There’s a change coming for the weather alerts you receive on a mobile phone, and it’s designed to better warn people about particularly dangerous storms.
The National Weather Service added “damage threat” tags to the severe thunderstorm warnings earlier this month. It’s a change similar to what has already been made to tornado and flash flood warnings. Storms with the highest potential for damage — winds of at least 80 mph or hail of 2.75 inches — will receive a destructive damage tag. The tag will activate wireless emergency alerts automatically.
People shouldn’t expect the new approach to dramatically increase the number of alerts they receive. Only 10 percent or so of all severe thunderstorms reach the levels required for a destructive designation. Most of those involve high winds.
While people generally think of events like tornadoes or hurricanes as the most dangerous weather events, that’s not always the case. In 2020, 13 of the 22 most costly weather events were severe thunderstorms. That list includes the derecho that did damage across multiple Midwestern states in August 2020 which, at $11 billion in damage, was the costliest thunderstorm of all time.
The new alerts will apply only to severe thunderstorm warnings, situations in which a severe thunderstorm is actually occurring. Severe thunderstorm watches, which mean forecasters believe conditions are right for storm formation, are not changing.