DENVER - Hundreds of flights have already been cancelled nationwide because of extreme weather in several states.
An apparent tornado was spotted near downtown Mobile, Alabama and caught on camera by CNN affiliate WALA. The footage shows the large funnel cloud sparking with electricity.
There are tweeted reports of downed power lines, fallen tree limbs and damage at a high school from Mobile's fire department.
Tornado watches are also in effect across southern Louisiana and Mississippi.
In Houston, a driver was killed when winds toppled a tree onto a pickup truck.
Icy roads are being blamed for a 21-vehicle pileup in Oklahoma, where authorities warned would-be travelers to stay home.
Nearly 350 flights nationwide have been canceled so far, according to the flight tracker FlightAware.com. More than half were canceled into and out of Dallas/Fort Worth International Airport which got a few inches of snow.
A 5:20 p.m. look at the statuses for flights out of Denver International Airport shows several delays to various destinations and at least three cancelled flights to Dallas. There are also many delays listed for incoming flights.
Meanwhile, blizzard conditions are possible for parts of Illinois, Indiana and western Kentucky with predictions of 4 to 7 inches of snow. Much of Oklahoma and Arkansas is bracing under a winter storm warning of an early mix of rain and sleet forecast to eventually turn to snow. About a dozen counties in Missouri are under a blizzard warning from tonight to noon tomorrow.