Central Pacific Basin Tropical Cyclones

Tropical Storm Gilma Forecast Discussion



265 
WTPA42 PHFO 280848
TCDCP2

Tropical Storm Gilma Discussion Number  41
NWS Central Pacific Hurricane Center Honolulu HI   EP072024
1100 PM HST Tue Aug 27 2024


Infrared satellite imagery shows new deep convection in Gilma's 
northeast quadrant this evening, with cloud tops colder than -70 
deg C. These thunderstorms have been unable to wrap around the 
center of the cyclone due to strong westerly winds aloft. The 
advisory intensity estimate is held at 45 kt based on a consensus 
of subjective Dvorak estimates of 3.0/45 kt from PHFO, JTWC and 
SAB. 

Gilma continues to move almost due west, and the initial motion 
estimate is 275/11 kt. A low-level ridge north of Gilma will 
steer the shallow cyclone westward to west-northwestward until it 
dissipates. There has been little change in the track guidance, and 
the new forecast track is similar to the previous track, and lies 
close to HCCA and FSSE guidance.

Although Gilma's recent rapid weakening trend has eased this 
evening, it is still expected to degenerate to a remnant low as it 
passes close to the Hawaiian Islands Friday and Saturday. Only 
slight changes to the intensity forecast have been made, mainly to 
keep Gilma at minimal tropical storm strength for a bit longer than 
previously indicated. Guidance indicates the strong westerly 
vertical wind shear currently impacting Gilma's circulation may 
briefly ease Wednesday as a passing trough aloft lifts north. 
Another trough aloft approaching from the west is expected to bring 
even stronger vertical wind shear Thursday and Friday, eventually 
leading to dissipation near Hawaii this weekend. The new intensity 
forecast follows trends presented by regional hurricane guidance and 
SHIPS guidance.


FORECAST POSITIONS AND MAX WINDS

INIT  28/0900Z 18.5N 144.5W   45 KT  50 MPH
 12H  28/1800Z 18.8N 146.1W   40 KT  45 MPH
 24H  29/0600Z 19.2N 148.4W   35 KT  40 MPH
 36H  29/1800Z 19.7N 150.6W   35 KT  40 MPH
 48H  30/0600Z 20.2N 153.0W   30 KT  35 MPH
 60H  30/1800Z 20.8N 155.3W   30 KT  35 MPH...POST-TROP/REMNT LOW
 72H  31/0600Z 21.7N 158.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  01/0600Z...DISSIPATED

$$
Forecaster Birchard




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