Hurricane Laura continued to strengthen Tuesday evening as it churned through the Gulf of Mexico toward Texas and Louisiana, where hundreds of thousands of coastal residents were evacuating.

The storm was moving west-northwest from the central gulf at around 17 mph with maximum sustained winds of 90 mph, according to the National Weather Service.

The National Hurricane Center warned that the storm surges could be life-threatening. Areas 30 miles inland between San Luis Pass in Texas and the mouth of the Mississippi River could see damage.

STRENGTHENING HURRICANE LAURA PROMPTS MANDATORY EVACUATIONS ALONG GULF COAST

Workers board up windows at the Galvez Hotel & Spa, Tuesday, Aug. 25, 2020, in Galveston, Texas, as Hurricane Laura heads toward the Gulf Coast. (AP Photo/David J. Phillip)

Workers board up windows at the Galvez Hotel & Spa, Tuesday, Aug. 25, 2020, in Galveston, Texas, as Hurricane Laura heads toward the Gulf Coast. (AP Photo/David J. Phillip)

“All of coastal Louisiana should brace for storm surge,” Louisiana Gov. John Bel Edwards said during a Tuesday news conference.

The NWS issued storm surge warnings for that entire span from San Luis Pass through most of Louisiana's coastline, and storm surge watches were in effect as far east as Biloxi, Miss., and as far west as Freeport, Texas. Peak surge could surpass 10 feet in southwestern Louisiana, according to the weather service, depending on whether the storm makes landfall during high tide.

Edwards warned that that could happen if Laura arrives at 1 a.m. Thursday morning on the Louisiana-Texas state line, as forecasts predict.

“This is a major hurricane,” Edwards said. “Laura’s shaping up to look a lot like Rita did 15 years ago.”

Municipal workers fill sandbags for the elderly and those with disabilities ahead of Hurricane Laura in Crowley, La., Tuesday, Aug. 25, 2020. (AP Photo/Gerald Herbert)

Municipal workers fill sandbags for the elderly and those with disabilities ahead of Hurricane Laura in Crowley, La., Tuesday, Aug. 25, 2020. (AP Photo/Gerald Herbert)

Hurricane Rita was the storm that pummeled the region shortly after Hurricane Katrina’s devastating arrival in 2005.

Some parts of Louisiana could see up to 15 inches of rain, according to Lake Charles, La.-based meteorologist Donald Jones. And Texas is also expected to see severe weather, with considerably less rain but strong winds and a storm surge potentially deeper than 9 feet.

"Hurricane Laura is rapidly intensifying and poses a major threat to communities in Southeast Texas and along the coast," Texas Gov. Greg Abbott warned Tuesday. "Texans in the path of this storm should waste no time preparing for the impact of Hurricane Laura and take immediate action to keep themselves and their loved ones safe.”

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With water levels expected to rise Wednesday, authorities urged the hundreds of thousands of residents facing evacuation orders to leave before the end of the day Tuesday.

Evacuees headed to shelters from Galveston and Port Arthur were told to bring just one bag each and a mask to reduce the spread of the coronavirus. Houston officials, who did not initially issue an evacuation order, began calling on residents of several zip codes to voluntarily head for safety Tuesday afternoon. Gov. Abbott waived all tolls in the area as residents fled the storm’s path.

Houston SPCA staff members Linnea Wood, foreground, and Calista Stover carry pets from the Galveston Island Humane Society, onto a Wings of Rescue plane headed to Dallas/Fort Worth Tuesday, Aug. 25, 2020, in Houston, as Hurricane Laura threatens the Texas coast. (Steve Gonzales/Houston Chronicle via AP)

Houston SPCA staff members Linnea Wood, foreground, and Calista Stover carry pets from the Galveston Island Humane Society, onto a Wings of Rescue plane headed to Dallas/Fort Worth Tuesday, Aug. 25, 2020, in Houston, as Hurricane Laura threatens the Texas coast. (Steve Gonzales/Houston Chronicle via AP)

And as residents moved to safety, animal rescue workers were busy packing up the shelters and getting ready to move cats and dogs to safety by plane. Photos show members of the Houston SPCA stocking up a Wings of Rescue plane with pet carriers to help relieve the Galveston Island Humane Society Tuesday morning.

The storm’s strongest winds were expected to whip the coast between San Luis Pass and Morgan City, La., Wednesday night and spread inland early Thursday.

Laura was upgraded from a tropical storm to a Category 1 hurricane Tuesday and is expected to make landfall late Wednesday or early Thursday as a Category 3, with winds of around 115 mph, according to the National Weather Service.

Authorities also warned that the threat of flooding would extend through Texas and Louisiana and into Arkansas as the storm moves toward the Ohio and Tennessee valleys near the weekend.

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Abbot had declared emergencies in dozens of Texas counties by Tuesday afternoon. State emergencies were also declared in Louisiana and Mississippi.

And the hurricane’s approach forced the Air Force’s 53rd Weather Reconnaissance Squadron Hurricane Hunters, known for flying into storms to collect vital data, to relocate their operations from Keesler Air Force Base in Mississippi to the Atlantic Aviation Charleston International Airport in South Carolina.

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Laura has already killed almost two dozen people after tearing through Cuba and the island of Hispaniola as a tropical storm earlier this week.

Fox News’ Danielle Wallace and the Associated Press contributed to this report.