251
WTNT45 KNHC 170842
TCDAT5
HURRICANE ERIN DISCUSSION NUMBER 24
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052025
500 AM AST SUN AUG 17 2025
SATELLITE AND DOPPLER RADAR DATA FROM SAN JUAN INDICATE THAT ERIN IS
GOING THROUGH SOME NOTABLE STRUCTURAL CHANGES. THE HURRICANE STILL
HAS A SMALL EYE IN RADAR IMAGES WITH A TIGHT AND CLOSED EYEWALL.
BEYOND THE SMALL CORE, THERE ARE NUMEROUS CONVECTIVE RAINBANDS THAT
ARE EXPANDING IN ALL QUADRANTS, WITH SOME INDICATION OF AN OUTER
EYEWALL BEGINNING TO TAKE SHAPE. DATA FROM THE AIR FORCE HURRICANE
HUNTERS A FEW HOURS AGO INDICATED THAT THE PEAK WINDS HAVE BEEN
DECREASING, AND THE INITIAL INTENSITY IS SET AT 110 KT USING A BLEND
OF THE LATEST SATELLITE ESTIMATES. THE OUTER BANDS TO THE SOUTH OF
THE CENTER ARE STILL AFFECTING PORTIONS OF THE VIRGIN ISLANDS,
PUERTO RICO, AND THE DOMINICAN REPUBLIC. THESE BANDS ARE PRODUCING
GUSTY WINDS AND LOCALLY HEAVY RAINS. THE AIR FORCE AND NOAA
HURRICANE HUNTERS ARE SCHEDULED TO INVESTIGATE ERIN AGAIN LATER THIS
MORNING, AND THEIR DATA WILL PROVIDE A BETTER ASSESSMENT OF THE
HURRICANE'S INTENSITY AND STRUCTURE.
ERIN HAS BEEN WOBBLING AROUND, BUT IT APPEARS TO BE MOVING A LITTLE
TO THE SOUTH OF THE PREVIOUS TRACK. THE HURRICANE IS STILL MOVING
WEST-NORTHWESTWARD AT 12 KT ON THE SOUTH SIDE OF A SUBTROPICAL
RIDGE. THIS RIDGE IS EXPECTED TO BREAK DOWN LATER TODAY DUE TO A
SERIES OF TROUGHS MOVING ACROSS THE NORTHWESTERN ATLANTIC. IN
RESPONSE TO THE PATTERN CHANGE, ERIN SHOULD GRADUALLY TURN TOWARD
THE NORTH AND EVENTUALLY THE NORTHEAST. THIS MOTION SHOULD TAKE THE
CORE OF ERIN TO THE EAST OF THE BAHAMAS ON MONDAY AND THEN ROUGHLY
MIDWAY BETWEEN BERMUDA AND THE EAST COAST OF THE U.S. AROUND THE
MIDDLE OF THE WEEK. THE NHC TRACK FORECAST HAS BEEN NUDGED TO THE
WEST IN THE SHORT TERM BASED ON THE INITIAL MOTION AND LATEST MODEL
GUIDANCE.
THE QUICK WEAKENING OVER THE PAST 6 TO 12 HOURS IS ASSOCIATED WITH
ERIN'S STRUCTURAL CHANGES AND NOT ENVIRONMENTAL CONDITIONS. SINCE
THE LARGE-SCALE ENVIRONMENT IS EXPECTED TO BE FAVORABLE FOR ABOUT
ANOTHER DAY, RE-STRENGTHENING IS POSSIBLE DURING THAT TIME PERIOD.
HOWEVER, IT SHOULD BE NOTED THAT PREDICTING THE INTENSITY EVOLUTION
FROM INTERNAL DYNAMICS ARE CHALLENGING, AND MODELS OFTEN PROVIDE
LITTLE RELIABILITY IN THEIR SOLUTIONS. BEYOND 24 TO 36 HOURS, A
BROADENING OF THE WIND FIELD AND SOME INCREASE IN SHEAR SHOULD CAUSE
A GRADUAL DECAY IN THE PEAK WINDS. REGARDLESS OF THE DETAILS, THERE
IS HIGH CONFIDENCE THAT ERIN WILL REMAIN A POWERFUL HURRICANE DURING
THE NEXT SEVERAL DAYS.
ERIN IS GROWING IN SIZE, AND THAT TREND IS EXPECTED TO CONTINUE OVER
THE NEXT FEW DAYS. THE EXPANDING WIND FIELD WILL RESULT IN ROUGH
OCEAN CONDITIONS OVER MUCH OF THE WESTERN ATLANTIC. GIVEN THE TRACK
ADJUSTMENTS AND INCREASING SIZE, THE GOVERNMENT OF THE BAHAMAS HAS
ISSUED A TROPICAL STORM WARNING FOR THE TURKS AND CAICOS ISLANDS AND
A TROPICAL STORM WATCH FOR THE SOUTHEAST BAHAMAS.
KEY MESSAGES:
1. HEAVY RAINFALL IS EXPECTED TO CONTINUE ACROSS THE VIRGIN ISLANDS
AND PUERTO RICO TODAY. LOCALLY CONSIDERABLE FLASH AND URBAN
FLOODING, ALONG WITH LANDSLIDES OR MUDSLIDES, ARE POSSIBLE.
2. TROPICAL STORM CONDITIONS ARE EXPECTED IN THE TURKS AND CAICOS
ISLANDS AND ARE POSSIBLE IN THE SOUTHEAST BAHAMAS TONIGHT AND
MONDAY. GUSTS TO TROPICAL STORM FORCE ARE POSSIBLE IN ERIN'S OUTER
RAINBANDS IN PORTIONS OF PUERTO RICO TODAY AND THE CENTRAL BAHAMAS
ON MONDAY AND TUESDAY.
3. ERIN IS EXPECTED TO PRODUCE LIFE-THREATENING SURF AND RIP
CURRENTS ALONG THE BEACHES OF THE BAHAMAS, MUCH OF THE EAST COAST OF
THE U.S., BERMUDA, AND ATLANTIC CANADA DURING THE NEXT SEVERAL DAYS.
4. INTERESTS ALONG THE NORTH CAROLINA AND MID-ATLANTIC COASTS,
AND BERMUDA SHOULD MONITOR THE PROGRESS OF ERIN AS THERE IS A RISK
OF STRONG WINDS ASSOCIATED WITH THE OUTER RAINBANDS DURING THE
MIDDLE PART OF THE WEEK.
FORECAST POSITIONS AND MAX WINDS
INIT 17/0900Z 20.6N 66.4W 110 KT 125 MPH
12H 17/1800Z 21.3N 67.9W 115 KT 130 MPH
24H 18/0600Z 22.5N 69.5W 125 KT 145 MPH
36H 18/1800Z 23.8N 70.6W 120 KT 140 MPH
48H 19/0600Z 25.2N 71.5W 115 KT 130 MPH
60H 19/1800Z 26.9N 72.1W 110 KT 125 MPH
72H 20/0600Z 28.9N 72.2W 105 KT 120 MPH
96H 21/0600Z 33.3N 70.2W 95 KT 110 MPH
120H 22/0600Z 38.6N 63.2W 85 KT 100 MPH
FORECASTER CANGIALOSI
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