If Waffle House Is Closed, It’s Time To Panic After a hurricane, the 24/7 restaurant provides one measure of how infrastructure and supply chains are holding up.

On a warm, cloudy morning in the first week of October, in an anonymous office park just outside Atlanta, operations analyst Matt Stark opened a computer program, ran through some data and looked thoughtfully at the results.

Out in the Atlantic Ocean, Hurricane Matthew was hurling winds of 115 miles an hour toward the coast of Florida. Hundreds of miles inland, in the headquarters of Waffle House Inc., Stark’s software predicted that 477 of the chain’s almost 1,900 restaurants might be affected by the onrushing storm.

This meant two things. First, as the storm made landfall, some locations of Waffle House — which boasts that every restaurant stays open 24 hours a day, 365 days a year — would probably have to close because of power loss or concerns for workers’ safety. And second, sometime after they did, someone would invoke the “Waffle House Index,” the slightly flippant measure of how bad a storm can get.

And Matthew brought on both those expected scenarios. Waffle House announced Oct. 6 that it was pre-emptively closing some restaurants on a 90-mile stretch of Interstate 95 between Fort Pierce and Titusville in Florida. (In the next few days, as the storm churned up the coast and flooded North Carolina, it would close 98 all told.) And as soon as the announcement went out, media tracking the storm, and customers on social media, invoked the closings as a sign of the apocalypse.

The Miami Herald: “When Waffle House surrenders to a hurricane, you know it’s bad.” The Washington Post: “Hurricane Matthew is so scary even the always-open eatery is evacuating.” A faithful customer on Twitter: “GOD IN HEAVEN THIS IS THE END!”

In those areas, the Waffle House Index had just gone to red.

Disaster responders pay attention to that index, which was created — in the midst of 2004’s devastating Hurricane Charley — by W. Craig Fugate, administrator of the Federal Emergency Management Agency since 2009. Fugate was director of emergency management for Florida when Charley slammed the state with unexpected force: Its winds strengthened abruptly and it went from a Category 2 to a Category 4, and the storm suddenly changed direction and struck the state’s Gulf Coast at Sanibel, 150 miles south of its predicted landfall. Tens of thousands of people were reportedly left homeless.

Fugate was in his office with state meteorologist Ben Nelson and members of the Florida National Guard, color-coding infrastructure loss on a map — green for operating, yellow for affected, and red for destroyed — and the group decided to take a look at some of the damage, and try to find a meal.

“They went to a Waffle House and noticed they had a limited menu, with nonperishable items,” Alexa Lopez, FEMA’s press secretary, told me. “The next day, they were driving around and they went to a different Waffle House, and the same thing happened, a limited menu.”

So, she said, the group was inspired first to rank Waffle Houses in the same way: green for fully operational, yellow for a limited menu and red for closed. “Which is pretty bad, because Waffle House is always open,” Lopez added. And, second, to use those observations as a proxy for how much a disaster disrupts a community. Fugate has since been quoted as saying: “If you get there and the Waffle House is closed? That’s really bad. That’s where you go to work.”

The concept of restaurant operations as an indicator of storm impact percolated slowly into emergency-management culture — the magazine Environment Health Safety Today wrote about it in July 2011 — and broke out into the open around the time of Hurricane Irene in August 2011 (when, according to The Wall Street Journal, 22 Waffle Houses lost power but only one stayed closed longer than a day).

But the so-called index isn’t actually an official metric. FEMA doesn’t publish it anywhere; no one, except for Waffle House itself, counts how many restaurants are running lean or forced to close. But the company does give that count to the agency, and FEMA uses it — along with wind speeds and power outages and other objective measures — to judge a storm’s impact, and to figure out where its own crews and other emergency responders can get fed.

So far, so obvious: If a storm is bad enough to close restaurants that “never close,” we can agree that storm is bad. Hurricane Matthew was the strongest storm of the 2016 Atlantic hurricane season, which ended Nov. 30.

But the Waffle House Index also stands for something less obvious. It is an indicator of how complex and long supply chains are — for food, for fuel, for power — and of what it takes to plan around infrastructure that can be fragile in unexpected ways.

“The essence of the index is not just that the situation is bad,” Panos Kouvelis, director of the Boeing Center for Supply Chain Innovation at Washington University in St. Louis, told me. “Companies like Waffle House, and Wal-Mart and Home Depot, operate in areas that are frequently hit by disasters, where their operations may go down at the same time the demand for their services go up. So they have had to develop very well-defined playbooks for being prepared.”

But preparation is a complicated endeavor in an economy where few things are sold in the places where they were made. Vanilla comes from Madagascar. The United States imports most of its salt. The plywood needed to protect windows from storm debris might have been manufactured in China, and a storm in the Gulf of Mexico can force enough interruption on petroleum refining to choke off supply on the other side of the country.

“When I talk to companies about whether they understand their supply chains, they generally know one step up and back: who they buy from and who they sell to,” said Amy Kircher, director of the Food Protection and Defense Institute at the University of Minnesota. “They don’t understand that there are five or 10 steps in the chain before the product reaches them. Or that the alternate suppliers they consider their contingency plan are all buying from the same place.”

At Waffle House headquarters in November, Stark and his colleagues on the chain’s storm team — Vice Presidents Pat Warner and Will Mizell and Communications Director Kelly Thrasher-Bruner, who handles social media in disasters — walked me through how they prepare. As we talked, Stark pulled up an updated post-Matthew map. Of 200 restaurants that ended up in the storm’s path, just one, in inland North Carolina, gleamed red, for “still affected”; it had been flooded and needed cleaning out.

“It’s a big deal for us to shut down, because we’re not used to turning everything off and turning the lights off and closing the door,” said Warner, who estimates that he has worked “more than 10” hurricane responses in 17 years. “So our goal is to open up as quickly as possible afterward. The operations team works with the distributor to get food ready to go in. The construction team lines up generators. If you have generators you have to have fuel, so we line up that.”

On the edge of the predicted storm zone — which Stark monitors from a temporary “war room” assembled by putting mobile giant screens in a conference room — the company positions personnel who can swoop in: carpenters, electricians, IT specialists, a food-safety expert and someone to talk to local governments and law enforcement and soothe concerns about curfews. A little farther out, restaurants in other markets line up “jump teams”: spare personnel who volunteer to work in place of locals who might have evacuated or might need to repair their homes or care for family. In Hurricane Matthew, the company sent in an extra 250 people.

“We say we throw chaos at chaos,” Mizell said. “We just throw a lot of resources down there to get restaurants open. Our CEO will be there. In Matthew, our chairman was there, too.”

Before the carpenters and computer specialists or the replacement cooks and servers arrive, the company assesses how long it has been since supplies were delivered and — just as crucial — how long since the local trash removal company last emptied the dumpster. “Most restaurants get a delivery once a week,” Stark said. “If it got there Wednesday and the storm hits Thursday, they should have enough food, but if the storm hits Tuesday, we may have to hurry up and get some food there.”

Waffle House uses one main distributor, Illinois-based US Foods, which has depots scattered across the Southeast, where most Waffle Houses are concentrated, and where many hurricanes that strike the U.S. make landfall. So supplies don’t need to travel far in advance of a storm and are close by once roads are clear.

That model of staging supplies and personnel in layers outside an emergency, in order to swoop in quickly once it abates, isn’t unique to Waffle House. It’s also followed by the military and by the Centers for Disease Control and Prevention, which oversees the Strategic National Stockpile of emergency medications, vaccines and antidotes for natural disasters and biological attacks.

“We think about, What are the timelines in which people have to be provided medications?” Greg Burel, the stockpile’s director, told me. “Our primary stock is laid down in undisclosed locations around the country that give us access to large swaths of the population and that are accessible” by more than one type of transportation.

But the CDC also puts smaller, lighter assets — the equivalent of a temporary field hospital or a stash of medications that could be deployed immediately — “as far forward as we can if we have advance notice, but not so far forward that it becomes victim to that event,” Burel said.

The first rule of operating in a disaster, though, is keeping personnel safe. Every Waffle House employee gets a key fob with lists of relevant phone numbers. Local managers keep track of who has challenging home situations — disabled parents, children with special needs, single heads of household — and might need extra help. Every location has a wall-mounted “crisis response” flier that includes detachable wallet cards listing personal-preparedness steps for hurricanes, tornadoes and ice storms.

The cards also remind employees how needed they will be at work. “We will be very busy,” the current hurricane-preparedness card says, “and you will make lots of money!”

Once employees arrive or return and a location can open, they work through the storm manual: a giant binder, a kind of choose-your-own-adventure game composed in eggs and grits. “Here’s how you run the restaurant if you’re without power, without gas for the grills, without water,” Mizell said. “We can cook on the grills even if we don’t have electricity. We can bring in bottled water and canned Coke products and serve on to-go plates. We can get porta-potties.”

The storm team examines what worked and didn’t after every disaster, each time learning new lessons. In Hurricane Katrina — when they closed 107 locations in Mississippi and on the north shore of Lake Ponchartrain — roads were so bad they stashed supplies in a refrigerated semi-trailer with armed guards, and fuel so scarce they brought in their own tank trucks. When Katrina struck in 2005, Twitter had not yet launched; now Bruner uses it not just to alert customers to closings, but to crowdsource whether roads are open and where the power is on.

Waffle House began working on storm response before Katrina — Warner said he thinks the first organized attempt was Hurricane Hugo, which hit Charleston, South Carolina, in September 1989 — but from then to now, the company’s biggest need in disasters hasn’t changed.

“People,” Warner said. “We can get the food there, by hook or by crook. It costs more, but we’re willing to spend it. But if we don’t have people, we can’t open up.”