Packing wind speeds of 150 mph and generating a life-threatening storm surge Thursday, Laura became one of the strongest hurricanes to make landfall in U.S. history as it struck Louisiana near the Texas border.
The "extremely dangerous" storm went ashore near Cameron in southwestern Louisiana about 1 a.m. (2 a.m. ET).
The storm's maximum sustained winds have fallen to 100 mph, according to the National Hurricane Center. That would make it a Category 2 hurricane, according to the Saffir-Simpson Hurricane Wind Scale.
Laura "is now tied for the most intense hurricane landfall on record in the state of Louisiana and ranks as one of the most powerful hurricane landfalls in U.S. history," said Bill Karins, an NBC News meteorologist.
The National Hurricane Center warned earlier that Laura's storm surge could be "unsurvivable" for those who remained in its path along the Gulf of Mexico.
Laura was weakening rapidly, and it was expected to become a tropical storm later Thursday, according to the hurricane center. However, tornadoes are still possible over parts of Louisiana, Arkansas and western Mississippi, the center said.
The hurricane had already knocked out power for hundreds of thousands of customers in Louisiana and Texas by early Thursday.
The eye of the storm initially took aim at the Texas-Louisiana border, and the coast from High Island, Texas, to the mouth of the Mississippi River was under a tropical storm warning, as well as a storm surge warning, according to the hurricane center. That means there is extreme danger of flooding as rising water moves inland from the coast, the center said.
"This is a life-threatening situation," the center said. "Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions."
"Promptly follow evacuation and other instructions from local officials," it added.
The storm surge could penetrate up to 40 miles inland from the immediate coastline, and floodwaters won't fully recede for several days after the storm, the center said. There could be an inland rush of seawater up to 20 feet, the center said earlier.
As Laura pushes northward, winds, flooding and rainfall are spreading inland over western and central Louisiana, the center said.
"Take cover now!" the center said earlier. "Treat these imminent extreme winds as if a tornado was approaching and move immediately to the safe room in your shelter."
Hurricane-force winds and damaging gusts are also expected to spread well inland into parts of eastern Texas and western Louisiana on Thursday morning, the center said.
Across parts of Louisiana and Mississippi and across Arkansas, the storm is expected to produce 6 to 12 inches of rain through Friday, with isolated totals of 18 inches. The rain will cause widespread flash and urban flooding, with small streams and creeks overflowing their banks and minor to moderate freshwater river flooding, the center said.
Meanwhile, swells produced by Laura are affecting the Gulf Coast from the west coast of Florida to Texas and northeastern Mexico, the center said. That is likely to cause life-threatening surf and rip-current conditions, it said.
Laura is moving north, and it is forecast to continue moving northward across western and northern Louisiana through Thursday afternoon. Laura's center is then forecast to move over Arkansas on Thursday night, the mid-Mississippi Valley on Friday and the mid-Atlantic states on Saturday.
MaryJane Mudd, the American Red Cross' communications director for the Texas Gulf Coast Region, told MSNBC that more than 600 volunteers had been deployed up and down the coast to help support the shelters and that more were on standby.
However, the coronavirus has meant that in handling the situation, there is "double the concern," she said.
It's "hard enough to get people to evacuate when you don't have fear of COVID," she said.
Wednesday, the sheriff's office in Vermilion Parish, just east of where Laura went ashore, warned residents who wouldn't or couldn't evacuate to keep identification on them.
"Please evacuate and if you choose to stay and we can't get to you, write your name, address, Social Security number and next of kin and put it [in] a ziplock bag in your pocket," the office said in a statement.
The National Weather Service said earlier that devastation could spread far inland in eastern Texas and western Louisiana.
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Hundreds of thousands of people were ordered to evacuate ahead of the storm. Late Wednesday, Health and Human Services Secretary Alex Azar declared public health emergencies in Texas and Louisiana.
Phil Klotzbach, an atmospheric scientist at Colorado State University, said on Twitter that Laura was the third hurricane to strike the continental United States this year. Only two other Atlantic hurricane seasons, those in 1886 and 1916, have had three or more continental landfalls by this date, he said.
CORRECTION (Aug. 27, 2020, 7:20 p.m. ET): A previous version of this article misspelled the last name of a Colorado State University atmospheric scientist. He is Phil Klotzbach, not Klotzback.