Issued at 500 PM AST Sat Aug 16 2025
219 WTNT45 KNHC 162043 TCDAT5 Hurricane Erin Discussion Number 22 NWS National Hurricane Center Miami FL AL052025 500 PM AST Sat Aug 16 2025 Erin's rapid intensification may have bottomed out near 16Z based on the last couple of passes of data from an Air Force Reserve Hurricane Hunter. At that time, the maximum winds were near 140 kt and the central pressure was near 915 mb. Both Air Force and NOAA aircraft reported concentric eyewalls forming, and during the last couple of hours the small eye seen in conventional satellite imagery is becoming cloud-filled. This suggests an eyewall replacement cycle may be starting. The initial intensity is held at 140 kt pending the upcoming arrival of a NOAA Hurricane Hunter. The eye has started to gain latitude during the past few hours and the initial motion is now 280/13 kt - a little slower than before. The track guidance still suggests that Erin will turn back to the west-northwest with a decrease in forward speed during the next 6-12 h on the south side of a subtropical ridge. This motion should then continue through 24-36 h. After 36 h, the western side of the ridge is still expected to weaken, due to a series of shortwave troughs moving through the mid-latitude westerlies, and that should cause Erin to slow further and make a gradual turn to the north. However, there remains a significant spread in the guidance in just when this turn will occur, and the spread has increased due to the 12Z ECMWF forecast shifting to the west. Overall, the guidance envelope has shifted to the left during the entire forecast track, and the new forecast track is also shifted to the west. The new track is still to the east of the consensus models during the northward motion, and additional track adjustments may be necessary in later forecasts. Fluctuations in intensity are expected during the next 24 hours due to possible eyewall replacement cycles. However, Erin should remain a strong hurricane during this time. Between 24-72 h, increasing northwesterly shear should cause a gradual weakening, although there are likely to be fluctuations superimposed on this. After 72 h, the storm should start to encounter the mid-latitude westerlies where the shear will increase further. The new intensity forecast will show an increased weakening rate, but will keep Erin as a major hurricane as it will still be over warm sea surface temperatures during that time. 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. Tropical-storm conditions are possible in the Turks and Caicos Islands during the next 48 h, where a Tropical Storm Watch is now in effect. Gusts to tropical storm force in Erin's outer rainbands are likely in portions of the northern Leeward Islands through tonight and over portions of the Virgin Islands and Puerto Rico through Sunday. Tropical-storm force wind gusts are possible in the Southeast Bahamas beginning on Sunday. 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., 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 16/2100Z 20.0N 64.0W 140 KT 160 MPH 12H 17/0600Z 20.4N 65.7W 140 KT 160 MPH 24H 17/1800Z 21.4N 67.6W 140 KT 160 MPH 36H 18/0600Z 22.7N 69.2W 135 KT 155 MPH 48H 18/1800Z 24.0N 70.2W 130 KT 150 MPH 60H 19/0600Z 25.5N 70.9W 125 KT 145 MPH 72H 19/1800Z 27.3N 71.3W 120 KT 140 MPH 96H 20/1800Z 31.7N 70.8W 110 KT 125 MPH 120H 21/1800Z 36.8N 65.0W 100 KT 115 MPH $$ Forecaster Beven