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Hurricane Gilma Discussion Number  23
NWS National Hurricane Center Miami FL       EP072024
500 PM HST Fri Aug 23 2024
 
Gilma's satellite depiction has changed very little since earlier 
today, as the eye has become filled and now the center resides 
beneath the central dense overcast (CDO) on both visible and 
infrared imagery. Deep convection continues to burst within the 
inner core with cold cloud tops to near -80 C, with generally good 
outflow in all directions. The subjective and objective intensity 
estimates have remained steady with this advisory as well, with a 
current intensity (CI) of 5.0 from both SAB and TAFB. Given the 
steady state of satellite imagery and the intensity estimates, the 
initial intensity is held at 90 kt for this advisory.
 
The hurricane is continuing to move generally westward at an initial 
motion of 280/8 kt.  A ridge has started to build to the north of 
Gilma, which will keep the system on a generally westward track, 
with a gradual increase in forward motion. The track model guidance 
is in fairly good agreement with the general direction the system 
moves, however how fast that increase in forward speed occurs leads 
to some along-track differences in the model suite, particularly at 
the end of the forecast period. The official NHC track forecast is 
near the previous forecast, just nudged slightly southward and 
faster, near the consensus aids.
 
Gilma is in a low wind shear environment, however the system is 
about to run into cooler sea surface temperatures with very little 
ocean heat content beyond the next 24 h or so. As the system moves 
over cooler waters it will also encounter a much drier and stable 
airmass. These changes in oceanic and atmospheric conditions will 
lead to gradual weakening over the next 24 hours followed by an 
increasing rate of weakening through the end of the period. Towards 
the end of the forecast period, conditions continue to become 
unfavorable with upper-level westerly wind shear increasing, and 
the GFS depicts the system struggling to produce convection, 
becoming a remnant low at 120 h. The official NHC intensity forecast 
is similar to the previous advisory, near the simple consensus 
intensity aids.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  24/0300Z 17.5N 128.4W   90 KT 105 MPH
 12H  24/1200Z 17.7N 129.7W   85 KT 100 MPH
 24H  25/0000Z 18.0N 131.5W   80 KT  90 MPH
 36H  25/1200Z 18.2N 133.4W   75 KT  85 MPH
 48H  26/0000Z 18.4N 135.1W   70 KT  80 MPH
 60H  26/1200Z 18.6N 137.0W   60 KT  70 MPH
 72H  27/0000Z 18.9N 139.0W   50 KT  60 MPH
 96H  28/0000Z 19.4N 143.7W   40 KT  45 MPH
120H  29/0000Z 20.3N 148.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 
$$
Forecaster Kelly
 
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