The New Orleans area, the River Parishes and three central Louisiana coastal parishes are under a tropical storm warning for a weak but moisture-intense low pressure system that is likely to strengthen before making landfall near Morgan City early Saturday, according to the National Hurricane Center.
In southeast Louisiana, the warning covers Ascension, Assumption, Livingston, Jefferson, Orleans, Lafourche, Plaquemines, St. Bernard, St. Charles, St. James, St. John the Baptist, St. Tammany, Tangipahoa and Terrebonne parishes. Along the central coast, it covers Iberia, St. Mary and Vermilion parishes but not Lafayette.
While included in heavy rainfall advisories, Baton Rouge and adjacent parishes are in the warning area.
Gov. John Bel Edwards declared a state of emergency after the Hurricane Center labeled the system Potential Tropical Cyclone Three on Thursday afternoon and predicted it will become Tropical Storm Claudette on Friday afternoon. Forecasters warn not to focus on the storm’s center, as its biggest effect is expected to be the delivery of as much as 10 inches of rain to the north and east of the center. That would inundate portions of Louisiana east of the Atchafalaya River and parts of Mississippi and Alabama.
The storm could deliver wind gusts of greater than 45 mph and a possible tornado or two in southeast Louisiana from Friday evening through Saturday.
“Right now everyone in Louisiana along the coast needs to be paying attention,” Gov. John Bel Edwards said Thursday, “because we have rivers that are already high and drainage ditches that are already full. Smaller rain than we may have experienced last month could be just as catastrophic.”
At 7 p.m., the storm’s center was about 455 miles south of Morgan City with maximum sustained winds of 30 mph. It was moving north at 9 mph. It’s expected to reach tropical storm strength by Friday evening, when it approaches the Louisiana coast, then weaken back to tropical depression strength after making landfall early Saturday.
The tropical storm warning covers the Gulf Coast from Intracoastal City in Louisiana to the Alabama-Florida border and includes metropolitan New Orleans and lakes Pontchartrain and Maurepas.
A flash flood watch has been issued for all of southeast Louisiana and south Mississippi from Friday afternoon through Sunday morning, with 6 to 10 inches of rain expected and possibly higher amounts at some locations. In New Orleans and Baton Rouge, as much as 8 inches of rain is expected.
A coastal flood warning is in effect from Intracoastal City east along the east bank of the Mississippi River and extending along the Mississippi Gulf Coast to the Alabama line. Between 2 and 3 feet of water are expected, but the National Hurricane Center decided against issuing more stringent storm surge watches and warnings.
A coastal flood advisory for 1 to 2 feet of water is in effect for areas along the north, south and western shores of lakes Pontchartrain and Maurepas, where high tides might also be elevated by rainwater from the storm over the next few days.
“Visible satellite images show that the cloud pattern associated with the broad area of low pressure located over the southwestern Gulf of Mexico is gradually becoming better organized,” National Hurricane Center meteorologists Richard Pasch and Dan Brennan said at 4 p.m. “Deep convection is beginning to form a broad curved band over the eastern portion of the system, similar to what one might see in a developing subtropical cyclone.”
“Although the upper-level winds are not particularly favorable for development, with lots of westerly shear over the area, the global models do suggest tropical/subtropical cyclogenesis within the next 12 hours or so,” they said. “Given the proximity of the disturbance to land, which requires tropical storm warnings at this time, advisories are being initiated on this system as a potential tropical cyclone.”
An Air Force Reserve Hurricane Hunter airplane based at Keesler Air Force Base, Mississippi, investigated the system on Thursday afternoon did not find a well-defined center. Forecasters think there won’t be much strengthening of the storm before it makes landfall.
After landfall, the system is predicted to turn northeast and head toward the southern Appalachian Mountains.
In New Orleans, officials urged residents to move vehicles to neutral grounds beginning Friday at noon, and warned them not to block intersections, streetcar tracks, sidewalks or bicycle paths.
The Sewerage & Water Board is expected to watch the storm carefully. The agency has all main drainage pumps working but only half of its in-house power system’s electric generators available. Two main workhorse turbines remain down since one exploded in late 2019 and the other failed ahead of Hurricane Zeta in 2020. Repairs aren’t expected to be complete until late in the 2021 hurricane season.
S&WB officials say their system can handle from 2 to 6 inches of rain at a time.
In Jefferson Parish, government administration officials said they were closely monitoring the weather. They said 192 permanent pumps were operational and eight more portable pumps have been sent to Grand Isle and Lafitte. Public Works officials said workers were cleaning catch basins and drain lines, but they urged residents to clear debris from streets and drains to reduce street flooding.
“Residents are reminded to stay indoors and away from windows during severe weather events,” the administration said. “In the event of a tornado, shelter in an interior room on the ground floor.”