Hurricane Delta forecast: See where it might come ashore and why the entire state is threatened | Environment

Noble Horvath

A slightly weaker but still dangerous Hurricane Delta is poised to deliver life-threatening storm surge, Category 2 force winds, and heavy rain along the central Louisiana coastline when it slams ashore just west of Avery Island on Friday afternoon, according to the National Hurricane Center. Forecasters with the Slidell and […]

A slightly weaker but still dangerous Hurricane Delta is poised to deliver life-threatening storm surge, Category 2 force winds, and heavy rain along the central Louisiana coastline when it slams ashore just west of Avery Island on Friday afternoon, according to the National Hurricane Center.

Forecasters with the Slidell and Lake Charles offices of the National Weather Service warned that conditions are likely to deteriorate along the western and central Louisiana coast by Thursday night, as Delta’s outer bands bring rain and possible tropical storm force gusts ashore.


LATEST:  These metro areas are now under hurricane, tropical storm warnings as Delta nears Gulf


In a Wednesday afternoon news conference, Gov. John Bel Edwards warned that if Delta took a jog to the east – as Hurricane Sally did last month – New Orleans could be squarely in its path. A slight shift west could provide another devastating blow to southwest Louisiana, which is still struggling to recover from Hurricane Laura.

And he also warned that Delta would remain a dangerous wind and flood threat throughout its 24-hour journey across the state.



Hurricane and tropical storm watches for Delta




“Delta is forecast to be a hurricane as far north as central Louisiana, too,” Edwards said. “We saw this with Hurricane Laura. We’re not just speaking to Louisiana residents in the coastal area of our state. We’re speaking to everybody in the state of Louisiana today. In fact, we don’t expect the hurricane to become a tropical storm until the time it exits northeast Louisiana.”  

Edwards said that President Donald Trump had already called him about the state’s request for a federal emergency disaster declaration, which would make the state eligible for reimbursement of emergency expenses associated with Delta. Edwards said Trump promised to sign the request.

Trump tweeted Wednesday that he had spoken with Edwards and Texas Gov. Greg Abbott and urged residents in the path of the storm to stay safe.

Hurricane Delta moves into the Gulf of Mexico on Wednesday afternoon.

In a 4 p.m. Wednesday forecast, the hurricane center said the storm would have 105 mph winds when it was about 30 miles off the coast at 1 p.m. Friday. The storm is then expected to cut diagonally across the state, entering Mississippi north of Vicksburg at midday Saturday.

A hurricane watch, meaning hurricane conditions are possible within the next 48 hours, is in effect from Grand Isle west to High Island, Texas, and a tropical storm watch is in effect from east of Grand Isle to Bay St. Louis, Miss. Lakes Pontchartrain and Maurepas are within the tropical storm watch area.



Peak storm surge levels




A storm surge watch is in effect from High Island, Texas, to the Alabama/Florida border, including Calcasieu Lake, Vermilion Bay, Lakes Pontchartrain, Maurepas and Borgne, and Mobile Bay.  



Potential storm surge heights




Surge levels of 4 to 7 feet are expected between Cameron and Pecan Island, increasing to between 7 and 11 feet between there and Port Fourchon, including Vermilion Bay. From the port to Ocean Springs, Miss, the surge could be between 4 and 6 feet. In Lakes Maurepas and Pontchartrain, the surge could be between 3 and 5 feet.  

The colored area shows coastal parishes where a storm surge watch is in effect. 

Delta will be accompanied by heavy rainfall well inland of its landfall, with 6 to 8 inches expected in Alexandria, 4 to 6 inches in Lafayette and 2 to 3 inches in Baton Rouge. New Orleans is only expected to see a maximum of 1.5 inches of rain. However, forecasters warn those totals could dramatically increase beneath the storm’s rainbands.

A flash flood watch is in effect for areas west of Interstate 55 in Louisiana, including the Baton Rouge area, from Thursday night through Saturday.



Delta's potential rainfall




Forecasters also warn of the possibility of tornadoes in some of the storm’s rainbands as they move ashore to the east of its center.

In a Wednesday news conference, New Orleans officials urged residents to keep track of Delta, but said few extraordinary preparations were needed because the storm’s path continued to shift westward, away from the city.

But officials did urge the more than 6,000 Hurricane Laura evacuees staying in New Orleans hotels not to trek back to southwestern Louisiana late this week, for fear they could be caught up in Delta’s impacts.

The state has temporarily suspended orders requiring evacuees to leave the hotels when power and other services have been restored to their homes, said city Homeland Security Director Collin Arnold. Anyone who has already left the shelters and seeks to evacuate ahead of Delta should call the state at 2-1-1 to be assigned to a new hotel, he said.

Mayor LaToya Cantrell said city officials would continue to be on alert for potential intense rainfall, storm surge, and the possibility of tornadoes.

“It’s something we have to be mindful and watch for,” Cantrell said.

The city did recommend that residents living outside the area’s hurricane levee system evacuate, but stopped short of issuing a mandatory evacuation order.

Parking rules will be suspended at 6 p.m. on Wednesday so personal vehicles can be parked on neutral grounds or sidewalks in case the city sees heavy rains from Delta’s bands.

On Wednesday, the Sewerage & Water Board had 98 of its 99 major drainage pumps in service, with the final pump expected to come online by Friday, S&WB General Superintendent Bob Turner said. All of the S&WB’s power systems are at their typical level of readiness as well, Turner said.

The east bank levee authority had already closed 43 minor gates in the levee system in New Orleans and Jefferson and St. Bernard parishes by Wednesday. Based on Wednesday’s forecast, the authority plans to close 10 major surge-related floodgates on Thursday afternoon, and could close another 16 on Friday.

The West Bank levee authority had closed 43 floodgates by Wednesday and could close three navigable waterway/surge gates and two vehicle gates on Louisiana 45 and at the Segnette Boat Launch on Thursday, based on the storm forecast.

On Grand Isle, two separate efforts were underway to repair levees damaged during previous storms.

In early June, Tropical Storm Cristobal damaged nearly 2,000 feet of the levee protecting the island’s southwest side. Waves gouged through about 85 feet of sand to reach the levee’s core, a wrapped tube of clay known as the “burrito.”

The Louisiana National Guard repaired levees on the southwest shore of Grand Isle on Wednesday, work funded by the state Coastal Protection an…

On Wednesday, Louisiana National Guard troops were depositing 350 3-foot by 3-foot “super sacks” of sand along the eroded area as reinforcement, paid for by the state Coastal Protection and Restoration Authority.

Jefferson Parish is funding an emergency repair of a levee on the north side of the island. 

A mandatory evacuation goes into effect for Grand Isle at 6 a.m. Thursday, a parish spokesperson said.

A voluntary evacuation went into effect for residents of Jean Lafitte, Lower Lafitte, Crown Point and Barataria at 7 a.m. Wednesday. A voluntary evacuation also is in effect for Port Fourchon.

Plaquemines Parish has issued a voluntary evacuation, effective at 3 p.m. Thursday, for the east bank from White Ditch to Pointe a la Hache, and on the west bank from Alliance Refinery to Venice.

In St. Tammany Parish, Parish President Mike Cooper issued an emergency declaration and said the parish emergency operations center will be activated at 7 p.m. Thursday.

Parish officials urged residents to be prepared for 3 to 5 feet of surge in low-lying areas near Lake Pontchartrain.

“This is becoming routine,” said Clarence Powe, the parish’s emergency preparedness director. He said Palm Lake and Coin du Lestin subdivisions in eastern St. Tammany, Lake Road in Lacombe, and the Mandeville and Madisonville lakefronts could expect to see some flooding.

North Shore Beach was closed and decisions on whether to close other recreational facilities will be made on Thursday.

Terrebonne Parish President Gordy Dove ordered a mandatory evacuation, effective at 4 p.m. Wednesday, for areas outside the hurricane levee system in the Houma region, and said an evacuation of mobile homes within the levees might be required if Delta’s effects worsened.

About 35 families live outside the system. Nearly all of them have homes on Isle de Jean Charles, a flood-prone island near Montegut that is the focus of a federally funded relocation project. The island’s residents are well-rehearsed in evacuations and likely will stay with friends and family further inland, Dove said.

He said all parish pump stations and backup generators are tested and operational.

A barge was sunk Wednesday in Grand Bayou along the border between Terrebonne and Lafourche parishes, where a permanent surge gate is under construction, to halt Delta’s storm surges.

On Wednesday, a weakened Delta hammered Mexico’s Yucatan Peninsula with winds of 85 mph, before gliding into the southern Gulf of Mexico, where it was expected to intensify to low Category 3, or major hurricane, strength, with top winds of 115 mph expected at 1 a.m. Friday.

That strengthening will result from Delta passing over deep, warm water in the southern and central Gulf in the absence of disruptive upper level wind shear, said Senior Hurricane Specialist Daniel Brown in a 4 p.m. forecast discussion message.

But after that, as the storm is dragged north by a trough of low pressure expected to be moving into Texas, Delta will run into increasing wind shear and cooler waters as it approaches the west-central Louisiana coastline, which will result in lower wind speeds, he said.

But Delta’s wind field also is expected to expand, increasing the area it will affect with both wind and rain when it goes ashore.

“Regardless of Delta’s landfall intensity, life-threatening storm surge and strong winds are likely over a large portion of the northwestern and northern Gulf coast,” Brown said.

 Staff writers Sam Karlin, Jessica Williams, Tristan Baurick, Sara Pagones, and Faimon Roberts contributed to this story. 

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