For most restaurants, closing during a major storm would only seem sensible. But when a Waffle House shuts its doors, even disaster specialists take notice.

In light of Hurricane Matthew, 25 Waffle House locations in Florida, Georgia, and South Carolina have shuttered. Thursday evening, Waffle House announced on Twitter that all restaurants between Titusville and Fort Pierce, Florida, would not be up and running during the hurricane, after previously promising to continue operations. It updated the list Friday to include even more storefronts.

Waffle House has such a notorious record of staying open during natural disasters that the Federal Emergency Management Agency unofficially analyzes the chain's activity to know how severe a storm is. The closure of even one location is significant.

FEMA's "Waffle House Index" monitors House closures, focusing on the aftermath of storms and other disasters. Following Hurricane Irene in 2011, for example, only one Waffle House in Virginia was closed the day after 22 locations lost power. That signaled to FEMA where to concentrate its resources.

People seem more affected by Waffle House's announcement than any made by local officials. Fox News host Todd Starnes tweeted, "Folks, when they shut down the Waffle House -- it's time to leave town." Another Twitter user wrote, "You know it’s serious when Waffle House shuts down." After Waffle House reported more closures this morning, Scott Klein, deputy managing editor at ProPublica, said that FEMA's "Waffle House index" for Hurricane Matthew had moved to red.