A package of mini bagels sits on a sparse shelf of bread items at a grocery store in New York on Monday. (REUTERS/Shannon Stapleton)

Alert: It's snowing, and if you are like many Americans, you're worried about how much bread and milk you have at home.

Grocery crews from across the Northeast on Monday reported waves of high pressure from panicked shoppers snatching all the bread and milk off their shelves. Zabar's, a specialty grocer in New York City, quadrupled its bread orders for Monday after selling out the day before, manager Scott Goldshine told CNN. "They all think the world is coming to an end," he said. "They cleaned us out of everything."

This mass accumulation of dairy and dough has become an American snowstorm tradition. The only problem: Milk and bread are pretty bad survival foods. That milk will die fast if your refrigerator loses power, and bread can only offer so much nutrition during its short expiration date. So what is it about snow warnings that make us the bread and dairy industries' biggest fans?

The milk-and-bread buy-up is perennially baffling to weather watchers and emergency preparedness heads. During a Monday press conference, New Jersey Gov. Chris Christie said, "I don't know why the rush on bread, but what the heck, if you want more bread I'm sure you're able to get it."

At this point, the panic has morphed into satire. Comedian Vic Dibitetto's YouTube video, in which his lack of bread and milk drives him increasingly more hysterical, has garnered more than 12 million views. And of course, there's a Facebook page, "Quick! Buy up all the Bread & Milk cos it's snowing." (The most recent post: "Hope you've all been out panic buying! There's snow about people!")

The French Toast Alert System, a bread-and-milk-focused weather emergency satire site, was set on Monday to "Severe": "RUSH to emergency supermarket NOW for multiple gallons of milk, cartons of eggs and loaves of bread. IGNORE cries of little old lady you've just trampled in mad rush to get last gallon of milk."

Everyone's shopping list is different -- toilet paper, eggs and booze fill many carts -- but bread and milk stand out as long-time staples of the panicking pre-storm bustle. A report from Pittsburgh during "The Big Snow" of 1950 said that milk "was the one shortage that has hit all sections," and that bread was being "doled out" in some grocery stores, a Pittsburgh Magazine writer found last year.

It's not just that bread and milk work poorly as emergency rations, critics say; they don't even work well with themselves. Twitter users have even criticized the un-versatility of the combo with a hashtag called #milksandwiches. Sensing a need for the pairing, Nigella Lawson, the celebrity chef of the Food Network's "Nigella Kitchen," created a recipe for a bread-and-milk dish. “Basically, it’s bread torn into pieces, sprinkled with sugar and with milk poured over it,” Lawson said. “I like to warm the milk up first.”

So what's behind our anxious enchantment with bread and milk? Paul Farhi guessed in the Washington Post in 2005 that the connection was intrinsically rooted: "Symbolically, they're easy to decode. Bread is the host, the staff of life, a palpable object of survival. Milk is ... the sustenance that a mother provides an infant, a biblical promise ('a land flowing with milk and honey')."

Maybe we grab up the goods because everyone else is, and mob mentality reigns. “Panic hits when the stores are jammed with other shoppers and the shelves look a little bare," Kit Yarrow, a consumer psychologist, told Time magazine. "We are prewired to fight for food when we sense that resources are scarce.”

Or maybe the stockpiling simply gives us a chance to stay calm by sticking to a comfortable routine, psychologists told HowStuffWorks. When we buy simple perishables, and not things we'd actually need long-term, it's maybe a hint of wishful thinking that we won't be stranded for long.

"The thought to get milk before a storm is followed by the action or compulsion to go out and stockpile it," said Lisa Brateman, a New York City-based psychotherapist. "Buying things you might throw out still gives the person a sense of control in an uncontrollable situation."

So what should you stock up on instead? Bottled water's not a bad choice. Neither are foods with more nutrients or longer shelf lives: canned goods like tuna, vegetables or soup; peanut butter and crackers; nuts, trail mixes or granola bars. They may break the routine or give less of a feeling of control. But at least you'll have something to eat.