Mexico. Thereafter, the system is forecast to 
accelerate northward across the eastern Gulf of Mexico within the 
flow between a digging deep-layer trough over the central United 
States and a ridge over the western Atlantic. This motion should 
bring the center of the system toward the northeastern Gulf Coast on 
Thursday. The track guidance agrees reasonably well on this 
scenario, and the initial NHC forecast lies near the simple and 
corrected consensus aids. Since the disturbance currently lacks a 
well-defined center, users are reminded that the average forecast 
track uncertainty is larger in these situations, and future track 
adjustments may be required. Given the large size of the 
tropical-storm-force wind field and fast forward speed that is 
forecast, storm surge, wind, and rainfall impacts will likely extend 
well away from the center, particularly to the east of the system.

While the system is currently broad and not well organized, the 
models suggest a more well-defined center should develop during the 
next day or so. Once the system becomes better organized and 
develops an inner core, the environmental and oceanic conditions 
appear favorable for significant strengthening. In fact, the DTOPS 
statistical guidance shows a 95 percent chance of a 65-kt increase 
in intensity during the next 72 h, and the hurricane regional models 
highlight the potential for strengthening to major hurricane 
intensity. Thus, the NHC forecast shows significant strengthening 
while the system moves across the eastern Gulf of Mexico, with a 
95-kt intensity in 72 h. While this forecast is aggressive, it lies 
near or slightly below the consensus aids, and future adjustments 
may be necessary.  An Air Force Reserve reconnaissance aircraft is 
scheduled to investigate the system this afternoon. 

Based on the NHC forecast, Tropical Storm Warnings and Hurricane 
Watches have been issued for portions of western Cuba the Yucatan 
Peninsula of Mexico. Interests along the northeastern Gulf Coast, 
including the Florida Panhandle and portions of the Florida west 
coast should monitor the progress of this system. 


KEY MESSAGES:

1. The disturbance is forecast to strengthen and be near hurricane 
strength when it reaches the far northwestern Caribbean Sea Tuesday 
night. Tropical storm conditions are expected over portions of 
western Cuba and the northeastern coast of the Yucatan Peninsula 
with hurricane conditions possible. 

2. The system is expected to intensify while it moves northward 
over the eastern Gulf of Mexico, and it could be a major hurricane 
when it reaches the northeastern Gulf Coast on Thursday. There is an 
increasing risk of life-threatening storm surge and damaging 
hurricane-force winds along portions of the northern and 
northeastern Gulf Coast, including the Florida Panhandle and 
portions of the Florida west coast. Although it is too soon to 
specify the exact location and magnitude of impacts, residents in 
these areas should monitor the latest forecast updates and ensure 
that they have their hurricane plan in place.

3. Potential Tropical Cyclone Nine will bring heavy rain to portions 
of the western Caribbean which may lead to flooding and possible 
mudslides in western Cuba.


FORECAST POSITIONS AND MAX WINDS

INIT  23/1500Z 17.6N  82.0W   25 KT  30 MPH...POTENTIAL TROP CYCLONE
 12H  24/0000Z 18.6N  82.4W   30 KT  35 MPH...TROPICAL CYCLONE
 24H  24/1200Z 19.5N  83.7W   40 KT  45 MPH
 36H  25/0000Z 20.6N  85.1W   50 KT  60 MPH
 48H  25/1200Z 22.1N  86.0W   65 KT  75 MPH
 60H  26/0000Z 24.2N  86.0W   85 KT 100 MPH
 72H  26/1200Z 27.1N  85.1W   95 KT 110 MPH
 96H  27/1200Z 34.0N  83.0W   35 KT  40 MPH...INLAND
120H  28/1200Z 38.5N  87.0W   20 KT  25 MPH...POST-TROPICAL

$$
Forecaster Reinhart