Issued at 500 AM AST Sat Aug 16 2025
767 WTNT45 KNHC 160835 TCDAT5 Hurricane Erin Discussion Number 20 NWS National Hurricane Center Miami FL AL052025 500 AM AST Sat Aug 16 2025 Erin is rapidly strengthening and is now a category 3 major hurricane. Satellite images indicate that Erin has a small eye and a compact and symmetric inner core. The hurricane has also been maintaining a large area of deep convection to the southwest of the core, and those outer rainbands are affecting the northern Leeward Islands. The Air Force Hurricane Hunters departed Erin a few hours ago, but on their last couple of passes through the center, the minimum pressure was steadily falling. Since the structure of the system has notably improved over the past few hours, the initial intensity is increased to 105 kt, and that could be conservative. Both the NOAA and Air Force Hurricane Hunters will be investigating Erin again later this morning, and that wealth of data will be very helpful in evaluating the cyclone's intensity and structure. The system continues to move fairly quickly to the west-northwest at about 17 kt on the south side of a subtropical ridge. This overall motion should continue through the weekend, taking the core of Erin to the north of the eastern Caribbean Islands through Sunday. After that time, the western side of the ridge is expected to weaken, due to a series of shortwave troughs, and that should cause Erin to slow down and make a gradual turn to the north. The models agree on this general theme, but there are some differences on where, when, and how sharply Erin makes the northward turn. The NHC track forecast is a touch to the left of the previous one to be in better agreement with the latest consensus aids. Confidence continues to increase that the core of Erin will pass to the east of the Bahamas and the United States. Erin is expected to continue to rapidly strengthen over the next 12 hours while it remains in favorable conditions of warm water, low wind shear, and in an environment of high moisture. Erin will likely become a Category 4 hurricane later today and strengthening could continue through tonight. By early next week, however, an increase in shear should end the strengthening trend and induce gradual weakening. The NHC intensity forecast lies above the guidance for the first 24 to 36 hours, and then falls near the middle of the guidance envelope after that. Although Erin is a somewhat compact hurricane now, the models are in strong agreement that the system will grow in size over the next several days. In fact, by the middle of next week, Erin is forecast to at least double or triple in size, which will result in rough ocean conditions over the western Atlantic. KEY MESSAGES: 1. Heavy rainfall at times through Sunday across the northern Leeward Islands, the Virgin Islands, and Puerto Rico may lead to locally considerable flash and urban flooding, along with landslides or mudslides. 2. Gusts to tropical storm force in Erin's outer rainbands are possible in portions of the the northern Leeward Islands later today and over portions of the Virgin Islands and Puerto Rico tonight and Sunday. 3. Erin is expected to produce dangerous surf and rip currents along the beaches of the Bahamas, much of the east coast of the U.S., and Atlantic Canada next week. 4. Interests in Bermuda should continue to monitor the progress of Erin since there is a risk of strong winds, heavy rainfall, and high surf by the middle part of next week. FORECAST POSITIONS AND MAX WINDS INIT 16/0900Z 19.8N 61.1W 105 KT 120 MPH 12H 16/1800Z 20.3N 63.3W 130 KT 150 MPH 24H 17/0600Z 21.1N 65.6W 130 KT 150 MPH 36H 17/1800Z 22.1N 67.5W 125 KT 145 MPH 48H 18/0600Z 23.3N 68.8W 120 KT 140 MPH 60H 18/1800Z 24.6N 69.8W 115 KT 130 MPH 72H 19/0600Z 26.2N 70.5W 110 KT 125 MPH 96H 20/0600Z 29.9N 70.9W 105 KT 120 MPH 120H 21/0600Z 34.7N 68.0W 95 KT 110 MPH $$ Forecaster Cangialosi/Gibbs