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
