448  
WTNT45 KNHC 211444  
TCDAT5  
 
HURRICANE ERIN DISCUSSION NUMBER 41  
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052025  
1100 AM EDT THU AUG 21 2025  
 
ERIN REMAINS A SPRAWLING HURRICANE, WITH ITS TROPICAL-STORM-FORCE  
WINDS EXTENDING NEARLY 500 N MI ACROSS. IN FACT, COMPARING ERIN WITH  
SYSTEMS AROUND THE SAME INTENSITY AND IN SIMILAR LOCATIONS OVER THE  
PAST COUPLE OF DECADES INDICATES THAT IT IS AROUND THE 90TH  
PERCENTILE IN SIZE. THE AIR FORCE HURRICANE HUNTERS INDICATE THAT  
THE PEAK WINDS HAVE COME DOWN A BIT, AND BASED ON THEIR DATA, THE  
INITIAL INTENSITY IS SET AT 85 KT. ALTHOUGH THE CORE OF ERIN IS  
PULLING AWAY FROM THE UNITED STATES, COASTAL FLOODING AND  
TROPICAL-STORM-FORCE WINDS CONTINUE ALONG PORTIONS OF THE NORTH  
CAROLINA AND VIRGINIA COASTS. THE CENTER OF ERIN PASSED JUST EAST OF  
NOAA BUOY 41001 EARLIER THIS MORNING, AND IT REPORTED A MINIMUM  
PRESSURE OF 962 MB AND A MAXIMUM SIGNIFICANT WAVE HEIGHT OF 45 FT.  
THE ASSOCIATED SWELLS ARE COVERING NEARLY THE ENTIRE WESTERN  
ATLANTIC FROM THE BAHAMAS TO ATLANTIC CANADA.  
 
ERIN IS MOVING NORTH-NORTHEASTWARD AT 16 KT. A TURN TO THE NORTHEAST  
OR EAST-NORTHEAST WITH A SIGNIFICANT INCREASE IN FORWARD SPEED  
WITHIN THE MID-LATITUDE WESTERLIES IS EXPECTED TO BEGIN TONIGHT,  
TAKING ERIN OUT TO SEA OVER THE NORTH ATLANTIC DURING THE NEXT  
SEVERAL DAYS. THE MODELS ARE IN GOOD AGREEMENT, AND ONLY MINOR  
CHANGES WERE MADE TO THE PREVIOUS NHC FORECAST.  
 
INCREASING SOUTHWESTERLY VERTICAL WIND SHEAR, DRIER MID-LEVEL AIR,  
AND COOLER SSTS SHOULD CAUSE ERIN TO GRADUALLY LOSE STRENGTH OVER  
THE NEXT SEVERAL DAYS. EXTRATROPICAL TRANSITION IS NOW EXPECTED TO  
BE COMPLETE BY EARLY SATURDAY, WHEN THE SYSTEM IS FORECAST TO  
DEVELOP FRONTS AFTER IT CROSSES THE NORTH WALL OF THE GULF STREAM.  
THE NHC INTENSITY FORECAST FOLLOWS HCCA AND IVCN IN THE SHORT TERM,  
BUT LEANS TOWARD THE GLOBAL MODEL GUIDANCE DURING THE PREDICTED  
EXTRATROPICAL PHASE.  
 
KEY MESSAGES:  
 
1. ERIN WILL CONTINUE 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.  
BEACHGOERS IN THOSE AREAS SHOULD FOLLOW ADVICE FROM LIFEGUARDS,  
LOCAL AUTHORITIES, AND BEACH WARNING FLAGS.  
 
2. STORM SURGE FLOODING AND TROPICAL STORM CONDITIONS WILL CONTINUE  
ON THE NORTH CAROLINA OUTER BANKS TODAY. THE STORM SURGE WILL BE  
ACCOMPANIED BY LARGE WAVES, LEADING TO SIGNIFICANT BEACH EROSION AND  
OVERWASH, MAKING SOME ROADS IMPASSIBLE.  
 
3. TROPICAL STORM CONDITIONS ARE EXPECTED TODAY ALONG THE VIRGINIA  
COAST. WIND GUSTS TO TROPICAL STORM FORCE ARE LIKELY ALONG  
PORTIONS OF THE REMAINDER OF THE U.S. MID-ATLANTIC AND SOUTHERN NEW  
ENGLAND COASTS TODAY THROUGH EARLY FRIDAY.  
 
4. TROPICAL STORM CONDITIONS ARE POSSIBLE ON BERMUDA THIS AFTERNOON  
THROUGH EARLY FRIDAY. GUSTS TO GALE FORCE ARE POSSIBLE ALONG THE  
COAST OF NOVA SCOTIA ON FRIDAY AND THE AVALON PENINSULA OF  
NEWFOUNDLAND ON SATURDAY.  
 
 
FORECAST POSITIONS AND MAX WINDS  
 
INIT 21/1500Z 35.4N 70.9W 85 KT 100 MPH  
12H 22/0000Z 37.0N 68.6W 80 KT 90 MPH  
24H 22/1200Z 39.1N 64.5W 80 KT 90 MPH  
36H 23/0000Z 41.0N 59.1W 75 KT 85 MPH  
48H 23/1200Z 43.2N 51.7W 70 KT 80 MPH...POST-TROP/EXTRATROP  
60H 24/0000Z 46.2N 43.7W 65 KT 75 MPH...POST-TROP/EXTRATROP  
72H 24/1200Z 49.4N 35.7W 60 KT 70 MPH...POST-TROP/EXTRATROP  
96H 25/1200Z 54.5N 25.0W 55 KT 65 MPH...POST-TROP/EXTRATROP  
120H 26/1200Z 56.9N 21.1W 45 KT 50 MPH...POST-TROP/EXTRATROP  
 
 
FORECASTER CANGIALOSI  
 
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