je.st
news
Hurricane Dorian Forecast Discussion Number 29
2019-08-31 16:56:08| National Hurricane Center (Atlantic)
Issued at 1100 AM EDT Sat Aug 31 2019 000 WTNT45 KNHC 311456 TCDAT5 Hurricane Dorian Discussion Number 29 NWS National Hurricane Center Miami FL AL052019 1100 AM EDT Sat Aug 31 2019 Dorian's satellite presentation is outstanding with a distinct eye of about 15 n mi in diameter. Both NOAA and Air Force Hurricane Hunter planes have been penetrating the eye this morning and based on a blend of the flight-level and SFMR winds, the initial intensity has been adjusted upward to 130 kt in this advisory. Dorian is forecast to move over a deep layer of very warm waters, which is like high octane-fuel for hurricanes. The combination of the warm ocean and the prevailing low shear along Dorian's path should favor some additional strengthening, but most likely the hurricane will experience some fluctuations in intensity due to eyewall replacement cycles that are difficult to predict. Beyond 3 days, as the hurricane begins to gain in latitude a gradual weakening is anticipated. Plane fixes indicate that Dorian is moving toward the west or 280 degrees at 7 kt, steered by weak flow to the south of the ridge of high pressure over the western Atlantic. Most of the global models shift the high eastward and deepens a trough over the eastern United States beyond 2 days. This steering flow would typically favor a gradual turn of the hurricane to the northwest and north, however there is large uncertainty in the exact location and timing of this northward turn. Although the latest guidance has shifted a little bit eastward again this morning, there are still ECMWF and GFS ensemble members that do not forecast the northward turn so soon. On this basis, NHC prefers to shift the track forecast just a little bit to the right of the previous one, and the new official forecast lies along the western edge of the guidance envelope. This will allow for further adjustments in the track during future forecast cycles. Key Messages: 1. A prolonged period of life-threatening storm surge and devastating hurricane-force winds are expected in portions of the northwestern Bahamas, particularly on the Abaco Islands and Grand Bahama Island. A hurricane warning is in effect for these areas, and residents should listen to advice given by local emergency officials and have their hurricane preparations completed today. 2. Life-threatening storm surge and dangerous hurricane-force winds are still possible along portions of the Florida east coast by the early to middle part of next week, but since Dorian is forecast to slow down and turn northward near or just offshore of the coast, it is too soon to determine when or where the highest surge and winds could occur. 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. The risk of strong winds and dangerous storm surge is increasing along the coasts of Georgia, South Carolina, and North Carolina during the middle of next week. Residents in these areas should continue to monitor the progress of Dorian. 4. Heavy rains, capable of life-threatening flash floods, are expected over portions of the Bahamas and coastal sections of the southeastern United States this weekend through much of next week. FORECAST POSITIONS AND MAX WINDS INIT 31/1500Z 26.0N 73.4W 130 KT 150 MPH 12H 01/0000Z 26.2N 74.7W 135 KT 155 MPH 24H 01/1200Z 26.6N 76.2W 130 KT 150 MPH 36H 02/0000Z 26.8N 77.4W 125 KT 145 MPH 48H 02/1200Z 27.0N 78.0W 120 KT 140 MPH 72H 03/1200Z 28.0N 79.0W 115 KT 130 MPH 96H 04/1200Z 30.5N 80.0W 100 KT 115 MPH 120H 05/1200Z 33.5N 78.0W 95 KT 110 MPH $$ Forecaster Avila
Tags: number
discussion
forecast
hurricane
Category:Transportation and Logistics