000 WTPZ43 KNHC 020236 TCDEP3 Hurricane Hilda Discussion Number 10 NWS National Hurricane Center Miami FL EP082021 800 PM PDT Sun Aug 01 2021 Hilda's satellite appearance is showing effects of easterly vertical wind shear this evening. Recent imagery shows a sharp edge to the upper-level outflow on the eastern side of the system. A 2130 UTC AMSR2 microwave pass reveals that the eyewall is no longer closed, as the inner core convection has been eroded on the eastern side of the circulation. Microwave data also indicate the vortex has become vertically tilted, with the mid-level center displaced about 10-15 n mi to the west-northwest of the low-level center. Thus, the initial intensity is lowered slightly to 70 kt for this advisory, in best agreement with the objective UW-CIMSS Dvorak estimates. Hilda is still moving west-northwestward at 285/8 kt, to the south of a ridge over the western U.S. and northern Mexico. A turn to the northwest is expected on Monday as the ridge weakens, likely in response to T.D. Ten-E located to the east-northeast of Hilda. A northwestward motion should continue through midweek before the ridge becomes reestablished and Hilda turns westward through the rest of the forecast period. There is greater track uncertainty later in the week due to possible interaction with another system that could redevelop from the remnants of T.D. Nine-E. The official NHC track forecast has been adjusted to the right of the previous one at 48 h and beyond based on the latest guidance, but it still lies slightly left of the multi-model consensus aids TVCE and HCCA. Environmental conditions are not expected to become any more favorable for strengthening during the next couple days, so Hilda's intensity has likely peaked. Moderate northeasterly shear is forecast to persist for the next 36-48 h, and the NHC forecast track brings Hilda north of the 26 deg C isotherm by the time these upper-level winds subside. Once over cooler waters, Hilda is forecast to quickly spin down and weaken to a tropical depression by 96 h. The NHC intensity forecast has again been lowered by 5-10 kt from the previous one at all forecast times, but it still lies slightly above the IVCN and HCCA consensus aids through 72 h. The system is forecast to degenerate to a remnant low by day 5. FORECAST POSITIONS AND MAX WINDS INIT 02/0300Z 15.1N 121.6W 70 KT 80 MPH 12H 02/1200Z 15.5N 122.5W 70 KT 80 MPH 24H 03/0000Z 16.2N 123.4W 65 KT 75 MPH 36H 03/1200Z 17.3N 124.3W 60 KT 70 MPH 48H 04/0000Z 18.4N 125.3W 50 KT 60 MPH 60H 04/1200Z 19.5N 126.6W 40 KT 45 MPH 72H 05/0000Z 20.3N 128.3W 35 KT 40 MPH 96H 06/0000Z 21.0N 132.3W 25 KT 30 MPH 120H 07/0000Z 21.5N 136.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Reinhart/Pasch