Issued at 500 AM HST Thu Aug 07 2025
000 WTPZ43 KNHC 071454 TCDEP3 Tropical Storm Henriette Discussion Number 14 NWS National Hurricane Center Miami FL EP082025 500 AM HST Thu Aug 07 2025 Henriette continues to hang in there despite straddling 25 C sea-surface temperatures. Since the prior advisory, a little more convection has redeveloped close to the estimated center, though overall the appearance of the tropical storm is still rather ragged looking. The current intensity estimate from TAFB has not changed for 12 UTC at 45 kt. In deference to this value and earlier scatterometer data, the initial intensity is being maintained at 45 kt this advisory. The tropical storm continues to move westward, or 280 degrees at 14 kt. This general motion will continue through today, followed by a turn west-northwestward and then more northwestward due to the influence of a subtropical ridge to its north that will become gradually eroded by a large mid-oceanic trough amplifying over the North-Central Pacific in 2-3 days. The track guidance is essentially a carbon copy of the previous cycle, and only slight changes were made to the official track forecast. This forecast lies near the various multi-model consensus aids. Henriette is already moving over cool ocean waters, which are expected to cool to 24C over the next 12-24 hours. While it would not be surprising to see a little more weakening over the short term, the storm has proven to be resilient thus far. Another environmental factor to consider is the upper-level temperatures, which are colder than normal due to a negatively tilted upper-level trough to the storm's west. This trough might help to sustain some convection over what would ordinarily be waters too cool to allow such activity to persist. Once Henriette begins to move over warmer ocean waters again in the Central Pacific west of 150W, the other environmental factors are expected to remain favorable, and intensification is shown in the latter half of the forecast period. In fact, Henriette could become a hurricane in 96-120 h well to the north of Hawaii. The latest NHC intensity forecast is a little higher than the prior advisory, though there remain some guidance aids that are even higher than the NHC forecast at the end of the period (HAFS-B). FORECAST POSITIONS AND MAX WINDS INIT 07/1500Z 18.6N 135.5W 45 KT 50 MPH 12H 08/0000Z 19.0N 137.9W 45 KT 50 MPH 24H 08/1200Z 19.5N 140.9W 45 KT 50 MPH 36H 09/0000Z 20.2N 143.8W 45 KT 50 MPH 48H 09/1200Z 21.4N 146.5W 45 KT 50 MPH 60H 10/0000Z 22.7N 148.9W 45 KT 50 MPH 72H 10/1200Z 24.3N 151.4W 50 KT 60 MPH 96H 11/1200Z 28.0N 155.8W 65 KT 75 MPH 120H 12/1200Z 31.5N 160.0W 70 KT 80 MPH $$ Forecaster Papin
