As very cold air crossed the mountains in Pennsylvania overnight, snow showers came along as well. Philadelphia had some of those during the morning commute. In the Buffalo area, the afternoon rush hour is a real nail biter. A band of heavy lake-effect snow is inching northward through the South Towns and could reach downtown Buffalo just as people are trying to get home. Wherever the band winds up, it will cause whiteout conditions and rapid accumulation. However, just outside the band it is just dry and very cold.
Here is my morning video. It includes two of several storm track scenarios.
The stronger the storm becomes, the heavier the snow on the cold side. However, a stronger storm will also tap much warmer air. This morning's NAM model suggests Philadelphia and New York City could get a few inches of snow late Saturday followed by a decisive change to rain. In Boston, however, the cold air appears more resilient, and this could result in a foot of snow. The GFS model last night portrayed a weaker storm with more cold air standing its ground. Check accuweather.com's latest info as the situation is resolved. This is a draft of the Thursday morning snow accumulation idea:
...speculation about a snowstorm Monday or Tuesday, and one is still possible. However, timing and placement remain elusive. This map shows the GFS ensemble mean "solution" for Tuesday morning showing snow just off the New England coast. Watch this story evolve on accuweather.com all weekend.
As we look father out this month, it looks cold for the Great Lakes and Northeast (as well as deep into the South) in the middle of next week but milder the following week. This map, for next Wednesday, shows a cold flow from way north in Canada.
A few tornadoes can also occur, especially from Mississippi and Alabama to Kentucky. This map shows the areas of potential severe weather through tonight as forecast by the NWS Storm Prediction Center.
A less prominent but strengthening band of snow showers was moving southeast across Wisconsin. That feature is the one that would cause snow showers tomorrow morning in the Northeast Corridor.
On Friday, a northwesterly flow of cold air heads across the Great Lakes and into the the Northeast. By Sunday afternoon, the flow shifts dramatically to send milder air from the southern Plains toward the Northeast.