000 WTPA43 PHFO 100834 TCDCP3 Tropical Storm Henriette Discussion Number 25 NWS Central Pacific Hurricane Center Honolulu HI EP082025 Issued by NWS National Hurricane Center Miami FL 1100 PM HST Sat Aug 09 2025 Satellite imagery shows that Henriette retains a well-organized low-level structure, with a curved band wrapping around the west side of the circulation. However, convection within the band has struggled to persist due to surrounding dry mid- to upper-level air. Subjective Dvorak current intensity estimates from SAB, JTWC, and HFO, along with objective estimates from UW-CIMSS, support holding the initial intensity at 35 kt for this advisory. The initial motion is toward the northwest at 13 kt, steered by a subtropical ridge to the northeast and an amplifying mid-latitude trough to the northwest. Henriette’s forward speed is expected to increase through 36 hours, level off near 60 hours, and then slow through 96 hours as the steering flow weakens. This motion will keep Henriette well northeast of the Hawaiian Islands. Guidance indicates the sharp upper trough will cut off into an upper low on Monday and retrograde westward, a pattern that should maintain Henriette’s northwestward motion. The track forecast is very similar to the previous one but is slightly left of the earlier forecast from days 3 to 4, and lies near the middle of the tightly clustered consensus aids. Sea-surface temperatures along Henriette’s forecast track should gradually warm from near 25 degrees C to around 26–27 degrees C through about 60 h. Despite surrounding dry mid- to upper-level air, a combination of warmer waters and increasing upper-level divergence associated with an upper trough to the northwest should enhance outflow and support gradual strengthening. The NHC forecast continues to show a peak near 55 kt in the 36–48 h period, nearly identical to the previous forecast and within the middle to upper end of the guidance envelope. Thereafter, cooler waters, increasing shear, and diminishing upper-level outflow should result in steady weakening, with Henriette expected to become a post-tropical remnant low by 96 h and dissipate by 120 h as it is absorbed into the mid-latitude flow. FORECAST POSITIONS AND MAX WINDS INIT 10/0900Z 23.8N 150.3W 35 KT 40 MPH 12H 10/1800Z 25.1N 151.9W 40 KT 45 MPH 24H 11/0600Z 27.2N 154.2W 50 KT 60 MPH 36H 11/1800Z 29.3N 156.8W 55 KT 65 MPH 48H 12/0600Z 31.4N 159.4W 55 KT 65 MPH 60H 12/1800Z 33.7N 161.8W 50 KT 60 MPH 72H 13/0600Z 35.4N 164.1W 45 KT 50 MPH 96H 14/0600Z 38.7N 168.4W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 15/0600Z...DISSIPATED $$ Forecaster Gibbs (CPHC)
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