The National Weather Service begins a new impact-based severe thunderstorm warning program

We see our share of severe thunderstorm warnings throughout the year here in North Carolina and Virginia, and we are familiar with the damage potential that comes with these storms. Now the National Weather Service has devised a better way to convey the destructive potential of severe storms since all storms are not the same. As of Aug. 2, the NWS is issuing ‘Impact Based’ Severe Thunderstorm Warnings. The warnings will now include damage threat tags to better convey the impacts these storms can have based on their severity level.

The ‘tags’ are broken up into three categories.

The BASE category is what we are typically used to seeing with severe thunderstorm warnings with winds of 60 mph and 1” diameter hail so no changes were implemented.

The CONSIDERABLE tag is for storms with winds of 70 mph and 1.75" diameter hail (golfball size).

Then we have the DESTRUCTIVE tag which is for storms with winds of 80 mph and 2.75" diameter hail (baseball size).

When a warning is issued with a DESTRUCTIVE tag the Wireless Emergency Alert system or WEA will be activated, and messages will be directed to wireless devices (smartphones) in the warned area to notify the public of the potential danger.

On average, only 10 percent of all severe thunderstorms reach the destructive category each year, nationwide.