Hurricane warnings in effect for Gulf Coast as Sally gathers strength

Sept. 12 (UPI) -- Hurricane and tropical storm warnings were in effect for portions of the U.S. Gulf Coast as AccuWeather meteorologists on Sunday continued monitoring the latest threat to the U.S.: Tropical Storm Sally, which had taken shape a day earlier.

Sally was gathering strength as it moved over the Gulf of Mexico, where water temperatures range from the low- to mid-80s F, and the storm is forecast to reach hurricane strength before making landfall along the Gulf Coast.

By 11 p.m. EDT on Sunday, the storm was centered 140 miles south-southwest of Panama City, Fla., and about 185 miles east-southeast of the mouth of Mississippi River. It was moving northwestward at 8 mph and maximum sustained winds had remained at 60 mph. Sally, formerly Tropical Depression 19, ramped up quickly and strengthened to a tropical storm at 2 p.m. EDT on Saturday afternoon.

Forecasters expect Sally to continue rapidly strengthening into Monday and anticipate Sally to become a Category 1 hurricane. Because of the wind and rain impacts combined, however, AccuWeather meteorologists have rated Sally a 2 on the AccuWeather RealImpact Scale for Hurricanes.

The AccuWeather RealImpact Scale for Hurricanes is a 6-point scale with ratings of less than one and 1 to 5 that was introduced by AccuWeather in 2019 to rate tropical systems based on multiple impacts, rather than just wind, like the Saffir-Simpson Wind Scale does.

As the system moved from the waters off Florida's southeast across the southern tip of the Sunshine State and over the Gulf, local officials along the Gulf Coast began taking action to prepare for Sally's arrival. Louisiana Gov. John Bel Edwards declared a state of emergency ahead of the storm's arrival and noted on Twitter that parts of his state were ravaged by Hurricane Laura late last month.

"This when combined with the COVID-19 pandemic, can make us all weary," Edwards said on Twitter. "I implore Louisianans to take their preparations seriously."

Mississippi Gov. Tate Reeves also signed a State of Emergency for Mississippi as Sally nears the coast. He also formally requested President Donald Trump for pre-landfall assistance.

With heavy rain and the threat of a life-threatening storm surge in the forecast, New Orleans mayor Latoya issued a mandatory evacuation order for areas that are located outside of the city's levee system. Cantrell said the order would go into effect at 6 p.m. local time on Sunday.

Sally is now the earliest named "S-Storm" to ever form in the Atlantic Ocean basin, beating out 2005's Hurricane Stan which was named on Oct. 2.

In less than 24 hours, Sally went from being a mass of showers and thunderstorms east of the Bahamas on Friday afternoon and to a tropical depression on Friday evening, before becoming a tropical storm on Saturday afternoon.

Torrential rain fell across South Florida as the tropical disturbance passed through. Marathon and Key West, Fla., both set preliminary daily and monthly rainfall records, with 8.13 inches and 9.37 inches falling, respectively, on Saturday.

The National Hurricane Center issued a hurricane warning for Morgan City, La., to Ocean Springs, Miss., as well as Lake Pontchartrain and Lake Maurepas including metropolitan New Orleans.

The National Hurricane Center issued a hurricane warning for areas from Morgan City, La., to the Mississippi/Alabama border, Lake Pontchartrain and Lake Maurepas, including metropolitan New Orleans. A hurricane watch is in effect for the Mississippi/Alabama border to the Alabama/Florida border.

A storm surge warning was issued for Port Fourchon, La., to the Alabama/Florida Border, Lake Pontchartrain, Lake Maurepas, Lake Borgne and Mobile Bay.

Beachgoers and boaters should be prepared for rapidly changing conditions that include sudden squalls, downpours and rough seas and surf. Sally could produce a couple of isolated tornadoes and waterspouts as its outer bands sweep along the western coast of Florida into Monday.

Slow-and-steady strengthening is expected as Sally travels over the warm waters of the Gulf of Mexico.

"With very warm water across the northeastern Gulf and relatively light vertical wind shear, Tropical Storm Sally is expected to have enough time to strengthen into a hurricane before making landfall," said AccuWeather Senior Meteorologist Adam Douty.

The water throughout the Gulf of Mexico is very warm, in the 80s to near 90 F, which is sufficiently warm to support strengthening of tropical systems.

All residents along the eastern and central Gulf coast should begin making preparations now for impacts from Sally, ranging from strong winds to heavy, flooding rainfall and storm surge.

With the anticipation of Sally reaching hurricane strength prior to landfall, damaging winds will also be a concern along the immediate coast.

Widespread wind gusts of 40 to 60 mph are expected from the central Florida Panhandle to eastern Louisiana, with the strongest wind near or east of the anticipated landfall.

An AccuWeather Local StormMax wind gust of 100 mph is possible near the track of the center of the storm.

Sally is expected to make landfall somewhere between southeastern Louisiana and the Mississippi-Alabama border on Tuesday.

Near the center of the storm, and to the east, is where coastal inundation is expected with Sally.

Storm surge of as much as 6-10 feet is anticipated in eastern Louisiana and along coastal portions of Mississippi, while storm surge of 1-3 feet extends all the way through the Florida Panhandle.

After moving inland, the storm will lose wind intensity, but continue to pull moisture northward into the Deep South.

Downpours are expected to spread across Louisiana, Mississippi and Alabama Monday into Wednesday.

"The heaviest downpours and highest rainfall accumulations are expected to set up over the Florida Panhandle, southern Alabama and southern Mississippi, and may persist for 48 hours in some locations," explained Douty.

With up to two days of heavy rain likely to deluge these areas, an AccuWeather Local StormMax of 18 inches is possible within this area along the Gulf Coast.

Significant, life-threatening flash flooding is possible due to such high rainfall amounts. Roads may become impassable and some communities may become cutoff from first responders and medical services for a time.

Between the potential threats closer to home and many others emerging from the depths of the basin, an unusual occurrence that hasn't happened since September of 1971 may unfold in the coming weeks. As many five named tropical systems may spin across the ocean at the same time by the middle of September. As of early Sunday morning, three named storms and one tropical depression were swirling in the Atlantic.

Tropical storms and hurricanes can form well beyond the statistical peak of hurricane season, which is Sept. 10-11.

Hurricane season does not officially end until the end of November, and named systems could emerge into December this year.

Once the list based on the English alphabet is exhausted, Greek letters will be assigned as names, and that has only happened one other time in history, in 2005.

Sign up for our daily Top News Newsletter

Sign Up
Continue Reading