It’s the latest in a seemingly ceaseless barrage of storms to target the country this year. Zeta is set to become the 11th named storm to impact the Lower 48 since May. Four hurricanes have hit the Gulf Coast so far, with two of them — Laura and Delta — hitting within 15 miles of each other in western Louisiana.
After striking the Yucatán Peninsula, the storm reemerged over the Gulf of Mexico on Tuesday, and is expected to intensify and reach hurricane intensity while churning northward and increasing its forward speed.
“Hurricane conditions and life-threatening storm surge are expected along portions of the northern Gulf Coast by late Wednesday,” the National Hurricane Center wrote.
Hurricane warnings span the coastline from Morgan City, La., to the Mississippi-Alabama state border. That includes New Orleans proper and much of the Mississippi River Delta. Lake Pontchartrain and Lake Maurepas are included in the warning.
Farther east, a tropical storm warning continues along the shore to the Okaloosa-Walton County line in the Florida Panhandle.
Storm surge warnings cover a broader area from the Mouth of the Atchafalaya River in La. to Navarre, Fla., highlighting the risk for a widespread two-to-four foot surge with inundation in some areas of as much as six feet possible.
After coming ashore sometime late Wednesday as a strong tropical storm or Category 1 hurricane, Zeta will weaken and move across the Southeast and Mid-Atlantic as a tropical rainstorm, with heavy rainfall totals and the potential for localized flooding.
At 11 p.m. Eastern time Tuesday, Tropical Storm Zeta contained maximum sustained winds of 70 mph and was gaining strength. Centered 435 miles south of New Orleans, the storm was barreling to the northwest at 15 mph.
“Satellite images show that Zeta is becoming better organized tonight with a ragged eye feature now present, plenty of deep convection and a more symmetric appearance,” the Hurricane Center wrote.
By Wednesday morning, the Hurricane Center predicts Zeta to regain hurricane intensity. “The improving cloud pattern of Zeta is usually one that favors intensification in the short term,” the Hurricane Center wrote.
Before emerging in the Gulf of Mexico Tuesday afternoon, Zeta produced sustained winds of 74 mph with a gust to 87 mph just south of Playa del Carmen, Mexico, early Tuesday. Winds in Cancun gusted to 79 mph. Zeta is the third named storm to hit the Yucatán Peninsula in just over two weeks, joining Gamma and Delta.
The wind threat
The strongest winds will be found within Zeta’s core and just to the east, with gusts topping 75 mph likely along the immediate coastline in extreme southeast Louisiana, coastal Mississippi and southwest Alabama. A few 85 mph gusts may be clocked in elevated locations near the beaches.
There remains a chance that Zeta could intensify at the last minute and come ashore stronger than forecast, perhaps reaching Category 2 strength. That would present the risk of higher wind gusts in exposed locations, but that does not yet appear likely.
In metropolitan New Orleans, damaging wind gusts to 70 mph are possible, with higher gusts over Lake Pontchartrain, if the storm’s center passes overhead as is anticipated.
Winds will weaken significantly as the system moves inland from the Gulf of Mexico, with 35 to 45 mph gusts in inland areas of south-central Mississippi and much of central Alabama and western Georgia.
A couple of isolated tornadoes can’t be ruled out in Zeta’s spiral rain bands east of the center.
Storm surge flooding
Storm surge could present a danger to numerous areas along the Gulf Coast, since Zeta will strike a low-lying region that is highly susceptible to inundation. Surge refers to the storm-driven rise in water above normally dry land at the coast.
Even though Zeta may only be a low-end hurricane, the slope of the sea floor and low elevation of land makes the region especially vulnerable. Sea level rise and land subsidence is increasing southeastern Louisiana’s susceptibility to storm surge flooding, in particular, and some coastal defenses in Louisiana may have been weakened by recent storms.
A surge of up to four to six feet is possible east of New Orleans, including on Lake Borgne. Mobile Bay in Alabama could experience a similar surge The surge could be a bit higher — between 5 and 8 feet — in coastal Mississippi.
Flanking those zones, a two to four foot surge is more likely, including on Lake Pontchartrain.
The greatest surge will occur near and east of Zeta’s center, where onshore winds will be more effective at piling water up against the coast.
Heavy rainfall will stretch well inland
A widespread two to four inches of rain is likely where Beta’s core passes, with localized four-to-six-inch amounts are possible in a swath from southeastern Louisiana through Mississippi and Alabama and potentially into northwestern Georgia. The greater Atlanta area is already under a flash flood watch because of the expectation of heavy downpours there.
Meanwhile, Zeta could also interact with a stalled cold front to bring what meteorologists refer to as a “Predecessor Rain Event,” or PRE, across portions of the Tennessee and Missouri valleys. Moisture north of Zeta will be squeezed out of the air by the front, converted into heavy rainfall that could lead to isolated four-inch totals from eastern Arkansas to southern Kentucky and west-central Tennessee. Some of that rain could break out as soon as Tuesday afternoon.
Zeta’s remnants could eventually merge with the cold front and deposit a two-to-three-inch slug of rainfall in the Mid-Atlantic on Thursday, affecting cities including Washington, Baltimore, Philadelphia and New York. The moisture will probably sweep through southern New England, too.
Where exactly the heaviest rain falls remains to be seen, but the potential exists in these areas for a late-week soaker.
Jason Samenow contributed to this article.