109
WTPZ43 KNHC 090235
TCDEP3
TROPICAL STORM COSME DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL EP032025
800 PM MST SUN JUN 08 2025
COSME IS GRADUALLY IMPROVING IN ORGANIZATION WITH DEEP CONVECTION
PULSING, ALBEIT WITH THE CENTER ON THE NORTHERN EDGE OF THE
CONVECTION. A RECENT MICROWAVE PASS DID SHOW A PROMINENT CURVED
BAND ESPECIALLY IN THE SOUTHERN SEMICIRCLE OF THE STORM. THE
INITIAL WIND SPEED WILL STAY AT 40 KT FOR THIS ADVISORY, BETWEEN
THE LOWER SUBJECTIVE DVORAK ESTIMATES AND HIGHER OBJECTIVE VALUES.
CONDITIONS LOOK CONDUCIVE FOR STRENGTHENING FOR ABOUT THE NEXT 24
HOURS WHILE COSME MOVES WITHIN A FAIRLY LOW SHEAR AND WARM SST
ENVIRONMENT. THEREAFTER, SOME INCREASE IN EASTERLY SHEAR IS
POSSIBLE, AND THE STORM SHOULD MOVE OVER A TIGHT SST GRADIENT INTO A
DRIER AIRMASS. COSME IS FORECAST TO RESPOND TO THESE CONDITIONS BY
WEAKENING QUICKLY BY MIDWEEK. THE ONLY CHANGE TO THE PREVIOUS
FORECAST IS A SMALL REDUCTION IN THE INTENSITY FORECAST AT 60 AND 72
H, CONSISTENT WITH THE LATEST MODEL CONSENSUS. IT WOULD NOT BE
SURPRISING TO SEE COSME BECOME A REMNANT LOW FASTER THAN SHOWN
BELOW.
THE STORM CONTINUES MOVING NORTHWESTWARD AT 8 KT, AND A
WEST-NORTHWEST TO NORTHWEST MOTION IS ANTICIPATED DURING THE NEXT
DAY OR SO. AFTER THAT TIME, TROPICAL STORM BARBARA CAUSES A
MID-LEVEL RIDGE TO ERODE, AND COSME SHOULD RESPOND BY TAKING A
SHARP TURN TO THE NORTHEAST AROUND BARBARA. MODEL GUIDANCE HAS
SHIFTED NOTABLY TO THE LEFT THIS EVENING, SUGGESTING A
LITTLE MORE SEPARATION OF THE TROPICAL CYCLONES BEFORE THEY
INTERACT. WHILE THE NEW FORECAST IS ADJUSTED TO THE WEST, THIS IS
NOT A PARTICULARLY CONFIDENT LONGER-RANGE FORECAST DUE TO
THE COMPLEXITY OF THE INTERACTION.
FORECAST POSITIONS AND MAX WINDS
INIT 09/0300Z 13.7N 111.9W 40 KT 45 MPH
12H 09/1200Z 14.4N 112.9W 50 KT 60 MPH
24H 10/0000Z 14.9N 114.1W 60 KT 70 MPH
36H 10/1200Z 15.3N 114.2W 60 KT 70 MPH
48H 11/0000Z 15.8N 113.8W 55 KT 65 MPH
60H 11/1200Z 16.9N 113.0W 40 KT 45 MPH
72H 12/0000Z 18.5N 113.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 13/0000Z...DISSIPATED
FORECASTER BLAKE
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