Tim’s 2011 – 2012 DC Winter Outlook

For Tim’s current 2012 – 2013 winter forecast please click here

Winter 2011-12 Overview

The La Nina pattern that continues across the globe has been responsible for a myriad of weather events.  The trade winds were much stronger this summer making conditions ripe for the very active hurricane season.  The drought in Texas (one of the worst in its history) as well as the severe drought in the horn of Africa can also be linked to the ongoing La Nina.  The National Oceanic and Atmospheric Association (NOAA) forecasts the current La Nina pattern to continue through the fall and upcoming winter (click here for story).

Sea Surface Temperature (SST) Anomalies October 10, 2011 (Image Courtesy: NOAA)

Washington Area La Nina Winters & Recorded Seasonal Snowfall

Average Jet Stream Pattern I Expect during the Winter of 2011-2012

Storms will enter the Pacific Northwest bringing heavy rain and snow and will then cross the Rockies before ejecting into the Central Plains & Midwest. From there the storm track will likely move along the spine of the Appalachians before heading north into New England.

Snowfall here in Washington will be heavily dependent on behavior of the North Atlantic Oscillation (NAO). If the NAO index enters a negative phase the storm track may shift more towards the coast delivering a Nor’easter.  Otherwise, Washington will mainly be on the eastern side of the storm track this winter favoring more mixed precipitation events versus heavy snow.

Winter 2011-2012 Average Storm Track

Predominant Storm Track – Neutral to Positive NAO during a La Nina Winter

  • The North Atlantic Oscillation fluctuates and is difficult to forecast more than a few weeks out… If the NAO tanks to its negative phase… the big cities could still dig out from a heavy snowfall.
  • The Piedmont zone of the Mid-Atlantic will be more susceptible to some snow, sleet and freezing rain events this winter.
  • The ski resorts of West Virginia, Maryland and Pennsylvania will likely receive the heaviest snowfalls.
  • The Poconos, Sussex county NJ, Adirondacks, Catskills and northern New England have the greatest chance of receiving more snow than mixed events this winter.

Average Seasonal Snowfall across the Washington DC Region

Washington National Airport’s “averaged snowfall” since records have been kept is approximately 17.5″

Dulles International Airport and Baltimore-Washington-International Airport typically receive closer to 23″

 

Northeast Snowfall Forecast

Tim’s 2011-2012 Northeast Snowfall Forecast

Temperatures

An active northern branch of the jet stream will bring rapidly changing temperatures to the Northeast Megalopolis. I expect wide swings in temperatures with cold blasts followed by mild periods.  December, January and February temperatures will be slightly below average (2 degrees below normal for the entire winter).

Tim’s Winter 2011-2012 Snowfall Forecast for the Washington Region: Downtown DC should see between 50 and 75% of its ‘average’ seasonal snowfall.

Tim’s 2011-2012 Snowfall Forecast for the Washington Region

Interstate 95 toward the beaches: slightly below to well below normal

Western Suburbs: slightly below to near normal snowfall

Mountains of WV, MD and PA: I think this is your year for above normal snowfall… last year’s snow drought will be a distant memory.

4 thoughts on “Tim’s 2011 – 2012 DC Winter Outlook

  1. K3 in DC

    I can live with this outcome! I just hope the cold periods are brief, late, and not TOO bitter.

  2. Pingback: Tim’s 2010 – 2011 DC Winter Outlook « Storms & Rumors of Storms

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