IE 11 is not supported. For an optimal experience visit our site on another browser.

Hurricane Laura grows stronger as it barrels toward Gulf Coast

A life-threatening storm surge is forecast for a long stretch of the Texas and Louisiana coastlines, with 7 to 11 feet possible.

Hurricane Laura strengthened to a Category 2 storm early Wednesday as it approached the U.S. Gulf Coast, with forecasters warning it is expected to get stronger still and be a "major hurricane" by the time it makes landfall.

The storm, which became a hurricane Tuesday morning, was "rapidly intensifying" at 2 a.m. Wednesday and had maximum sustained winds of 105 mph, the National Hurricane Center said. It was forecast to approach the upper Texas and southwestern Louisiana coasts Wednesday evening.

The hurricane forecast to reach category 3 strength Wednesday and make landfall late Wednesday or early Thursday near the Texas-Louisiana border. The hurricane center warned of "potentially catastrophic damage" from storm surge.

Hundreds of thousands of people in the two states have been ordered to evacuate.

"Devastating situation when it comes to the storm surge, the hurricane-force winds and the rain" hurricane center Director Ken Graham said in a video update Tuesday afternoon. He urged people to heed evacuation orders and to leave.

"The leading cause of fatalities in these tropical systems is water," Graham said.

A storm surge warning was issued from the San Luis Pass strait in Texas to the mouth of the Mississippi River, while a hurricane warning was in effect from the strait to the unincorporated community of Intracoastal City, Louisiana.

Other areas, including Sargent, Texas, were under tropical storm warnings.

Rain showers could reach the coasts of Texas and Louisiana by Wednesday afternoon, with strong winds arriving later in the day. The storm's impact is forecast to be felt far away.

A life-threatening storm surge is forecast for a long stretch of the Texas and Louisiana coastlines, with 7 to 11 feet possible. Even Lake Pontchartrain, even though it is forecast to be far from the center of the storm, is forecast to experience 2 to 4 feet of storm surge.

The storm surge, combined with high tide cycles and large destructive waves crashing on shore, will lead to exceptionally dangerous conditions along the coast.

In addition, from Wednesday afternoon into Saturday, Laura is expected to produce rainfall of 4 to 8 inches, locally up to 12 inches, across parts of the west-central Gulf Coast near the Texas and Louisiana borders north into parts of the lower Mississippi Valley. That will lead to widespread flash and urban flooding, as well as minor to moderate river flooding.

Several counties and cities along the coast of Texas issued mandatory evacuation orders beginning Tuesday morning, including the city of Galveston, Orange County and Jefferson County, which has a population of more than 250,000.

Texas A&M University at Galveston tweeted Monday that it was ordering an evacuation.

Galveston Mayor Pro Tem Craig Brown told The Weather Channel: "Today is the day. The weather is still nice here in Galveston. This is the day for everybody to get their belongings together and, for the safety of themselves and their family, to go ahead and evacuate today. Do not wait."

Mayor Thom Kolupski issued a voluntary evacuation order for Seabrook in Harris County, and he encouraged elderly residents and people with medical conditions to take precautions.

"This notice is very important to elderly residents and/or people with medical conditions. We encourage these residents to evacuate these portions of the city at your convenience, however, due to rain, storm surge and the probability of heavy traffic you are encouraged to do so sooner rather than later," he wrote in a Facebook post.

Download the NBC News app for breaking news and weather

The mayor of Grand Isle, a small town in Jefferson Parish, Louisiana, issued a mandatory evacuation order Sunday. Other parts of Jefferson Parish were under voluntary or mandatory evacuation orders, The Weather Channel reported.

Authorities have begun moving prisoners in Louisiana and Texas in preparation for landfall Wednesday evening. The Calcasieu Parish Sheriff's Office said Tuesday on Facebook that it was preparing to move more than 900 inmates to other facilities in Louisiana.

"The Sheriff's Office will be increasing manpower on patrol and will do everything we can to keep you and your property safe, but at some point it will be too hazardous for deputies to respond and for that time frame you need to ensure your own personal safety if you choose to stay," the post said.

About 3,400 offenders will be moved from prisons at risk from the hurricane's winds and storm surge to other locations in Texas, the state Criminal Justice Department said.

Louisiana Gov. John Bel Edwards on Tuesday pleaded with residents to take the hurricane seriously. Storm surges could impact the entire state coast, and residents in central and northern Louisiana also need to prepare.

"I don't know the last time you've seen a storm come ashore that is basically going to have hurricane-force winds associated with it until it exits Louisiana," the governor said.

Texas Gov. Greg Abbott told reporters Monday that the third anniversary of the devastating Hurricane Harvey is approaching this week. Abbott reminded residents to be aware of the risk of contracting the coronavirus as the state's positive test results begin to decline following an alarming rise in the number of cases last month.

"Remember, just because a hurricane is coming to Texas does not mean that COVID-19 either has or is going to leave Texas," Abbott said. "COVID-19 is going to be in Texas throughout the course of the hurricane."

Abbott recommended hotels and motels as the ideal options for evacuated residents, but officials promised that shelters throughout the state will have personal protective equipment and testing teams.

Doha Madani contributed.