Bone-chilling cold in the West collided with a rare winter warm front over the East Monday, generating heavy snow, sleet and rain that caused serious flooding in parts of the South.

A slew of winter weather warnings and advisories were posted from coast to coast as the Arctic front that froze most of the West last week edged toward the Atlantic.Snow fell in the Ohio Valley, and was forecast for the northern Cascades and Rocky Mountains, northern Plains and Great Lakes region. Heavy rain was expected in the East, Southeast and Appalachian states. Subfreezing temperatures were common throughout the West and Midwest.

After record highs throughout the East on Sunday, including 71 degrees as far north as Washington, D.C., and highs in the 60s into southern Maine, temperatures cooled considerably. By Christmas Day, East Coast highs were likely to peak around 30 degrees. A cold snap continued in the West, but frigid temperatures were expected to moderate somewhat.

There was very little middle ground when the two fronts met. Typifying the contrast was Pennsylvania, which had freezing rain and high winds in the west Sunday, and record highs in the east. Philadelphia peaked at 66, while 300 miles away the city Christmas tree in downtown Pittsburgh, where highs reached only the mid-30s, was blown down by 55 mph winds.

On the other side of the front, icy temperatures dominated. Subzero cold was commonplace and even typically balmy Arizona was no oasis from the chill, with subfreezing lows statewide.

"I don't know what to say . . . my mouth's frozen," said Bill Alder, a National Weather Service meteorologist in Utah, where a minus 57 reading was recorded in Middle Sink, in high mountains near Logan.

Montana rancher Jim Brenden has been putting in 20-hour days to care for livestock weathering wind-chilled cold as low as 40 below. Chores include chipping ice from water troughs and animals' hooves.

"Cows are like wood stoves," Brenden said while untying bales of hay. "The colder it gets, the more you have to feed them."

At least five dozen deaths have been blamed on weather since Tuesday. Most were traffic fatalities.