Friday, October 28, 2011

Snow in Virginia before Halloween!

Snow is likely in the mountains of western Virginia from late Friday night through Saturday afternoon. After last night's cold frontal passage through the Commonwealth, a much cooler air-mass is invading the region. That will be reinforced by an approaching upper-level disturbance diving out of the Plains, pulling in another blast of even colder air. You can see the upper disturbance forecast for later today in the yellow on this map stretching from the Dakotas to Mississippi:

This upper disturbance will generate a surface low pressure system along the southeast US coast, which will track northeast past the Mid-Atlantic (bringing us rain in most of the area, but snow to the mountains) and intensify as a nor'easter for New England, bringing them their first heavy, wet snow of the season.

While this low is intensifying off our shoreline, it will pull in deeper, colder air into western Virginia. As a result, snow is likely from Friday night through Saturday afternoon in elevations 1500 feet and higher, with rain in the lower terrain. You can see the affected regions on this Winter Storm Watch map highlighted in blue:

Here is one forecast of snowfall accumulation (it's probably a little overestimated because of the wetness of this snow):

All precipitation will end in the Commonwealth from southwest to northeast by Saturday evening. With clearing skies Saturday night, temperatures area-wide will fall into the 30s, with many locations reaching the freezing mark or colder. This would be the first frost/freeze of the season across much of central Virginia on Sunday morning. If you have any plants outdoors that you want to survive this first plant-killing cold, bring them indoors or insulate them properly.
Stay with CBS6, we'll keep you ahead of the storm.
--Meteorologist Carrie Rose