Cold & Dry

How do those 2 words greet you this cold Thursday morning?  With one of the colder mornings in recent times...and it's about time...people living in the eastern US face the prospect of watching an extremely deep trough pass through our part of the continent without any atmospheric fanfare, save for some feisty lake effect snows in the lee of the "warm" lakes.  As I type this, the 5 am obs at KCXY is 23ºF with a dew point of 13ºF.  What makes that somewhat impressive in light of our recent above normal temps is that the air is still moving with a W wind of 5 mph!  It might drop to the coldest temp yet this winter (19ºF) prior to our 7:30 am sunrise!

Just take a look at our near year end climatogram for Harrisburg.  73 inches+ of precip is unreal.  And also note how the temps this December have been up in the "pink" band of above normal in terms of temps.  Only a small amount of the temp has spent any time down in the "blue"...and for lovers of the winter wx, that gives us the blues!

But that will change, both in the precip department and the temperature department as an Arctic front appears to be scheduled to cross our area on/about Sunday afternoon.  Once we get into the true arctic origin air (with dew points in the single digits and below 0ºF), it appears that most of next week will be featuring reinforcing shots of arctic air with little in terms of precip, save for some flurries that make it SE of the mountains.  Take a look at the Euro for next Monday evening...that is one deep trough!

And being supported by a vast arctic high located from Quebec down to SC...that map below screams of clipper type systems only affecting us here in PA...

As does the 500 mb vorticity map for the middle of next week...there is simply no modeled energy "upstream" so to speak as shown by the yellow patches of vorticity (atmospheric spin or energy)...again a bit disheartening as the modeling is squelching any idea of storm system developing in the flow.

The storms are developing out over the Atlantic as shown by both the Euro (storm well out to sea)...

and the Canadian...Yesterday, both the Euro and the Canadian had storms much closer to the coast.  Today, they have trended these storms even further out to sea.  There is still a chance of a weaker system developing along the natural baroclinicity of the cold land/warm ocean interface, but that is frankly grasping at straws for snow-lovers here in the eastern US.

 One thing, however, is that the snow guns will be going full bore as the arctic air will allow for decent artificial snow making at places like Roundtop.  The other snow guns will be downwind of the Great Lakes as shown by the snowfall graphic below.  Note the accumulations in the favored snow belts around the lakes...

Compare that to the initialization of the model seen below...also note the glacier beginning to form up in Quebec above...

So there you have it.  Cold and dry.  Nothing fancy. I will, however, issue a static electricity warning as the lower dew points will support speedy electrons traveling from people to ground at the most unsuspecting times as well as the most predictable ones!  I hate sliding out of my car and getting lit up with what seems to be at least 1,000 Volts!  But as my E&M prof at PSU reminded us so often, "it's not the voltage that will kill you, it's the amperage!".  Heck, all I know is that I HATE STATIC ELECTRIC POTENTIAL, and next week will be very conducive to generating ample electric potential between human and everything!

Have a great Thursday...and I'll keep looking for a storm to develop on the arctic front!

Smitty

AA:    Coldest air of the winter next week...very little if any precip to accompany it however....but plenty of static electricity will!  Beautiful baby my friend! Glad everyone is healthy & your kids get their looks from their mom!