675
WTNT45 KNHC 151447
TCDAT5
HURRICANE ERIN DISCUSSION NUMBER 17
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052025
1100 AM AST FRI AUG 15 2025
ERIN HAS BECOME BETTER ORGANIZED DURING THE PAST SEVERAL HOURS. THE
LAST FEW NOAA AND AIR FORCE RESERVE AIRCRAFT PASSES THROUGH THE
CYCLONE HAVE INDICATED THE FORMATION OF AN EYEWALL, WITH THE AIR
FORCE RESERVE AIRCRAFT REPORTING 700-MB FLIGHT-LEVEL WINDS OF 75 KT
NORTHEAST OF THE CENTER. IN ADDITION, CONVENTIONAL SATELLITE IMAGERY
SHOWS THE DEVELOPMENT OF A CENTRAL DENSE OVERCAST, AND A RECENTLY
RECEIVED WSFM MICROWAVE OVERPASS SHOWS A WELL-DEFINED RING OF
SHALLOW TO MODERATE CONVECTION IN THE 37 GHZ IMAGERY. BASED ON
THESE DATA, THE INITIAL INTENSITY IS INCREASED TO 65 KT AND ERIN
BECOMES THE FIRST HURRICANE OF THE 2025 ATLANTIC HURRICANE SEASON.
THE INITIAL MOTION IS 290/15. THE SUBTROPICAL RIDGE TO THE NORTH
WILL CONTINUE TO STEER ERIN WEST-NORTHWESTWARD INTO THE WEEKEND.
ENCROACHING MID-LATITUDE WESTERLY FLOW IS FORECAST TO CAUSE A
WEAKNESS TO DEVELOP IN THE RIDGE DURING THE LATTER PART OF THE
FORECAST PERIOD, AND THIS WILL RESULT IN THE HURRICANE GRADUALLY
TURNING NORTHWESTWARD AND NORTHWARD BY 120 H. THE GUIDANCE REMAINS
IN FAIRLY GOOD AGREEMENT THROUGH ABOUT 60-72 HOURS. AFTER THAT TIME,
THERE ARE SOME DIFFERENCES IN BOTH THE FORWARD SPEED AND CROSS-TRACK
SPREAD WITH THE TURN TOWARD THE NORTH. THE REGIONAL HURRICANE MODELS
AGAIN LIE ALONG THE WESTERN EDGE OF THE GUIDANCE ENVELOPE, WHILE THE
GFS AND GOOGLE DEEPMIND MODELS REMAIN ON THE EASTERN EDGE. ALTHOUGH
STILL SPREAD, THE GUIDANCE ENVELOPE HAS NOT SHIFTED SIGNIFICANTLY
SINCE THE LAST ADVISORY, AND THE NEW TRACK FORECAST IS AN UPDATE OF
THE PREVIOUS FORECAST. THERE IS STILL UNCERTAINTY ABOUT WHAT IMPACTS
ERIN MAY BRING TO PORTIONS OF THE BAHAMAS, THE EAST COAST OF THE
UNITED STATES, AND BERMUDA IN THE LONG RANGE.
ERIN IS CURRENTLY IN A FAVORABLE ENVIRONMENT FOR STRENGTHENING,
ALTHOUGH THERE ARE SOME UNCERTAINTIES ON WHETHER DRY AIR IS
ENTRAINING INTO THE CORE. THE IMPROVED LOW-LEVEL STRUCTURE
INDICATES POTENTIAL FOR RAPID STRENGTHENING, AND BASED ON THIS THE
FIRST 36-48 H OF THE NEW INTENSITY FORECAST SHOWS A FASTER
DEVELOPMENT RATE. AFTER 48 H, THE HURRICANE IS FORECAST TO
ENCOUNTER SOME NORTHERLY TO NORTHWESTERLY VERTICAL SHEAR THAT SHOULD
AT LEAST SLOW DEVELOPMENT. HOWEVER, THE GLOBAL AND REGIONAL
HURRICANE MODELS ARE IN GOOD AGREEMENT THAT ERIN WILL BECOME A
POWERFUL AND INCREASINGLY LARGE HURRICANE OVER THE SOUTHWESTERN
ATLANTIC OVER THE WEEKEND AND INTO NEXT WEEK. IT SHOULD BE NOTED
THAT THE THE FLORIDA STATE SUPERENSEMBLE AND THE US NAVY COAMPS-TC
MODELS FORECAST HIGHER PEAK INTENSITIES THAN THE OFFICIAL FORECAST,
SO IT WOULD NOT BE TOO SURPRISING IF ERIN BECAME STRONGER THAN
CURRENTLY FORECAST.
KEY MESSAGES:
1. HEAVY RAINFALL TONIGHT THROUGH SUNDAY ACROSS THE NORTHERN LEEWARD
ISLANDS, THE VIRGIN ISLANDS, AND PUERTO RICO MAY LEAD TO ISOLATED
AND LOCALLY CONSIDERABLE FLASH AND URBAN FLOODING, ALONG WITH
LANDSLIDES OR MUDSLIDES.
2. TROPICAL STORM CONDITIONS ARE POSSIBLE FOR PORTIONS OF THE
NORTHERN LEEWARD ISLANDS, WHERE TROPICAL STORM WATCHES ARE IN
EFFECT, BEGINNING ON SATURDAY AS THE CORE OF ERIN PASSES NORTH OF
THOSE ISLANDS. GUSTS TO TROPICAL STORM FORCE ARE POSSIBLE IN
RAINBANDS OVER PORTIONS OF THE VIRGIN ISLANDS AND PUERTO RICO LATER
IN THE WEEKEND.
3. WHILE THE THREAT OF DIRECT IMPACTS IN THE BAHAMAS AND ALONG THE
EAST COAST OF THE UNITED STATES APPEARS TO BE GRADUALLY DECREASING,
THERE WILL STILL BE A SIGNIFICANT RISK OF DANGEROUS SURF AND RIP
CURRENTS ALONG WESTERN ATLANTIC BEACHES NEXT WEEK.
4. INTERESTS IN BERMUDA SHOULD CONTINUE TO MONITOR THE PROGRESS OF
ERIN SINCE THERE IS STILL A RISK OF STRONG WINDS, HEAVY RAINFALL,
AND HIGH SURF BY THE MIDDLE PART OF NEXT WEEK.
FORECAST POSITIONS AND MAX WINDS
INIT 15/1500Z 18.2N 56.1W 65 KT 75 MPH
12H 16/0000Z 18.9N 58.4W 75 KT 85 MPH
24H 16/1200Z 19.8N 61.4W 90 KT 105 MPH
36H 17/0000Z 20.6N 63.8W 105 KT 120 MPH
48H 17/1200Z 21.6N 66.0W 110 KT 125 MPH
60H 18/0000Z 22.7N 67.9W 115 KT 130 MPH
72H 18/1200Z 23.8N 69.2W 120 KT 140 MPH
96H 19/1200Z 26.5N 70.8W 115 KT 130 MPH
120H 20/1200Z 30.3N 71.0W 110 KT 125 MPH
FORECASTER BEVEN
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