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#903891 (Received by flhurricane at: 10:37 AM 20.Sep.2017) TCDAT2 Tropical Storm Jose Discussion Number 61 NWS National Hurricane Center Miami FL AL122017 1100 AM EDT Wed Sep 20 2017 The Air Force Hurricane Hunters have been investigating Jose this morning and found maximum flight-level winds of 78 kt at 5,000 feet and peak SFMR surface winds of 56 kt. Based on these data, the initial wind speed is set at 60 kt, which is slightly higher than the previous estimate. Jose remains a sprawling cyclone, with tropical storm force winds extending 180 n mi from the center. Although Jose does not have a purely tropical appearance, it still has a warm core and well-defined convective bands, especially to the north of the center. Jose is moving northeastward at 7 kt toward a mid- to upper-level trough over eastern Canada. A slightly slower northeastward to east-northeastward motion is expected through tonight. Thereafter, the trough is expected to lift out, allowing a mid-level high pressure system to build to the northwest of Jose. This will likely cause the storm to reverse its course and drift westward or west-southwestward. In about 3 days, however, the models suggest that Jose will be caught in very weak steering currents, and the NHC official track forecast now shows Jose stationary from 72 to 120 hours. The tropical storm is moving over a tight SST gradient associated with the north wall of the Gulf Stream current, and it will likely remain over this gradient for the next several days. These relatively cool SSTs and dry air should cause a slow weakening trend, and a gradual transition to a post-tropical cyclone. The NHC intensity forecast is not too different from the previous one and is in best agreement with the consensus models. KEY MESSAGES: 1. While the center of Jose is forecast to remain offshore of the U.S. east coast, the large cyclone is expected to cause some direct impacts in portions of New England during the next couple of days, and a tropical storm warning is in effect for Cape Cod, Block Island, Martha`s Vineyard, and Nantucket. 2. Minor to moderate coastal flooding is possible from Delaware to southern New England during the next several days. Please see products issued by local National Weather Service forecast offices. 3. Swells generated by Jose are affecting Bermuda and much of the U.S. east coast and will likely cause dangerous surf and rip current conditions for the next several days in these areas. 4. Jose is expected to produce additional rainfall accumulations of 1 to 2 inches over Martha`s Vineyard and Cape Cod, and 2 to 4 inches in Nantucket as it passes offshore today into Thursday. This rainfall could cause isolated flash flooding. FORECAST POSITIONS AND MAX WINDS INIT 20/1500Z 39.0N 70.0W 60 KT 70 MPH 12H 21/0000Z 39.5N 69.0W 60 KT 70 MPH 24H 21/1200Z 39.8N 68.1W 55 KT 65 MPH 36H 22/0000Z 39.6N 68.3W 45 KT 50 MPH 48H 22/1200Z 39.5N 69.0W 40 KT 45 MPH...POST-TROPICAL 72H 23/1200Z 39.3N 70.0W 40 KT 45 MPH...POST-TROPICAL 96H 24/1200Z 39.3N 70.0W 35 KT 40 MPH...POST-TROPICAL 120H 25/1200Z 39.3N 70.0W 30 KT 35 MPH...POST-TROPICAL $$ Forecaster Cangialosi |