New "Destructive, Severe" Thunderstorm Warnings to Alert Cell Phone Users with Emergency Alerts
The National Weather Service (NWS) will better communicate upcoming severe and potentially dangerous weather, when on July 28, the agency adds, “severe thunderstorm warnings,” in addition to its previous tornado and flash flood warnings that trigger emergency alerts on cell phones.
Storms that the NWS categorizes as “destructive” will trigger a Weather Emergency Alert (WEA) to cell phones to better convey to the public to take urgent action to prepare for a life-threatening event that also may cause substantial damage to property.
The public’s advance knowledge of severe thunderstorms is important because 13 of the 22 most expensive weather disasters in 2020 were severe thunderstorms that came without warning to people and caused up to $11 billion in damages.
With the NWS’s addition of severe thunderstorms to its messaging system, the agency hopes to promote the public to take immediate, preparatory action.
The NWS’s criteria for issuing warning or basic or considerable thunderstorms, which the agency defines as storms that produce in one-inch, quarter-sized hail and/or 58 miles per hour winds, or 1.75 inches in diameter, or the size of golf balls and/or 70 mph thunderstorm winds, respectively, will not activate WEA warnings because in those cases, damage is expected to be minimal.
However, when severe thunderstorms reach more destructive and dangerous heights, which is usually only 10% of the time, by eliciting hail that is at least 2.75 inches in diameter, or the size of baseballs, and/or produces winds that rage at 80 miles per hour, cell phone users in the area of the storm will automatically receive a WEA.
Most of the intense thunderstorms that cause the most damage are include destructively strong winds that are called, “derechoes,” which occurred in Iowa in August 2020.
Many of the destructive thunderstorms that rain down outsize hail in their paths are called “supercell storms. d some of the larger, more intense thunderstorms, called “Supercell” storms.