New cell phone alerts warning of potentially "destructive" thunderstorms will begin appearing when storms meeting certain criteria are approaching, federal officials said Monday.
The alerts will become available to local National Weather Service stations starting Aug. 2, according to the National Oceanic and Atmospheric Agency (NOAA), which oversees the NWS.
"The National Weather Service will better convey the severity and potential impacts from thunderstorm winds and hail by adding a “damage threat” tag to Severe Thunderstorm Warnings, similar to our Tornado and Flash Flood Warnings," NOAA said in a release on its website.
The two new categories are "destructive damage" and "considerable damage" threats. The Mount Holly station of the National Weather Service, which covers most of the Philadelphia region, tweeted out the criteria for when a push alert to cell phones would be issued.
Get Philly local news, weather forecasts, sports and entertainment stories to your inbox. Sign up for NBC Philadelphia newsletters.
About 10% of all thunderstorms -- one in 10 -- nationwide produce hail and high winds that reach the "destructive damage" category, NOAA said.
"Most of these storms are damaging wind events such as derechoes and some of the larger, more intense thunderstorms, called “supercell” storms that can typically produce very large hail in their path," NOAA officials said. "The new destructive thunderstorm category conveys to the public urgent action is needed, a life-threatening event is occurring and may cause substantial damage to property. Storms categorized as destructive will trigger a WEA to your cell phone."