Battle Royale

I'm not sure where to start this am!  The 2 minimal snows that did not phase earlier this week; the BRIEF warm-up coming this week; or the day late for a White Christmas battle zone setting up for Christmas week?  You know me, I'll address these and a few others...

Well, with yesterday's 0.5" official snowfall, we are nickel and diming ourselves to a "normal" December snowfall total (2.4" so far at KMDT!)  The problem is that this is not the normal way for us to achieve our 6" or so normal snows in December; usually it comes in one shot!  A string of cold days is not the norm for us in this month of advent!  The warm ocean off to the east usually rears its strong arm ridge westward into the continent and we often experience a mild spell until the cold can hold from the northlands, usually in January.  However, the battle zone will set up nicely for what SHOULD be a very wintry week between Christmas and New Years.  

 First, yesterday's light snow was a result of an upper air bump that was a bit slow to create the Mauler I alluded to last week...That screaming jet to our south (below) along with with a smidge of vorticity a tad lower in the atmosphere created yesterday's winter wonderland...

Since I displayed the jet stream above, note the direction of the air coming into PA...the general flow is from the SW; obviously a much milder flow than from Nunavut!  That will be the mainstay this week; zonal (west to east) flow.  Latitudinal as opposed to highly meridinal if you care...The warm-up will be slow as low level cold is difficult to erode in the SusQ Valley;.  However, this week will average normal to slightly above.  Friday looks to be the warmest going by the 850 mb temps...take a look...

However, the cold from O Canada will push and bully its way south with the arrival of the "Big Guy"...

That purple above is the key to how much precip we get Christmas week.  I've seen battle zones set up like this many times before.  Warm air tries to push north much to its demise but delivers a solid blanket of ice and snow in these parts.  I'm going to use the snowfall prog to show you this battle zone.  The Euro depicts it very nicely...(El Paso (for you MrMazz) to I wanna be a part of it (not really) NY, NY!)  It's too early to forecast, but I believe the depth and strength of the cold will rule the roost and cold and dry will be the weather elements we observe...but stay tuned!

There's so much to share, but I don't want to bore my loyal readers...so I'll stop now.  I'll likely try to show you the super ensemble analogs tomorrow...do you remember Christmas 1983 for KMDT.  That might be in store for Boxing Day 2017!?!

OK...I'm out, but before I go, I'd love to see this group perform at the Red Rocks Amphitheater (not necessarily singing this ditty), but it would be fun for Christmas in July!  Enjoy!

And enjoy your 3rd Sunday of Advent (a time to wait, wonder, and ponder of the arrival of Christ the King!)  And I sincerely hope none of your Christmases are "blue"; I just like the tune!

Out...

Smitty

AA:  A slow and brief warm-up leading to Christmas, but watching for a very cold and potentially stormy Christmas to New Years time period...Stay Tuned!

Dissecting a Visible Satellite Pic

Just a very brief post this morning as I'd like to show y'all the beauty of the atmosphere from above.  The satellite picture in question is from MODIS (Moderate Resolution Imaging Spectroradiometer).  I know...nerd; geek!  Relax!  It's a good tool to inspect from above terra mater.  Let's use yesterday's snowfall as the snapshot to observe...

I tried to snip from a mosaic the region around the mid-Atlantic coast which includes most of VA, WVA, NY, PA, NJ, DE, and southern New England.  I also "highlighted" 3 areas to inspect in greater detail.  Let's start with the blue arrows.  Note the linear band that runs SSW to NNE similar to I-81. This is a good shot of the nature of the banding of the precipitation in yesterday's snow.  Often, this is the case with a coastal developing storm.  The cyclonic flow brings waves of moisture off the ocean and aligns with the topography of the adjacent landmass.  Have an imagination...that line, and several others align parallel to the coast as the forced lifting from the elevated land helps in forming these bands.  If you're under one of these bands, voila, heavier snow!  Lancaster and Berks county had a solid 5-6" event as these locations remained under one of these more intensely precipitating bands for several hours as the storm moved up the coast!  Meanwhile, a mere 50-75 west of the last band, skies were filled only with high cirrus or no clouds at all as very dry air was moving in on the backside flow from O Canada. 

Now, note the red region.  Very bubbly clouds indicating good upward motion and thus good pockets of precipitation.  Bucks, Chester, Delaware, Lehigh and Montgomery counties all reported a solid 6" event yesterday.  Pockets of 1/4 mile visibility snows are clearly evident as seen from MODIS. 

Lastly, the convection and thunderstorms that evolved over the "warm" oceans!  The gulf stream runs ENE off the mid-Atlantic coast and carries vast quantities of fuel (warm water) for these storms.  A nice baroclinic (a temp, pressure, density thing!) zone (I know...nerd, geek!) steers these storms up along the coast and helps deepen the storm.  Look at the anomalous warmth of our coastal waters...

And here is a graphic depiction the observed Sea Surface Temps (SST)...that's mid-upper 60sºF water just off the Delmarva and deepening lows love that energy!  You can also clearly note the gulf stream starting with the "loop current" in the Gulf of Mexico and migrating northward along the Florida coast...

OK...enough "Sunday School"!  Enjoy the 2nd Sunday of Advent...and enjoy this Christmas ditty...

 I'm out...the gym awaits...

Smitty

AA:  Technological Device output Analysis (TDA) of a MODIS satellite pic!