3 Snows During The Christmas Week

Christmas Eve, the day after Christmas, and now it is looking as if there will be yet another round of winter precip in the form of accumulating snows Friday night into Saturday.  Before we jump ahead to the weekend event, let's look back at what just transpired during the last 24 hrs.  At my humble abode, I measured 3.4 inches of snow prior to the changeover to freezing rain and ultimately some plain rain well after sunset.  The total amount of precip was 0.72"; therefore, roughly half of the precip fell as snow.  I believed that the primary low and its overrunning precip would hold longer than it did.  Once the energy transfer took over, so did the upper air support for the precip that did come fast & furious for a time.  Look at the obs at KCXY in terms of visibility...4 hrs of less than 1 mile vis...and visibilities were far less during the height of the snowfall Wed afternoon!

Here is the storm now as seen from space...Note the cold air rushing out over the Gulf creating the clouds off the TX and LA coasts!  Lots of StratoCu for us here in PA today on strong NW winds!

Here is another graphic with the isobars/pressures overlaid...

And the current temps across the CONUS...note that the 32°F isotherm traverses PA...quite cold in the plains of O Canada!

After yesterday's snow, take a look at the snow covered US...

...and compare the map above to the map below from last year at this time!

And more snow will be added to the CONUS by this weekend as yet another disturbance will track from the southern plains towards the New England coast.  The runs have been getting closer and closer to the coast, but we are still a bit away from the onset of the event and all the "players" are yet on the continent for the models to properly ingest...Here is the Euro...it's a nice moderate snowfall for KMDT Sat am...

What is interesting is that the 500 mb lowest pressures of the Euro ensembles are in a quite favorable area for even greater deepening of a surface low that would impact southern PA to an even greater extent than the operational indicates.

Here is the Ukie's take...

And the GFS...a bit further SE...but the ensembles again argue for a bit closer in towards the continent...

Here are the ensembles...the lowest heights are again in a favorable position to spin up a nice storm for southern PA...and the trough is somewhat negatively tilted...

Here is the operational's take on the vorticity in the middle levels...if that vort max can become less sheared and more "phased" a stronger storm is in the cards for Sat am...note where I circled in RED...

OK...I've bored y'all enough...so if you take a stroll outside anytime this week...keep this Christmas-time ditty in mind...I think Annie makes most songs sound great...enjoy!

Smitty

AA:  Looking at yet another snowfall for Friday night into Saturday midday...then getting "brutally" cold for the New Year's celebrations!