000 WTPA42 PHFO 291440 TCDCP2 Tropical Depression Gilma Discussion Number 46 NWS Central Pacific Hurricane Center Honolulu HI EP072024 500 AM HST Thu Aug 29 2024 Gilma's satellite presentation continues to degrade. A few strong thunderstorms developing north of Gilma's weakening low-level circulation center are doing little to sustain it as a tropical cyclone as they remain well removed from the center, and lack significant banding. 0643Z ASCAT and 0918Z Oceansat passes showed primarily 25-30 kt winds north of the center, and only isolated pockets of 32-34 kt winds, respectively. Given the degraded satellite appearance and assuming continued gradual spin-down, the initial intensity for this advisory is estimated to be 30 kt. The initial motion estimate remains 280/12 kt, although the potentially elongating low-level circulation center is somewhat obscured, leading to a reduction in confidence. A low-level ridge to the north will continue to steer Gilma just north of due west today, with a turn toward the west-northwest expected Friday as the ridge weakens. The updated track forecast is similar to the previous forecast, as track guidance remains consistent and well clustered. Gilma is moving into an area of increasing westerly vertical wind shear on the order of 20-30 kt, associated with a trough aloft approaching from the west. GFS and ECMWF simulated satellite imagery indicate that Gilma will struggle to produce organized deep convection, and Gilma will likely become a post-tropical remnant low by tonight. The forecast indicates it will continue to gradually weaken as it passes just north of the Hawaiian Islands on Friday, and dissipate in the vicinity of Kauai on Saturday, in line with global model and SHIPS guidance. FORECAST POSITIONS AND MAX WINDS INIT 29/1500Z 19.7N 150.7W 30 KT 35 MPH 12H 30/0000Z 20.1N 152.5W 30 KT 35 MPH 24H 30/1200Z 20.7N 154.9W 30 KT 35 MPH...POST-TROP/REMNT LOW 36H 31/0000Z 21.6N 157.2W 25 KT 30 MPH...POST-TROP/REMNT LOW 48H 31/1200Z 22.6N 159.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 60H 01/0000Z...DISSIPATED $$ Forecaster Birchard