000 WTNT45 KNHC 010859 TCDAT5 Hurricane Dorian Discussion Number 32 NWS National Hurricane Center Miami FL AL052019 500 AM EDT Sun Sep 01 2019 Dorian continues to exhibit a well-defined eye surrounded by very cold cloud tops on satellite images. Observations from an Air Force Hurricane Hunter aircraft from several hours ago indicated that the intensity was still near 130 kt, and since the cloud pattern remains very impressive, it is assumed that Dorian has at least maintained that strength through the present time. The hurricane will remain in a fairly low-shear environment for the next few days, however since it is forecast to move quite slowly over the shallow waters of the northwesternnmost Bahamas through Monday, this would likely result in less available oceanic heat content. Therefore, a very slow weakening is anticipated to commence after 12 hours or so. The official intensity forecast is near the high end of the numerical guidance suite. The hurricane continues moving westward, or about 280/7 kt. A high pressure ridge to the north of Dorian should maintain this westward movement through today. By tonight, the global models show the ridge weakening, and this evolution should result in a slowing of the forward speed, with the hurricane becoming nearly stationary around 48 hours. In comparison to its earlier runs, the new ECMWF track forecast takes the system farther to the west during the next couple of days, and is the southwesternmost model through 48 hours. As a result, the official track forecast has been shifted a little west during that time frame. In 2 to 4 days, Dorian should turn northward in response to a trough over the eastern United States. By the end of the period, the flow on the south side of the trough should cause the cyclone to move northeastward near the Carolinas. The westward shift of the NHC track within the first 48 hours necessitates the change from a Tropical Storm Watch to a Tropical Storm Warning for a portion of the Florida east coast. Although the official track forecast does not show landfall, users should not focus on the exact track since a Florida landfall is still a distinct possibility. Key Messages: 1. A prolonged period of life-threatening storm surge, devastating hurricane-force winds, and heavy rains capable of producing life-threatening flash floods are expected on the Abaco Islands and Grand Bahama through Monday, and a hurricane warning is in effect for these areas. 2. A tropical storm warning is now in effect for a portion of the Florida east coast. Since Dorian is forecast to slow down and turn northward as it approaches the coast, life-threatening storm surge and dangerous hurricane-force winds are still possible along portions of the Florida east coast by the middle part of this week. Residents should have their hurricane plan in place, know if they are in a hurricane evacuation zone, and listen to advice given by local emergency officials. 3. There is an increasing risk of strong winds and dangerous storm surge along the coasts of Georgia, South Carolina, and North Carolina later this week. Residents in these areas should continue to monitor the progress of Dorian. 4. Heavy rains, capable of producing life-threatening flash floods, are possible over coastal sections of the southeast and lower mid-Atlantic regions of the United States through late this week. FORECAST POSITIONS AND MAX WINDS INIT 01/0900Z 26.4N 76.0W 130 KT 150 MPH 12H 01/1800Z 26.6N 77.1W 135 KT 155 MPH 24H 02/0600Z 26.7N 78.1W 125 KT 145 MPH 36H 02/1800Z 26.9N 78.7W 120 KT 140 MPH 48H 03/0600Z 27.0N 79.0W 120 KT 140 MPH 72H 04/0600Z 28.9N 79.8W 100 KT 115 MPH 96H 05/0600Z 31.8N 79.6W 85 KT 100 MPH 120H 06/0600Z 34.5N 76.0W 80 KT 90 MPH $$ Forecaster Pasch