The Nation's Weather 12.19.09

By WEATHER UNDERGROUND (AP)

A major winter storm was forecast to keep moving up the Eastern Seaboard on Saturday.

The storm was expected to take a dangerous trajectory as it dropped widespread snow first in the Mid-Atlantic and northern Appalachians and then through the southern and coastal New England states.

Many winter storm warnings were posted from eastern Kentucky through eastern New England. The storm was also expected to bring strong winds that would blow the falling snow into blizzard conditions for many areas.

Frigid air was forecast to fill into the Upper Midwest and Mississippi Valley behind the storm. That cold air was expected to plunge toward the Gulf Coast and would greatly dampen daytime high temperatures throughout the East.

In the West, a warm front was forecast to stretch into the Northwest from the Pacific, providing rain and high-elevation snow in the Northwest and into the Intermountain West.

Temperatures in the Northeast were expected to rise into the 20s and 30s, while the Southeast was forecast to see temperatures in the 40s, 50s and 60s. In the Upper Midwest, temperatures were set to rise into the 10s, 20s and 30s, while the Rockies were expected to see temperatures in the 20s and 30s. The Southwest was forecast to see temperatures rise into the 60s and 70s.

In the Lower 48 states, temperatures on Friday ranged from a low of -25 degrees at Saranac Lake, N.Y., to a high of 83 degrees at Santee, Calif.