Southwest

Weather Underground Forecast for Saturday, December 19, 2009. A major winter storm will continue moving northeastward up the eastern seaboard on Saturday. This storm will take a dangerous trajectory as it provides widespread snow first in the Mid-Atlantic and northern Appalachians and then through the southern and coastal New England states. Because of all this snow, many Winter Storm Warnings have been posted from eastern Kentucky through eastern New England. This nor'easter storm will also instigate strong winds that will blow the falling snow into blizzard conditions for many areas. The exact track of the storm remains somewhat uncertain, and any deviation from the expected track will alter snow intensity for many areas of the East. Thus, residents should monitor local weather conditions throughout the day.

Frigid air will fill into the Upper Midwest and Mississippi Valley behind the aforementioned storm. This cold air will plunge toward the Gulf Coast and will greatly dampen daytime high temperatures throughout the East.

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

The Northeast will rise into the 20s and 30s, while the Southeast will see temperatures in the 40s, 50s, and 60s. The Upper Midwest will rise into the 10s, 20s, and 30s, while the Rockies will see temperatures in the 20s and 30s. The Southwest will rise into the 60s and 70s.

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