174
WTNT44 KNHC 070238
TCDAT4
TROPICAL STORM DEXTER DISCUSSION NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042025
1100 PM AST WED AUG 06 2025
DEXTER IS VERY CLOSE TO BEING AN EXTRATROPICAL CYCLONE. SATELLITE
IMAGES SUGGEST THAT FRONTAL FEATURES ARE FORMING BOTH TO THE EAST
AND SOUTH OF THE CENTER, AND THE OVERALL CLOUD PATTERN IS BEGINNING
TO TAKE ON AN EXTRATROPICAL APPEARANCE. STRONG WESTERLY VERTICAL
WIND SHEAR HAS CAUSED THE LOW-LEVEL CENTER TO BECOME COMPLETELY
EXPOSED WITH DISORGANIZED CONVECTION LIMITED TO THE NORTHEAST
QUADRANT. THE INITIAL INTENSITY IS HELD AT 45 KT, WHICH IS IN LINE
WITH THE LATEST SATELLITE INTENSITY ESTIMATES AND RECENT ASCAT DATA.
A MID- TO UPPER-LEVEL TROUGH CURRENTLY OVER THE CANADIAN MARITIMES
IS EXPECTED TO MERGE WITH THE SYSTEM EARLY THURSDAY, WHICH SHOULD
COMPLETE DEXTER'S EXTRATROPICAL TRANSITION. THIS WILL ALSO LIKELY
CAUSE STRENGTHENING DUE TO BAROCLINIC FORCING, AND DEXTER COULD
BECOME A HURRICANE-FORCE EXTRATROPICAL LOW IN ABOUT 24 HOURS.
GRADUAL WEAKENING IS EXPECTED AFTER THAT TIME AS THE UPPER-LEVEL
TROUGH DAMPENS OUT. THE NHC INTENSITY FORECAST IS SLIGHTLY ABOVE
THE GUIDANCE IN THE SHORT TERM, BUT IN LINE WITH THE BULK OF THE
MODELS FROM 48 TO 96 HOURS.
DEXTER IS MOVING A LITTLE FASTER TO THE EAST NOW, WITH THE LATEST
INITIAL MOTION ESTIMATED TO BE 085/14 KT. A NORTHEASTWARD MOTION IS
EXPECTED DURING THE NEXT DAY OR TWO AS DEXTER INTERACTS AND MERGES
WITH THE AFOREMENTIONED TROUGH. AFTER THAT TIME, A TURN BACK TO
THE EAST-NORTHEAST OR EAST IS PREDICTED IN THE MID-LATITUDE
WESTERLY FLOW. THE NHC TRACK FORECAST LIES FAIRLY CLOSE TO THE
VARIOUS CONSENSUS AIDS.
FORECAST POSITIONS AND MAX WINDS
INIT 07/0300Z 40.2N 54.2W 45 KT 50 MPH
12H 07/1200Z 40.9N 51.1W 55 KT 65 MPH...POST-TROP/EXTRATROP
24H 08/0000Z 42.6N 46.7W 65 KT 75 MPH...POST-TROP/EXTRATROP
36H 08/1200Z 44.3N 43.0W 60 KT 70 MPH...POST-TROP/EXTRATROP
48H 09/0000Z 45.3N 38.5W 50 KT 60 MPH...POST-TROP/EXTRATROP
60H 09/1200Z 46.0N 34.4W 40 KT 45 MPH...POST-TROP/EXTRATROP
72H 10/0000Z 46.7N 29.7W 35 KT 40 MPH...POST-TROP/EXTRATROP
96H 11/0000Z 47.4N 22.0W 30 KT 35 MPH...POST-TROP/EXTRATROP
120H 12/0000Z...DISSIPATED
FORECASTER CANGIALOSI
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page