US & World News

(CBS) A large, fast-moving snowstorm closed sections of major highways in the Plains on Saturday and threatened to dump more than a foot of snow on the Upper Midwest.

Interstate 70, the major cross-country route, was closed in both directions Saturday east of Denver to the Kansas line, according to the Colorado Department of Transportation.

Between the city and the beginning of the highway closure, about 35 cars collided in a pileup in whiteout conditions Saturday morning on an icy section of I-70. No major injuries were reported.

The weather service reported wind gusts of 68 mph in the area.

A number of other highways also were closed in the two states.

"Basically there's zero visibility at this time," Kansas Department of Transportation spokeswoman Barb Blue said just before noon. "Travel is not recommended unless absolutely necessary."

In Chicago, CBS station WBBM-TV is reporting wind gusts of around 30 miles per hour in the area with that figure expected to rise as a blast of wintry weather moves across the U.S.

The National Weather Service has issued a winter storm warning for most of the Chicago area from 4 p.m. Saturday to noon Sunday.

In outlying Lake and McHenry Counties a blizzard warning is in effect.

A blizzard is defined by winds at 35 miles per hour or more, or frequent gusts to 35 miles per hour, as well as visibility of 1/4 mile or less because of falling or blowing snow.

WBBM-TV Meteorologist Jeff Taylor reports that snow totals in Chicago and the western suburbs could total 1 to 3 inches. Light sleet and freezing rain may also be seen. The city itself is expected to be on the lighter side of the storm with possibly 1 inch of snow.

The weather system is expected to first hit the area with rain on Saturday afternoon with the precipitation turning to snow overnight in most of the area. Freezing rain is likely in some parts of the state.

In Wisconsin a severe storm bore down that meteorologists warned would last through the weekend, bringing howling winds and up to 27 inches of snow or more in parts of the state.

One fatality was already blamed on the conditions in the Township of Springfield near Madison, where a vehicle slid off the road and struck an embankment on Friday night.

"Every deputy we have is tied up right now on traffic accidents," said Dane County Sgt. Kerry Porter early Saturday morning. "We've got nine deputies working third shift, and we've held over a couple of additional deputies."

Madison is one of the areas expected to be hit hard, said National Weather Service meteorologist Tom Zajdel. The suburb of Verona had already received 6 inches, according to spotters, and between 6 and 9 inches were forecast to fall by Saturday morning, with a second band of heavy snow delivering another 9 to 14 inches beginning Saturday afternoon.

Zajdel said the storm could bring blizzard-like conditions due to winds whipping above 35 mph for prolonged periods.

"If we do get those winds and get the snow falling at the same time, that could reduce the visibility to near zero," Zajdel said. "That could be very, very difficult, if not impossible, to travel in."

Minneapolis CBS station WCCO-TV is also reporting that a winter storm warning is in effect for the area. New snow and sleet accumulation is expected to hit two to five inches in the afternoon with snow accumulation forecast to be around seven inches tonight.

Minnesota Department of Transportation officials say they will be ready when the snow starts to fly.

"We're totally prepared; we're confident we can handle it," said Mary McFarland from MNDoT. "Our snow plow drivers live for this."

MNDot officials told WCCO-TV that they've already put de-icing chemicals down on areas they know will get icy -- mostly bridge decks and ramps. They also have all of their salt and sanding trucks ready to go.

The snowstorm expected to hit the Upper Midwest this weekend has also prompted Northwest Airlines to issue a winter weather waiver for passengers with tickets for travel through Sunday.

Passengers traveling to, from or through several cities in Minnesota, North Dakota, South Dakota and Wisconsin can delay their travel through Tuesday without penalty or administrative change fees, subject to availability.

Northwest also isn't accepting unaccompanied minors or pets traveling in the hold to, from or through Minneapolis-St. Paul on Saturday.

All passengers should check flight and gate status prior to leaving for the airport.

Meanwhile, in Pittsburgh, CBS station KDKA-TV has reported that the National Weather Service issued a Winter Storm Watch for the area that takes effect late Saturday night and last through Sunday afternoon.

There is a potential for a wintry mix of precipitation including freezing rain.

"The National Weather Service decided to issue a blanket Winter Storm Watch as a result of the icing potential that exists for most of the area," said KDKA-TV weathercaster Jon Burnett.

The storm brings a potential for a coat of ice a quarter-inch thick.

(© 2007 CBS Broadcasting Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)