A blast of Arctic air and stinging wind swept across the Plains into the Midwest and South today, sending the temperature plummeting nearly 60 degrees overnight. Mild weather in the East caused flooding, and hundreds fled their homes ahead of rising water in West Virginia.

Cities that saw record high temperatures on Thursday woke up to a deep freeze today. Moline, Ill., fell to minus 2 degrees, a 58-degree drop; Chicago went from 61 degrees on Thursday to 10 today, with a wind chill of 21 degrees below zero. Indianapolis was 61 degrees on Thursday, and 4 degrees this morning. Temperatures in north Georgia fell from the 60s into the 20s.

Ahead of the storm, a thaw in the East melted snow from last week's blizzard, sending rivers spilling over their banks. Hundreds of people were evacuated from their homes in Marlinton, W.Va., where the Greenbrier River was expected to crest at 10 feet above flood stage this afternoon.

``We're stranded and no one can get to us,'' said Cindy McQueen of Marlinton, a town of 1,100 on the backbone of the Appalachian Mountains about 180 miles west of Washington, D.C.

``If it gets to our house, the whole town will be wiped out,'' she said. ``Water is running in basement windows in our section of town.''

In far northeastern West Virginia, a 75-year-old man died when he apparently tried to drive through icy floodwaters and his car was swept into a ditch. And in a nearby section of western Maryland, Allegany County officials declared a state of emergency and ordered some homes near streams evacuated.

``The 40 inches of snow filled the ditches, and then when the rain came, it couldn't go anywhere,'' said Richard Byrd, emergency services director for Bath County, Va.

The cold front began blowing into western New York today with winds up to 57 mph. The temperature in Buffalo dropped 17 degrees in one hour.

``It really is weird,'' said Carolanne Kerl, a police dispatcher in Lancaster, N.Y. ``The sky looks strange. I'm not sure what it's going to do next.''

In North Dakota, 20 inches of snow fell in Wahpeton on Thursday and the wind chill made it feel like 80 below in Fargo. Bismarck hit a record minus 39 and Minot had a record 31 below.

``As far as I'm concerned, nobody should be leaving home or work or wherever they are,'' Fargo Police Sgt. Dean Mueller said. ``To get out and get stranded is to risk dying.''

The storm dumped more than a foot of snow in Minnesota, Nebraska, Michigan and Wisconsin, knocked out power to thousands of homes in several states and forced schools and offices to close. Many remained closed today.

Searchers today were looking for two ice fishermen in Kansas, but the cold and wind hampered rescue efforts.

At least six deaths were blamed on the storm in Minnesota, which had the nation's low temperature of 44 degrees below zero this morning, at Fosston. Morris, Minn., recorded a wind chill reading of 76 degrees below. Snowplows broke down when their heaters burned out.

Despite power outages and the bitter cold, few people took refuge in Red Cross emergency shelters.

``Minnesotans seem to be hardy souls who will put up with just about anything for an evening,'' said Paula Beck, a Red Cross communications manager.

Visibility was so poor in rural Clay County, Minn., that snowplows were pulled off the roads.

``Until the wind dies down, plowing won't do a darn bit of good,'' said highway department superintendent Lee Livdahl.

In Superior, Wis., heavy snow kept a 23-year-old woman in labor from getting to the hospital. Her husband delivered the baby at home Thursday.

The mother and her baby, who were eventually dug out by firefighters and taken to the hospital, were reported doing well.

In Oil City, Pa., a creek overflowed and closed a five-mile stretch of state Route 8. Ice that broke free from a jam punched a hole in a riverfront building occupied by a beer distributor, sending empty kegs bobbing down the Allegheny River.