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Hurricane Gilma Discussion Number 21
NWS National Hurricane Center Miami FL EP072024
500 AM HST Fri Aug 23 2024
The cloud pattern associated with Gilma has lost some organization
since the last advisory, with the eye become less distinct and the
central dense overcast becoming more ragged. The various objective
and subjective satellite intensity estimates have trended downward
during the past 6 h, and based on these data the initial intensity
is decreased to 100 kt.
The westward jog mentioned in the previous advisory continues, with
the initial motion now 275/7 kt. A deep-layer trough north of Gilma
near the west coast of the United States is expected to lift out
over the next couple of days, which will allow a high pressure ridge
to gradually build westward over the eastern North Pacific. As a
result, Gilma should move generally west-northwestward to westward
at a faster forward speed during the next several days. Due to the
current westward jog, the guidance envelope has shifted a little to
the south and west since the previous advisory. Based on this
guidance, the new track forecast, which lies close to the consensus
models, will also shift a bit to the south.
Gilma is gradually moving toward cooler water, with the center
expected to cross the 26C isotherm in about 36 h. The hurricane is
also moving into a drier and more stable air mass. This combination
should lead to gradual weakening for the next 60 h or so. Beyond
that time, increasing shear and sea surface temperatures near 25C
should cause a faster weakening rate, and Gilma is now expected to
degenerate to a remnant low by 120 h. The new intensity forecast
follows the trend of the intensity guidance, but is nudged downward
a little from the previous forecast.
FORECAST POSITIONS AND MAX WINDS
INIT 23/1500Z 17.4N 126.8W 100 KT 115 MPH
12H 24/0000Z 17.6N 128.0W 95 KT 110 MPH
24H 24/1200Z 18.0N 129.6W 90 KT 105 MPH
36H 25/0000Z 18.3N 131.3W 85 KT 100 MPH
48H 25/1200Z 18.6N 133.1W 75 KT 85 MPH
60H 26/0000Z 18.9N 134.9W 70 KT 80 MPH
72H 26/1200Z 19.2N 137.0W 60 KT 70 MPH
96H 27/1200Z 19.9N 141.7W 45 KT 50 MPH
120H 28/1200Z 20.6N 147.0W 30 KT 35 MPH...POST-TROP/REMNT LOW
$$
Forecaster Beven
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