Atlantic Tropical Weather Outlook
253
ABNT20 KNHC 191140
TWOAT
Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Fri Sep 19 2025
For the North Atlantic...Caribbean Sea and the Gulf of America:
Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Gabrielle, located in the central tropical Atlantic.
Eastern Tropical Atlantic:
A tropical wave just off the west coast of Africa is producing
disorganized shower and thunderstorm activity. Some slow
development of this system is possible through the middle to
latter part of next week while it moves west-northwestward across
the eastern and central tropical Atlantic.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.
$$
Forecaster Beven
Summary for Tropical Storm Gabrielle (AT2/AL072025)
...GABRIELLE FORECAST TO STRENGTHEN AND BECOME A HURRICANE BY SUNDAY... As of 5:00 AM AST Fri Sep 19 the center of Gabrielle was located near 21.9, -54.8 with movement WNW at 12 mph. The minimum central pressure was 1004 mb with maximum sustained winds of about 50 mph.
Tropical Storm Gabrielle Public Advisory Number 9
Issued at 500 AM AST Fri Sep 19 2025855 WTNT32 KNHC 190846 TCPAT2 BULLETIN Tropical Storm Gabrielle Advisory Number 9 NWS National Hurricane Center Miami FL AL072025 500 AM AST Fri Sep 19 2025 ...GABRIELLE FORECAST TO STRENGTHEN AND BECOME A HURRICANE BY SUNDAY... SUMMARY OF 500 AM AST...0900 UTC...INFORMATION ---------------------------------------------- LOCATION...21.9N 54.8W ABOUT 595 MI...960 KM ENE OF THE NORTHERN LEEWARD ISLANDS ABOUT 945 MI...1520 KM SE OF BERMUDA MAXIMUM SUSTAINED WINDS...50 MPH...85 KM/H PRESENT MOVEMENT...WNW OR 300 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES WATCHES AND WARNINGS -------------------- There are no coastal watches or warnings in effect. Interests in Bermuda should monitor the progress of Gabrielle. DISCUSSION AND OUTLOOK ---------------------- At 500 AM AST (0900 UTC), the center of Tropical Storm Gabrielle was located near latitude 21.9 North, longitude 54.8 West. Gabrielle is moving toward the west-northwest near 12 mph (19 km/h), and this motion is expected to continue today. A gradual turn toward the northwest is forecast by tonight, followed by a north-northwestward motion by Saturday night and northward motion by Sunday night. On the forecast track, the center of Gabrielle is expected to pass east of Bermuda Sunday night and Monday. Maximum sustained winds are near 50 mph (85 km/h) with higher gusts. Gradual strengthening is forecast, and Gabrielle is expected to become a hurricane by Sunday. Tropical-storm-force winds extend outward up to 150 miles (240 km) from the center. The estimated minimum central pressure is 1004 mb (29.65 inches). HAZARDS AFFECTING LAND ---------------------- Key messages for Gabrielle can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT2 and WMO header WTNT42 KNHC. SURF: Swells generated by Gabrielle are expected to reach Bermuda tonight and build through the weekend. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next complete advisory at 1100 AM AST. $$ Forecaster Berg
Tropical Storm Gabrielle Forecast Advisory Number 9
Issued at 0900 UTC FRI SEP 19 2025000 WTNT22 KNHC 190845 TCMAT2 TROPICAL STORM GABRIELLE FORECAST/ADVISORY NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL AL072025 0900 UTC FRI SEP 19 2025 TROPICAL STORM CENTER LOCATED NEAR 21.9N 54.8W AT 19/0900Z POSITION ACCURATE WITHIN 30 NM PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 10 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1004 MB MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. 34 KT.......130NE 100SE 0SW 70NW. 4 M SEAS....315NE 150SE 90SW 180NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 21.9N 54.8W AT 19/0900Z AT 19/0600Z CENTER WAS LOCATED NEAR 21.5N 54.1W FORECAST VALID 19/1800Z 22.6N 56.0W MAX WIND 45 KT...GUSTS 55 KT. 34 KT...120NE 90SE 0SW 70NW. FORECAST VALID 20/0600Z 23.9N 57.7W MAX WIND 50 KT...GUSTS 60 KT. 50 KT... 20NE 0SE 0SW 0NW. 34 KT...120NE 90SE 0SW 70NW. FORECAST VALID 20/1800Z 25.4N 59.2W MAX WIND 55 KT...GUSTS 65 KT. 50 KT... 25NE 15SE 0SW 15NW. 34 KT...120NE 90SE 0SW 80NW. FORECAST VALID 21/0600Z 27.1N 60.3W MAX WIND 60 KT...GUSTS 75 KT. 50 KT... 30NE 20SE 10SW 20NW. 34 KT...140NE 110SE 40SW 80NW. FORECAST VALID 21/1800Z 28.9N 61.2W MAX WIND 70 KT...GUSTS 85 KT. 64 KT... 20NE 15SE 0SW 0NW. 50 KT... 40NE 30SE 20SW 25NW. 34 KT...140NE 120SE 50SW 90NW. FORECAST VALID 22/0600Z 31.0N 61.2W MAX WIND 80 KT...GUSTS 100 KT. 64 KT... 20NE 20SE 15SW 15NW. 50 KT... 50NE 50SE 30SW 40NW. 34 KT...140NE 120SE 60SW 90NW. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 125 NM ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY OUTLOOK VALID 23/0600Z 35.9N 56.9W MAX WIND 90 KT...GUSTS 110 KT. 50 KT... 70NE 80SE 60SW 50NW. 34 KT...160NE 170SE 120SW 90NW. OUTLOOK VALID 24/0600Z 39.8N 46.0W MAX WIND 75 KT...GUSTS 90 KT. 50 KT... 70NE 90SE 90SW 50NW. 34 KT...200NE 220SE 220SW 150NW. REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 21.9N 54.8W NEXT ADVISORY AT 19/1500Z $$ FORECASTER BERG
Tropical Storm Gabrielle Forecast Discussion Number 9
Issued at 500 AM AST Fri Sep 19 2025859 WTNT42 KNHC 190846 TCDAT2 Tropical Storm Gabrielle Discussion Number 9 NWS National Hurricane Center Miami FL AL072025 500 AM AST Fri Sep 19 2025 Gabrielle's low-level center is located near the western edge of an area of deep convection that has now persisted since late yesterday afternoon. While the overall convective structure is gradually improving, the change hasn't been enough to deviate from a current intensity of 45 kt. UW-CIMSS SATCON, with a value of 42 kt, is currently the closest satellite intensity estimate. The storm is maintaining a west-northwestward heading of 300 degrees at 10 kt, with the subtropical ridge located to its north. A general pattern of troughing is expected to persist near the southeastern U.S. coast and far western Atlantic for the next several days, which should cause Gabrielle to recurve around the western periphery of the ridge over the next 4 days. There has been further tightening of the track guidance during this period, including a convergence of the HCCA and Google DeepMind ensemble mean, and no significant adjustments were required for this updated track forecast. The reliable track models now show Gabrielle's center passing at least 140 n mi east of Bermuda in about 3 days. However, interests on the island should continue to monitor Gabrielle's progress since NHC's average track error at 3 days is about 90 n mi, and hazards can extend well away from the center. There is currently a 20-25 percent chance of tropical-storm-force winds occurring on Bermuda. The moderate westerly shear currently affecting Gabrielle is forecast to gradually lessen below 10 kt by 36 hours. This should begin to mitigate the effects of surrounding dry air and allow for gradual strengthening. The NHC intensity forecast has been nudged upward, particularly during the first 3 days, to trend toward the latest IVCN and HCCA consensus aids, and Gabrielle is expected to become a hurricane by Sunday. The forecast peak intensity on day 4 is unchanged. By day 5, the onset of significantly stronger shear and cooler waters should induce some weakening. At the moment, there is significant uncertainty about when Gabrielle might become extratropical and how that would affect the cyclone's intensity. KEY MESSAGES: 1. Gabrielle is forecast to become a hurricane by Sunday and pass east of Bermuda Sunday night and Monday. Interests on Bermuda should monitor Gabrielle's forecasts since it is too soon to specify the magnitude of potential wind and rainfall impacts. 2. Swells generated by Gabrielle are expected to reach Bermuda tonight and build through the weekend. These swells are likely to cause life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 19/0900Z 21.9N 54.8W 45 KT 50 MPH 12H 19/1800Z 22.6N 56.0W 45 KT 50 MPH 24H 20/0600Z 23.9N 57.7W 50 KT 60 MPH 36H 20/1800Z 25.4N 59.2W 55 KT 65 MPH 48H 21/0600Z 27.1N 60.3W 60 KT 70 MPH 60H 21/1800Z 28.9N 61.2W 70 KT 80 MPH 72H 22/0600Z 31.0N 61.2W 80 KT 90 MPH 96H 23/0600Z 35.9N 56.9W 90 KT 105 MPH 120H 24/0600Z 39.8N 46.0W 75 KT 85 MPH $$ Forecaster Berg
Tropical Storm Gabrielle Wind Speed Probabilities Number 9
Issued at 0900 UTC FRI SEP 19 2025 857
FONT12 KNHC 190846
PWSAT2
TROPICAL STORM GABRIELLE WIND SPEED PROBABILITIES NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL AL072025
0900 UTC FRI SEP 19 2025
AT 0900Z THE CENTER OF TROPICAL STORM GABRIELLE WAS LOCATED NEAR
LATITUDE 21.9 NORTH...LONGITUDE 54.8 WEST WITH MAXIMUM SUSTAINED
WINDS NEAR 45 KTS...50 MPH...85 KM/H.
Z INDICATES COORDINATED UNIVERSAL TIME (GREENWICH)
ATLANTIC STANDARD TIME (AST)...SUBTRACT 4 HOURS FROM Z TIME
EASTERN DAYLIGHT TIME (EDT)...SUBTRACT 4 HOURS FROM Z TIME
CENTRAL DAYLIGHT TIME (CDT)...SUBTRACT 5 HOURS FROM Z TIME
WIND SPEED PROBABILITY TABLE FOR SPECIFIC LOCATIONS
CHANCES OF SUSTAINED (1-MINUTE AVERAGE) WIND SPEEDS OF AT LEAST
...34 KT (39 MPH... 63 KM/H)...
...50 KT (58 MPH... 93 KM/H)...
...64 KT (74 MPH...119 KM/H)...
FOR LOCATIONS AND TIME PERIODS DURING THE NEXT 5 DAYS
PROBABILITIES FOR LOCATIONS ARE GIVEN AS OP(CP) WHERE
OP IS THE PROBABILITY OF THE EVENT BEGINNING DURING
AN INDIVIDUAL TIME PERIOD (ONSET PROBABILITY)
(CP) IS THE PROBABILITY OF THE EVENT OCCURRING BETWEEN
06Z FRI AND THE FORECAST HOUR (CUMULATIVE PROBABILITY)
PROBABILITIES ARE GIVEN IN PERCENT
X INDICATES PROBABILITIES LESS THAN 1 PERCENT
PROBABILITIES FOR 34 KT AND 50 KT ARE SHOWN AT A GIVEN LOCATION WHEN
THE 5-DAY CUMULATIVE PROBABILITY IS AT LEAST 3 PERCENT.
PROBABILITIES FOR 34...50...64 KT SHOWN WHEN THE 5-DAY
64-KT CUMULATIVE PROBABILITY IS AT LEAST 1 PERCENT.
- - - - WIND SPEED PROBABILITIES FOR SELECTED LOCATIONS - - - -
FROM FROM FROM FROM FROM FROM FROM
TIME 06Z FRI 18Z FRI 06Z SAT 18Z SAT 06Z SUN 06Z MON 06Z TUE
PERIODS TO TO TO TO TO TO TO
18Z FRI 06Z SAT 18Z SAT 06Z SUN 06Z MON 06Z TUE 06Z WED
FORECAST HOUR (12) (24) (36) (48) (72) (96) (120)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
LOCATION KT
BERMUDA 34 X X( X) X( X) X( X) 16(16) 7(23) X(23)
BERMUDA 50 X X( X) X( X) X( X) 2( 2) 3( 5) X( 5)
BERMUDA 64 X X( X) X( X) X( X) X( X) 1( 1) X( 1)
$$
FORECASTER BERG
Tropical Storm Gabrielle Graphics
5-Day Uncertainty Track last updated Fri, 19 Sep 2025 08:49:09 GMT
Wind Speed Probabilities last updated Fri, 19 Sep 2025 09:21:54 GMT