The Medium Range is Murky But No Real Cold Air

The only thing that can be stated with much confidence is that appears the true Arctic air will be kept well north of our region and the much above normal December temps will continue.  Through Dec 22, KMDT has averaged 5.3ºF above normal for all of December with an average temp of 40.3ºF.  We hit 61ºF on the 6th and a low of 19ºF on the 12th.  If not for the cold mornings that 2nd week, we'd be closer to 7-8 above!  Here is the climatogram to this point.  Note the "spring-like" last few days!

As for Christmas Eve, here is the official surface map from the Hydrometeorological prediction Center (HPC).  Note the storm off the Carolina coast.  That was our hope for a White Christmas.  It now appears nearly certain that the storm will be well off to our SE and high pressure will keep our wx high and dry through the weekend.

Here is the forecast map for Christmas Day.  Again, note lack of any strong storms across the lower 48 with the exception of the Pacific NW where an onshore flow of maritime polar air will result in mountain snows and lower elevation liquid sunshine.  In fact, i do believe that the Pacific NW will be the area of focus of interesting winter wx over the next couple of weeks.  News-making wx will be emanating from our friends in OR and WA!

Early next week, things get very murky with the modeling all over the place!  The numerical guidance is having a very difficult time assessing the atmospheric situation as the equatorial Pacific is moving from a La Nina to a neutral ENSO (El Nino Southern Oscillation).  Take a look at the modeling for the upcoming 3 month periods for the ENSO signal.  Clearly, it suggests we are heading towards a neutral bias by next summer.  With this changing energy in the earth's largest ocean, the atmospheric jet responds in ways not yet clearly understood and the medium range numerical guidance is struggling this year at best!  Look at the NASA outlier!  If that would verify, according to the analogs, we'd be looking at a very cold and stormy 2nd half of winter for the east.  Don't hang your hat on that one!

Take a look at the comparison of the GFS and the Euro for the next Day8-10 period in the upper atmosphere.  The Euro (left) has a zonal or even a SW flow whereas the GFS has a mean trough in the east.  One thing to clue everyone on; however, is that when it is that cold in AK, it is often nearly impossible to get any real sustained cold into the eastern half of the US.  It is now painfully evident that the Pacific "fire hose" is going to flood the lower 48 with Pacific origin air which spells a rather benign winter well into January.  For those wanting to experience true winter wx and winter outdoor activities, you'll need to head to O Canada and MN, ME or the Rockies for skiing, ice fishing, or even just seeing frozen ponds, etc.  This pattern does not bode well winter wx enthusiasts here in the eastern part of the US.

Well it will be January and with it opportunity for snow events, but it appears that for the next 2 weeks or so from my seat that any real cold will be kept NW of us.  It does not mean there will be no snow, but any winter storm will likely be the proverbial "mixed bag" for persons living in south central PA.  And I do believe the pattern will continue to serve up many opportunities for precip with such an active Pacific jet.  However, the GFS keeps the storm track over the next week well to the south of PA across the SE US.  Also note the incredible precip totals in the NW.  Build that snow pack in the Cascades and northern Rockies!

OK, I've rambled long enough.  In summation, just no real winter wx for us to get excited about around here.  But one thing that is awesome is Pandora's Holiday Folk channel.  I'm not one to usually tout a specific ideal or even infringe upon one's  individual freedom of choice (just that strand of Libertarian in me!); yet I do highly recommend that you check out Pandora's Holiday Folk station for a wonderful mix of strings and keys playing a vast array of Christmas tunes.  In stark contrast to what you'd be listening to on the above mentioned station, I'll leave y'all with this outstanding version of one of my favorite Christmas Carols.  Just kinda gets you going...

Enjoy your potentially frantic pre-Christmas weekend Friday!

Smitty

AA:  No real cold air in sight.  It's been mild and will continue to be mild into January.  Looks as if bulk of moisture stays south of us this upcoming week.  Good tunes on Pandora Christmas Folk station!