000 WTPZ43 KNHC 031436 TCDEP3 Tropical Storm Hilda Discussion Number 16 NWS National Hurricane Center Miami FL EP082021 800 AM PDT Tue Aug 03 2021 There's been little change with the structure of Hilda overnight as deep convection continues to be mostly south of the center due to persistent northeasterly shear. The low-level eye feature in 37 GHz microwave data remains on the latest passes, but it isn't very deep because of the shear. A blend of the T- and CI-numbers from TAFB/SAB, plus the UW-CIMSS SATCON, yields 60 kt as the initial wind speed. Hilda should weaken during the next several days, first primarily due to shear, then cool water temperatures and a more stable environment on Wed-Fri. Model guidance is in good agreement on this scenario, and the latest forecast is close to the previous NHC advisory and the model consensus. Hilda should decay into a remnant low by Friday and dissipate as a trough this weekend well east of the Hawaii. The initial motion estimate, 315/7 kt, is the same as the previous advisory. Hilda is maintaining this motion as it is steered by a mid-level ridge centered over southern California. The global models are consistently building this ridge westward over the eastern Pacific during the next several days as a shortwave trough lifts out along 135W, causing Hilda to turn west-northwestward by Thursday. The only significant forecast difference is how quickly the cyclone moves, mostly in the latter stages, with more of the guidance showing a faster motion, perhaps because the models are showing a weaker Hilda being steered by the quicker low-level flow. The new NHC prediction shows that acceleration at long-range as well, near or just behind the latest model consensus. FORECAST POSITIONS AND MAX WINDS INIT 03/1500Z 17.5N 124.5W 60 KT 70 MPH 12H 04/0000Z 18.2N 125.3W 50 KT 60 MPH 24H 04/1200Z 19.1N 126.4W 45 KT 50 MPH 36H 05/0000Z 19.9N 127.7W 40 KT 45 MPH 48H 05/1200Z 20.8N 129.4W 35 KT 40 MPH 60H 06/0000Z 21.6N 131.4W 30 KT 35 MPH 72H 06/1200Z 22.3N 133.5W 25 KT 30 MPH...POST-TROP/REMNT LOW 96H 07/1200Z 23.0N 138.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 08/1200Z...DISSIPATED $$ Forecaster Blake