EAST PEORIA, Ill. (HOI) – The National Weather Service announced on July 22, 2021, that the government body will enact a new severe thunderstorm warning criteria. The change is expected to go into effect on August 2, 2021, and will add two new damage threat categories alongside a severe thunderstorm warning, one of which will trigger the Wireless Emergency Alert system.

The biggest change and the addition that is the most different is the new “destructive” damage threat category. When this is issued, a wireless emergency alert will be triggered on smartphones in the warned area. The criteria for a destructive severe thunderstorm warning is at least 80 mile per hour wind and/or baseball-sized hail.

Wireless Emergency Alerts were implemented several years ago by FEMA and the FCC, allowing for emergency alerts to be sent to every smartphone in the country, given that the user has not disabled them (which is not recommended).

“You will get a message that says that a severe thunderstorm warning for either destructive wind and or destructive hail is anticipated in your area.” Said Chris Miller, Warning Coordination Meteorologist at the NWS Lincoln Office.

It is believed that these will be very rare in nature, only about 10 percent of all severe thunderstorms reach the destructive category nationwide.

According to Chris Miller, the Heart of Illinois might see one of these per year, one average. A recent storm that would have applied to the destructive category would be the derecho event of 2020 that caused widespread damage across Iowa and Illinois.

The second new category that will be implemented will be the “considerable” damage threat category. This will be issued when a severe thunderstorm has observed 70 mile per hour wind and/or golf ball-sized hail. This category will NOT trigger a wireless emergency alert.

The WEA system has been in place for many years and the NWS Lincoln office currently uses it for tornado warnings and dangerous flash flood warnings.

A standard severe thunderstorm warning has not changed and will not trigger the WEA system.