Messy winter storm likely for Mid-Atlantic on Wednesday, with heavy snow in western areas.

[elleng]

D.C. area straddles rain-snow line, while Interstate 81 corridor is in sweet spot for major snowstorm

'Confidence is building that a strong storm will plow north along the Mid-Atlantic coast on Wednesday and Thursday, unloading widespread heavy precipitation. Cold air feeding into the storm means heavy snow may fall toward the mountains while a wintry mix of snow, ice and rain is most likely toward the Interstate 95 corridor.

As so little snow occurred last winter, this event has a strong chance to be the most disruptive winter storm since 2019. The storm may also unload heavy snow and/or mixed precipitation into the Northeast, from Philadelphia to Boston, later Wednesday into Thursday.

In the Washington-Baltimore region, confidence is highest in a significant snowstorm for areas in the zone along and west of Warrenton, Leesburg, and Frederick. Heading east, computer model forecast a fairly strong likelihood that a mix of snow, ice and rain will fall. Toward the Chesapeake Bay and Southern Maryland, more rain is likely to fall than frozen precipitation.

Precipitation is forecast to begin between sunrise and early afternoon Wednesday and end late Wednesday night or early Thursday morning.

There’s a high chance most places in the Washington region, except perhaps Southern Maryland, will see a period of snow at the onset of the event. But, as the storm cranks up in the eastern Carolinas, it will draw milder ocean air northwestward. The question then becomes where and when a changeover to ice and rain occurs and how much snow falls before the changeover.

At the moment, most models indicate the rain-snow line will push as far west as the Interstate 95 corridor, changing snow to ice and rain in Washington-Baltimore, and perhaps even farther west closer to Leesburg and Frederick on Wednesday afternoon or evening. This would limit the amount of snow that would fall in the immediate Washington area (all locations within about 10 miles of the Beltway). However, some models hold the cold air in enough for precipitation to remain mostly snow, even in the District.

There is also a chance that after flipping from snow to mixed precipitation, some areas could change back to snow before ending when the storm passes north.'>>>

https://www.washingtonpost.com/weather/2020/12/12/winter-storm-wednesday-mid-atlantic/?

[SharonClark]

1. It hit the Midwest today - 7 inches of heavy snow in Des Moines.