The measure is based on the reputation of the restaurant chain Waffle House for staying open during extreme weather and for reopening quickly, albeit sometimes with a limited menu, after very severe weather events such as tornadoes or hurricanes. Waffle House, along with other chains (such as Home Depot, Walmart, and Lowe’s) which do a significant proportion of their business in the southern US where there is a frequent risk of hurricanes, have good risk management and disaster preparedness. Because of this, and a cut-down menu prepared for times when there is no power or limited supplies, the Waffle House Index rarely reaches the red level [full closure of the restaurant].
The Waffle House Index sits alongside more formal measures of wind, rainfall, and other weather information, such as the Saffir–Simpson Hurricane Scale, which are used to indicate the intensity of a storm.