BATON ROUGE, La. (AP) — Tropical Storm Francine churned in the Gulf of Mexico with increasing strength and was expected to reach hurricane status on Tuesday before reaching landfall in Louisiana.

A storm surge warning was in effect for an area stretching from just east of Houston to the mouth of the Mississippi River south of New Orleans, according to the National Hurricane Center. Such a warning means there’s a chance of life-threatening flooding.

Louisiana Gov. Jeff Landry urged residents “not to panic, but be prepared” and heed evacuation warnings. Forecasters said Francine’s landfall in south Louisiana was expected Wednesday afternoon as a Category 2 hurricane with winds of 96 to 110 mph (155-175 kph).

“We do not want people to wait to the last minute to get on the road and then run out of fuel,” Landry said. “We put a lot of information throughout the summer, throughout hurricane season, so that people can be prepared. The more prepared we are, the easier it is for us.”

Francine is taking aim at a Louisiana coastline that has yet to fully recover since hurricanes Laura and Delta decimated Lake Charles in 2020, followed a year later by Hurricane Ida. Over the weekend, a 22-story building in Lake Charles that had become a symbol of storm destruction was imploded after sitting vacant for nearly four years, its windows shattered and covered in shredded tarps.

Francine’s storm surge on the Louisiana coast could reach as much as 10 feet (3 meters) from Cameron to Port Fourchon and into Vermilion Bay, forecasters said.

“It’s a potential for significantly dangerous, life-threatening inundation,” said Michael Brennan, director of the hurricane center, adding it could also send “dangerous, damaging winds quite far inland.”

He said landfall was likely somewhere between Sabine Pass — on the Texas-Louisiana line — and Morgan City, Louisiana, about 220 miles (350 kilometers) to the east.

Louisiana officials urged residents to immediately prepare while “conditions still allow,” said Mike Steele, spokesperson for the Governor’s Office of Homeland Security and Emergency Preparedness.

“We always talk about how anytime something gets into the Gulf, things can change quickly, and this is a perfect example of that,” Steele said.

Residents of Baton Rouge, Louisiana’s capital, began forming long lines as people filled gas tanks and stocked up on groceries. Others filled sandbags at city-operated locations to protect homes from possible flooding.

“It’s crucial that all of us take this storm very seriously and begin our preparations immediately,” Baton Rouge Mayor-President Sharon Weston Broome said, urging residents to stock up on three days of food, water and essentials.

A mandatory evacuation was ordered for seven remote coastal communities by the Cameron Parish Office of Homeland Security & Emergency Preparedness. They include Holly Beach, a laid-back stretch dubbed Louisiana’s “Cajun Riviera,” where many homes sit on stilts. The storm-battered town has been a low-cost paradise for oil industry workers, families and retirees, rebuilt multiple times after past hurricanes.

In Grand Isle, Louisiana’s last inhabited barrier island, Mayor David Camardelle recommended residents evacuate and ordered a mandatory evacuation for those in recreational vehicles. Hurricane Ida decimated the city three years ago, destroying 700 homes.

Officials warn that flooding, along with high winds and power outages, is likely in the area beginning Tuesday afternoon through Thursday.

In New Orleans, Mayor LaToya Cantrell urged residents to prepare to shelter in place. “Now is the time to finalize your storm plans and prepare, not only for your families but looking out for your neighbors,” she said.

City officials said they were expecting up to 6 inches (15 centimeters) inches of rain, gusty winds and “isolated tornado activity” with the most intense weather likely to reach New Orleans on Wednesday and Thursday.

The hurricane center said Francine was last about 125 miles (205 kilometers) south-southeast of the mouth of the Rio Grande, and about 425 miles (690 kilometers) south-southwest of Cameron, with top sustained winds of about 65 miles per hour (100 kilometers per hour). It was moving north-northwest at 5 mph (7 kph).

As rain fell Monday in northern Mexico, more than a dozen neighborhoods in Matamoros — across the border from Brownsville, Texas — flooded, forcing schools to close Monday and Tuesday. Marco Antonio Hernandez Acosta, manager of the Matamoros Water and Drainage Board, said they were waiting for Mexico’s federal government to provide pumps to drain affected areas.

The storm was expected to move in north-northeast motion through Monday evening and then accelerate to the northeast beginning Tuesday before nearing the upper Texas and Louisiana coastlines Wednesday.

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Stengle contributed to this report from Dallas and Alfredo Peña from Ciudad Victoria, Mexico.