Tropical Storm Sally will bring flooding rain and wind to the Central Gulf Coast early in the week, but first Paulette will pound Bermuda as a hurricane.
Gulf Coast residents were rushing preparations to completion on Monday as the region braced for another hit from a hurricane — a little over two weeks after Laura’s devastating blow to areas farther west. Sally slowly strengthened over the north-central Gulf of Mexico, with maximum sustained winds increasing to 65 mph Monday morning, as outer rain bands began soaking parts of the Florida Panhandle and western Florida. The storm is expected to strengthen further into a hurricane before it makes its first landfall over southeastern Louisiana late Monday evening.
Sally was churning 140 miles east-southeast of the mouth of Mississippi River around midday Monday. It was crawling slowly west-northwestward at 6 mph.
Forecasters expect Sally to continue strengthening into Monday night, reaching Category 1 intensity, with winds greater than 75 mph. Because of the wind, coastal flooding and inland flooding 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.
State of emergency declarations have been issued by Louisiana Gov. John Bel Edwards and Mississippi Gov. Tate Reeves prior to Sally closing in on the region. Mandatory evacuations have been ordered in low-lying areas of both states, including for areas outside of New Orleans levee system.
“Assuming Sally remains on its forecast track and speed, the first of a few landfalls will be over the marshland Mississippi Delta portion of Louisiana late Monday evening to very early Tuesday morning,” according to AccuWeather Senior Meteorologist Alex Sosnowski.
“Another landfall is possible in the marshy areas south of Lake Borgne, Louisiana later Tuesday morning with landfall on the U.S. mainly near the Louisiana/Mississippi border possible late Tuesday evening to early Wednesday morning,” Sosnowski added.
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. Edwards noted on Twitter that parts of Louisiana 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 formally requested pre-landfall assistance from President Donald Trump.
Sally was 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.
This image, captured around 8 a.m. CDT Monday, Sept. 14, 2020, shows thunderstorms erupting near the center and just to the east of the center of strong Tropical Storm Sally. (CIRA at Colorado State/GOES-East)
Torrential rain fell across South Florida as the tropical disturbance passed through. Marathon and Key West, Florida, both set preliminary daily and monthly rainfall records, with 8.13 inches and 9.37 inches falling, respectively, on Saturday.
The National Hurricane Center (NHC) issued a hurricane warning for areas from Morgan City, Louisiana, 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, Louisiana, 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 Monday.
Slow-and-steady strengthening is expected as Sally travels over the warm waters of the Gulf of Mexico. Sea surface temperatures were in the 80s to near 90 F, plenty warm to support strengthening of a tropical system, forecasters said.
“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.
All residents along the eastern and central Gulf coast should finalize preparations and heed all evacuation orders. Impacts from Sally will range from strong winds to heavy, flooding rainfall and dangerous storm surge.
With the anticipation of Sally becoming a hurricane 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 120 mph is possible near the track of the center of the storm.
Near the center of the storm, and to the east, is where coastal inundation is expected with Sally.
“The shape of the southeasterly Louisiana coast, combined with the circulation of the storm and the storm’s track will push a significant amount of water into Lake Borgne and Lake Pontchartrain,” Sosnowski said. “The levee system around New Orleans will be tested.”
Storm surge of 6-10 feet is anticipated in eastern Louisiana and along coastal portions of Mississippi with locally higher levels possible, 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 24 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.
“Rivers will be on the rise in the region, especially in portions of Mississippi and Alabama, where torrential rainfall will spread slowly inland,” Sosnowski said.
And Sally wasn’t the only system that meteorologists were busy monitoring on Monday. As Paulette slams Bermuda, Sally aims for the Gulf Coast and Rene harmlessly dissipates over the open Atlantic, forecasters are also keeping tabs on the latest additions to the basin — Tropical Storm Teddy and Tropical Storm Vicky. Sept. 14, 2020, marked the first time and the only other documented time since Sept. 10-12, 1971, that there have been five tropical cyclones swirling simultaneously in the basin.
Hurricane season does not officially end until the end of November, and forecasters say that named systems could emerge into December this year.