For live updates on the severe weather situation, be check out the latest live blog.
Severe thunderstorms are dropping down through the South Central states to close out Wednesday.
A line of violent thunderstorms will continue to drop down from eastern Oklahoma and Arkansas to northeastern and north-central Texas through Wednesday evening.
Cities in the path of the severe weather include Little Rock and Texarkana, Arkansas; Oklahoma City and McAlester, Oklahoma; and Dallas and Tyler, Texas.
Stretches of interstates 20, 35, 40 and 44 lie within the threat zone.
Damaging winds and flooding downpours are the main dangers from the severe thunderstorms. Some thunderstorms will also drop quarter-sized hail.
The downpours will also pose hazards to motorists, including those heading home from work, by dramatically reducing visibility and heightening the danger of vehicles hydroplaning at highway speeds.
Winds within the strongest thunderstorms could even overturn high-profile vehicles.
Airline passengers catching a late-day flight should prepare for delays and a temporary ground stop.
Fueling the severe thunderstorms later Wednesday is the very warm and humid air in place across the South Central states. Many places will record highs in the 90s before the thunderstorms roll through.
Wednesday's warmth is fairly typical for this time of year but a dramatic change from the unseasonable chill late last week.
The thunderstorms will wane and diminish by early Thursday morning, followed by building heat for Thursday and Friday.
Oklahoma City is set to record its first 100-degree day on Friday.
Conditions will improve across the Northeast on Friday as this week's nor'easter shifts away from the region.
Sunshine and cooler air will be around Los Angeles for the weekend and into early next week.
Temperatures will gradually rise into the weekend in Chicago.
Dallas is facing a week of abundant sunshine as temperatures climb well above seasonal averages for this time of year.
A siege of Pacific storms will continue to drench and blast the coastal Northwest into next week and will be joined by Ana.
The remnants of Tropical Depression 9 will move over Mexico's Yucatan Peninsula through Friday, bringing heavy rain and gusty winds. Another system nearby bears watching.
Tornado sweeps through Sunset Crater National monument. 600-700 trees destroyed. The twister was 150 yards wide at times.
New England (1785)
Four day rains put Merrimac River in NH and MA to greatest flood height ever known -- extensive bridge and mill damage.
Mid-Atlantic Coast (1878)
Hurricane did extensive damage in NC, VA, MD, NJ and PA. "Philadelphia's worst" -- 84 mph wind gust at Cape May, NJ; 28.82" pressure at Annapolis, MD.