New NWS destructive storm categories begin, will trigger phone alerts

New Severe Thunderstorm Categories
New Severe Thunderstorm Categories(KLTV)
Published: Aug. 2, 2021 at 1:58 PM CDT
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TYLER, Texas (KLTV) - Effective Aug. 2, the National Weather Service will implement new categories of severe thunderstorms based on their wind and hail threat. Another way to put it, how much damage the storm is capable of.

The NWS points out that not all storms are the same. “Hazardous conditions range from tornadoes, large hail storms, and widespread straight-line winds called Derechos, to cloud-to-ground lightning and flash flooding. Starting Aug. 2, the National Weather Service will better convey the severity and potential impacts from thunderstorm winds and hail by adding a “damage threat” tag to severe thunderstorm warnings, similar to our tornado and flash flood warnings.”

Prior to Aug. 2, when a severe thunderstorm warning was issued, there was no damage “tag”. The warnings typically would include what the threats were, for example, quarter size hail and 60mph wind speeds. With the new categories, a severe thunderstorm will be tagged based on how large the hail it is producing and/or, how fast the wind is.

“The criteria for a baseline or “base” severe thunderstorm warning remains unchanged, 1.00 inch (quarter-sized) hail and/or 58 mph thunderstorm winds. This will not activate a WEA. When no damage threat tag is present, damage is expected to be at the base level.”

“The criteria for a considerable damage threat is at least 1.75 inch diameter (golf ball-sized) hail and/or 70 mph thunderstorm winds. This will not activate a WEA.”

“The criteria for a destructive damage threat is at least 2.75 inch diameter (baseball-sized) hail and/or 80 mph thunderstorm winds. Warnings with this tag will automatically activate a Wireless Emergency Alert (WEA) on smartphones within the warned area.”

According to the weather service, only 10% of severe thunderstorms will reach the destructive category each year. Typically these will be Derechos or supercells producing large hail. In addition to the WEA capability on your phone, you should have multiple ways to receive severe weather information. The free KLTV or KTRE weather app is one resource, as well as a NOAA Weather Radio.

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