A big storm is moving across the US – on one side of the system it's snowy and windy with temperatures below average. Meanwhile, warm air in parts of the Midwest leaves the region bracing for tornadoes. The East Coast, however, experienced record-highs. Weather Channel meteorologist Mike Seidel reports from Aurora, Colo.

The storm that dumped snow across parts of the Rockies and northern Plains on Tuesday was expected to bring more severe weather on Wednesday.

Storm chasers move into Colorado just ahead of wild spring weather as others are fleeing. KUSA's Kevin Torres reports.

The central and southern Plains areas were at risk for severe weather, according to the National Weather Service's Storm Prediction Center.

Swaths of land from New Mexico to Wisconsin were under winter storm warnings,while parts of Utah were under blizzard warnings.

According to the National Weather Service, Oklahoma City and Wichita Falls, Texas, were at risk for tornadoes and possible hailstorms Tuesday night and into Wednesday.

Earlier Tuesday, blizzard warnings were in effect in Colorado, where the temperature plunged more than 50 degrees in less than 24 hours and the wind chill approached zero. Wyoming got more than a foot of snow.

The culprit is a deep dip in the jet stream that swung west and pulled arctic air far into the country. As it collides with warm, moist air from the Gulf of Mexico, strong storms and tornadoes are possible in the Great Plains and Texas.

“It’s just brutal to be outside,” said Eric Fisher, a meteorologist for The Weather Channel.

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In Denver, the temperature plummeted from 71 degrees at 2 p.m. Monday to 16 degrees at 7 a.m. Tuesday, with a wind chill of 1. More than 250 flights were canceled into and out of Denver on Tuesday alone.

In Wyoming, authorities closed two stretches of interstate more than 100 miles long — I-25 between Cheyenne and Douglas and I-80 between Laramie and Rawlins. More than a foot of snow fell by midmorning in the city of Lander, and one town near the Nebraska state line reported 2-foot snow drifts.

Snow was also falling at midday Tuesday in Colorado, Utah, the Dakotas and Minnesota.

Brennan Linsley / AP A man crosses the street during a winter storm that brought snow and a fast plunge in temperature overnight to downtown Denver on Tuesday.

The calendar may say spring, but April is the second-snowiest month of the year in Denver. The city has averaged 9 inches in April since 1882, second only to the 11.5 inches it gets in an average March, according to the National Weather Service.

The weather pattern threatened to bring damaging wind, large hail and perhaps tornadoes to parts of Texas, Oklahoma, Nebraska and Iowa, and weaker storms later in the day in the Ohio Valley.

“We’re looking at the gamut today for severe weather,” Weather Channel meteorologist Kevin Roth said.

As the system moves east, severe storms are possible Wednesday across a boomerang-shaped swath of the country from the Texas Gulf Coast north through Indiana and into western Pennsylvania.

Severe storms could move into Georgia, West Virginia and the Carolinas on Thursday.

NBC News' Becky Bratu and The Associated Press contributed to this report.

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