Exactly just how bad is Hurricane Matthew, the newly minted Category 3 storm tearing across Florida’s coast? If the Waffle House Index—the Federal Emergency Management Agency’s unofficial but undoubtedly telling metric for measuring a storm’s severity—is any indication, it’s a real doozy. Waffle House restaurants are famously resilient during storms; they’re usually among the last businesses to close in the event of a disaster and the first to open after the worst has passed. On Wednesday, Waffle House’s Vice President of Culture Pat Warner said its Southern chains were stocking up on extra food and planning to keep serving customers during the storm, likely with a limited menu. But last night, as conditions intensified in the Southeast, the 24-hour restaurant company announced on Twitter that all of its locations along I-95 between Titusville and Fort Pierce, Florida were closed. This morning, it reported that 25 locations had closed in Florida, Georgia, and South Carolina. This is not a good sign.

FEMA director Craig Fugate started developing the Waffle House Index (not to be confused with the Personal Waffle House Index) when he was head of Florida’s emergency management department in 2004. Since the early days of the Obama administration, the Miami Herald reports, the federal agency has used a simple color-coded system to roughly determine the extent of the damage and assess how quickly the area affected would likely bounce back in the aftermath. Green means Waffle House is open for business and offering a full menu. Yellow means a limited menu is available. Red means the restaurant is closed. 

“If you get there and the Waffle House is closed? That’s really bad. That’s where you go to work,” Fugate said.

Things may look dire now, but when Hurricane Matthew departs, it’s likely Waffle House will be ready to fire up the griddles in no time. According to Fox, Waffle House has a top-notch emergency response plan, which the company developed after Hurricane Katrina forced massive closures and destroyed several restaurants in Louisiana in 2005. Now, when calamity strikes, the company dispatches a fleet of vehicles equipped with generators and communications technology from its Atlanta headquarters to just outside the emergency zone. When they get the all-clear, the vehicles can quickly reach the impacted restaurants and help get them back up and running.

“A lot of times, especially after a big storm, we’re the only ones still open because we’ve got generators,” Warner told Fox. “Right after storms, business is brisk. We have a lot of people come in and are only able to get their first hot meal at a Waffle House."