Saturday, December 22, 2012

Could It Be True? Part II


Three years ago this weekend, 18-24" lay across MD. 
10:00 PM EST 12/22 (Winter Stormcast Team) – “I’m Dreaming… of a White… Christmas. “ – It’s something on our minds every year around this time, but snow near or on Christmas is actually quite rare for the Mid-Atlantic. For example, Baltimore, MD's last white Christmas was 2009, but it hasn’t snowed on Christmas Day since 2002! 

This year, however, our team is watching the potential for a possibly notable winter storm to move through the Mid-Atlantic and Northeast on Christmas Eve into Christmas morning, which could give some areas that taste of snow some have been waiting to see, for years. We first outlined this possibility in our "Could It Be True?" article posted earlier this week.


  • The system in question is just a very weak upper-level shortwave at present, but because of its timing, it is certainly worth mentioning. 
  • The general situation we expect is a very weak low pressure tracking along the Ohio River and then into the Mid-Atlantic. 
  • Since we still have a bit of time, and uncertainty is high, we have outlined three possible scenarios for this event as noted below.

STORM OVERVIEW Precipitation may begin during the evening hours of Christmas Eve for the Mid-Atlantic, then continuing into the overnight before departing by the early afternoon on Christmas Day and moving out to sea. 

  • SCENARIO A: The storm remains weak, and has little access to cold air. This means that rain would be the most likely form of precipitation for Maryland, southern Pennsylvania, and southern New Jersey, but some mixing could occur to start. In this situation, some light snow up to an inch or two is possible for central and northern Pennsylvania, northern New Jersey, and southern New York. 

  • SCENARIO B: The storm is still weak and moves through quickly, but cold air is more entrenched over the region, pushing the storm ever so slightly south. This could bring some light snow up to an inch or two to northern Maryland and Delaware, Pennsylvania, New Jersey, and southern New York with mixing possible into northern Virginia.

  • SCENARIO C: The storm is slightly stronger and large, first bringing snowfall into areas north of the Ohio River, then into West Virginia, then spreading snowfall up to a few inches into much of the Mid-Atlantic north and west of I-95, including VA, MD, PA, NJ, NY, and into New England. The storm would gain strength along the coast pulling in more cold air behind it as it pulls away early afternoon on Christmas Day. 

OUR PRELIMINARY PROJECTION? This point, we think Scenario C is the least likely, but we also believe that Scenario’s A and B are equally likely. Many things could change with this system, so stay with us here as we continue to track this exciting system!

Mid-Atlantic Winter Stormcast Director Zach Fasnacht, Mid-Atlantic Director GregJackson, Forecasters Mike Natoli, Jason Mitchell, Connor Meehan, Andrew Barney, Ross Harris, Mr. Foot 


Andy, Southern York County Pa said...

WOW! Our snow chances fell off a cliff today. Both the Christmas event and the Kahuna have turned into puddles. All guidance is showing a further north track for the Christmas event that most of PA will see mostly rain and MD all rain. The second storm looks like 1-2 inches of rain with temps in the 40s because the storm now cut west flooding us with warmth. If you want to see snow then go to Boston, but even there you should not look out the window but on the Christmas movie of your choice as out the window you will se a wind driven rain! OUCH. Here is hoping for a New Years storm.

Andy, Southern York County Pa said...

It is remarkable how quickly things have gone from good agreement on a snowy solution to rain. The problem is the storm is now stronger and wound up forcing it to cut north into the Ohio valley. That in turn puts us now on the east side and warm air is pulled from the south all the way up to New England. This shows us the limitations of long ranger forecasting. Outside of 5 days the models can't be trusted. The best bet is to hold off honking the horns until they are inside 3. At some point we will get snow, unfortunately not during the upcoming week.

ravensbbr said...

GFS did trail off earlier, but latest run seems to show some snow around Mason-Dixon back in play?

ravensbbr said...

Just realized that link may or may not work. Oh well, models can change back and forth, here's to landing a good one!

Andy, Southern York County Pa said...

I agree. Next storm to watch is around New Year. Right now it looks like a cutter but a lot can change.

NeedaSnowday said...

::grumbling:: no snow in immediate forecast...

::muttering:: game flexed to 4:25 when is colder sittin' in stadium....
Go Bengals... Go Ravens!