A major winter storm is sweeping across the central United States rapidly on Christmas eve Thursday, prompting the governor of Oklahoma to declare a statewide emergency.

"I am urging all Oklahomans to take winter storm precautions and stay off the roads unless travel is absolutely necessary," Brad Henry, the governor, said in a statement.

Blizzard warnings were issued for parts of Oklahoma, Texas, North Dakota, South Dakota and Minnesota, according to the National Weather Service, or NWS.

"Anyone with travel plans over the Christmas holiday period should keep up to date with the latest weather information," it said in an online statement.

Tornado watches were issued for southern Louisiana, Mississippi and southwestern Alabama.

A Louisiana man was killed Thursday when strong wind caused a tree to fall on his house.

Flooding was reported in and around Little Rock, Arkansas, after heavy rain fell throughout Wednesday night and Thursday morning.

Flood watches, warnings and advisories have been issued for much of Missouri and Illinois, where several inches of rain is causing flooding in streams and rivers.

The inclement weather is the second major storm system to hit the United States in a week.

Last weekend, a major snow storm blanketed a swath of the U.S. east coast in snow, forcing the cancellation of hundreds of flights.