Thoughts from DT: The operational GFS model for the past few days has been trying to drive the cold front rapidly through New England, into the northern half of the Mid-Atlantic region on Thursday, and into New Jersey, Pennsylvania, Maryland, northern Virginia, West Virginia, on Friday. The result would be rain changing to heavy snow and ice in much of Pennsylvania, New York State, and New England (which seems like a good probability). Undoubtedly, even coastal New England is going to see significant ice as well as New York City, New Jersey and southeastern Pennsylvania Thursday night into Friday morning. And because the GFS model is so aggressive with the cold air it actually allows the rain change to sleet and freezing rain in most of Maryland. the Eastern portions of West Virginia and the northern half of Virginia during the day on Friday February 4.
If that were to happen then they would be a tremendous ice storm in Southern New England most of Pennsylvania, northern New Jersey, NYC, and Southeast New York. the ice would change to snow and there would be significant ice buildup and snow accumulations on top of the ice in the northern half of New England most of New York State and Northwest Pennsylvania would see all snow. Indeed, this is exactly what the operational GFS model has been showing for the past few days.
But there is a problem with this particular kind of scenario. It has to do with the development of waves of LOW pressure tracking along the front in a SW to NE direction — from Arkansas to Tennessee to Virginia to the Delmarva on Thursday and Friday. As a general rule, when LOW pressure tracking along of front in SW to NE direction, it is hard to get the cold air that is located Northeast of the surface LOW pressure to advance the Southward. You have to wait until the LOW pressure area is clear as the region. Only then will the cold front sweeps in, temperatures will drop and the precipitation comes to an end