It is the largest U.S. evacuation of the pandemic.
Forecasters expect Laura to grow to a major Category 3 hurricane over the Gulf of Mexico before hitting the U.S. coastline late Wednesday or early Thursday. The National Hurricane Center warns of potentially devastating damage.
READ MORE: Houstonians urged to stay off roads for people evacuating from Hurricane Laura
Eyewitness News spoke with Jeff Lindner of the Harris County Flood Control District on Tuesday to discuss what Houston-area residents can expect when Laura makes landfall.
He first urged everyone under any evacuation order to take them seriously.
"Move out of this area," he said. "You don't need to go hundreds of miles inland, you just need to get over to the western part of Harris County or Fort Bend County. You know, out toward Sealy or Bastrop, or even up to College Station. That will get you outside of the impact area."
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Lindner predicts strong wind conditions may extend as Laura moves.
"We are going to see very strong winds," he said. "The faster the storm moves, the further inland these winds extend. We can see hurricane conditions well up to Lake Livingston, Lufkin, Longview, possibly up to portions of Shreveport, [Louisiana.]"
READ ALSO: County by County: Breakdown of voluntary evacuations ahead of Laura
If you happen to be new to southeast Texas, Lindner said to be prepared in case you hear trees or tree limbs falling and power transformers exploding.
"You're going to hear a lot more stuff," Lindner warned as he discussed Laura's landfall in the overnight hours. "[You're going to] hear the noises. You're not necessarily going to be able to see what's happening so it's a little bit scarier to go through these type of things at night."
READ MORE: Harris County storm evacuation zones and routes
The Associated Press contributed to this report.