It’s because the average American goes to the grocery store 3 times a week.
Working the last 18 months for the leading food production machine producer has uniquely given me an insight to the food industry that I’d never seen before. Getting to sit in and talk with CEOs from major companies like Kraft, Philip Morris, Kelloggs, Smithfield, Oscar Meyer etc park as very eye opening.
But to your question, most Americans buy 1-2 days worth of food per trip to the grocery store. On average, each person in America drinks 12-18 gallons of milk per YEAR. So what happens when storms hit, they rush out to stock up based on decades old habits rooted in the old days where being snowed in for days on end was norm