During the winter of 2010-2011, forecasters in the Washington DC –Baltimore, MD metro region faced two challenging forecasts of significant winter precipitation; both with significantly different outcomes. In one case, a major East Coast storm developed on 26 December 2010 and moved up the eastern seaboard. Heavy snow (upwards of 80 cm) fell along coastal sections of the seaboard from North Carolina and Virginia northward into southern New England. Blizzard conditions were experienced along coastal portions of the Northeast, including New York City and Boston. Forecasts for the Washington DC-Baltimore MD metro region had called for a significant snowfall, but owing to a sharp gradient and cutoff in precipitation, the region was spared from this storm (although the transportation sector was impacted, for example, by airlines canceling flights into/out of the DC metro region).

By contrast, an intense snowfall occurred on 26 January 2011 that produced severe wintertime conditions: heavy wet snow falling at the rate of 2-3 inches per hour that started at the beginning of the evening commuter rush hour and continued into the early evening. Arterial roadways north and west of DC and Baltimore quickly became impassable as the intense snowfall created widespread and massive gridlock. Thousands of commuters in these areas were stranded for hours. Warnings and statements issued by the National Weather Service Weather Forecast Office in Sterling VA for the 26 January event were considered by many to be reasonably timely and accurate. However, massive gridlock was still a result. This study will highlight some of the pertinent meteorological aspects of each storm and contrast the challenges faced by forecasters for each event.