The Importance of Storm Track

Current Weather Map for the United States  (Source: NOAA)

Snow lovers in the DC Metro area know how important the storm track is in determining precipitation type and amount.  While sufficient cold air is necessary for snowfall, the storm track is important in providing moisture.  When there is only a marginal amount of cold air, the storm track assumes heightened importance since it can either help or hinder the amount of cold air.  That could make the difference between snow, snow mixed with freezing rain and sleet, or just rain.

Some of the largest snowstorms on record in the Mid-Atlantic region occurred with marginal temperatures.  The “Superstorm of March 1993” was one of the most significant on record in the eastern United States, with snow as far south as Florida and significant accumulations in Atlanta, Georgia and Birmingham, Alabama.  According to the National Weather Service, snow totals of more than 40” were common from West Virginia to New England.  However, there wasn’t enough cold air in place for pure snow to fall in Washington, D.C.  Instead, sleet fell at National Airport which reduced snowfall accumulations to 6.3”, far less than the 14.1” that fell at Dulles Airport and the 11.9” in Baltimore.

During “Snowmageddon” in February 2010, temperatures were just above freezing at the onset of the storm in the Nation’s Capital, with a few inches of heavy, wet snow to start.  The storm track made significant snowfall in the Nation’s Capital possible because it drew in just enough cold air to produce one of the largest snowfalls on record.  Washington, D.C. had its 4^th largest snowfall with 17.8”, while Dulles Airport had its largest snowfall on record with 32.0”.

Last month when the “Blizzard of 2016” was developing, a lot of Washingtonians were concerned about losing power again.  However, the circumstances were different as there had been an arctic air mass in place prior to the arrival of the blizzard which allowed the snowfall that occurred to be much drier than in 2010.  Consequently, there weren’t any significant power outages during this storm which tied for Washington, D.C.’s 4^th largest on record with 17.8”.  It was Baltimore’s largest snowstorm on record with 29.2” and was the second largest snowfall at Dulles with 29.3”. 

While coastal storms bring the Mid-Atlantic Region its largest snowfalls, significant snow can sometimes occur under different circumstances.  “Alberta Clippers” tend to be fast-moving, moisture starved systems that originate in the Canadian province of Alberta, but do on occasion bring accumulating snow along with a reinforcing shot of arctic air.  For example, a particularly vigorous Alberta Clipper brought 2.4” of snow to Washington, D.C. on January 6, 2015. 

Although today’s forecast includes winter weather for tonight and tomorrow, the setup is entirely different and much more unpredictable than last month's record-setting snowfall.  That’s because there is only a marginal amount of cold air in place, coupled with a higher degree of uncertainty in the exact storm track.  On a warmer note, Washington, D.C. tied its record high of 68 degrees for February 8 just one year ago today.