Ammon News - Road conditions were deteriorating Saturday in the central U.S. as a winter storm brought a mix of snow, ice and plunging temperatures, with forecasts calling for the dreaded combo to spread eastward in the coming days.

"Winter returned," said Bob Oravec, lead forecaster at the National Weather Service in College Park, Maryland.

More than 32 Million people are under winter alerts from Kansas to the East Coast stretching over 1500 miles, the National Weather Service said.

The polar vortex of ultra-cold air usually stays penned up around the North Pole, spinning like a top. But sometimes it escapes or stretches down to the U.S., Europe or Asia — and that's when large numbers of people experience intense doses of cold.

Studies show a fast-warming Arctic gets some of the blame for the increase in polar vortex stretching or wandering.

By Saturday evening, widespread heavy snow was likely between central Kansas and Indiana, especially along and north of Interstate 70. Part of the interstate was closed in central Kansas by the afternoon. Total snow and sleet accumulations for parts of Kansas and northern Missouri were predicted to be as high as 14 inches.

The storm was forecast to move then into the Ohio Valley, with severe travel disruptions expected. It will reach the Mid-Atlantic states on Sunday into Monday, with a hard freeze even expected as far south as Florida.

Severe thunderstorms, with the possibility of tornadoes and hail, were also possible ahead of the storm system's cold front as it crosses the Lower Mississippi Valley, the National Weather Service warned.

Parts of upstate New York saw 3 feet or more of snow from a lake effect event expected to last until late Sunday afternoon.

CBS