James Lileks has the DC Metro area take on snow down:

Everyone ran to the grocery store for the usual requisites, because we might be snowed in for weeks, if not months. I saw this behavior in Washington DC, when the threat of a half-inch of snow would empty the shelves of bread and Charmin. And milk. I presume you mash them all up into a stiff, nutritious paste that will keep you alive until the rescue teams find your body.

Suffice to say, you don't want to be at the local grocery store the day before a winter storm.