000 WTPZ43 KNHC 060853 TCDEP3 Tropical Storm Henriette Discussion Number 9 NWS National Hurricane Center Miami FL EP082025 1100 PM HST Tue Aug 05 2025 The satellite presentation of Henriette has changed little since the previous advisory, with intermittent bursts of deep convection continuing, primarily located over and west of the cyclone’s low-level center. Recent subjective Dvorak intensity estimates from TAFB and SAB were 3.0/45 kt and 2.5/35 kt, respectively, while objective estimates from UW-CIMSS have ranged between 34 and 46 kt over the past several hours. A timely 06/0525Z Metop-C ASCAT pass revealed several 40–45 kt wind barbs north of the low-level center. Based on these data, the initial intensity for this advisory remains 45 kt. Henriette has recently turned toward the west, or 280 degrees, at 13 kt. This general motion is expected to persist over the next couple of days as the cyclone is steered by a strengthening subtropical ridge situated to the north. By around 72 hours, a gradual turn toward the west-northwest or northwest is anticipated as an amplifying longwave trough northwest of Hawaii begins to erode the western periphery of the ridge. The official track forecast is closely aligned with the latest multi-model consensus aids and remains very similar to the previous advisory. Henriette is forecast to remain in a low vertical wind shear environment for the next several days. During this period, sea surface temperatures are expected to gradually decrease to near or slightly below 24C, while mid-level moisture drops below 50 percent. Despite these marginal thermodynamic conditions, Henriette’s broad circulation and well-established inner core should allow the system to remain relatively resilient in the low shear environment. Only slight weakening is forecast during the next few days, followed by little change in strength. Toward the end of the forecast period, sea surface temperatures are expected to rise again. If the system manages to endure the cooler waters, as persistently suggested by both the GFS and ECMWF models, some re-intensification is possible. The official forecast reflects this potential and lies near the middle of the intensity guidance envelope. FORECAST POSITIONS AND MAX WINDS INIT 06/0900Z 17.8N 128.2W 45 KT 50 MPH 12H 06/1800Z 18.1N 130.4W 45 KT 50 MPH 24H 07/0600Z 18.4N 133.4W 40 KT 45 MPH 36H 07/1800Z 18.7N 136.4W 40 KT 45 MPH 48H 08/0600Z 19.2N 139.4W 40 KT 45 MPH 60H 08/1800Z 19.9N 142.3W 40 KT 45 MPH 72H 09/0600Z 20.9N 145.2W 40 KT 45 MPH 96H 10/0600Z 23.3N 149.9W 40 KT 45 MPH 120H 11/0600Z 26.1N 154.1W 50 KT 60 MPH $$ Forecaster Jelsema (CPHC)
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