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| #1105648 (Received by flhurricane at: 10:36 PM 03.Sep.2022) TCDAT1 Tropical Storm Earl Discussion Number 5 NWS National Hurricane Center Miami FL AL062022 1100 PM AST Sat Sep 03 2022 There are no indications that Earl has strengthened further than it did this afternoon. The low-level center is a little difficult to locate since it`s obscured by high-level cirrus clouds, but it appears to have moved out ahead of the deep convection again. The initial intensity remains 45 kt, and this fits a blend of the latest Dvorak estimates of T3.5 and T2.5 from TAFB and SAB, respectively. Earl continues to move west-northwestward, or 285/9 kt, to the south of a low- to mid-level ridge. However, a break is developing in the ridge over the western Atlantic, which should allow Earl to turn northwestward on Sunday, followed by a recurvature toward the north and northeast Tuesday through Thursday. Although the track models agree on this scenario, the biggest differences among them is the along-track component, or how much Earl accelerates toward the north and northeast on days 3 through 5. Interestingly, both the GFS and ECMWF ensemble means are well west and slower than their respective deterministic runs, and the deterministic GFS in particular is an extreme outlier and much faster than all other guidance by day 5 (likely because it carries a much stronger cyclone). With so many ensemble solutions slower and to the west, the updated NHC track forecast is placed to the west of many of the multi-model consensus aids, and it`s just slightly west of the previous forecast. The moderate to strong shear affecting Earl is unlikely to abate through much of the forecast period. Despite this shear, very warm waters of at least 29 degrees Celsius and an unstable atmospheric environment are expected to encourage gradual strengthening during the next couple of days. Then, around day 3, Earl could get an additional positive boost from interaction with an upper-level trough over the western Atlantic, and the official forecast shows the system reaching hurricane strength by day 4 and intensifying through the end of the forecast period. It should be noted that a few models show significant strengthening by days 4 and 5, but for now the official forecast is conservative and is only nudged upward toward the IVCN model consensus. Tropical-storm-force winds are still forecast to remain on the northern and eastern side of the circulation, and are not expected to move across the northern Leeward Islands, the Virgin Islands, or Puerto Rico. However, gusty winds in squalls are possible at these locations through Sunday. KEY MESSAGES: 1. Heavy rainfall from Earl is expected to lead to limited flash, urban, and small stream flooding impacts over the Leeward Islands, U.S. and British Virgin Islands, and Puerto Rico this weekend. Rapid rises on rivers and mudslides in areas of steep terrain are possible in Puerto Rico. 2. Earl is forecast to pass to the north of the the Virgin Islands and Puerto Rico overnight and on Sunday. Gusty winds, especially in squalls, area possible on those islands through Sunday. FORECAST POSITIONS AND MAX WINDS INIT 04/0300Z 19.5N 64.2W 45 KT 50 MPH 12H 04/1200Z 20.0N 65.3W 45 KT 50 MPH 24H 05/0000Z 20.9N 66.1W 50 KT 60 MPH 36H 05/1200Z 21.7N 66.6W 50 KT 60 MPH 48H 06/0000Z 22.7N 66.9W 55 KT 65 MPH 60H 06/1200Z 23.5N 67.0W 60 KT 70 MPH 72H 07/0000Z 24.3N 66.9W 60 KT 70 MPH 96H 08/0000Z 25.6N 65.8W 70 KT 80 MPH 120H 09/0000Z 27.5N 63.6W 80 KT 90 MPH $$ Forecaster Berg |
