BRIEF OUTLOOK & CURRENT SITUATION
At 1100 AM EDT (1500 UTC), the eye of Hurricane Dorian was located near latitude 26.8 North, longitude 78.3 West, or around 30 northeast of Freeport, Grand Bahama Island. Dorian is moving very slowly toward the west near 1 mph (2 km/h). A slow westward to west-northwestward motion is forecast during the next day or so, followed by a gradual turn toward the northwest and north. On this track, the core of extremely dangerous Hurricane Dorian will continue to pound Grand Bahama Island through much of today and tonight. The hurricane will then move dangerously close to the Florida east coast late tonight through Wednesday evening and then move dangerously close to the Georgia and South Carolina coasts on Wednesday night and Thursday.
Maximum sustained winds are near 155 mph (250 km/h) with higher gusts. Dorian is an extremely dangerous category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale. Although gradual weakening is forecast, Dorian is expected to remain a powerful hurricane during the next couple of days.
Hurricane-force winds extend outward up to 45 miles (75 km) from the center and tropical-storm-force winds extend outward up to 140 miles (220 km).
The estimated minimum central pressure is 922 MB (27.23 inches).
Satellite and radar imagery shows that Dorian is moving very slowly over Grand Bahama Island this morning. The hurricane remains quite symmetric and still exhibits a very well-defined eye, but there is somewhat less evidence of concentric eyewalls in Bahamas radar imagery. Satellite intensity estimates from UW/CIMSS, SAB, and TAFB are slightly lower this morning, and the initial intensity has been reduced to 135 kt. As Dorian moves very slowly during the next 24 hours, some upwelling in the deeper waters around the Bahamas could cause some gradual weakening. After that time, the hurricane is expected to experience a gradual increase in southwesterly shear, which should lead to a slow decrease in wind speed. However, Dorian is forecast to remain a very powerful hurricane while it moves near the southeastern United States coast. The NHC intensity forecast is close to the statistical guidance during the first day or so, then near the HFIP corrected consensus model later in the period.
As anticipated, the ridge to the north of the storm has weakened and the eye of Dorian has only been inching westward this morning. The hurricane is expected to drift westward or west-northwestward over the next 24 hours, which will cause a prolonged period of devastating winds and storm surge over Grand Bahama Island. By late Tuesday, the weakness in the ridge becomes more pronounced and Dorian should turn northwestward near the east coast of Florida. By day 3, the hurricane is expected to make a northeastward turn ahead of a broad mid-latitude trough. The overall track envelope has not changed much, and little adjustment to the previous NHC forecast was required.
It cannot be stressed enough that only a small deviation to the left of the NHC forecast could bring the core of the extremely dangerous hurricane onshore of the Florida east coast within the hurricane warning area. In addition, Dorian’s wind field is predicted to expand, which would bring hurricane-force winds closer to the east coast of Florida even if the track does change.
CURRENT WATCHES & WARNINGS
A Storm Surge Warning is in effect for Lantana to the Flagler/Volusia County Line
A Storm Surge Watch is in effect for…
* North of Deerfield Beach to south of Lantana
* Flagler/Volusia County Line to the Savannah River
A Hurricane Warning is in effect for…
* Grand Bahama and the Abacos Islands in the northwestern Bahamas
* Jupiter Inlet to the Flagler/Volusia County Line
A Hurricane Watch is in effect for…
* North of Deerfield Beach to Jupiter Inlet
* Flagler/Volusia County Line to the Altamaha Sound Georgia
A Tropical Storm Warning is in effect for north of Deerfield Beach to Jupiter Inlet
A Tropical Storm Watch is in effect for…
* North of Golden Beach to Deerfield Beach
* Lake Okeechobee
HAZARDS AFFECTING LAND
WIND: Catastrophic hurricane conditions continue on Grand Bahama Island. Do not venture out into the eye, as winds will suddenly increase after the eye passes.
Hurricane conditions are expected within the Hurricane Warning area in Florida by late tonight or Tuesday. Hurricane conditions are possible in the Hurricane Watch area on Wednesday.
Tropical storm conditions are expected within the Tropical Storm warning area today and Tuesday and are possible in the Tropical Storm watch area by tonight.
STORM SURGE: A life-threatening storm surge will raise water levels by as much as 18 to 23 feet above normal tide levels in areas of onshore winds on Grand Bahama Island. Near the coast, the surge will be accompanied by large and destructive waves. Water levels should very slowly subside on the Abaco Islands during the day.
The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide…
Lantana to the Savannah River…4 to 7 ft
North of Deerfield Beach to Lantana…2 to 4 ft
Water levels could begin to rise well in advance of the arrival of strong winds. The surge will be accompanied by large and destructive waves. Surge-related flooding depends on how close the center of Dorian comes to the coast and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office.
RAINFALL: Dorian is expected to produce the following rainfall totals through late this week:
Northwestern Bahamas…12 to 24 inches, isolated 30 inches.
Central Bahamas…Additional 1 to 3 inches, isolated storm totals of 6 inches.
Coastal Carolinas…5 to 10 inches, isolated 15 inches.
Atlantic Coast from the Florida peninsula through Georgia…4 to 8 inches, isolated 10 inches.
This rainfall may cause life-threatening flash floods.
SURF: Large swells are affecting east-facing shores of the Bahamas and the Florida east coast, and will spread northward along the southeastern United States coast during the next few days. These swells are likely to cause life-threatening surf and rip current conditions.
TORNADOES: Isolated tornadoes are possible this afternoon into tonight along the immediate coast of east-central Florida.
1. A prolonged period of catastrophic winds and storm surge will continue to affect Grand Bahama Island through today and tonight. Everyone there should remain in shelter and not venture into the eye.
2. Life-threatening storm surge and dangerous hurricane-force winds are expected along portions of the Florida east coast and Georgia coast, regardless of the exact track of Dorian’s center. Water levels could begin to rise well in advance of the arrival of strong winds. Residents in these areas should follow the advice given by local emergency officials.
3. The risk of life-threatening storm surge and hurricane-force winds continues to increase along the coasts of South Carolina and North Carolina. Residents in these areas should follow the advice given by local emergency officials.
4. Heavy rains, capable of producing life-threatening flash floods, are expected over northern portions of the Bahamas and coastal sections of the Southeast and lower Mid-Atlantic regions of the United States into Friday.
All information from the National Hurricane Center.