February 16, 2004
A potential Nor'easter is headed our way by Tuesday night, but exact track and intensity is yet to be determined, though a solution is beginning to come around. Here is the lowdown:
By monday night, an area of low pressure will be organizing itself off the South Carolina coastline. This is in response to an upper level distrubance swinging through. The developing storm will begin to track NNE early on Tuesday and precipitation will overspread Delaware and South Jersey by late in the day on Tuesday. Precipitation type in the Southern areas looks to start out as snow, and then change over to mix overnight on Tuesday. However, temperatures will be marginal, so a flux either way of one or two degrees will be the dividing line between all snow and just a very cold rain. Precipitation amounts look modest, but not overwhelming.
Light snow will break out in and around the city of Philadelphia Tuesday night. Any accumulations look light at this time, however, a shift to the West of the storm track by about 30 miles will put Philly into moderate snowfall. Right now, it appears that this scenario is unlikely, but I must urge caution -> On January 25, 2000, we had a very similair upper air setup, with an upper disturbance swinging through the base of a 500mb trough in the East. This system surprised many a forecaster by closing off an upper low and allowing the system to develop rapidly, giving much of the East a surprise blizzard.
In any event, right now looks like the majority of snowfall will be from Eastern VA, into Southern Delaware, and across parts of Southern New Jersey. A range of 3-6" seems reasonable for these areas at this time. Remember, this is a tricky call because a slight shift will be the difference between flurries and moderate snowfall. A more detailed discussion coming late tonight or early on Tuesday. Right now, it appears that the Philadelphia area (especially South and East)will see some accumulating snowfall Tuesday night into Wednesday. Exact amount still to be determined. Please check back later tonight as more computer model data become available.
S.B.
