000
WTPZ43 KNHC 041434
TCDEP3
 
Tropical Storm Hilda Discussion Number  20
NWS National Hurricane Center Miami FL       EP082021
800 AM PDT Wed Aug 04 2021
 
Hilda continues to weaken early this morning due to cool sea-surface 
temperatures (SST) and modest northerly vertical wind shear. The 
current intensity is estimated to be 35 kt based on an average of 
subjective satellite classifications of T2.5/35 kt from both TAFB 
and SAB, and objective estimates of 31 kt and 41 kt from UW-CIMSS 
ADT and SATCON, respectively. Hilda is currently moving over sub-25C 
SSTs with even cooler water and increasing westerly wind shear still 
ahead of the cyclone. As a result of these unfavorable environmental 
parameters, Hilda is forecast to weaken further, becoming a 
depression later today and a remnant low by late tonight or early 
Thursday. Dissipation is expected by late Friday or Saturday well 
to the east of the Hawaiian Islands. The new NHC official intensity 
forecast is similar to the previous advisory, and follows a blend 
of the HCCA and IVCN consensus intensity models.
 
Hilda has been moving west-northwestward or 295/08 kt. This 
general motion should continue into Thursday. Low- to mid-level 
ridging to the north of Hilda is expected to gradually build 
westward over the next several days, forcing the cyclone and its 
remnants more westward on Friday and Saturday. The new NHC forecast 
track is essentially just an update of the previous advisory, and 
lies down the middle of the tightly packed consensus track models.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  04/1500Z 19.1N 127.4W   35 KT  40 MPH
 12H  05/0000Z 19.7N 128.7W   30 KT  35 MPH
 24H  05/1200Z 20.6N 130.6W   25 KT  30 MPH
 36H  06/0000Z 21.5N 132.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  06/1200Z 22.2N 135.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 60H  07/0000Z 22.7N 137.3W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  07/1200Z...DISSIPATED
 
$$
Forecaster Stewart