NWS begins categorizing severe storms this week
‘Destructive’ storms will trigger a Wireless Emergency Alert
(WDBJ) - Not every thunderstorm is the same and the National Weather Service (NWS) has known this.
In part of its an ongoing effort to restructure its sometimes complicated alert system, the NWS is implementing a new severe thunderstorm warning product beginning this week.
A severe thunderstorm will now be tagged one of three levels of severity. From highest to lowest, the categories are: destructive, considerable, and the standard base level.
“This new impact-based warning format is going to give us the tool to ring the bell louder,” said Phil Hysell of NWS Blacksburg.
The National Weather Service is categorizing severe thunderstorms based on a couple things: the strength of storm’s winds and/or the size of hail in storms.
In a base-level storm, this will be unnoticed with no change from what we had. One-inch-sized hail (quarter-sized), and 58 mph winds. This will not activate an alert on your phone. The next step up is the considerable tag. That is 1.75” hail (golf ball-sized) or 70 mph winds. This will also not send an alert on your phone. However, the biggest change coming from all this will be the destructive tag. A ‘destructive’ storm will feature 2″ hail (baseball-sized) or 80 mph winds. That will send an alert to your phone.
Severe storms deemed ‘destructive’ will activate a Wireless Emergency Alert on smart phones like an AMBER alert or presidential message. This means that if you are located close enough to a cell tower within the severe warning polygon, you will receive the wireless alert to your phone. The age of your phone could affect alerts ranges.
“It’s really important that we take all warnings seriously,” said Hysell “You should move inside, get away from windows to make sure you’re not exposed to that severe weather.”
Overall, destructive storms will be rare. The NWS found on average, only 10% of all severe storms reach the destructive category each year, nationwide. These storms are often damaging wind events like derechos or intense supercells.
The takeaway here is that if you ever receive that alert to your phone, immediate action should be taken and that is exactly what the NWS is hoping to achieve.
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