If you haven't realised yet, in the DC area:

1) Weather speak: "chance of snow/dusting/less than 2"/slushy/rain & snow mix" = nothing.

2) "2-4 inches of accumulation" = dusting. Negated if "slushy" is used.

3) "4-8 inches of accumulation" = 3-4" tops.

A) When a flake of snow is present on the roadways, everyone panics and runs to the grocery store and prepare to hunker down for the apocalypse. Folks bring out their SUVs and 4x4s, drive no more than 40km/h, and get into collisions at the rate of 4 per 10 kilometres. Traffic grinds to a halt.

B) Should Case 2 present itself, schools are cancelled. Governments get liberal leave.

C) Should Case 3 occur, everything is shut down. State of Emergency declared.