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| #1106324 (Received by flhurricane at: 11:09 AM 08.Sep.2022) TCDAT1 Hurricane Earl Discussion Number 23 NWS National Hurricane Center Miami FL AL062022 1100 AM AST Thu Sep 08 2022 The convective structure of Earl this morning is interesting, with a large convective band with cloud tops below -70 C completing one full cyclonic orbit around the hurricane. The NOAA Hurricane Hunters earlier indicated that the central pressure had fallen from last night, with the final reading at 965 mb. However, the 700 mb flight level, SFMR, and tail Doppler radar winds have yet to respond to the continued falling pressure. Therefore, the wind speed this advisory will be held at 90 kt. Of note, the aircraft mission is reporting that Earl has a fairly large closed eye , with an estimated diameter of 50 n mi. Based on the last few center fixes, Earl is starting to make the turn to the north-northeast as it gradually accelerates, estimated at 030/11 kt. A shortwave trough in the process of moving offshore of the Eastern U.S. coastline and this feature, in combination with mid-level ridging to the east of Earl, is expected to cause Earl to bend further eastward as the flow accelerates. There have been very few changes made to the NHC forecast track over the first 24-48 hours, with Earl expected to pass 75-100 n mi to the southeast of Bermuda tonight into tomorrow morning. Shortly after 48 hours, Earl will be captured by the digging shortwave trough with model guidance indicating it will undergo a warm-seclusion-type extratropical transition. This process will also likely result in a substantial slow-down in the forward motion between 48-72 hours, and this portion of the track forecast has the largest along-track spread, related to the degree of phasing between Earl and this trough. Thereafter, their combination should begin to move eastward into the Atlantic Maritimes by the end of the forecast period, opting to favor a blend between the GFS and ECMWF track solutions. Per the latest SHIPS guidance, vertical wind shear over Earl is now under 10 kt and is forecast to remain that way for the next 24 hours as Earl traverses over 29 C sea-surface temperatures. Thus, steady intensification is expected, with the assumption that the current core structure of Earl fully consolidates and takes advantage of this favorable environment. The peak intensity of 115 kt is still under the latest LGEM and HCCA guidance. After 36 hours, Earl will begin to undergo extratropical transition as the trough interaction introduces substantial baroclinicity as vertical wind shear rapidly increases. Earl is expected to transition into a powerful hurricane-force extratropical low sometime between 48-60 hours, with this low filling rather quickly thereafter, in good agreement with the intensity consensus aids. KEY MESSAGES: 1. Although Earl`s center is forecast to pass southeast of Bermuda, tropical-storm-force winds are expected on the island this afternoon through early Friday morning. Hurricane-force winds are possible on Bermuda this evening or tonight if Earl`s track shifts farther west than is currently forecast. 2. Swells generated by Earl are building near Bermuda and are expected to reach the U.S. East Coast later today and tonight. 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 08/1500Z 29.0N 65.0W 90 KT 105 MPH 12H 09/0000Z 30.7N 64.2W 100 KT 115 MPH 24H 09/1200Z 33.5N 61.7W 110 KT 125 MPH 36H 10/0000Z 37.0N 57.7W 115 KT 130 MPH 48H 10/1200Z 40.9N 53.5W 100 KT 115 MPH 60H 11/0000Z 43.6N 49.9W 70 KT 80 MPH...POST-TROP/EXTRATROP 72H 11/1200Z 44.9N 48.1W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 12/1200Z 46.1N 46.2W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 13/1200Z 47.1N 40.7W 40 KT 45 MPH...POST-TROP/EXTRATROP $$ Forecaster Papin |
