Issued at 1100 AM AST Tue Sep 23 2025
000 WTNT42 KNHC 231448 TCDAT2 Hurricane Gabrielle Discussion Number 27 NWS National Hurricane Center Miami FL AL072025 1100 AM AST Tue Sep 23 2025 Gabrielle's structure on the GOES-19 mesoscale sector over the hurricane has not changed a whole lot since the prior advisory, with a very cold and distinct eye surrounded by cold eyewall convection below -70 C. However, a recent GMI microwave pass did show that the tilt between low-level eye at 37 GHz and the mid-level eye at 89 GHz was starting to increase. Given little change in structure, it is not surprising that the subjective and objective satellite intensity estimates have remained steady, and thus the initial intensity is being held at 120 kt this advisory. Gabrielle continues to turn and is now moving east-northeastward at 060/17 kt. The hurricane could turn a little more eastward over the next 12-24 hours as it rounds the edge of the subtropical ridge centered to its southwest. Thereafter, a large mid-latitude trough ejecting out of Atlantic Canada will dig toward the tropical cyclone, with a piece of this trough forecast to phase with the cyclone in about 72 hours. This evolution should result in Gabrielle starting to move more poleward again, but not before it passes very close to or over the Azores during this period. There has been a southward shift in the track guidance this morning, and the NHC track forecast has been shifted a little south, especially after 48 hours. The latest track is roughly a blend between the HCCA and GDMI aids, which have preformed well so far this hurricane season. While Gabrielle has been resilient against gradually increasing westerly shear, this shear is starting to disrupt its structure ever so slightly, and the tilt observed on microwave imagery is also becoming more evident on GOES-19 visible imagery too. The shear is forecast to soon increase above 20 kt in 24 hours, and then increase above 30 kt in 48 h. Thus, gradual weakening should begin soon, with that rate of weakening increasing through the forecast period. As mentioned previously, the aforementioned trough interaction could provide some baroclinic enhancement in the form of enhanced upper-level divergence, but should also initiate extratropical transition, which is expected to complete in 3-4 days just after it passes the Azores. The new intensity forecast is similar to the previous forecast in 12-24 h, but a little lower thereafter, and remains in good agreement with the intensity consensus. Given the latest updates to the track and intensity forecast of Gabrielle, the Azores meteorological Service has issued a Hurricane Watch for all of the islands of the Azores. KEY MESSAGES: 1. Gabrielle is forecast to approach the Azores late on Thursday as a hurricane. In response, a Hurricane Watch is now in effect for all of the islands of the Azores and interests there should closely monitor Gabrielle's progress. 2. Swells generated by Gabrielle will continue to affect Bermuda, the east coast of the United States from North Carolina northward, as well as Atlantic Canada, during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. FORECAST POSITIONS AND MAX WINDS INIT 23/1500Z 33.9N 58.3W 120 KT 140 MPH 12H 24/0000Z 34.8N 55.2W 115 KT 130 MPH 24H 24/1200Z 35.6N 49.9W 110 KT 125 MPH 36H 25/0000Z 35.9N 43.7W 95 KT 110 MPH 48H 25/1200Z 37.0N 37.4W 85 KT 100 MPH 60H 26/0000Z 38.8N 30.7W 75 KT 85 MPH 72H 26/1200Z 40.7N 25.2W 65 KT 75 MPH 96H 27/1200Z 44.0N 16.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 28/1200Z 43.0N 10.8W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Papin
NHC Atlantic
