Issued at 1100 PM EDT Mon Aug 18 2025
624 WTNT45 KNHC 190234 TCDAT5 Hurricane Erin Discussion Number 31 NWS National Hurricane Center Miami FL AL052025 1100 PM EDT Mon Aug 18 2025 Erin has weakened some since the last advisory. Multiple microwave overpasses show that the convection has eroded on the northwestern side and that the mid-level center is displaced to the southeast of the low-level center by northwesterly shear. Reports from NOAA and Air Force Reserve Hurricane Hunter aircraft show that the central pressure has risen to near 949 mb, and that flight-level winds at 8000 and 10000 ft are in the 105-115 kt range. The initial intensity is reduced to 110 kt for this advisory, and this could be a bit generous. It should be noted that the wind field has become very spread out, with flight-level winds of hurricane force noted by the two aircraft more than 100 n mi from the center. Erin has slowed its forward speed with the initial motion now 320/7 kt. The overall track reasoning remains unchanged, with Erin expected to turn northward during the next day or two into a break in the subtropical ridge, followed by recurvature into the westerlies with some acceleration thereafter. However, there is some spread in the track guidance in both direction and speed. The UKMET and ECMWF are slower and on the left side of the guidance envelope, while the GFS and Canadian are on the right side of the guidance and faster. The new forecast track is similar in direction to the previous track, but it is going to be slower than the previous track in deference to the ECMWF/UKMET and the consensus models. The dynamical model guidance suggests that the current shear should diminish in 18-24 h, and as that happens the upper-level winds become divergent over the hurricane. However, due to the current poor organization, it is unclear whether Erin will be able to take advantage of the more favorable environment. The intensity forecast first calls for some additional weakening due to the ongoing shear. After that, it calls for modest re-intensification as the upper-level winds become more favorable. Once Erin has recurved into the westerlies, there should be substantial weakening due to another round of shear and the onset of extratropical transition. Erin's expanding wind field will result in rough ocean conditions over much of the western Atlantic. It should be noted that the 34- and 50-kt wind speed probabilities beyond 36 hours in the text and graphical products are likely underestimating the risk of those winds occurring. This is because the forecast wind field of Erin is considerably larger than average compared to the wind field used to derive the wind speed probability product. KEY MESSAGES: 1. Heavy rainfall is expected into Wednesday for portions of the southeastern Bahamas. Flash and urban flooding are possible. 2. Tropical storm conditions are expected in the Turks and Caicos Islands and in the southeast Bahamas for a few more hours. Tropical storm conditions are possible in portions of the central Bahamas tonight through Tuesday. 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., Bermuda, and Atlantic Canada during the next several days. Beachgoers in those areas should follow advice from lifeguards, local authorities, and beach warning flags. 4. Tropical storm conditions and coastal flooding are possible in the North Carolina Outer Banks beginning late Wednesday where Tropical Storm and Storm Surge Watches are in effect. Interests in Bermuda should also monitor the progress of Erin as strong winds are possible beginning on Thursday. FORECAST POSITIONS AND MAX WINDS INIT 19/0300Z 24.4N 71.7W 110 KT 125 MPH 12H 19/1200Z 25.4N 72.3W 105 KT 120 MPH 24H 20/0000Z 27.1N 73.2W 105 KT 120 MPH 36H 20/1200Z 29.2N 73.7W 110 KT 125 MPH 48H 21/0000Z 31.4N 73.5W 110 KT 125 MPH 60H 21/1200Z 33.5N 72.5W 105 KT 120 MPH 72H 22/0000Z 35.4N 70.0W 100 KT 115 MPH 96H 23/0000Z 38.5N 62.9W 80 KT 90 MPH 120H 24/0000Z 41.1N 54.8W 65 KT 75 MPH $$ Forecaster Beven