How the Waffle House Index became one way to judge hurricane risk

Store windows are boarded up. A state of emergency is in effect. Hurricane Ian has arrived.

• Yes, but: Is Waffle House open?

Driving the news: The Waffle House Index is how many people throughout the South will gauge Hurricane Ian's significance this week.

• Waffle House has closed 21 locations across Florida, USA Today reports.

Why it matters: Before a hurricane comes a flurry of information, leaving people scrambling to decide who to listen to and when to act.

• When the trusty 24/7, 365-days-a-year diner shuts down, you know it's time to go.

Catch up quick: Former FEMA administrator Craig Fugate is credited with developing the Waffle House Index — a color-coded scale used to determine the risk of any given hurricane — according to a 2011 report in the Wall Street Journal.

• Green: The local WaHo is serving a full menu. Business as usual.
• Yellow: A limited menu is being served. Proceed with caution.
• Red: The diner is closed. This is the danger zone.

Be smart: The Georgia-based chain has more than 1,900 locations, many of which are in the Southeast — meaning the company has been around for many a major storm.