December 5-6, 2009 Winter Storm Outlook...

Discussion...
Basically from 3 days ago, I said I agreed with HPC's D3 4"+ Outlook, which was centered over the Appalachian Ridges of Western VA and adjacent Eastern WV. That idea has stuck, and this is reflected in our accumulation outlook for this storm by a 3-6" region over this area.

Because of factors like the forward speed of the storm, Liquid:Snow ratios likely being <10:1 in most areas, and rather warm ground temperatures, we are taking the conservative route with a general 1-3" snowfall, with the possibility of a few localized areas picking up slightly more, perhaps 4 or 5". The region with the best chance of this happening is the area which we have highlighted by the hollow (as opposed to filled) 3-6" range, which extends from South Central PA to interior Eastern New England.

Previous Discussion from Mike...
Ultimately, the heaviest snow that will fall from this system is going to be in the mountains of the VA/WV border up into the NOVA (northern VA) region, where a general 3-6 inches will fall. This region has been the area showing the best probabilities on the SREFs from Ewall of having 4+ inches of snow. Further north, we have continued the zone as our trademark dashed area. Generally, outside of the solid 3-6 zone, we expect a widespread 1-3 inch snowfall. The dashed area indicates where some more widespread 2-4 amounts may occur with the possibility of an isolated higher amount here and there. You'll notice this is backed pretty far from the big cities, where I think there may be some precip issues at the onset and accumulation issues when its snowing due to temps. Back in the dashed zone, there will be better conditions for some higher ratio snows coupled with half decent precip. But generally for all of the megalopolis, a 1-3 inch snowfall is our call.

Things to watch:
-The western edge of the 1-3 may end up not being far enough west, especially closer to the Mason-Dixon and points south.

-New England snow totals may be a bit conservative and may end up warranting the solid 3-6 area.

..EGAN.. 12/5/2009