Thursday, December 27, 2012

Third Time May Be Charm For City

The first two storms of a three storm week were appetizers of sorts for the snowstarved -- Monday's Christmas Eve snow was a nice paint of white around the north and west suburbs, albeit briefly as rain and drizzle helped wash most of it away.  Yesterday's larger storm started as snow before changing to rain in many spots.   If these two weren't enough of a tease, we have a third storm system that's poised to hit on Saturday -- this one has a better potential for snow for most of the region, including you guys in South Jersey...perhaps even to the Shore.

The Euro and GFS have some differences in track and details given there are two pieces of energy that are poised to work through the region in tandem -- the Euro tries to strengthen the coastal feature into the dominant player while the GFS emphasizes a piece of  energy to the northwest of the coastal feature, slower to develop the coastal until after the disturbance pushes through.   This results in about a 50 mile difference in snow swath but which feature wins determines who gets the most snow.  We're not talking major, crippling, back-breaking type stuff but snow is snow.

The GFS plays up that northern energy a bit more -- the result is a general 2-4" swath of snow northwest of Philadelphia (see below for detail).  It's nothing special -- it's a nice event -- but it's the downplayed, low key, nice snowfall that rewards the north and west.  Because the northern energy gets played a bit more heavily on the GFS, the coastal doesn't have as much energy and doesn't have as much moisture to work with.  There could be a bit of a dryslot in South Jersey and Southern Delaware if this scenario takes hold.  There could also be some light rain at the Shore for the duration of the event.

Consequently, the Euro is different -- the coastal gets going sooner and strengthens a bit more robustly than the GFS' thinking.  The result is that Jersey gets the most snow but everyone south and east of Route 222 would pick up a couple of inches.  Parts of interior New Jersey could see six inches of snow in this scenario as the coastal fires up and backside snow banding creates some good snows just inland from the coast.  The Shore wouldn't see the max snow but could stand to get a couple of inches from this setup as well.   Philly would probably get 1-3/2-4 type accumulations if the Euro were right.

There's not a ton of difference in setup or what falls -- both models suggest it's snow for the most part for most everyone.  There would be some mixing with at the Shore at times on the Euro on the front end of the storm, perhaps some plain light rain on the GFS from Wildwood south if the GFS is right. Once inland, this looks like a snow event for the most part.  The question is whether the northern energy wins out or whether that coastal can get cranking first.  If the northern energy wins, snowfall totals in our region will be a bit more modest and highest totals positioned probably north/west of the city.  If it's the coastal, Jersey stands to win the most snow.  In either case, most of the region should see snow, including Philadelphia, on Saturday.