Two Rounds of Rain but Cold Air Lurking

A wave of low pressure riding along a frontal system is moving into Southern New England this morning bringing with it some heavy downpours.

Northeast Radar Image 611 AM EST

While the rain is heavy it is moving quickly and should be clearing the area by 11 AM.  Temperatures for the next four days will be above average and Wednesday is a sunny and mild, by December standards.  Today's temperature will be near 50 degrees.  Here is the surface chart for early this morning; note the warm front lifting north.

This will keep temperatures above average for a few days

Here is the temperature anomaly for the first 5 days of our forecast period (through Saturday) in Celsius 

GFS ensemble 00z 12/18/12 temperature anomaly forecast (image credit Dr Maue and Weatherbell)

Now look whats coming in time for Christmas

Days 5-10 temperature anomaly 

The Upper Plains are in line to see some wicked Arctic cold in this period.  This is only the GFS which has a questionable reputation...but the EURO agrees.  Here is the EURO ensemble for Christmas Eve at 7 PM EST

Sees the warmth holding on in Texas and Arctic air surging into  Plains

No surprise with the Arctic Oscillation crashing to negative values.  This is allowing the polar vortex to send shots of cold Arctic air into the United States.  I posted my weekly snowfall thoughts over at Tornado Titans which can be found here.

AO or Arctic Oscillation

The NAO wants to remains somewhat neutral and the PNA wants to move towards average.  The PNA is Pacific North American Pattern.  When negative mild Pacific air tends to stream across the US.  Never the less the cold air looks to be in place for next week (and beyond?) so get the ice fishing poles ready, sharpen up the skates, wax up the boards, fire up the snow blower winter is ready to make a comeback.