501 WTPA43 PHFO 092039 TCDCP3 Tropical Storm Henriette Discussion Number 23 NWS Central Pacific Hurricane Center Honolulu HI EP082025 Issued by NWS National Hurricane Center Miami FL 1100 AM HST Sat Aug 09 2025 Deep convection has evolved a bit since the previous advisory with a curved band wrapping around the west side of Henriette. The latest subjective Dvorak classifications range from 25-30 kt, and the objective intensity estimates from UW-CIMSS have been ranging between 35-37 kt. Based mainly on the objective estimates, it is estimated that Henriette has regained tropical storm strength with maximum winds estimated at 35 kt. Henriette is moving a little faster now in a direction between west-northwest and northwest, at 14 kt. Henriette will round the southwestern periphery of the subtropical ridge tonight as a deep-layer mid-latitude trough approaches from the west. In a couple of days, the trough will become stationary or even retrograde westward. This steering pattern favors a continued northwestward motion through the forecast period. The new NHC track forecast is a little faster than the previous one, but along a similar track line, and is in agreement with the consensus aids. Henriette will move over gradually warming sea-surface temperatures (SSTs) and through gradually cooling upper-level temperatures now through the next 60 h or so. SSTs currently near 25C are forecast to warm to the 26.5 to 27C range along the cyclone's path. The cyclone is also currently embedded in very dry mid-tropospheric air, and these dry conditions are expected to persist for the next couple of days. Given the competing factors mentioned above, slow strengthening seems likely over the next couple of days. The latest NHC intensity forecast is similar to the previous one and is near the middle of the guidance envelope. Beyond day 3, wind shear should increase, and Henriette will also reach cooler water again as it gains latitude. These factors should cause the system to lose its convection and become post-tropical by day 4, with dissipation in about 5 days. FORECAST POSITIONS AND MAX WINDS INIT 09/2100Z 22.3N 148.1W 35 KT 40 MPH 12H 10/0600Z 23.3N 149.8W 40 KT 45 MPH 24H 10/1800Z 25.1N 151.9W 45 KT 50 MPH 36H 11/0600Z 27.2N 154.3W 50 KT 60 MPH 48H 11/1800Z 29.3N 156.9W 55 KT 65 MPH 60H 12/0600Z 31.4N 159.5W 55 KT 65 MPH 72H 12/1800Z 33.5N 162.0W 50 KT 60 MPH 96H 13/1800Z 37.7N 166.2W 35 KT 40 MPH...POST-TROPICAL 120H 14/1800Z...DISSIPATED $$ Forecaster Hagen
Source link