Hurricane Gilma Forecast Discussion

000
WTPZ42 KNHC 220232
TCDEP2

Hurricane Gilma Discussion Number  15
NWS National Hurricane Center Miami FL       EP072024
800 PM PDT Wed Aug 21 2024

Infrared and visible satellite imagery of Gilma this evening 
continues to depict a strong inner core with a well-defined eye. 
Deep convection with cold cloud tops near -80C have been persistent 
in the southern eye wall.  Over the last hour or so the northern 
portion of the inner core has become a little more broken in 
infrared imagery, which suggests the rapid intensification has 
stopped. Subjective Dvorak satellite intensity estimates for this 
cycle remained unchanged from TAFB and SAB, both T5.0/90-kt. The 
objective intensity estimates from UW-CIMSS range from 90 to 100 
kt. Using a blend of theses estimates, Gilma's initial intensity is 
set to 95 kt for this advisory.

Gilma is moving slowly west-northwestward with an estimated motion 
of 290/6 kt. A large subtropical ridge will continue to steer Gilma 
generally westward to west-northwestward during the next few days, 
with a gradual acceleration by the weekend. The latest NHC track is 
slightly to the right of the previous forecast, and lies between 
the previous forecast and the latest consensus aids.

Gilma is expected to continue to strengthen over the next day or so 
as the system moves over warm sea surface temperature with low 
vertical wind shear. The main change this cycle is that the peak and 
entire forecast period intensity guidance is much lower compared to 
6 hours ago. The NHC peak intensity forecast is slightly lower than 
previous but still shows steady strengthening over the next 24h. 
However, the system should then begin to traverse cooler waters and 
a drier more stable airmass, with a faster weakening trend compared 
to the previous advisory. Note that the NHC intensity forecast is 
above most of the intensity guidance, primarily due to continuity 
constraints, and additional changes in the intensity forecast may be 
needed in subsequent forecasts if intensity aid trends continue.

FORECAST POSITIONS AND MAX WINDS

INIT  22/0300Z 16.5N 123.8W   95 KT 110 MPH
 12H  22/1200Z 16.8N 124.7W  105 KT 120 MPH
 24H  23/0000Z 17.1N 125.9W  110 KT 125 MPH
 36H  23/1200Z 17.3N 127.2W  100 KT 115 MPH
 48H  24/0000Z 17.5N 128.7W   95 KT 110 MPH
 60H  24/1200Z 17.8N 130.4W   90 KT 105 MPH
 72H  25/0000Z 18.0N 132.2W   85 KT 100 MPH
 96H  26/0000Z 18.5N 135.9W   75 KT  85 MPH
120H  27/0000Z 19.1N 140.0W   65 KT  75 MPH

$$
Forecaster Kelly