Friday, December 21, 2012

Dreams of White Christmas May Be Reality For Some

If you're dreaming of a White Christmas, there *could* be a bit of snow in your future on Christmas Eve night.  A weak disturbance will develop in Arkansas on Christmas Eve morning and models for the past day or two have been suggesting that this disturbance would track close enough to the region to bring flurries or snow showers as it moved by.

This isn't the talked about (hyped about) storm that's projected for Thursday of next week but a weaker appetizer before the bigger course of storminess.

Last night's models have inched up the precipitation a notch or two on this disturbance and the possibility of accumulating snow can't be ruled out on Christmas Eve night as it moves through, especially if you are northwest of the city.

First, the GFS, which suggests mainly snow for the region.   The model indicates the possibility of 2-4" of snow across Southeast and Eastern Pennsylvania with this wave of energy moving through, with the city straddling the fence between snow and no snow as temperatures would be very marginal.  South and east of the city would get some snow on the front end before a changeover to rain.

The Euro has a track farther to the west -- generally up into Western Pennsylvania and then across Pennsylvania as opposed to across the Delmarva and into New Jersey.  Light snow would change over to rain across Philly and the suburbs; however, Allentown, Reading, and the Poconos could pick up a couple of inches of snow on this more northern track.  Temperatures locally in this scenario would be a bit too mild for snow throughout the event although some could fall on the front end of it on Christmas Eve night.

The GFS track is much more ideal for snowstarved denizens as the low responsible for this precipitation would track to our south.  You want a weaker, more southerly track such as the GFS depiction or perhaps a bit more south of that GFS track if you're looking to get snow out of this upcoming system across the region.  A Euro-type track is simply a bit too warm for all snow (although we can't rule out some on the front end).

This first wave will likely help pave the way for the second storm system on the 27th, which is modeled as of this morning to track overhead.  We'll continue to monitor that storm in addition to the Christmas Eve event.