Issued at 900 AM GMT Thu Sep 25 2025
610 WTNT42 KNHC 250840 TCDAT2 Hurricane Gabrielle Discussion Number 34 NWS National Hurricane Center Miami FL AL072025 900 AM GMT Thu Sep 25 2025 The center of Gabrielle has moved over colder sea surface temperatures during the past few hours, and the associated convection is starting to weaken. However, the low-level center is still well embedded inside the convective cloud mass. Various satellite intensity estimates are now in the 60-77 kt range, and based on these and earlier scatterometer data the initial intensity is held at a possible generous 75 kt. The initial motion remains quite fast at 080/28 kt. Mid-latitude westerly flow associated with a baroclinic trough to the west of Gabrielle is expected to steer the storm eastward to east-northeastward for the next day or two as it passes near or over the Azores late today into early Friday. After 48 h, the cyclone is expected to slow its forward speed and turn southeastward as it rounds the northeastern side of the subtropical ridge over the eastern Atlantic, with this motion likely to bring the system near or over southern Portugal before the cyclone dissipates. The track guidance is tightly clustered through 48 h, and the new forecast track is little changed from the previous forecast. Gabrielle could weaken a little during the next 6-12 hours due to a combination of shear and cold sea surface temperatures. However, the ECMWF, GFS, and regional hurricane models are in good agreement that interaction with the baroclinic trough will start Gabrielle's extratropical transition process before the cyclone reaches the Azores, causing some re-intensification with a band of hurricane-force winds wrapping around the west side of the system around the time it moves over the Azores. The forecast intensity of 80 kt in 24 h is based on a blend of the above-mentioned models. After passing the Azores, Gabrielle should finish this transition and become a decaying extratropical low over the northeastern Atlantic. Based on the global model, the associated winds are currently forecast to decrease below gale-force before the low moves near Portugal, and the cyclone is forecast to dissipate after 96 h. KEY MESSAGES: 1. Gabrielle is forecast to approach the Azores late today as a hurricane. A Hurricane Warning is in effect for all of the islands of the Azores, and hurricane conditions are likely tonight into Friday. Significant hurricane-force wind gusts are likely across portions of the Azores even after the center passes. 2. A dangerous storm surge is expected to produce significant coastal flooding in areas of onshore winds in the Azores. The surge will be accompanied by large and destructive waves. 3. Heavy rainfall from Gabrielle could produce flash flooding across the terrain of the central Azores tonight through Friday morning. 4. Swells generated by Gabrielle will continue to affect Bermuda during the next couple of days, and the east coast of the United States from North Carolina northward and Atlantic Canada for the next day or so. 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 25/0900Z 36.5N 38.8W 75 KT 85 MPH 12H 25/1800Z 37.1N 33.8W 75 KT 85 MPH 24H 26/0600Z 38.7N 27.6W 80 KT 90 MPH 36H 26/1800Z 40.1N 21.9W 70 KT 80 MPH...POST-TROP/EXTRATROP 48H 27/0600Z 40.7N 17.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 60H 27/1800Z 40.2N 13.1W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 28/0600Z 38.8N 10.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 96H 29/0600Z 36.0N 7.0W 25 KT 30 MPH...POST-TROP/EXTRATROP 120H 30/0600Z...DISSIPATED $$ Forecaster Beven
NHC Atlantic
