ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM
Hurricane Gilma Discussion Number 29
NWS National Hurricane Center Miami FL EP072024
1100 PM HST Sat Aug 24 2024
After a brief period of rapid strengthening earlier this evening,
Gilma's intensity has leveled off. Conventional GOES-18 satellite
imagery shows that the deep inner core convection has eroded
considerably in the western half of the cyclone. The initial
intensity is set at 115 kt and is based on a blend of the
subjective Dvorak intensity estimates and various UW-CIMSS
objective techniques. Although the current intensity is higher
than noted in the previous advisory, Gilma likely peaked a few
hours ago based on earlier ADT intensity estimates of 115-119 kt
and the 0000 UTC constrained Data-T 6.5 subjective estimates from
both TAFB and SAB.
Although Gilma's period of rapid intensification has likely ended,
some intensity fluctuations, common in major hurricanes, are
possible in the short term, and the official forecast indicates
little intensity change through Sunday. Afterward, the cyclone is
expected to traverse cooler oceanic surface temperatures and move
into a thermodynamically inhibiting dry and stable marine layer by
the middle-part of the forecast. Early next week, the statistical
SHIPS intensity guidance shows an increase in west-southwesterly
shear spreading east of the Big Island of Hawaii. These negative
intensity contributions should result in a weakening trend through
the remainder of the forecast period. The NHC intensity forecast
has been nudged upward slightly from the previous one and is based
on a blend of the Decay SHIPS statistical aid and the IVCN consensus
model.
Gilma's initial motion is estimated to be west-northwestward, or
285/8 kt. A strengthening mid-troposphere subtropical ridge
situated to the north of the hurricane should steer Gilma on a
generally west-northwest or west track through day 5. The official
track forecast is a little bit slower than the previous advisory
beyond day 3 and is a compromise of the HCCA and TVCE consensus
guidance.
Gilma's wind radii have been adjusted based on a 0530 UTC METOP-B
ASCAT overpass.
FORECAST POSITIONS AND MAX WINDS
INIT 25/0900Z 18.0N 132.5W 115 KT 130 MPH
12H 25/1800Z 18.1N 133.8W 115 KT 130 MPH
24H 26/0600Z 18.3N 135.5W 100 KT 115 MPH
36H 26/1800Z 18.5N 137.3W 85 KT 100 MPH
48H 27/0600Z 18.7N 139.1W 75 KT 85 MPH
60H 27/1800Z 18.9N 141.0W 65 KT 75 MPH
72H 28/0600Z 19.2N 142.8W 55 KT 65 MPH
96H 29/0600Z 20.0N 146.6W 40 KT 45 MPH
120H 30/0600Z 20.6N 150.1W 30 KT 35 MPH...POST-TROP/REMNT LOW
$$
Forecaster Roberts
NNNN