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| #1105831 (Received by flhurricane at: 5:03 AM 05.Sep.2022) TCDAT1 Tropical Storm Earl Discussion Number 10 NWS National Hurricane Center Miami FL AL062022 500 AM AST Mon Sep 05 2022 Satellite imagery this morning shows that Earl continues to produce strong convection to the northeast of the center. However, data from the SHIPS model and analyses from CIMSS at the University of Wisconsin indicate that there is now 20-25 kt of southwesterly vertical shear impacting the cyclone. As a result, the low-level center remains located near or just outside of the southwestern edge of the main convective mass. Satellite intensity estimates have changed little since the last advisory, and data from NOAA buoy 41043 suggests the central pressure is still in the 998-1000 mb range. Based on this, the initial intensity remains 45 kt. Earlier scatterometer data showed that the circulation center was elongated from northeast to southwest, and recent wind obs suggest the northeast end of the elongation is near the NOAA buoy. Earl is turning more northward, with the initial motion now 335/4 kt. For the next three days or so, the storm should move slowly northward in the flow between the subtropical ridge to the east and a mid- to upper-level trough to the west and northwest. After that, a motion more toward the northeast is expected as Earl reaches the southern edge of the mid-latitude westerlies. The large-scale models are in poor agreement on the features in the westerlies that Earl will encounter, with the GFS showing stronger flow and a faster motion than the UKMET and ECMWF. The new forecast track is changed little through 60 h, then it is nudged a little westward based on a shift in the guidance envelope. The track lies close to the various consensus models, and the speed at the end is a compromise between the faster GFS and the slower UKMET/ECMWF. The large-scale models suggest that the current shear will persist for about the next 48 h. After 48-60 h, Earl may find a region of lighter shear that could allow more significant strengthening. The new intensity forecast is a little slower to intensify Earl through 48 h based on the shear forecast, and it is possible that Earl could strengthen less than forecast during this time. Later on, the new forecast is similar to the previous forecast. It should be noted that if Earl does find a more favorable environment later in the forecast period, there are several models with a higher 120-h forecast intensity than the current official forecast of 105 kt. While tropical-storm-force winds are still forecast to stay north of the northern Leeward Islands, the Virgin Islands, and Puerto Rico, training rainbands are producing heavy rainfall over portions of these islands. Users should refer to products issued by local weather offices in these areas. 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 today. Rapid rises on rivers and mudslides in areas of steep terrain are possible in Puerto Rico. Considerable flood impacts cannot be ruled out in areas that receive heavier rainfall totals. 2. Earl is forecast to remain to the north of the the Virgin Islands and Puerto Rico today, but gusty winds, especially in squalls, remain possible on those islands for a few more hours. FORECAST POSITIONS AND MAX WINDS INIT 05/0900Z 20.9N 65.3W 45 KT 50 MPH 12H 05/1800Z 21.7N 65.5W 50 KT 60 MPH 24H 06/0600Z 22.9N 65.7W 55 KT 65 MPH 36H 06/1800Z 24.0N 65.8W 60 KT 70 MPH 48H 07/0600Z 25.1N 65.9W 60 KT 70 MPH 60H 07/1800Z 26.2N 65.7W 70 KT 80 MPH 72H 08/0600Z 27.3N 65.4W 75 KT 85 MPH 96H 09/0600Z 30.0N 64.0W 90 KT 105 MPH 120H 10/0600Z 33.5N 60.0W 105 KT 120 MPH $$ Forecaster Beven |
