...CATASTROPHIC AND LIFE-THREATENING FLOODING LIKELY ALONG PORTIONS OF THE NORTHERN GULF COAST...
Hurricane Sally Intermediate Advisory Number 21A
NWS National Hurricane Center Miami FL AL192020
700 AM CDT Wed Sep 16 2020
SUMMARY OF 700 AM CDT...1200 UTC...INFORMATION
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LOCATION...30.4N 87.6W
ABOUT 15 MI...25 KM NNE OF GULF SHORES ALABAMA
ABOUT 25 MI...40 KM WSW OF PENSACOLA FLORIDA
MAXIMUM SUSTAINED WINDS...100 MPH...155 KM/H
PRESENT MOVEMENT...NNE OR 20 DEGREES AT 3 MPH...6 KM/H
MINIMUM CENTRAL PRESSURE...967 MB...28.56 INCHES
WATCHES AND WARNINGS
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CHANGES WITH THIS ADVISORY:
The Storm Surge Warning has been discontinued west of Dauphin Island, Alabama.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Storm Surge Warning is in effect for...
* Dauphin Island Alabama to the Walton/Bay County Line Florida
A Hurricane Warning is in effect for...
* Mississippi/Alabama border to the Okaloosa/Walton County line Florida
A Tropical Storm Warning is in effect for...
* East of the Okaloosa/Walton County line Florida to Indian Pass Florida
* Mississippi/Alabama border to the Mouth of the Pearl River
A Storm Surge Warning means there is a danger of life-threatening inundation, from rising water moving inland from the coastline, during the next 12 hours in the indicated locations. This is a life-threatening 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 Hurricane Warning means that hurricane conditions are occurring somewhere within the warning area. Preparations to protect life and property should have been completed.
A Tropical Storm Warning means that tropical storm conditions are occurring within the warning area.
DISCUSSION AND OUTLOOK
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At 700 AM CDT (1200 UTC), the center of the eye of Hurricane Sally was located by NOAA Doppler weather radars near latitude 30.4 North, longitude 87.6 West. Sally is moving toward the north-northeast near 3 mph (6 km/h). A north-northeastward to northeastward motion at a slightly faster forward speed is expected later today and tonight, followed by a faster northeastward motion on Thursday. On the forecast track, the center of Sally will move across the extreme western Florida panhandle and southeastern Alabama through early Thursday, and move over central Georgia Thursday afternoon through Thursday night.
Doppler weather radar data indicate that the maximum sustained winds are near 100 mph (155 km/h) with higher gusts. Weakening is expected as the center moves inland today and tonight.
Hurricane-force winds extend outward up to 40 miles (65 km) from the center and tropical-storm-force winds extend outward up to 125 miles (205 km). A sustained wind of 74 mph (119 km/h) and a gust to 92 mph (148 km/h) were recently reported at the Pensacola Naval Air Station in Pensacola, Florida.
The estimated minimum central pressure based on surface observations is 967 mb (28.56 inches).
HAZARDS AFFECTING LAND
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RAINFALL: Through this afternoon, Sally will produce additional rainfall totals of 8 to 12 inches with localized higher amounts possible along and just inland of the central Gulf Coast from west of Tallahassee, Florida to Mobile Bay, Alabama. Storm totals of 10 to 20 inches to isolated amounts of 35 inches is expected. Historic and catastrophic flooding is unfolding. In addition, this rainfall will lead to widespread moderate to major river flooding.
Sally is forecast to turn northeastward after making landfall today and move across the Southeast through Friday, producing the following rainfall totals:
Southern and central Alabama to central Georgia: 4 to 8 inches, with isolated maximum amounts of 12 inches. Significant flash and urban flooding is likely, as well as widespread minor to moderate flooding on some rivers.
Western South Carolina into western and central North Carolina: 4 to 6 inches, with isolated maximum amounts of 9 inches. Widespread flash and urban flooding is possible, as well as minor to moderate river flooding.
Southeast Virginia: 2 to 5 inches, with isolated maximum amounts of 7 inches. Scattered flash and urban flooding is possible, as well as scattered minor river flooding.
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...
AL/FL Border to Okaloosa/Walton County Line, FL including Pensacola Bay and Choctawhatchee Bay...4-7 ft
Okaloosa/Walton County Line, FL to Walton Bay County Line, FL...2-4ft
Dauphin Island, AL to AL/FL Border including Bon Secour Bay...2-4 ft
Walton Bay County Line, FL to Chassahowitzka, FL including Saint Andrew Bay...1-3 ft
The deepest water will occur along the immediate coast in areas of onshore winds, where the surge will be accompanied by large and damaging waves. Surge-related flooding depends on the relative timing of the surge and the tidal cycle, 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.
WIND: Hurricane conditions are spreading onshore within the hurricane warning area in Florida and Alabama. Tropical storm conditions will continue in portions of the warning areas through tonight.
TORNADOES: A few tornadoes may occur today and tonight across portions of the Florida Panhandle, southern Alabama, and southwestern Georgia.
SURF: Swells from Sally will continue to affect the coast from the Florida Big Bend westward to southeastern Louisiana during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office.
Forecaster Brown
