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!

Merry Christmas

Just like Bing sang about, many around KMDT will awaken to a beautiful snow covered landscaped around the Harrisburg area!  I was not at home to witness the onset of the snow, but it did come just prior to sunset and fell rather steadily as per the obs at KCXY for ~4 hrs.  Take a look at how the visibility was rapidly decreased once the snow began to fall.  The roads in the Lancaster area quickly became snow covered and slick as many cars slid off the roadway as I witnessed driving to Christmas Eve services!  Not good...I was wondering where PENN DOT was...this was not a secret...

Here is a quick map of where the snow accumulated across the Lower Susquehanna Valley as reported to the NWS in State College.  Not the highest amounts shaded right across the central part of York County with a bulls-eye right at my humble abode!  When I returned from Christmas Eve services, there was measured 2.5 inches on the ground...so I'm sure a reading of closer to 3" was accurate nearer to the ending of the heaviest accumulating snows!  Not too shabby for Christmas Eve in these parts...!

And there is more on the way...but the modeling, although increasing in its consistency, is still waffling back and forth on many issues from exact surface low placement to upper air flow downstream and upstream, to the amount of warm ocean air that intrudes ~1 mile above the surface.  All of these factors lead to a rather difficult and challenging forecast.  Over the years, I've seen these synoptics usually do the following in these parts:

1.  Begin as snow...and snow rather heavily at the start...
2.  Slowly mix with and then change to sleet and rain...
3.  End as a brief period of accumulating snow before getting blustery and very cold...

I believe this will once again be the scenario in these parts.  There will be an extremely tight gradient as well with the heaviest snow; places like Blaine, Perry Co may receive 12" while KMDT only 4-6", and Philly just 1".  If you are looking for the heaviest snows with this storm, I feel that State College, Dubois, Clearfield, Renovo, Lock Haven, etc are in the "sweet spot" as the upper levels will struggle to get above 0°C and copious amount of precip will fall as snow.  The latest GFS shows this rather narrow gradient in terms of accumulated snows...

This is a tricky forecast.  I just wished there was a stronger high pressure in southern Quebec!  Not that 1033 mb is a small high...just a few mb greater in terms of its air's density would make me feel a bit more confident in forecasting a major event for KMDT!

As I've been touting for the last several days now, we are looking at a plowable and possibly a high impact snow event later Wed into Thursday.  The other thing that makes me just a tad hesitant is that the 00Z Euro trended just a smidgen warmer overnight...but the GFS has been trending colder with each of its last several (6?) runs...so we will see what we will see.

And by the way there is potentially more fun and games waiting in the wings for this upcoming weekend!  We need to get closer to that event once the atmosphere exerts its energy potential the next few days...

So I wish y'all a very Merry Christmas...and I truly appreciate you taking the time to reads these posts, as I try to inform you of things the TV guys and the NWS State College may not be...I will leave you with this....Enjoy!

Merry Christmas y'all!

Smitty

AA:  Looking at a snow to rain back to brief snow event Wed-Thurs; then another potential storm over the weekend.  Getting MUCH colder next week!

Cold to Follow...?

Not sure about the upcoming MAJOR storm this Wed-Thurs, but one thing I am fairly confident about and that the anomalous cold that will greet us on the the 1st few days of the New Year!  I for one...if I were going to be hanging outside anywhere in the northeast USA to usher in the New Year,... be dressed for winter's harshest cold!  Here is the 5 day anomalies centered on New years Day!  It is a cold graphic....no doubt!  This is in degrees C...so it is essentially -10°F from the norms!  That's darn cold!  If there is any snow pack, it will be much colder than indicated!

The Euro and the GFS both promote a cold and relatively dry pattern as per the 500 mb upper air pattern as seen below...

And the US generated model of the Climate Forecast System Version 2 suggests that January will be severely cold!

So I am fairly confident of cold weather hanging tough here in the month of January...and the pattern of storms will be prevalent across the CONUS...but how much the cold dome of high pressure can be attacked by the southern stream will be interesting.  This could be a January where many will want an early spring as the severity of winter weighs on many.  It could also be a January that is simply dominated and overwhelmed by NW flow; cold and dry.  But cold should rule the month of January!  We will see what we will see...

As for the Wed-Thurs system, WISH-CASTING...as opposed to forecasting...I'm rooting for the Japanese model...this is a major hit!  KMDT would be looking at 12-18" if this would verify!  Bring it!

OK...I'll leave y'all with this...and I'll try to update tomorrow morning once the Euro rolls in...(Check Twitter...) and before I spend my time away from the models, climatology, and meteorology in general to spend with family and friends...

Merry Christmas, Happy Hanukkah...or whatever you so desire to celebrate.  For me, I celebrate the birth of the Christ child...or as the lyricist wrote years ago...my favorite Carol...

What child is this, who, laid to rest,On Mary's lap is sleeping?Whom angels greet with anthems sweet,While shepherds watch are keeping?This, this is Christ the King,Whom shepherds guard and angels sing,Haste, haste to bring him laud,The Babe, The Son of Mary!...

I will also link to this since it is one of my favorites...

Once again, MERRY CHRISTMAS!

AA:  A cold January looks to be in the cards...

Post Christmas Wx Uncertainty

With the threat of a major nor'easter 3-4 days away, there remains a tremendous amount of uncertainty within this time frame.  Quickly here before I receive some divine intervention with my addiction with the wx, I will show you the Euro Model for the path of this storm...unfortunately, the "free" Euro model output is for only 24 hour increments and cannot really depict where the exact path of the LOWS will track.  With that said, there will be 2 lows...the primary traveling up towards KPIT with a secondary low forming as energy is transferred towards the natural baroclinic zone of the coast/ocean interface.  Here are the 3 Euro positions...

Christmas Night

Wednesday night

 Thursday Night

Note in the Wed. night graphic, you can see centers of low pressure; one in WV and one forming over in the coastal plain of VA/NC.  The sooner the secondary forms, the more likely for a major snowfall.  IT IS WAAAAAAY TOOOOO EARLY to determine an exact path or precip type for KMDT with this storm.  I do feel that in excess of 1" will fall from the skies...the million dollar question WHITE OR WET???  Not sure...I do like the high pressure to the north on all of the modeling.  I will not bore you with the 500 mb map now, but there is adequate (not very strong what I like to see) confluence over the province of Quebec.  This supports cold air funneling southwestward towards PA and helping hold the cold in place.  The synoptics of this pattern are very complicated with the extreme cold just to the NW of the CONUS and the anomalously warm oceans to our east.  Many of you will see forecasts for rain...that is because the GFS is the furthest west of all of the global modeling and as of this writing...AN OUTLIER!  It does develop a secondary storm, but too far north and east to make it snow much in these parts.  Here it is...

GFS Model

As for Christmas Eve snow, we are still looking at a skiff of ~1-2" before changing to very light freezing drizzle by early Christmas morning.  A white frosting SHOULD greet anxious youngsters and adult winter wx lovers alike!  But the big ticket item is most certainly Wed-Thurs...and I'll try to keep y'all updated as best as I can.  

Follow me on Twitter...if you so desire!  It is very quick and easy for me to quickly post a graphic or quick statement concerning the wx.  Heck, I can even post while pumping out some cardio on the arc trainer.  In fact, it makes the workout go a bit quicker!  If you have a smart phone, Twitter is extremely easy to utilize.  No...you do not need to tweet!  Just get a screen name and a valid email address...and you can access Twitter!  Do it...it's perfectly legal to be a Twit!  And I think most of you will be pleasantly surprised as to what you QUICKLY find out!

OK...off to receive divine intervention.  Let me leave y'all with this wonderful ditty...

Merry Christmas!

Smitty

AA:  Nice Sunday, increasing clouds and cold Christmas Eve with light snow arriving late in the day.  Cold and mostly cloudy Christmas Day awaiting the bigger storm for Wed-Thurs.  By the way, another for the weekend...different story for a different day!  Merry Christmas my friend!

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!

The Pattern; It Is A Changin'

I decided to type this out since I had no voice today and was pretty freaked about it all...ask my wife!  That was a situation in which I felt most uncormtable... I did not like it at all...I even did what most experts say not to do and that was research the larynx and see what the deal might be...when I read the most common cause for laryngitis is the common cold, I felt quite relieved...inflammation of the larynx...weird...don't ya think?

Anywhoooo...With apologies to Bob Dylan in the title above, I waited for several runs of the global modeling before I decided to opine about the upcoming several weeks of weather here in the eastern USA...let alone across most of the USA.  After a warm start to December...understatement...see graphic below, I do believe we will again see cold air invade and reign over most of the CONUS much like November was in these parts.  I was surprised that many did not seem to think November was cold in the Harrisburg area; however, only THREE days exceeded the norms in terms of temps with the month averaging nearly 4˚F below normal!  Below is this December to date in terms of its anomalous warmth...remember...when its cold in AK, its difficult for cold air to move SE into the CONUS!  The map below would have the global warming crowd frothing at the mouth!

Ah...but things are about to change I do believe!  In fact, if you believe the modeling, much of the nation will have a "White Christmas".  Take a look at the GFS suggested snowcover over the CONUS centered on Christmas Day!  Ho...Ho...Ho!  Personally, my vote is the one in the upper right!  But all runs are suggesting a snowy period before and around Christmas Day.  And it does continue beyond...

I looked at the super-ensembles analogs for Day 8 and found 2010 come up numerous times!  In case you forgot, December 2010 was quite cold and a major blizzard crippled the northeast corridor the day after Christmas!  So the pattern is ripe for storms deepening and traveling from the SE states to the maritimes of O Canada delivering the snow goodies to the megalopolis of the NE USA.  

The fun and games may begin this weekend, but the Sunday event should be a cold rain for these parts; however, Tuesday-Wednesday might actually be our first major snowstorm for the upcoming winter season...Maybe of greater concern is for the ravaged barrier islands along the Mid-Atlantic and Jersey that if this verifies will suffer yet another major flooding event next week!  For us in KMDT, we would be borderline for snow...but with 2 highs to the north...I learned at a young age, predict the High; predict the snow!

Here's the GFS for the same system...it is a bit faster and a bit warmer...The GFS doesn't have as large of a cold High pressure system as does the Euro...

And cold will hang tough for the foreseeable future...this is in ˚C and shows the anomalous cold over the eastern US centered on Christmas Day!  Sweaters, hats, and gloves would make appropriate gifts this year if Santa is any meteorological guru!  And note what is upstream in MN and ND waiting to invade points SE!

So...I've done my job...to help y'all get excited about experiencing true winter wx and King Kold laying down a blanket of white for all of his winter minions!  I will leave y'all with this winter song from Sarah McLachlan...Wintersong.  It's part of my softer side as I mellow with age...just like a fine wine!

Enjoy your end of the week...and this upcoming weekend!

Smitty

AA:  After a beginning mild December, starting this weekend, December will turn on a dime and become cold and stormy with possibly 3 accumulating snows by Jan 1!

Tuesday's Winter Wx Event

On this frosty morning, it is not too difficult to imagine that snow is in the forecast.  It is especially understandable if you spent any appreciable amount of time outside over the weekend...it was raw!  And it is now increasingly evident that a minor winter wx event is on the way for Tuesday, commencing in the pre-dawn hours.  The majority of the precip that does fall will do so in the form of snow as the upper air supports snow growth at the proper levels.  However, the question begs as to how much water will fall from the sky?!?  With the lowest levels being so dry and the dynamics not very strong, I'm of the belief that although we will certainly see snow on Tuesday, this will be a nuisance event at best.  It will get the populous into the Christmas spirit via the white, winter wx, but as i will show, it will all be but a not-so-distant memory once the weekend arrives.  Here is the NAM hi-resolution solution for snow fall...

This is suggesting that KMDT is actually the "sweet spot" for snowfall accumulations, especially in the higher elevations in our vicinity.  I also like to look at the subsequent morning lows from the models that follow a snowfall event to help pinpoint the area of snowfall accumulation...here is that map as well....lows in the teens suggests snow on the ground Wed. am...

And the cold air is being seen by the larger grid global modeling as well...-10°F for morning lows in our region...

But the cold will moderate and by the middle of next week, we are looking at temps well above normal!  The map below shows temps ~20°F above normal for the 1st part of 1st week of December.  But the longer term does spell a cold and ultimately stormy December once past the 2nd weekend of December...

...but that is a different story for a different day!

I'll leave y'all with a song whose lyrics in the middle of the song are very reminiscent of how the wx was this past weekend...

Don't your feet get cold in the winter time? 
The sky won't snow and the sun won't shine 
It's hard to tell the night time from the day 
You're losin' all your highs and lows 
Ain't it funny how the feeling goes away? 

Have a good first day of rifle deer season...

Smitty

AA:  Looking for a skiff of snow Tuesday...cold remainder of the week then becoming milder over the weekend into next week.  Looks like the 2nd part of December could be quite cold and stormy...?