Sep 20, 2025-T-Storm Gabrielle Possible to Affect Bermuda Disturbance (1) Near Cabo Verde Island

⚠️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.

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.

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 nautical miles 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 65 mph (55 knots) 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 nautical miles east of the previous forecast track, and using the revised position yields a 12 hours motion of 325/9. Other than the center re-location, there is little change to the track forecast philosophy. During the next 48 hours 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 hours or so, and steady strengthening is expected during this time. After being less aggressive on the 06:00 UTC runs, the 12:00 UTC runs of the regional hurricane models have trended stronger. The new intensity forecast keeps a peak intensity of 105 mph (90 knots), 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.

Forecaster Beven. Advisory Number 15. Information provided by the National Hurricane Center (NHC).

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