ZCZC MIATCDAT5 ALL TTAA00 KNHC DDHHMM Hurricane Dorian Discussion Number 48 NWS National Hurricane Center Miami FL AL052019 500 AM EDT Thu Sep 05 2019 Dorian continues to exhibit a large eye of about 50 n mi in diameter on satellite and radar images. Earlier data from hurricane hunter aircraft indicate little change to the minimum central pressure, and flight-level winds still support an intensity close to 100 kt at this time. Dorian should soon begin to experience increasing southwesterly shear, which should lead to at least slow weakening during the next couple of days. The official forecast maintains the cyclone at hurricane strength through 72 hours, which is in general agreement with the LGEM guidance and on the high side of the guidance suite. By 72 hours, the global models show Dorian becoming embedded within a baroclinic zone, and simulated satellite imagery from the ECMWF model depicts a highly asymmetric cloud pattern. Therefore, the NHC forecast shows the system becoming extratropical by that time. Dorian's initial motion is about 010/6 kt. The hurricane is currently moving through a break in the subtropical ridge. Within a day or so, the cyclone should turn northeastward with increasing forward speed in response to a broad mid-tropospheric trough to the north. The official track forecast remains in good agreement with the dynamical model consensus. The forecast track and wind radii now require the issuance of a tropical storm watch for extreme southeastern New England. The center of Dorian is still expected to move very near or over the coastline of the Carolinas and the southern Mid-Atlantic states. Residents of these areas should already be prepared for damaging winds, life-threatening storm surges, and flooding rains. Key Messages: 1. Life-threatening storm surge and dangerous winds are expected along portions the coasts of South Carolina and North Carolina, and portions of southeast Virginia and the southern Chesapeake Bay, regardless of the exact track of Dorian's center. Water levels could rise well in advance of the arrival of strong winds. Residents in these areas should follow advice given by local emergency officials. 2. Flash flooding will become increasingly likely across the eastern Carolinas today. There is a high risk of flash flooding over coastal sections of the Carolinas where life-threatening flash flooding is expected. FORECAST POSITIONS AND MAX WINDS INIT 05/0900Z 31.7N 79.5W 100 KT 115 MPH 12H 05/1800Z 32.7N 78.9W 95 KT 110 MPH 24H 06/0600Z 34.2N 77.2W 90 KT 105 MPH 36H 06/1800Z 36.1N 74.5W 85 KT 100 MPH 48H 07/0600Z 38.3N 70.8W 80 KT 90 MPH 72H 08/0600Z 46.0N 61.5W 65 KT 75 MPH...POST-TROP/EXTRATROP 96H 09/0600Z 53.0N 52.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 10/0600Z 58.0N 38.0W 40 KT 45 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch