Alton, IL

Weather Underground Forecast for Saturday, February 11, 2012.

Precipitation will spread across the East Coast on Saturday, while more rain and mountain snow showers are anticipated for parts of the West. A trough of low pressure and associated cold front continue moving eastward across the Eastern Valleys into the Eastern Seaboard. Cool temperatures to the north will allow for snow showers to develop across the Northeast and New England, while rain showers are likely over the Mid-Atlantic states. Rain showers over the Southeastern states should wind down in the early morning hours as the tail end of the system pushes offshore early in the day. Expect the New York metropolitan area to see 1 to 3 inches of snow, while the Washington D.C. area will see a messy combination of snow and freezing rain as high temperatures reach into the lower 40s.

Behind this system, a ridge of high pressure continues to build in from the Plains, pushing cold and dry air in from Canada. This allows for plenty of sunshine to spread from the Plains over the Mississippi River Valley and into the Eastern Valleys. Expect the Northern Plains and Upper Midwest to see highs in the teens again, while the Midwest will see highs in the 20s. Strong winds will accompany this system, pushing windchill values below zero in these areas. The Southern Plains will remain in the 40s on Saturday.

Out West, a trough of low pressure pushes a cold front over the Pacific Northwest and continues pulling moisture onshore with it. This will kick up more rain showers with high elevation snow showers likely in the Cascades. The tail end of the frontal boundary will sweep through California, bringing light rain showers to the coasts and interior valleys. Expect light snow showers in the Sierra Nevadas by Saturday evening.