(CNN) As the monstrosity that's Hurricane Florence moves closer to the Carolinas, the Waffle House is joining the list of agencies and businesses tracking the storm's every twist and turn.
The Southern breakfast chain, which is open 24 hours a day all year, activated a storm center to monitor the Category 2 hurricane. Waffle House restaurants are known for staying open during natural disasters, and federal officials use them to determine the severity of a hurricane, tornado or other hazards on a local area.
The Federal Emergency Management Agency coined the term "Waffle House Index" to measure the effect of a natural disaster on an area. If a Waffle House shuts down or limits its menu after such hazards, federal officials conclude the community took a major hit.
"The Waffle House test just doesn't tell us how quickly a business might rebound — it also tells how the larger community is faring," FEMA said in a 2011 blog post when Craig Fugate was administrator.
"The sooner restaurants, grocery and corner stores, or banks can re-open, the sooner local economies will start generating revenue again — signaling a strong recovery for that community."
In a 2016 interview with NPR, Fugate described how FEMA applied the Waffle House test.
"They are open most of the time. And that was the index. If a Waffle House is closed because there's a disaster, it's bad. We call it red. If they're open but have a limited menu, that's yellow," he said. "If they're green, we're good, keep going. You haven't found the bad stuff yet."
Waffle House spokesman Pat Warner said Fugate came up with the test during the 2004 hurricane season in Florida.
"If we are open quickly after the storm, that means the community is coming back and folks are out, we are getting back to that sense of normalcy," Warner told CNN's Brooke Baldwin on Wednesday. "After a storm, they're really looking to us to be there to help them out because they're used to us being there the rest of the year."
Waffle House is headquartered in Georgia, and has more than 2,000 restaurants, most of them in the South.