Starting next week some Severe Thunderstorm Warnings may set off an alert automatically on your phone which hasn't happened before. These warnings won't depend on you having an app or closely watching the weather. Here's a look at what that alert will look like:
Starting July 28, Severe Thunderstorms deemed “destructive” will activate a Wireless Emergency Alert (WEA) on smartphones. Criteria for a destructive threat is at least 2.75 inch diameter hail and/or 80 mph thunderstorm winds.Read more: https://t.co/Vu9HyjsoRw pic.twitter.com/6Qi6s5l8ce— National Weather Service (@NWS) July 22, 2021
Cell phones are set up to receive Wireless Emergency Alerts (WEA) that can be activated by local authorities during an emergency. Now the most destructive thunderstorms are part of that list of emergencies that will trigger a WEA on your phone. There are now three "levels" of Severe Thunderstorm Warnings, which you can read more about in this post I wrote a few months ago:
Severe weather warnings are changing, and you have already seen some of these this season!
Thunderstorm Warnings will all look the same to you, but the top level will now set off the WEA on your phone. That top level means the National Weather Service expects wind gusts up to 80 mph (stronger than hurricane strength) and/or hail at least 2.75" in diameter. That's at least the size of a baseball!
For what it's worth, a similar change has already been made to Flash Flood Warnings and to Tornado Warnings. When you are inside the warning box for one of these "destructive" Severe Thunderstorm Warnings, the WEA on your phone will automatically send you an alert with the warning information. According to the National Weather Service, "On average, only 10 percent of all severe thunderstorms reach the destructive category each year, nationwide (...) 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." They added that of the 22 costliest weather disaster in 2020, thirteen were severe thunderstorms. This won't change anything about outdoor warning sirens. Setting those off is still determined county-by-county by local emergency managers. If you want to make sure your phone is set up to receive these Wireless Emergency Alerts, check the settings app in your phone.