Sunday, December 25, 2011

Modestly Mild Christmas Ahead

Christmas isn't shaping up to be too terribly cold, nor terribly mild.  It will end up just a nudge or two above average and several degrees "warmer" than yesterday, when we could only coax a high of 40 degrees out of the day.   We're starting with 20's outside of the city, 30 in Philly at 6 AM with a mix of clouds and stars through the sky.

That cloud/star (er, sun later on) mix is what we should see for the balance of the day.  Expect more sun than clouds for a while later this morning before a disturbance crosses to our north.  The trailing "front" with the disturbance will agitate and throw some clouds out there later on and there could be some flurries or snow showers north of I-78 this evening and early tonight.  I don't expect any accumulations but a few flakes of snow can't be ruled out later on with this "ripple" in the atmosphere if you're up north of town.   Today's high should get to near 50 in the city (49 to be exact), around 50 south, and in the upper 40's north.   Tonight will be breezy in the wake of the ripple moving through -- winds will shift from the southwest today to the northwest tonight and increase to 12-18 mph.

The front itself won't cool us off too much in its wake -- Monday will be a couple of notches cooler but will feature mostly sunny skies with some higher clouds possible late in the day.  Expect highs on Monday to get to 47 in Philly, mid 40's north, near 50 south.

The Week Ahead:  The next storm system's low pressure center will track along I-95 on Tuesday evening.  It would not surprise me to see 60 degree temperatures crop up across South Jersey and Delaware, while the northern/western burbs hang in the lower 40's Tuesday night as a period of steady rain moves in during the afternoon.  If the low tracks a nudge or two north/west of the city, Philly could nudge 60 degrees Tuesday night but it's a semantic argument at this point as the main point is warmer air will move up to the east of the low...and that this storm will be rain for the vast majority of the region.  In the Poconos, it could start as snow/sleet but turn to rain quickly as temperatures will moderate above freezing above the ground and at the surface.     Post-storm, cooler and more typical December conditions bounce back in...with a clipper type low for New Years Eve bringing a chance of rain or snow showers.

There are some "hints" that we trend chillier after New Years Day but model specifics are waffling between the Euro (much warmer with a more powerful storm that ushers in cold shot) and GFS (clipper train that pushes in cooler shots).  Both models do show a cooldown in about eight to ten days' time.  We'll start looking at Winter Classic Weather after Christmas as we get a more "refined" look at the weather from the models regarding the storm.