1. A prolonged period of catastrophic winds and storm surge will affect the Abaco Islands and Grand Bahama Island for several more hours. Everyone there should take immediate shelter and not venture into the eye.

2. Life-threatening storm surges and dangerous hurricane-force winds are expected along portions of the Florida east coast through mid-week, and storm surge and hurricane warnings are in effect. Only a slight deviation to the left of the official forecast would bring the core of Dorian near or over the Florida east coast. Residents should listen to advice given by local emergency officials.

3. There is an increasing likelihood 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 and listen to 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 through late this week.

WHAT'S NEW:

A Hurricane Watch has been extended northward from the Flagler/Volusia County Line to the Mouth of the St. Mary's River.

A Storm Surge Watch has also been extended northward from the Flagler/Volusia County Line to the Mouth of the St. Mary's River.

SUMMARY OF ALERTS:

A Storm Surge Warning is in effect for...
- Lantana to the Volusia/Brevard County Line

A Storm Surge Watch is in effect for...
- North of Deerfield Beach to Lantana
- Volusia/Brevard County Line to the Mouth of the St. Mary's River

A Hurricane Warning is in effect for...
- Northwestern Bahamas excluding Andros Island
- Jupiter Inlet to the Volusia/Brevard County Line

A Hurricane Watch is in effect for...
- Andros Island
- North of Deerfield Beach to Jupiter Inlet
- Volusia/Brevard County Line to the Mouth of the St. Mary's River

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

A Storm Surge Warning means there is a danger of lifethreatening inundation, from rising water moving inland from the coastline, during the next 36 hours in the indicated locations. For a depiction of areas at risk, please see the National Weather Service Storm Surge Watch/Warning Graphic, available at hurricanes.gov. This is a lifethreatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials.

A Storm Surge Watch means there is a possibility of life threatening inundation, from rising water moving inland from the coastline, in the indicated locations during the next 48 hours.

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.

A watch is typically issued 48 hours before the anticipated first occurrence of tropicalstormforce winds, conditions that make outside preparations difficult or dangerous.

A Tropical Storm Warning means that tropical storm conditions are expected within the warning area within 36 hours.

A Tropical Storm Watch means that tropical storm conditions are possible within the watch area, generally within 48 hours. Interests elsewhere along the east coast of Florida should continue to monitor the progress of Dorian, as additional watches or warnings may be required later today. For storm information specific to your area in the United States, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office. For storm information specific to your area outside of the United States, please monitor products issued by your national meteorological service.

WIND: [TOP] Catastrophic hurricane conditions continue in the Abacos and Grand Bahama Islands. Do not venture out into the eye, as winds will suddenly increase as the eye passes.

Hurricane conditions are expected within the hurricane warning area in Florida by late Monday or Tuesday.

Tropical storm conditions are expected within the tropical storm warning area on Monday and Tuesday and are possible in the tropical storm watch area by Monday night.

STORM SURGE: [TOP] 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 the Abaco Islands and Grand Bahama Island. Near the coast, the surge will be accompanied by large and destructive waves.

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 Mouth of the St. Mary's River...4 to 7 ft North of Deerfield Beach to Lantana FL...2 to 4 ft

The surge will be accompanied by large and destructive waves. Surge-related flooding depends on the how close the center of Dorian comes to the Florida east 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. Coastal Carolinas...5 to 10 inches, isolated 15 inches. The Atlantic Coast from the Florida peninsula through Georgia...3 to 6 inches, isolated 9 inches. Southeastern Virginia...2 to 4 inches, isolated 6 inches. Central Bahamas...2 to 4 inches, isolated 6 inches.

This rainfall may cause life-threatening flash floods.

SURF: [TOP] 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. Please consult products from your local weather office.

At 1100 PM EDT (0300 UTC), the center of Hurricane Dorian was located near latitude 26.6 North, longitude 77.9 West. Dorian is moving toward the west near 6 mph (9 km/h). A slower westward to west-northwestward motion is forecast during the next day or so, followed by a gradual turn toward the northwest. On this track, the core of extremely dangerous Hurricane Dorian will continue to pound Great Abaco and Grand Bahama islands overnight and through much of Monday. The hurricane will move dangerously close to the Florida east coast late Monday through Tuesday night.

Maximum sustained winds are near 180 mph (285 km/h) with higher gusts. Dorian is a category 5 hurricane on the Saffir-Simpson Hurricane Wind Scale. Slow weakening is forecast, but fluctuations in intensity could occur couple of days. Regardless, Dorian is expected to remain a powerful hurricane during the next few 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 914 mb (26.99 inches).

Dorian remains an incredibly powerful hurricane and it is currently making landfall on the eastern end of Grand Bahama Island. Satellite images show an symmetrical cyclone with a circular 10 n mi diameter eye and intense eyewall convection with lots of lightning being detected. Doppler radar data from Miami and the Bahamas show that Dorian has developed concentric eyewalls, and this feature is also noted by a double wind maximum that is evident in data from the Air Force Hurricane Hunters. The initial intensity of Dorian is set at 155 kt based mostly on the SFMR winds from the aircraft. The aircraft data also indicated that the radii of tropical-storm-force winds are a little larger than they were earlier today.

Dorian is still moving slowly westward at about 5 kt. The ridge to the north of Dorian is gradually weakening and shifting eastward in response to a mid- to upper-level trough that is moving across the eastern U.S. This change in the steering pattern should cause Dorian to slow down even more and perhaps stall, before it turns to the northwest late Monday or early Tuesday. This expected slow motion will likely be devastating to the Great Abaco and Grand Bahama Islands since it would prolong the catastrophic winds, storm surge, and rainfall over those areas. The timing of the northwest or north turn is very critical in determining how close Dorian will get to the Florida peninsula on Tuesday and Wednesday. In general, the track models have changed little from the previous cycle, and the NHC forecast continues to show the core of Dorian very near, but offshore, of the Florida peninsula on Tuesday and Wednesday. The hurricane is then expected to track near the Georgia and Carolina coasts late this week. This forecast is in best agreement with the various consensus models, which typically have the lowest errors. It is once again emphasized that although the official track forecast does not show landfall, users should not focus on the exact track. A small deviation to the left of the track could bring the intense core of the hurricane and its dangerous winds closer to or onto the Florida coast.

Category 5 hurricanes like Dorian usually don't hold that intensity for very long, and it is expected that Dorian will weaken slowly during the next few days. However, the observed eyewall replacement cycle will likely cause fluctuations in strength, both up and down, while the system is near Florida. The models show an increase in shear when Dorian tracks near Georgia and the Carolinas, which should cause more notable weakening. This forecast is near the high end of the latest model guidance.

Based on this forecast, the hurricane watch has been extended northward to the Florida-Georgia line.