by: Robert J. Leffler
Volume 2012, No. 1, 6 Mar 2012
The winter of 2009-2010 in the Washington D.C. area will likely be remembered by many arearesidents as the snowiest in their lifetimes. A rare combination of a weak-to-moderate El Nino (wet) anda very persistent negative North Atlantic Oscillation (NAO) (cold) brought a potent combination of sub-tropical moisture and cold air together over the mid-Atlantic states including the nation’s capital, resulting in an unprecedented number of major snowstorms and totalsnowfall. The extreme winter snowfalls during the most intense periods of the winter earned the winter the nickname “Snowmageddon”.
The largest snowfallsoccurred to the north of the Capital and west and northwest of Baltimore in north-central Maryland. An analysis of historical snowfall reports for the Washington D.C. metropolitan area suggests Snowmageddon’s snowfalls were unprecedented in number and amount since historical reports are available beginning in early colonial times in the early 1600’s.