Hurricane Laura is expected to slam into the Louisiana and Texas coasts as a Category 3 storm on Wednesday evening.

At least 20 million people are in the storm's path and half a million have been ordered to evacuate. 

The hurricane, currently a Category 2, was "rapidly intensifying" over the Gulf of Mexico early Wednesday, the National Hurricane Center said, adding that it's expected to "produce a life-threatening storm surge, extreme winds and flash flooding over eastern Texas and portions of Louisiana."

The Port of Houston has set the X-RAY 'Readiness' condition, having closed the Houston Ship Channel to inbound traffic.

The Port of New Orleans meanwhile is under the ZULU 'Danger' condition and is closed for all operations. 

As of 5 a.m. EDT, Laura was located about 315 miles south/southeast of Lake Charles, Louisiana and 3335 miles southeast of Galveston, Texas, according to the hurricane center. It was moving northwest at 15 mph and had maximum sustained winds of 110 mph.

In a customer advisory, shipping company Sealand said is expecting delays and disruptions to some of its services.

"As we continue to monitor Hurricane Laura and Post-Tropical Cyclone Marco, the safety of our teams and cargo operations remains our top priority," it said. "We want to keep you informed on a frequent basis about how the storms may affect your supply chain on the U.S. gulf coast."

"Our operational team is in constant touch with the US Coast Guard and Port leaders to ensure the latest updates."