Hurricane Gilma Forecast Discussion

000
WTPZ42 KNHC 240834
TCDEP2

Hurricane Gilma Discussion Number  24
NWS National Hurricane Center Miami FL       EP072024
1100 PM HST Fri Aug 23 2024

Gilma continues to exhibit a central dense overcast pattern in
geostationary satellite images, though earlier microwave data did
show that the hurricane still had an eye feature.  The objective and
subjective satellite intensity estimates have decreased a little
this cycle, and range from about 75 to 90 kt.  Based on that data,
the initial wind speed is nudged downward to 85 kt.  Gilma has a
compact appearance in satellite images, and the wind field is
estimated to be relatively small.  The associated tropical storm and
hurricane-force winds are estimated to extend outward up to 100 n mi
and 30 n mi from the center, respectively.

The hurricane continues to move westward at a relatively slow 8 kt. 
A westward to west-northwestward motion with a gradual increase in 
forward speed is expected during the next several days as a 
mid-level ridge builds to the north of the cyclone.  There 
continues to be along-track, or forward speed, differences in the 
models, but they are all showing a similar theme.  The NHC track 
forecast is similar to the previous one and near the TVCE consensus 
model.  

Gilma is expected to remain over marginally warm waters and in a 
low wind shear environment during the next day or two, so only a 
little weakening is expected during that time frame.  However, 
after that time, a notable increase in westerly shear coupled with 
a drier environment and slightly cooler waters should cause 
steady weakening.  The NHC intensity forecast shows Gilma falling 
below hurricane strength by early Monday and degenerating into a 
post-tropical low in about 4 days.  This forecast lies roughly near 
the middle of the guidance envelope.


FORECAST POSITIONS AND MAX WINDS

INIT  24/0900Z 17.6N 129.3W   85 KT 100 MPH
 12H  24/1800Z 17.8N 130.7W   80 KT  90 MPH
 24H  25/0600Z 18.1N 132.4W   80 KT  90 MPH
 36H  25/1800Z 18.3N 134.2W   75 KT  85 MPH
 48H  26/0600Z 18.5N 135.9W   70 KT  80 MPH
 60H  26/1800Z 18.7N 137.8W   60 KT  70 MPH
 72H  27/0600Z 18.9N 139.9W   50 KT  60 MPH
 96H  28/0600Z 19.5N 144.7W   35 KT  40 MPH...POST-TROPICAL
120H  29/0600Z 20.3N 149.6W   30 KT  35 MPH...POST-TROP/REMNT LOW

$$
Forecaster Cangialosi