The so-called “Waffle House Index” is informally used by FEMA to gauge storm severity

If you want to know how severe a storm was, simply check the “Waffle House Index”, the informal storm-grading system that FEMA uses. The Waffle House Index is quite simple and is basically exactly what it says it is. It is made up of three levels: green, yellow, and red. Basically, green means the waffle house is still open and operating at full capacity, yellow means that due to bad weather the waffle house was forced to limit its menu and staff, and red means that due to severe weather the waffle house was forced to close and send its staff home.