Here is a very brief write-up on the weekend time-frame for the Mid-Atlantic. Many people have inquired about a potential winter storm that some of the numerical guidance is showing. This potential event is several days out, and we all know many changes will emerge within the models on a run-to-run basis. It’s too early for all the specifics on the potential winter storm during this time frame, however, I will say, the Mid-Atlantic bears watching during this time-frame. So, what do we ‘know’ at this point?
It appears a cold airmass will move into Mid-Atlantic by Friday. This cold air will be in place as a potent low-pressure system potentially moves into the area from the west by Sunday. With the low possibly deepening as it moves out of the Tennessee Valley late-Saturday into early-Sunday, it’s likely the system will draw in deep Gulf moisture to aid in heavy precipitation. Some of this precipitation could fall in the cold airmass, which would set the stage for a heavy wet snow in parts of the Mid-Atlantic. What are the uncertainties?
The evolution, track, and timing of the system are uncertain. The amount of cold air that remains in place, the position of the freezing-line, and the vertical temperature profile of the atmosphere are uncertain. There should, however, be enough cold air in place for snow in some areas. It should be noted, with a low this strong, as some of the guidance is showing, it is possible for a warm-nose to develop and cause a forecasting headache.
Again, this is several days out and a lot will change, and there is considerable variance among the models; but there has been an overall trend in the models over the past 48 hours indicating a stronger, colder, further south solution. This map below shows which areas I am watching right now–in the pink shaded region. The red ‘L’ shows you the position of the low from late Friday near Arkansas, moving through the Tennessee Valley late in the day Saturday, and exiting the East Coast by Sunday afternoon. Please keep checking back for updates.