Sunday Technical Discussion

Synopsis: Scattered Lake Effect snow showers have moved into most of the Commonwealth this Sunday morning. This will be the case for the next few days over the Laurel Highlands, Northwest and North Central regions.  The recovery day will be Thursday before a Clipper system moves in from the West for late Friday.

Short-term:  Winds are out of the Northwest, coupled with warmer lake waters and cooler land, Lake Effect snow is born.  The GFS and NAM are both in agreement that Lake Effect snow will take place for much of the Western half of the Commonwealth.  Both models do get hairy once we move eastward; with no lake effect snow for State College, Williamsport and Scranton.  This will not be the case however, as evident of the past few days all three locations have received up to a trace of snow within this time span.  So going off of this concept, these three locations have been forecasted to have scattered Lake Effect snow showers compared to the constant Lake Effect snow out west.  Philly and Harrisburg look to remain partly/mostly cloudy during this span.  Winds will pick up on Monday and Tuesday as the clipper system that dove into North Carolina and Southern Virginia back tracks over Quebec, greatly enhancing our winds from the Northwest.

Long-term:  As mentioned at the end of the short-term, the winds will be greatly enhanced by the strong storm system over Quebec until Tuesday.  Lake Effect snows still show up on the GFS until late Wednesday Night when they begin to die down for the regions mentioned above.  Total Accumulations for the Lake Effect snow region will be up to 12".  Now the fun begins.  The 0z GFS shows at 12z Friday (the end of the forecasting period) a Clipper system entering the region.  While the 0z EURO shows the clipper system entering the region late Friday Afternoon and early evening.  Since the EURO seems to beat the GFS, and the GFS is always playing checkup, we went with the 0z EURO.  So the only thing that the clipper system will do is bring clouds into the region late Thursday night and Friday morning.

Temperatures will remain below normal, especially out west of I 99, with temperatures not getting out of the 20's for this area.