000 WTNT41 KNHC 091435 TCDAT1 Hurricane Earl Discussion Number 27 NWS National Hurricane Center Miami FL AL062022 1100 AM AST Fri Sep 09 2022 During the past six hours, Earl's satellite appearance has oscillated between periods of gaining symmetry and becoming more ragged, with the latter winning out right now. In fact, Earl's previously clear eye has become partially obscured by clouds during the last hour or two. Satellite-based intensity estimates range from 70-100 kt, but since those estimates generally haven't changed much since the last advisory, the hurricane's intensity is held at 85 kt for now. Whether Earl's recent satellite degradation is another temporary hiccup or the start of a weakening trend as it undergoes extratropical transition over the next 24 h isn't yet clear, but either way the intensity guidance is now in good agreement that little or no intensification is expected going forward. Dynamical models including the GFS and ECMWF are also in very good agreement that Earl will become post-tropical by Saturday afternoon or evening. This transition should coincide with the cyclone's maximum winds to decreasing sharply while the extent of its tropical storm or gale-force winds expands. The NHC intensity forecast shows a slightly faster rate of weakening than the previous advisory, but is still on the high end of the narrow intensity guidance envelope through 72 h. The official intensity forecast is based heavily on the consensus after that. Earl continues to accelerate toward the northeast ahead of an approaching shortwave trough off the New England and Atlantic Canada coasts. This should cause Earl to accelerate further today and tonight before it merges with the trough and slows to a relative crawl southeast of Newfoundland as a post-tropical cyclone in about 48 h. Around day 4-5, the broader mid-latitude system should move faster eastward, bringing extratropical Earl with it. Only minor adjustments were made to the NHC track forecast. KEY MESSAGES: 1. Swells generated by Earl are affecting Bermuda and the U.S. East Coast and are expected to reach Nova Scotia and Newfoundland tonight and on Saturday. These swells are likely to cause life-threatening surf and rip current conditions through the weekend. Please consult products from your local weather office. FORECAST POSITIONS AND MAX WINDS INIT 09/1500Z 34.2N 61.0W 85 KT 100 MPH 12H 10/0000Z 37.0N 57.9W 90 KT 105 MPH 24H 10/1200Z 41.0N 54.1W 85 KT 100 MPH 36H 11/0000Z 43.5N 52.0W 70 KT 80 MPH...POST-TROP/EXTRATROP 48H 11/1200Z 44.4N 51.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 60H 12/0000Z 45.1N 50.2W 45 KT 50 MPH...POST-TROP/EXTRATROP 72H 12/1200Z 45.5N 49.4W 40 KT 45 MPH...POST-TROP/EXTRATROP 96H 13/1200Z 45.5N 45.0W 35 KT 40 MPH...POST-TROP/EXTRATROP 120H 14/1200Z 46.0N 40.5W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster D. Zelinsky