The Heat Is Online

Massive storm system brings chaos to Midwestern US

Storm chaos: Massive system closes interstates, grounds planes, derails train, April 10, 2013

An unseasonably cold air mass brought ice, heavy snow and high winds to the Plains and parts of the Midwest on Wednesday on its way to spawning potentially severe thunderstorms in the Ohio and Mississippi valleys.

The cold air, being pulled south from the Arctic region by a deep, southward dip in the jet stream, is crashing into warm air, producing disturbances – some of them odd. They included a thunder-and-ice storm that quickly coated Sioux Falls, S.D., in a crystalline layer that brought down tree limbs and left cars encased, according to

The storm was having significant effects on travel. Ice, snow and subzero wind chills have made even interstate highways in the Plains and Midwest treacherous, according to

South Dakota has been hit already and is likely to see snow totals nearing two feet, the National Weather Service said, noting that Rapid City had broken its single-day snowfall record with 20 inches of accumulation. Interstate 90 between Rapid City and Sioux Falls was closed Tuesday night, Reuters reported.

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.

In Denver, snow set in and the temperature plummeted. reported more than 250 flight canceled Monday and Tuesday at Denver International Airport as the temperature dropped from 71 to 14 degrees.

In Chicago, where low ceilings set in ahead of the storm, 290 flights were canceled Tuesday at O’Hare International Airport. The same problem on Wednesday was delaying some arriving flights by nearly three hours, and 163 flights had been canceled by 8:30 a.m. ET.

In Wyoming, stretches of Interstates 25 and 80 were closed for parts Tuesday, and blowing snow made driving dangerous along other highways. About 180 miles of I-25 between Cheyenne and Casper were under whiteout conditions, according to The Associated Press.

In eastern Nebraska, strong wind gusts caused 21 cars of a freight train to derail Tuesday west of North Bend, AP reported, adding that no injuries were reported.

The Midwest appears to be the storm’s current winter-weather target, with up to a foot of snow expected by Friday in southern Minnesota and northern Wisconsin.

In a single hour on Tuesday, the town of Marshall, Minn., experienced drenching rain, hard sleet and heavy snow with flakes “the size of cotton balls,” NBC station KARE-11 Minneapolis-St. Paul reported.

The temperature in Denver plunged from 71 degrees Monday to 14 degrees Tuesday as a massive cold-air mass plunged south from the Arctic, according to the National Weather Service.

The largest city in the region, Chicago, is likely to escape with thunderstorms Wednesday, the weather service predicted. The second-largest, Minneapolis, won't be so lucky. It remains under a winter storm warning and could see a foot of snow or more.
On the eastern edge of the cold front, severe thunderstorms are predicted for Wednesday over a huge arc from Houston to Pittsburgh, reported, adding: “In terms of tornado threat, this appears to be the peak day.”

On Thursday, as the system continues to move east, severe storms could strike a band of the country from New Orleans and the Florida Panhandle northward to Cleveland and Indianapolis, predicted.

Reuters and The Associated Press contributed to this report.