2010/2011 Forecast Verification

Data Verification

For Philadelpia/South Jersey: Philadelphia International Airport.

For the Washington D.C and surrounding suburbs: Dulles and Regan International Airport


Overall, this was a very cold winter. December ended up being the coldest, but it remained cold and below average for all of January and the first 10 days of February. February overall was the warmest. The amazing thing about this winter was the contrast in snowfall. Philadelphia and Southern NJ had another harsh winter with 40+ inches of snow and big snow events. However, it was a whole different story for the Washington, D.C. area, which saw much less with only 10-18 inches in general. As mentioned in the forecast, there were some things that compared to the winter of 1917-1918. That season ended up being a very good match for what we saw this winter, especially with temperatures(see maps below). The equatorial pacific ocean experienced La Nina conditions of moderate to strong intensity. When this is the case, research has shown that the mid-atlantic area and south of New York City does not see a lot of snow, nor big snowstorms, and has warm temperatures.

Another phenomenon that may have offset the La Nina was the Arctic Oscillation. Like last winter, it was in the negative phase all of December and January and when this is the case, the Eastern U.S. experiences much colder and snowier conditions. Please see the links below for more information on the Arctic Oscillation.


Total Seasonal Snowfall

Philadelphia/South Jersey - 44.0 inches

Washington, D.C. - 9.9 inches

D.C. suburbs(North and West) - While Dulles Airport reported 12.5", on average, most areas(20-40 miles from the city)received around 15-20"

Monthly Analysis

Washington, D.C. and Surrounding Suburbs




Philadelphia/South Jersey




Maps(Comparison this season with 1917/1918)