Way out there but euro ai has had a number of runs recently that spin up a big storm in the D11-13 range and brings in cold air behind it. Probably would be first freeze chance for IAD and NW burbs if something like that happens.
02-03 winter in state college was epic and made up (mostly) for the dismal first 3 winters I had there. We had snow for Halloween 2002 and winter kept going until Easter 2003.