National Weather Service to Add “Damage Threat” Categories to Severe Thunderstorm Warnings
Starting August 2, the National Weather Service says it will add a “damage threat” category to severe thunderstorm warnings.
The National Weather Service says not all severe storms are the same. The variables include the possibility of hail and high winds.
The NWS has developed three damage threat categories for severe thunderstorm warnings. The categories, in order of highest to lowest damage threat, are destructive, considerable and base.
A destructive damage threat includes: at least 2.75 inch diameter (baseball-sized) hail and/or 80 mph winds. The NWS says this threat will automatically activate an alert on smartphones in the warned area.
A considerable damage threat includes: at least 1.75 inch diameter (golf ball-sized) hail and/or 70 mph winds. This will not activate a smartphone alert.
A baseline severe thunderstorm warning remains unchanged: 1 inch (quarter-sized) hail and/or 58 mph winds. This will not activate a smartphone alert. When no damage threat tag is added to a warning, that means damage is expected to be at the base level.
On average, the NWS says only 10% of all severe thunderstorms reach the destructive category each year.
The new categories will tell you whether urgent action is needed, a life-threatening event is occurring and may cause substantial damage to property.
The NWS says 13 of the 22 costliest weather disasters in 2020 were severe thunderstorms.