Snow is currently falling across Wisconsin, Michigan and Illinois from the next clipper system in a long series of clippers and this too will be a fast-mover with limited moisture content. There is plenty of instability well ahead of this system; consequently, snow showers could break out at any time this afternoon in the Mid-Atlantic region and continue well into the evening hours as the clipper approaches. Accumulations of a coating to an inch or two are possible by late this evening; especially, in areas with heavier snow bands.
A big difference in the overall weather pattern is shaping up for the end of the week. While there will be a clipper-type northern stream disturbance, this time there will also be a disturbance coming out of the south as the southern branch of the jet stream starts to get more active. Indications are growing that the northern and southern disturbances will phase together on Friday generating a strong coastal storm. By Friday morning, the southern system will be gathering strength around the Cape Hatteras region of North Carolina. It will then phase together with the northern disturbance and intensify as it moves off the east coast to a position east of the New England coast by late Friday night. Another key player in this late week scenario will be a large, strong and cold high pressure system locked in across SE Canada and this will supply a lot of cold air for much of the Northeast US. For now, this looks like a potential massive snowstorm for much of New England including the Boston metro region. The NYC region and Long Island, NY could have a mixture of rain, ice and snow initially, but that could all change to significant accumulating snow. Philly looks to be right on the edge temperature-wise with a mixture of rain, ice and/or snow from this storm that could end up as important accumulating snow on the back end. Odds favor rain in the DC metro region with less in the way of total precipitation amounts as the storm intensifies while moving to the northeast and away from the DC area.
Stay tuned. Finally, something other than a clipper to talk about.