WTNT45 KNHC 152043 TCDAT5 Hurricane Erin Discussion Number 18 NWS National Hurricane Center Miami FL AL052025 500 PM AST Fri Aug 15 2025 Erin continues to slowly become better organized, with convective banding increasing near the center and a couple of attempts to form an eye. Earlier Air Force Reserve Hurricane Hunter data did not show any increase in winds after the previous advisory, although the central pressure fell to near 993 mb. Satellite intensity estimates are in the 60-75 kt range and are gradually increasing. The initial intensity is held at 65 kt pending the arrival of the next NOAA and Air Force aircraft this evening. The initial motion is 290 to 295 degrees at 15 kt. The subtropical ridge to the north will continue to steer Erin west-northwestward through the weekend, although the motion during the next 36 h or so may be closer to 285 degrees. After that time, encroaching mid-latitude westerly flow is forecast to cause a weakness to develop in the ridge, and this will cause Erin to gradually turn northward with a decrease in forward speed. The guidance remains in fairly good agreement through about 72 hours. After that time, there are still differences in both the forward speed and cross-track spread with regards the turn toward the north. The regional hurricane models again lie along the western edge of the guidance envelope, while the GFS remains on the eastern edge. Overall, though, there again has been little change in the guidance envelope and the new forecast track has only minor adjustments from the previous track. Erin is forecast to be in an environment of light to occasionally moderate northwesterly vertical shear and over sea surface temperatures that warm to 29-30C along the forecast track. However, there is also a large area of mid-level dry and African dust to the north of the hurricane, and the satellite appearance suggests Erin is ingesting tongues of dry air. Although the environment may not be ideal, the regional hurricane models are in excellent agreement that Erin will reach a peak intensity at or above 120 kt during the next 2-4 days. Based on this, the new intensity forecast now calls for a peak intensity of 125 kt in 72 h, and it is possible Erin could get stronger than this. As the hurricane gets stronger, there is a high chance that eyewall replacement cycles will cause fluctuations in intensity that are not included in the current forecast. It is also expected that Erin will become very large and powerful hurricane by the end of the forecast period in the southwestern Atlantic, and the current forecast wind radii at 96-120 h may not be large enough. 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 15/2100Z 18.9N 57.6W 65 KT 75 MPH 12H 16/0600Z 19.6N 59.9W 75 KT 85 MPH 24H 16/1800Z 20.4N 62.7W 90 KT 105 MPH 36H 17/0600Z 21.2N 65.1W 105 KT 120 MPH 48H 17/1800Z 22.3N 67.1W 115 KT 130 MPH 60H 18/0600Z 23.4N 68.5W 120 KT 140 MPH 72H 18/1800Z 24.8N 69.5W 125 KT 145 MPH 96H 19/1800Z 27.9N 70.6W 120 KT 140 MPH 120H 20/1800Z 32.2N 69.7W 115 KT 130 MPH $$