Tornadoes in South kill at least two as blizzard-like conditions hit Great Plains

A destructive winter storm was marching across the United States on Wednesday, delivering blizzard-like conditions to the Great Plains hours after tornadoes touched down in parts of Texas, Oklahoma and Louisiana.

A tornado in the Pecan farms area of Keithville, in Caddo Parish in northwest Louisiana, south of Shreveport, killed a mother and her young son, according to the sheriff's office. The woman was found a block from their home, which was destroyed, and the boy was found in a nearby wooded area. 

In addition, the office said a man and woman were hospitalized.

In Farmerville, in north-central Louisiana, Detective Cade Nolan told CBS News as many as 25 people were hurt, at least two critically, when a twister raced through. It was the "most damage I've ever seen in 17 years in this (Union) parish," he said as he stood next to an overturned GMC SUV.

CBS  Monroe, Louisiana affiliate KNOE-TV is there:

Five tornadoes were confirmed across north Texas as of Tuesday afternoon based on video and eyewitness reports, but potentially a dozen may have occurred, the National Weather Service in Fort Worth, Texas, reported. Search crews were looking for any other victims.

Dozens of homes and businesses were damaged by the line of thunderstorms, and several people were injured in the suburbs and counties stretching north of the Dallas-Fort Worth area. More than 1,000 flights into and out of area airports were delayed, and over 100 were canceled, according to the tracking service FlightAware.

The severe weather threat continued into Wednesday for Louisiana, Mississippi, Alabama and the Florida Panhandle, according to the Storm Prediction Center in Norman, Oklahoma.

Blizzard warnings stretched from Montana into western Nebraska and Colorado, and the National Weather Service said as much as 2 feet of snow was possible in some areas of western South Dakota and northwestern Nebraska. Winds of more than 50 mph at times will make it impossible to see outdoors in Nebraska, officials said.

"There's essentially no one traveling right now," said Justin McCallum, a manager at the Flying J truck stop at Ogallala, Nebraska.

Forecasters expect the storm system to hobble the upper Midwest with ice, rain and snow for days, and move into the Northeast and central Appalachians. Residents from West Virginia to Vermont were told to watch out for a possible significant mix of snow, ice and sleet, and the National Weather Service issued a winter storm watch from Wednesday night through Friday afternoon, depending on the timing of the storm.

In the Dallas suburb of Grapevine, police spokesperson Amanda McNew reported five confirmed injuries Tuesday.

A possible tornado blew the roof off the city's service center - a municipal facility - and left pieces of the roof hanging from powerlines, said Trent Kelley, deputy director of Grapevine Parks and Recreation.

It was also trash day, so the storm picked up and scattered garbage all over, he said.

Photos sent by the city showed downed power lines on rain-soaked streets, as well as toppled trees, damaged buildings and a semitrailer that appeared to have been tossed around a parking lot.

A tornado damaged the Oklahoma town of Wayne Tuesday. There were no deaths or injuries reported, McClain County Sheriff's Capt. Bryan Murrell said, but authorities said there was widespread damage. Wayne is about 45 miles south of Oklahoma City.

"We've got multiple family structures with significant damage ... barns, power lines down," Murrell said.

All roads were closed in the northeast quadrant of the Colorado. The severe weather in the ranching region could also threaten livestock. Extreme winds can push livestock through fences as they follow the gale's direction, said Jim Santomaso, a northeast representative for the Colorado Cattlemen's Association.

"If this keeps up," said Santomaso, "cattle could drift miles."

A blizzard warning has been issued on Minnesota's north shore, with some areas expecting up to 24 inches of snow and wind gusts up to 40 mph. And in the south of the state, winds gusting up to 50 mph were reducing visibility.

National Weather Service meteorologist Melissa Dye in the Twin Cities said this is a "long duration event" with snow, ice and rain through Friday night. Minnesota was expecting a lull Wednesday, followed by a second round of snow.

The same weather system dumped heavy snow in the Sierra Nevada and western U.S. in recent days.

-- Patrick Torphy contributed reporting.