SIOUX CITY, Iowa (KCAU) – The National Weather Service will add a ‘damage threat’ tag to Severe Thunderstorm Warnings, like Tornado and Flash Flood Warnings on mobile phones.
Beginning August 1, the National Weather Service will provide more information about the severity and potential impacts of thunderstorm winds and hail.
National Weather Service Sioux falls Warning Coordination Meteorologist Peter Rogers said some may have already noticed alerts similar to the new tag, “Impacts from wind or hail can be quite extensive, so we want to disseminate these warnings to higher amounts of people so they can take action.”
There will be three categories in order of highest to lowest damage threat. Each tag and additional messaging are designed to promote immediate action, based on threats, according to the National Weather Service.
- Base is the lowest threat, with one inch or quarter sized hail and/or 58 mph thunderstorm winds. This will not activate Wireless Emergency Alerts (WEA), which means damage is expected to be at the base level.
- Considerable damage threat is at when hail is at least golf-ball sized (1.75 inch), and/or 70 mph thunderstorm winds. This also will not activate a WEA.
- Destructive is the highest damage threat, with baseball sized hail (2.75 inch), and/or 80 mph thunderstorm winds. This tag will automatically activate a WEA on smartphones within the warned area.
“We don’t want to diminish the base warnings, because they can cause damage, too,” Rogers said, “the main idea is to warn people so they can get inside, find sturdy shelter, and remain safe.”
Rogers said severe weather watch notifications are sent hours before the expected impact, this is the best time to prepare if a warning is issued. Using radar apps, checking in with local weather updates, and taking vehicles inside a garage can help minimize the damage that can occur from severe weather.
According to the release from the National Weather Service, the new ‘destructive’ tag would have activated a WEA for the costliest thunderstorm in U.S. history, the $11 billion derecho that affected Iowa in August 2020.
All National Weather Service Severe Thunderstorm Warnings will continue to be distributed through weather.gov, NOAA Weather Radio, Emergency Alert System, and dissemination systems. The addition of damage threat tags is part of the broader Hazard Simplification Project to improve communication of watches and warnings to the public.