117
WTNT44 KNHC 052046
TCDAT4
TROPICAL STORM DEXTER DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042025
500 PM AST TUE AUG 05 2025
THIS AFTERNOON DEXTER CONTINUES TO EXHIBIT A PULSING CONVECTIVE
STRUCTURE. AFTER BRIEFLY BECOMING EXPOSED EARLIER TODAY, THE
LOW-LEVEL CIRCULATION HAS TUCKED UNDERNEATH A RENEWED CONVECTIVE
BURST ON ITS DOWN-SHEAR SIDE. DESPITE ITS RAGGED APPEARANCE, AN
EARLIER SCATTEROMETER PASS INDICATED THAT DEXTER'S CIRCULATION HAD
TIGHTENED UP SOME WITH A SMALLER RADIUS OF MAXIMUM WIND. THE PEAK
WIND VALUE RETRIEVED WAS 35 KT, WHICH STILL SUPPORTS A CURRENT
INTENSITY OF 35 KT THIS ADVISORY. THIS VALUE IS HIGHER THAN THE 18
UTC SUBJECTIVE DVORAK INTENSITY ESTIMATES, BUT A BIT LOWER THAN THE
SOME OF THE OBJECTIVE INTENSITY ESTIMATES (DMINT, SATCON).
DEXTER CONTINUES TO MOVE OFF TO THE NORTHEAST, WITH THE LATEST
MOTION ESTIMATED AT 055/11 KT. THIS DIRECTION OF MOTION IS EXPECTED
TO CONTINUE FOR THE NEXT FEW DAYS WITH A GENTLE BEND TOWARDS THE
EAST-NORTHEAST, ACROSS THE NORTH ATLANTIC. HOWEVER, THE SPEED OF THE
FORWARD MOTION CONTINUES TO BE UNCERTAIN, WITH LARGE ALONG-TRACK
SPREAD IN THE GUIDANCE. THE GFS CONTINUES TO BE ON THE SLOW END,
WHILE THE ECMWF AND GOOGLE DEEP MIND ENSEMBLE MEAN (GDMI) ARE ON THE
FASTER END OF THE GUIDANCE SUITE. THE LATEST NHC TRACK FORECAST
CONTINUES TO FAVOR THE FASTER TRACK SOLUTIONS, AND IS A BLEND OF THE
PRIOR FORECAST TRACK, WITH SOME OF THE MORE RELIABLE CONSENSUS AIDS
(HCCA).
VERTICAL WIND SHEAR OVER THE SYSTEM IS NOW ABOVE 30 KT OUT OF THE
WEST-SOUTHWEST, AND IS FORECAST TO INCREASE FURTHER OVER THE NEXT
24-48 HOURS. HOWEVER, THE MAJORITY OF THE INTENSITY GUIDANCE
INDICATES DEXTER MAY STRENGTHEN DUE TO BAROCLINIC DYNAMICS FROM A
FAVORABLE TROUGH INTERACTION. THUS, THE NHC INTENSITY FORECAST SHOWS
SOME STRENGTHENING, PEAKING DEXTER AS A 50 KT EXTRATROPICAL CYCLONE
IN ABOUT 48 HOURS. THIS FORECAST IS ROUGHLY IN THE MIDDLE OF THE
INTENSITY GUIDANCE ENVELOPE, THOUGH NOTABLY LOWER THAN THE LATEST
HAFS-A/B FORECASTS, WHICH DEVELOP A POTENT STING-JET-LIKE STRUCTURE
AS DEXTER BECOMES EXTRATROPICAL. AFTER THE EXTRATROPICAL LOW
OCCLUDES, IT SHOULD GRADUALLY WEAKEN, EVENTUALLY OPENING UP INTO A
TROUGH BY THE END OF THE FORECAST PERIOD.
FORECAST POSITIONS AND MAX WINDS
INIT 05/2100Z 38.6N 62.2W 35 KT 40 MPH
12H 06/0600Z 39.2N 60.5W 35 KT 40 MPH
24H 06/1800Z 39.9N 57.6W 40 KT 45 MPH
36H 07/0600Z 40.6N 53.9W 40 KT 45 MPH
48H 07/1800Z 41.9N 49.8W 50 KT 60 MPH...POST-TROP/EXTRATROP
60H 08/0600Z 43.1N 46.0W 50 KT 60 MPH...POST-TROP/EXTRATROP
72H 08/1800Z 44.0N 42.0W 45 KT 50 MPH...POST-TROP/EXTRATROP
96H 09/1800Z 45.3N 33.0W 35 KT 40 MPH...POST-TROP/EXTRATROP
120H 10/1800Z...DISSIPATED
FORECASTER PAPIN
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