Waffle Houses dot many states in hurricane country, including Florida. Current FEMA administrator Craig Fugate began using the "Waffle House Index" when he headed disaster response in Florida.
Simple signs, like fewer menu items being available, can signal that it's hard to get supplies after a disaster or that maybe power is limited.
"They're spending a lot of time cleaning up, they're assessing the damage to their properties, they're trying to make sure their families are okay, and it's kind of like a place where everybody can meet," said Waffle House Division Manager Emily Coleman. "We tend to be one of the first places that opens up."
FEMA points out that when businesses like a Waffle House reopen quickly, it indicates a stronger recovery for a disaster area.