Waffle House Index: Explaining benchmark of severe weather | USA TODAY

Discover why the "Waffle House Index" is the unofficial way to gauge a hurricane or tornado's impact on a community.

The Waffle House Index is an informal way of measuring the severity of a hurricane.

For restaurant locations, it has three code tiers: green, yellow and red. Green means the store will operate fully, and yellow means the restaurants will be open but the menu or power is limited. Red means the store will be closed.

The index has been used to predict how severely weather will affect an area's accessibility to food, water and essential resources.