Tropical Cyclone Discussion
Issued by NWS
Issued by NWS
908 WTPZ43 KNHC 080845 TCDEP3 Tropical Storm Henriette Discussion Number 17 NWS National Hurricane Center Miami FL EP082025 1100 PM HST Thu Aug 07 2025 Henriettes satellite presentation remains unimpressive this evening, having lost nearly all deep convection and with the low-level center fully exposed. The latest subjective Dvorak current intensity estimate from TAFB was T2.5/35 kt, while objective estimates from UW-CIMSS have ranged from 26 to 34 kt over the past several hours. A timely 08/0534z Metop-B Ascat pass depicted quite a few 30 to 33 kt wind barbs and this was the basis for holding the initial intensity steady at 35 kt for this advisory. Henriette is moving westward, or 280 degrees at 15 kt. A turn toward the west-northwest is expected soon, with this general motion expected to persist over the next couple of days as the cyclone tracks along the southwestern periphery of a subtropical ridge to its northeast. A turn toward the northwest is forecast this weekend and into early next week as Henriette becomes steered between an amplifying longwave trough northwest of Hawaii and the subtropical ridge to its northeast. The official track forecast remains in close agreement with the latest multi-model consensus aids and is very close to the previous advisory. Confidence remains high that Henriette will remain far to the north of Hawaii. Henriette will traverse sea surface temperatures near 24C with mid-level relative humidity below 50 percent during the next 24 hours or so. Despite these unfavorable thermodynamic conditions, the cyclones well-defined circulation is expected to remain fairly resilient within the prevailing low-shear environment, allowing for occasional pulses of deep convection to continue. As a result, little change in intensity is anticipated during the next day or so. If Henriette can withstand the next 24 hours over cooler waters, as continues to be indicated by the GFS and ECMWF models again with the 00Z cycle, re-intensification will likely occur over the weekend and into early next week as sea surface temperatures steadily rise to levels conducive for strengthening. The official forecast continues to reflect intensification, bringing Henriette to hurricane strength by 72 hours. The cyclone will begin to experience increasing vertical wind shear as it moves toward the higher latitudes, which should result in rather rapid weakening beginning between 96 and 120 hours. The intensity forecast is on the higher end of the guidance envelope, and is most closely aligned with the CTCI and HMNI intensity aids, but below the peak depicted by the HAFS models. Future information on Henriette can be found under Central Pacific basin headers beginning at 500 AM HST. Future Tropical Cyclone Discussions will be issued under AWIPS header HFOTCDCP3 and WMO header WTPA43 PHFO. Products will continue to be available on the web at hurricanes.gov. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 19.2N 140.1W 35 KT 40 MPH 12H 08/1800Z 19.7N 142.3W 35 KT 40 MPH 24H 09/0600Z 20.7N 145.0W 35 KT 40 MPH 36H 09/1800Z 21.9N 147.5W 40 KT 45 MPH 48H 10/0600Z 23.3N 149.8W 45 KT 50 MPH 60H 10/1800Z 24.9N 152.0W 55 KT 65 MPH 72H 11/0600Z 26.9N 154.5W 65 KT 75 MPH 96H 12/0600Z 31.1N 159.2W 70 KT 80 MPH 120H 13/0600Z 35.8N 163.8W 55 KT 65 MPH $$ Forecaster Jelsema (CPHC)