|
Show Selection: |
| #1105617 (Received by flhurricane at: 5:00 PM 03.Sep.2022) TCDAT1 Tropical Storm Earl Discussion Number 4 NWS National Hurricane Center Miami FL AL062022 500 PM AST Sat Sep 03 2022 Earl has strengthened this afternoon. Satellite data indicate the previously exposed low-level center of the cyclone has been drawn underneath an area of deep convection, with cloud top temperatures colder than -70C. An Air Force Hurricane Hunter aircraft that recently investigated the storm reported max flight-level (925 mb) winds of 56 kt. This would support surface winds between 40 and 45 kt using a standard reduction factor. Based on these data, the cyclone`s improved satellite structure, and falling surface pressures throughout the day, the initial intensity of Earl is raised to 45 kt for this advisory. The cyclone has strengthened some today despite facing moderate deep-layer southwesterly shear. The shear is forecast to persist or even increase during the next couple of days, so some fluctuation in intensity is possible if the deep convection gets stripped away and the center becomes exposed again. But, sea-surface temperatures greater than 29C should continue to support convective development, and the overall trend in the latest intensity guidance favors at least slow strengthening into early next week. Then, the models suggest that favorable interaction with an upper-level trough over the warm waters of the western Atlantic will promote additional strengthening, along with a broadening of the wind field. The latest NHC intensity forecast has been raised closer to the HCCA and IVCN consensus aids, and it now brings Earl up to hurricane strength at days 4-5. The initial motion of Earl is west-northwestward, or 290/9 kt. The general forecast track reasoning has not changed. Earl is expected to slow down as it moves west-northwestward to northwestward over the next couple of days. A weakness in the subtropical ridge should allow the cyclone to gradually turn northward early next week, then move northeastward as it becomes steered by a mid- to upper-level trough over the western Atlantic. The official NHC forecast track is very similar to the previous forecast and lies slightly to the left of the HCCA and TVCA aids. 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 tonight and Sunday. Gusty winds, especially in squalls, area possible on those islands through Sunday. FORECAST POSITIONS AND MAX WINDS INIT 03/2100Z 19.3N 63.2W 45 KT 50 MPH 12H 04/0600Z 19.7N 64.3W 45 KT 50 MPH 24H 04/1800Z 20.5N 65.4W 50 KT 60 MPH 36H 05/0600Z 21.3N 66.0W 50 KT 60 MPH 48H 05/1800Z 22.2N 66.4W 55 KT 65 MPH 60H 06/0600Z 23.0N 66.6W 55 KT 65 MPH 72H 06/1800Z 24.1N 66.6W 60 KT 70 MPH 96H 07/1800Z 25.6N 65.6W 65 KT 75 MPH 120H 08/1800Z 27.7N 63.7W 75 KT 85 MPH $$ Forecaster Reinhart |
