Issued at 500 PM AST Sat Sep 20 2025 000
WTNT42 KNHC 202033
TCDAT2
Tropical Storm Gabrielle Discussion Number 15
NWS National Hurricane Center Miami FL AL072025
500 PM AST Sat Sep 20 2025
At about the time of the last advisory, an small eye-like feature
appeared in Gabrielle’s central dense overcast. An NOAA Hurricane
Hunter aircraft then confirmed the presence of a 6 n mi wide eye
with a well-defined inner wind core. After that, a combination of
flight-level and dropsonde data from both NOAA and AF Reserve
aircraft showed maximum winds near 55 kt with a central pressure
near 996 mb. One note is that the aircraft flight-level wind data
suggests an outer wind maximum is forming around the small eye,
which coincides with convective bands seen in NOAA aircraft radar
data.
The aircraft found that the center of Gabrielle was about 30 n mi
east of the previous forecast track, and using the revised position
yields a 12-h motion of 325/9. Other than the center re-location,
there is little change to the track forecast philosophy. During
the next 48 h or so, Gabrielle is expected to recurve to the north
and northeast between the subtropical ridge to the east and a
mid-latitude trough over the southeastern United States and
adjacent parts of the Atlantic. While the track guidance for this
part of the forecast remains tightly clustered, the guidance has
shifted to the east based on the initial position, and it is also
showing a slower forward speed. So, the official forecast is also
nudged to the east and slowed down. With this change, the reliable
guidance models and the official forecast continue to keep
Gabrielle well to the east of Bermuda during recurvature. After
recurvature, Gabrielle should move east-northeastward to eastward
as it becomes embedded in zonal westerly flow. This part of the
track guidance has again shifted south from the previous advisory
and also shows a slower forward speed, with the new official
forecast adjusted accordingly.
Gabrielle is expected to be in a light-to-moderate shear
environment for the next 48 h or so, and steady strengthening is
expected during this time. After being less aggressive on the 06Z
runs, the 12Z runs of the regional hurricane models have trended
stronger. The new intensity forecast keeps a peak intensity of 90
kt, which is above the intensity consensus but below the regional
models. After peak intensity, it again appears that Gabrielle’s
extratropical transition will not occur until after the end
of the forecast period. So, the intensity forecast shows steady
weakening due to increasing westerly shear and decreasing sea
surface temperatures along the forecast track. The new intensity
forecast again has some minor adjustments from the previous
forecast.
KEY MESSAGES:
1. Gabrielle is forecast to become a hurricane by Sunday and pass
east of Bermuda Sunday night and Monday. While the chances of
impacts are decreasing, interests on Bermuda should continue to
monitor Gabrielle’s forecasts since some wind and rainfall impacts
are still possible.
2. Swells generated by Gabrielle are beginning to reach Bermuda
and will build through the weekend. These swells are also expected
to reach the coast of the United States from North Carolina
northward, along with the coast of Atlantic Canada, late this
weekend into early next week. These swells are likely to cause
life-threatening surf and rip current conditions.
FORECAST POSITIONS AND MAX WINDS
INIT 20/2100Z 25.6N 59.0W 55 KT 65 MPH
12H 21/0600Z 26.7N 60.0W 65 KT 75 MPH
24H 21/1800Z 28.4N 61.1W 75 KT 85 MPH
36H 22/0600Z 29.9N 61.5W 85 KT 100 MPH
48H 22/1800Z 31.6N 60.8W 90 KT 105 MPH
60H 23/0600Z 33.3N 58.9W 90 KT 105 MPH
72H 23/1800Z 34.8N 55.8W 85 KT 100 MPH
96H 24/1800Z 36.6N 46.2W 70 KT 80 MPH
120H 25/1800Z 38.6N 33.8W 60 KT 70 MPH
$$
Forecaster Beven
