je.st
news
Hurricane Hilda Forecast Discussion Number 11
2021-08-02 10:36:49| National Hurricane Center (East Pacific)
Issued at 200 AM PDT Mon Aug 02 2021 000 WTPZ43 KNHC 020836 TCDEP3 Hurricane Hilda Discussion Number 11 NWS National Hurricane Center Miami FL EP082021 200 AM PDT Mon Aug 02 2021 SSMIS microwave data received just after the previous advisory indicate that Hilda's structure may have improved slightly, with a closed mid-level eye noted in the 85-GHz channel. However, the microwave data also showed that the low- and mid-level centers remain offset from each other by about 15 n mi due to continued moderate easterly shear. The initial intensity remains 70 kt, which is a blend of the latest final-T Dvorak numbers from TAFB and SAB. Hilda has begun to turn to the right and slow down, and the initial motion is west-northwestward (295 degrees) at 7 kt. Although the subtropical ridge remains positioned to the north of Hilda, the hurricane's close proximity to Tropical Depression Ten-E and the remnants of Tropical Depression Nine-E is expected to cause some binary interaction over the next couple of days, with Hilda likely to slow down further and turn toward the northwest later today and continue on that heading through Wednesday. In fact, the newest track guidance has trended to the northeast during the first 48 hours, and the updated NHC forecast has therefore been shifted a bit to the right during that period. However, it should be noted that the track adjustment is conservative, and does not show a turn quite as sharp as that shown by the TVCE and HCCA consensus aids. Low-level ridging should play a more prominent role in about 3 days, causing Hilda to turn back toward the west-northwest and then west by the end of the forecast period. No significant track changes were required during the day 3-5 time period. Moderate east-northeasterly shear is expected to continue for the next 36 hours or so, with Hilda also heading toward cooler waters during that time. Therefore, gradual weakening is expected to commence later today, and the NHC intensity forecast is close to the HCCA and ICON consensus aids for the next day or so. Sub-26 degree Celsius waters are likely to cause quicker weakening from 36 hours onward, and the NHC intensity forecast has been nudged downward during that period. This new forecast is lower than the statistical-dynamical models but not nearly as low as the latest HCCA solution. Hilda is now forecast to weaken to a tropical depression by day 3 and degenerate into a remnant low by day 4, although the HCCA scenario suggests that these transitions could occur as much as a day earlier. FORECAST POSITIONS AND MAX WINDS INIT 02/0900Z 15.3N 122.1W 70 KT 80 MPH 12H 02/1800Z 15.8N 122.7W 70 KT 80 MPH 24H 03/0600Z 16.7N 123.5W 65 KT 75 MPH 36H 03/1800Z 17.8N 124.3W 55 KT 65 MPH 48H 04/0600Z 18.9N 125.5W 45 KT 50 MPH 60H 04/1800Z 19.8N 127.0W 35 KT 40 MPH 72H 05/0600Z 20.5N 128.8W 30 KT 35 MPH 96H 06/0600Z 21.2N 132.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 07/0600Z 21.5N 136.5W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Berg
Tags: number
discussion
forecast
hurricane
Category:Transportation and Logistics