000 WTNT45 KNHC 050255 TCDAT5 Hurricane Dorian Discussion Number 47 NWS National Hurricane Center Miami FL AL052019 1100 PM EDT Wed Sep 04 2019 Satellite imagery indicated that the cloud pattern associated with Dorian was a little better organized with a clear eye surrounded by a ring of very deep convection. This trend was confirmed with data from both NOAA and Air Force reconnaissance planes, which measured a minimum central pressure of 955 mb. SFMR and flight-level winds support an initial intensity of 100 kt. In fact, Dvorak numbers also call for 100 kt. Dorian could maintain this intensity for about 12 hours or so, but guidance is showing shear increasing, and that should result in gradual weakening. The intensity forecast is basically the same as the previous advisory, keeping Dorian at the border of category 2 or 3 intensity as it moves near the southeast coast of the United States. This forecast is consistent with the intensity models, which unanimously gradually weaken the cyclone. On the other hand, the wind field is expected to gradually expand during the next several days until the cyclone becomes extratropical near Atlantic Canada. Aircraft fixes yield a northward motion or 010 degrees at 6 kt. Dorian is already recurving as it is becoming steered by the south- southwesterly flow ahead of an eastward-moving mid-level trough. The track guidance is tightly clustered, and the NHC forecast follows very closely the multi-model consensus. No significant change to the previous track forecast was necessary. The forecast motion should bring the core of Dorian near the coast of South Carolina during the next 6 to 12 hours and over the Outer Banks of North Carolina between 24 and 36 hours. Since the NHC track prediction continues to take Dorian dangerously close to the southeast U.S. coast, all interests from Georgia to the Carolinas should remain vigilant to the possibility of experiencing destructive winds, flooding rains, and life- threatening storm surges from this hurricane. Key Messages: 1. Life-threatening storm surge and dangerous winds are expected along portions the coasts of Georgia, 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 coastal Georgia into the eastern Carolinas overnight. On Thursday, there is a high risk of flash flooding over coastal sections of the Carolinas, where significant, life-threatening, flash flooding is expected. FORECAST POSITIONS AND MAX WINDS INIT 05/0300Z 31.3N 79.6W 100 KT 115 MPH 12H 05/1200Z 32.2N 79.4W 100 KT 115 MPH 24H 06/0000Z 33.6N 78.1W 90 KT 105 MPH 36H 06/1200Z 35.2N 75.9W 85 KT 100 MPH...OVER NC OUTER BANKS 48H 07/0000Z 37.5N 72.2W 80 KT 90 MPH 72H 08/0000Z 45.0N 62.8W 65 KT 75 MPH 96H 09/0000Z 53.5N 52.5W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 10/0000Z 58.0N 38.5W 40 KT 45 MPH...POST-TROP/EXTRATROP $$ Forecaster Avila