Active Winter Wx Has Begun

After a December that has seen all but 3 days to this point above normal in terms of temps and little precipitation, it appears that we are now beginning to enter a period of active winter wx that will keep those of you who love winter's worst quite entertained!  The storm that caused all of the rain overnight into early this morning, will cause strong WNW winds over the next 36 hours.  First, take a look at this impressive cyclone from above...classic comma shaped cloud pattern!

And the surface representation of this classic mid-latitude cyclone.  Note the new triple point low forming and moving through eastern PA at this time...

You know this storm has some life as the County Warning Area for NWS CTP looks like a Christmas Tree...O Tannenbaum, O Tannenbaum..wie treu sind deine Blätter! Du grünst nicht nur zur Sommerzeit,
Nein auch im Winter, wenn es schneit. O Tannenbaum, O Tannenbaum, wie treu sind deine Blätter!

As this low slowly pulls NE and fills, backlash lake effect snows will bury the Laurel Highlands under blizzard conditions as the winds will be sustained easily above 30 mph with gusts to near 50 mph from time to time.  The winds will be harsh around KMDT as well...take a look for the prog of the winds for Saturday morning.

Cold high pressure will eventually allow the winds to slacken by Sunday and a period of relatively cold but nice wx will be on tap for Sunday and early Monday.  But later in the day for Christmas Eve, a small wave of low pressure will pass off to our south and deliver a nice little skiff of snow late Christmas Eve into early Christmas Day.  Snow falling during midnight mass will be most enjoyable!  Here is the GFS' interpretation of snow depth by Christmas morn!

Here is the surface prog causing the brief snowfall on Christmas Eve...most certainly snow...1-3" or so...

Then 36 hours later, another more impressive impulse at the 500 mb level will traverse the country and spin up another rather impressive cyclone, this time with its target more towards PA with its wintry wx! This is nearly in a perfect position to smack central PA with well over a foot of snow...IF ALL PARAMETERS WOULD COME TOGETHER!  Now that is a big IF since this potential is about one week away!

Here would be the surface reflection...this of the EURO since some of my colleagues are so wx savvy they only look at the Euro anymore!  Remember...predict the high (to the north over O Canada); predict the snow!

And the GFS' snowfall totals once all is said and done...I'd like to see that brown bulls-eye right over northern York County!

Once that occurs, there will be more cold and storms as we are going into a rather active pattern as far as this eye can see...I do believe...Below is the 500 mb for next weekend.  2 more waves to traverse the country and possibly affect the east coast!

And the cold wx will be sticking around with the snow on the ground.  Remember, cold breeds cold and snow breeds snow.  The air masses are unable to modify as quickly as they move over frozen surfaces and the very little bit of sunlight at this time of year aids little in warming these polar and arctic air masses!

So there you have it...a cold and stormy period is in store for at least the next 2 weeks.  I do believe that the end of December into the 1st part of January will be rockin' with cold and storminess.  In fact, if the cold gets to be severe in terms of true arctic air, the storm track may even get suppressed south of PA and we simply bask in arctic air with static electricity warnings and dry skin advisories!  I'll leave you with one of my favorite "winter" time songs that Kay turned me onto last year.  It is sung by so many people, originally written by Gordon Lightfoot in 1967.  You know...those Canucks sure know a little bit about the winter season!  Song For A Winter's Night...enjoy...

And enjoy your festivities whatever they may be...for me...MERRY CHRISTMAS AND A HAPPY NEW YEAR!

Smitty

AA:  Windy through Saturday...cold...then watching the potential for a 1-3" snowfall for Christmas morn!  Then, a major nor'easter will affect the east coast.  If the modeling holds serve, we are looking at a +1' event!  Cold continues into the New Year...Merry Christmas my friend!

White Christmas?

As Bing sang so eloquently...and many of us desire to witness, a white Christmas is possibly on the docket for next week.  In fact, I feel that there are 2 very possibilities of snowfall next week; a minor event on Christmas Day and a major event a few days past!  Let me explain...First, look at this monster today that is most undoubtedly wreaking havoc with the best of travel plans in the Midwest today!

With such a strong temperature and pressure gradient, there is no doubt these cyclones will develop to do their dirty work and mix the contrasting air masses about.  Blizzards complete with thundersnows in IA and WI, tornadoes in AL and the panhandle of FL...followed by freeze warnings...20' waves on Lake Michigan...it's all about the cyclone.  The sleet that was observed today shows that the antecedent air mass in place is still quite cold and that some fun 'n' games are just around the corner as the next few storms pass this way!  Here is the upstairs view Mr. 984 mb!

This storm will usher in polar air of O Canadian origin that is actually quite cold.  Frankly, we will be experiencing "normal" temps with some gusty winds the next couple of days...and it will feel like the remote hinterlands of the frozen tundra since we've had such an easy time of it to date this December.  However, this storm will lay down snow as will the subsequent lake effect which will not allow air masses advecting SE to as quickly modify...thus cold breeds colds; snow breeds snow!  Therefore, the next system coming will have a bit more antecedent cold air and thus the potential for a white as opposed to a wet event...here is the numerical prog GFS style for Christmas morning...just after midnight mass...

Gut feeling is the the low pressure will consolidate into a bit more of a precip event and therefore deliver the white goods in the neighborhood of 1-3" of snow for Christmas Day.  It is a gutsy call...but the other other global models suggest something in that general quantity...but that is the appetizer or should i say...appe-teaser for this beautiful scenario!

Yokes...if this verifies...you'll get to test that blower for the darn cul de sac!  For me, I may make snow angels until the New Year!  Then...in this storm's wake, look at that beautiful cold high coming down from Lake Winnipeg!  I just might have to pinch myself if this winter starts to...well...act like winter!  The GFS seems to think that by next weekend, we might be buried in these parts!

OK...enough for now.  Let me leave you with another Sarah McLachlan take of an older poem written by Christina Rosetti.  It was voted as the best Christmas carol in 2008 by those musical gurus who would know!  I just think the lyrics and the song are awesome...enjoy!

And enjoy your upcoming holidays...Christmas and New Years for me...whatever you might celebrate for y'all.  Just be safe and enjoy!

Smitty

AA:  Looking for winter to pay us a visit next week with 2 accumulating snows by next weekend.  One minor and one MAJOR!   Or as I might say...crippling?  At the very least, highly impactful!