Friday, February 17, 2012

PD III junior?

12:00 PM EST 2/17/12 For those tracking the latest updates on this developing President's Weekend storm, this snowfall probability map from NOAA shows which areas of the Mid-Atlantic have the highest likelihood of 4 or more inches of snow Sunday into Monday. Prior to the snow even occuring, there is increasing risk of severe weather in the Southeast as indicated in Saturday's Outlook from the Storm Prediction Center as shown below. 

Recent computer model runs from the Global Forecast System (GFS) indicate the low pressure system, once it develops over the Southern Plains on Saturday, may position 40 or more miles farther north, and slow in forward speed. This would expand the area of possible severe weather across the Southeast, and is evidence the eventual low may track slower, and stay inland longer. 

Impacts on the "snow" timing: This northern shift would delay the onset of snow in this manner:

  • Southern Appalachians by Sunday morning;
  • Blue Ridge by Sunday afternoon;
  • Mid-Atlantic by Sunday evening. 
Visit our Winter Stormcast Zone for additional analyses.

Forecast Collaborators Jason Isaacs (Metro Atlanta), Advisors Forrest (West Virginia)  Foot and Berk (Baltimore)


Andy, Southern York County, PA said...

<span>The storm threat for our area is largely over.  The trend is to take it WAY SOUTH.  Baltimore/ Washington may not even see any flurries out of this.  Sunday should be a mostly cloudy day in our area with a chance of some scattered flurries south of DC.    
At least we have had something to track in a winter that has featured no threats for warning type snow.  This was a nice THREAT but it is way south to have ANY IMPACT on our region.  
Maybe we can sneak in a few incher before winter is truly over? </span> :)

Jason Mitchell said...

Wow Andy, I didn't think you'd give up on this storm. The Sterling VA NWS is ramping up on the storm, especially for my area (Southern MD)!

Andy, Southern York County, PA said...

I think your area has the best chance at seeing falling snow.  The storm is clearly tracking further south.  Even in your area you will not see accumulating snow as the ground temps are far too warm and the snowfall rates not high enough to overcome the surface warmth.  I do not expect any accumulating snow within 60 miles of Baltimore, and that might be generous based on current data.  Now I have not given up on the storm and will continue to track it, but it does look like a non event for all of us.

BioPat said...

Is the trend still southerly?  I'm seeing some newer information indicating a later storm but still filled with accumulating snow.

Andy, Southern York County, PA said...

<span>The storm is trending south and weaker overall.  With the warm air mass in place, and light snowfall rates, it will not stick.  This for the Baltimore area and DC for that matter will be nothing more than non accumulating snow showers, UNLESS somethening DRASTIC changes tonight that would show us otherwise.  I will be hoping for a DRASTIC change but I understand that it is a long shot.  No I have not GIVEN UP on the storm, but have adjusted my HONEST expectations accordingly.  I expect flurries and snow showers where I live, and heavier snowshowers in Baltimore that will not accumulate.  Here is to the 0z guidance proving me wrong.  </span> :)