When confronted with winter storms, grocery store owners, managers and employees note an interesting phenomenon dubbed the "squirrel effect." The term applies to the fact that when confronted with any sort of disaster or potential disaster, shoppers come into the store and hoard whatever they can lay their hands on, much like squirrels stocking food away for the winter. The same reaction happens when natural disasters - hurricanes, tornadoes, etc - seem to be on the horizon, as well as directly after a disaster occurs.
At one point in time, "stocking up" meant grabbing kitchen staples, water and canned goods. Bread, milk and bananas are all popular items. But these days the definition of a staple food has changed somewhat and more shoppers are forsaking the component parts for the whole. Stores in the northern part of the country, for example, sold out of pizzas and other frozen goods, as well as sodas. Rental videos/dvd were also hot items, with people anticipating that a lot of time might be spent indoors while snow fell outside.
Here in California, I do have an earthquake supply kit (no frozen pizza in that, though), but there aren't many disastrous occasions to anticipate unless you count traffic. What do you - or would you - stock up on if you were to squirrel away some supplies in the face of a storm?