817
WTNT45 KNHC 130238
TCDAT5
TROPICAL STORM ERIN DISCUSSION NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052025
1100 PM AST TUE AUG 12 2025
DEEP CONVECTION HAS RETURNED NEAR ERIN THIS EVENING, THOUGH IT
APPEARS TO MOSTLY BE WEST OF THE CENTER. AN ASCAT PASS FROM A FEW
HOURS AGO SHOWED MAXIMUM WINDS OF ABOUT THE SAME MAGNITUDE AS THE
EARLIER DATA, 35-40 KT, THOUGH IT DID DISPLAY A LARGER AREA OF
TROPICAL-STORM-FORCE WINDS. WITH NO SIGNIFICANT CHANGE IN THE
SATELLITE INTENSITY ESTIMATES, THE INITIAL WIND SPEED REMAINS 40 KT.
THE ENVIRONMENT AROUND ERIN GRADUALLY GETS MORE CONDUCIVE FOR
STRENGTHENING DURING THE NEXT DAY OR SO, INCLUDING A SLOW RISE IN
SSTS AND INSTABILITY. BY LATE THURSDAY, SSTS RISE ABOVE 28C WITH
CONTINUED LIGHT OR MODERATE SHEAR. THIS EVOLUTION SHOULD PROMOTE
SLOW INTENSIFICATION IN THE NEAR-TERM, FOLLOWED BY QUICK
INTENSIFICATION IN A COUPLE OF DAYS, ESPECIALLY IF ERIN CONTINUES
TO HAVE A SMALL CORE. THE NEW NHC INTENSITY FORECAST IS SIMILAR TO
THE PREVIOUS ONE, BUT A LITTLE HIGHER TO FOLLOW THE LATEST
CORRECTED CONSENSUS GUIDANCE. BEYOND 96 HOURS, THE GLOBAL MODELS
ALL SUGGEST THAT SHEAR WILL INCREASE, SO THE WIND SPEED IS LEVELED
OFF AT THAT POINT.
ERIN CONTINUES TO MOVE QUICKLY SOUTH-OF-DUE-WEST (260/17) DUE
TO STRONG LOW- TO MID-LEVEL RIDGING LOCATED TO THE NORTH OVER THE
CENTRAL AND EASTERN ATLANTIC. MODEL GUIDANCE HAS TRENDED A BIT
SOUTHWARD IN THE NEAR-TERM, SO THE FIRST DAY OR SO OF THE FORECAST
HAS BEEN ADJUSTED EQUATORWARD. IN A COUPLE OF DAYS, A WEAKENING OF
THAT RIDGE IS ANTICIPATED, WHICH SHOULD CAUSE ERIN TO BEGIN MOVING
WEST-NORTHWESTWARD BY FRIDAY. THERE ARE NO SIGNIFICANT CHANGES TO
THE LONG-RANGE NHC FORECAST, AND NOTE THAT THE 18Z GFS APPEARED TO
BE A SIGNIFICANT OUTLIER AND WAS MOSTLY DISREGARDED IN THIS PACKAGE.
THE NEW FORECAST REMAINS ALONG THE SOUTHERN PART OF THE GUIDANCE
ENVELOPE, LYING CLOSEST TO THE HFIP CORRECTED CONSENSUS (HCCA) AND
GOOGLE DEEP MIND (GDM) MODELS. KEEP IN MIND THAT NHC TRACK
FORECASTS HAVE AN AVERAGE ERROR OF 120-180 N MI (150-215 STATUTE
MILES) AT DAYS 4 AND 5, AND FUTURE ADJUSTMENTS IN THE FORECAST ARE
STILL POSSIBLE.
KEY MESSAGES:
1. ERIN COULD MOVE CLOSE ENOUGH TO THE NORTHERN LEEWARD ISLANDS,
VIRGIN ISLANDS, AND PUERTO RICO OVER THE WEEKEND TO PRODUCE SOME
IMPACTS ON THOSE ISLANDS. HOWEVER, THE MAGNITUDE OF THOSE IMPACTS
IS STILL NOT KNOWN, AND INTERESTS THERE SHOULD CONTINUE TO MONITOR
THE PROGRESS OF THIS STORM.
2. THERE IS EVEN GREATER UNCERTAINTY IN WHAT IMPACTS MIGHT OCCUR IN
PORTIONS OF THE GREATER ANTILLES, THE BAHAMAS, THE EAST COAST OF
THE UNITED STATES, AND BERMUDA NEXT WEEK. AS WE APPROACH THE
CLIMATOLOGICAL PEAK OF THE HURRICANE SEASON, THIS IS AN OPPORTUNE
TIME TO ENSURE YOUR PREPAREDNESS PLANS ARE IN PLACE.
FORECAST POSITIONS AND MAX WINDS
INIT 13/0300Z 16.7N 40.1W 40 KT 45 MPH
12H 13/1200Z 16.3N 42.6W 45 KT 50 MPH
24H 14/0000Z 16.2N 45.5W 45 KT 50 MPH
36H 14/1200Z 16.6N 48.4W 50 KT 60 MPH
48H 15/0000Z 17.3N 51.4W 60 KT 70 MPH
60H 15/1200Z 18.1N 54.6W 75 KT 85 MPH
72H 16/0000Z 18.9N 57.5W 85 KT 100 MPH
96H 17/0000Z 20.5N 62.6W 100 KT 115 MPH
120H 18/0000Z 22.5N 66.5W 100 KT 115 MPH
FORECASTER BLAKE
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