At 1:00 pm, Hurricane Isaias is Emerging Over the Straits of Florida

SUMMARY OF 200 PM EDT…1500 UTC…INFORMATION

LOCATION…24.9N 78.4W
ABOUT 115 MI…185 KM S OF FREEPORT GRAND BAHAMA ISLAND
ABOUT 140 MI…225 KM SE OF FORT LAUDERDALE FLORIDA
MAXIMUM SUSTAINED WINDS…75 MPH…120 KM/H
PRESENT MOVEMENT…NW OR 305 DEGREES AT 12 MPH…19 KM/H
MINIMUM CENTRAL PRESSURE…990 MB…29.23 INCHES

WATCHES AND WARNINGS

A Hurricane Warning is in effect for…
* Boca Raton to the Volusia/Flagler County Line Florida
* Northwestern Bahamas

A Hurricane Watch is in effect for…
* Hallandale Beach to the south of Boca Raton Florida

A Storm Surge Watch is in effect for…
* Jupiter Inlet to Ponte Vedra Beach Florida

A Tropical Storm Warning is in effect for…
* North of Ocean Reef to the south of Boca Raton Florida
* Lake Okeechobee
* Volusia/Flagler County Line to Ponte Vedra Beach Florida

A Tropical Storm Watch is in effect for…
* North of Ponte Vedra Beach Florida to Altamaha Sound Georgia

Interests elsewhere along the southeast coast of the United States should monitor the progress of Isaias. Additional watches or warnings may be required later today.

DISCUSSION AND OUTLOOK

At 200 PM EDT (1800 UTC), the center of Hurricane Isaias was located by an Air Force Reserve Hurricane Hunter aircraft and the Miami NOAA Doppler weather radar near latitude 24.9 North, longitude 78.4 West. Isaias is moving toward the northwest near 12 mph (19 km/h). A general northwestward motion with some decrease in forward speed is expected for the next day or so, followed by a north-northwestward motion by late Sunday. On the forecast track, the center of Isaias will move over the Straits of Florida tonight and approach the southeast coast of Florida early Sunday morning. Isaias is then forecast to move near or along the east coast of the Florida peninsula Sunday and Sunday night.

Data from the reconnaissance aircraft and Doppler radar indicate that maximum sustained winds have decreased to near 75 mph (120 km/h) with higher gusts. Although Isaias has weakened after passing over Andros Island, some re-strengthening is expected tonight and Sunday morning when the cyclone will be moving over the warm waters of the Straits of Florida and the Gulf Stream. Isaias is forecast to remain a hurricane through Monday, followed by slow weakening beginning Monday night or Tuesday.

Hurricane-force winds extend outward up to 25 miles (35 km) from the center and tropical-storm-force winds extend outward up to 115 miles (185 km). A wind gust to 49 mph (80 km/h) was recently observed at Nassau, Bahamas. Doppler radar indicates that tropical-storm-force winds are located just offshore Broward and Miami-Dade Counties.

The estimated minimum central pressure is 990 MB (29.23 inches).

HAZARDS AFFECTING LAND

STORM SURGE: 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…

Jupiter Inlet to Ponte Vedra Beach FL…2-4 ft
North Miami Beach to Jupiter Inlet FL…1-3 ft

The deepest water will occur along the immediate coast near and to the right of the center, where the surge will be accompanied by large waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle and can vary greatly over short distances.

A dangerous storm surge will raise water levels by as much as 3 to 5 feet above normal tide levels in areas of onshore winds in the Northwestern Bahamas.

WIND: Hurricane conditions will continue to spread over the Northwestern Bahamas through today.

Hurricane conditions are expected to reach the coast within the hurricane warning area in Florida tonight and will spread northward through Sunday. Winds are expected to first reach tropical storm strength later today, making outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion. Tropical storm conditions are expected within the tropical storm warning area, and are possible within the watch area, over southern Florida by this afternoon or evening.

Tropical storm conditions are expected in the warning area in northeast Florida by late Sunday and are possible in the watch area in northeast Florida and southeast Georgia by Monday morning.

RAINFALL: Isaias is expected to produce the following rain accumulations:

Bahamas: 4 to 8 inches, with isolated maximum totals of 12 inches.

Cuba: 1 to 2 inches, with isolated maximum totals of 4 inches.

Eastern Florida: 2 to 4 inches, with isolated maximum totals of 6 inches.

Northeast Florida into coastal Georgia: 1 to 2 inches.

Carolinas into the mid-Atlantic, including the southern and central Appalachians: 2 to 4 inches, with isolated maximum totals of 6 inches.

Across the Northeast, from eastern Pennsylvania into New Jersey, southeast New York, and much of New England: 2 to 4 inches, with isolated maximum totals of 6 inches.

Heavy rainfall from Isaias could result in potentially life-threatening flash flooding in the Bahamas and flash and urban flooding, especially in low-lying and poorly drained areas in eastern Florida and across the Carolinas to the Mid-Atlantic and Northeast. Minor river flooding is possible across portions of the Carolinas and into Virginia.

SURF: Swells generated by Isaias are affecting portions of Hispaniola, eastern Cuba, the Turks and Caicos, and the Bahamas. These swells will spread along the east coast of Florida and the southeastern United States coast today. These swells are likely to cause life-threatening surf and rip current conditions.

Category: ALL POSTS, Severe Weather, Tropical