| I know it's already been posted, but I wanted to start it in a new thread so the 11am info appears in the main list more visibly. Track: https://www.nhc.noaa.gov/refresh/graphics_at5+shtml/?cone#contents 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 Hurricane Dorian Advisory Number 29 NWS National Hurricane Center Miami FL AL052019 1100 AM EDT Sat Aug 31 2019 ...DORIAN'S FURY AIMING AT THE NORTHWESTERN BAHAMAS... SUMMARY OF 1100 AM EDT...1500 UTC...INFORMATION ----------------------------------------------- LOCATION...26.0N 73.4W ABOUT 415 MI...670 KM E OF WEST PALM BEACH FLORIDA ABOUT 260 MI...415 KM ENE OF THE NORTHWESTERN BAHAMAS MAXIMUM SUSTAINED WINDS...150 MPH...240 KM/H PRESENT MOVEMENT...W OR 280 DEGREES AT 8 MPH...13 KM/H MINIMUM CENTRAL PRESSURE...945 MB...27.91 INCHES WATCHES AND WARNINGS -------------------- CHANGES WITH THIS ADVISORY: None. SUMMARY OF WATCHES AND WARNINGS IN EFFECT: A Hurricane Warning is in effect for... Northwestern Bahamas excluding Andros Island A Hurricane Watch is in effect for... Andros Island A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. Preparations to protect life and property should be rushed to completion. A Hurricane Watch means that hurricane conditions are possible within the watch area. Interests in southern and central Florida should continue to monitor the progress of Dorian. Watches may be required for portions of the east coast of Florida later today. For storm information specific to your area, please monitor products issued by your national meteorological service. DISCUSSION AND OUTLOOK ---------------------- At 1100 AM EDT (1500 UTC), the distinct eye of Hurricane Dorian was located near latitude 26.0 North, longitude 73.4 West. Dorian is moving toward the west near 8 mph (13 km/h) and a slower westward motion should continue into early next week. On this track, the core of Dorian should move over the Atlantic well north of the southeastern and central Bahamas today, be near or over the northwestern Bahamas on Sunday, and move near the Florida east coast late Monday through Tuesday. Data from both NOAA and Air Force Hurricane Hunter planes indicate that the maximum sustained winds have increased to near 150 mph (240 km/h) with higher gusts. Dorian is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Some fluctuations in intensity are likely, but Dorian is expected to remain a powerful hurricane during the next few days. Hurricane-force winds extend outward up to 30 miles (45 km) from the center and tropical-storm-force winds extend outward up to 115 miles (185 km). The minimum central pressure reported from both reconnaissance planes was 945 mb (27.91 inches). HAZARDS AFFECTING LAND ---------------------- WIND: Hurricane conditions are expected in the hurricane warning area across the northwestern Bahamas by Sunday, with tropical storm winds beginning tonight. STORM SURGE: A life-threatening storm surge will raise water levels by as much as 10 to 15 feet above normal tide levels in areas of onshore winds in the northwestern Bahamas. Near the coast, the surge will be accompanied by large and destructive waves. RAINFALL: Dorian is expected to produce the following rainfall accumulations this weekend into the middle of next week: Northwestern Bahamas...10 to 15 inches, isolated 25 inches. Coastal sections of the southeast United States...4 to 8 inches, isolated 12 inches. Central Bahamas...2 to 4 inches, isolated 6 inches. This rainfall may cause life-threatening flash floods. SURF: Swells will begin affect the east-facing shores of the Bahamas, the Florida east coast, and the southeastern United States coast during the next few days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office. NEXT ADVISORY ------------- Next intermediate advisory at 200 PM EDT. Next complete advisory at 500 PM EDT. $$ Forecaster Avila |