Enhanced Severe Thunderstorm Warning System Revolutionises Weather Safety Alerts

Understanding the New Warning System

Severe thunderstorms pose significant life-threatening risks, with hazards ranging from tornadoes and large hail storms to widespread straight-line winds (derechos), cloud-to-ground lightning, and flash flooding.

The National Weather Service has implemented an improved warning system that includes a ‘damage threat’ tag for Severe Thunderstorm Warnings. This new system features three categories of damage threats, arranged from lowest to highest: base, considerable, and destructive.

Breaking Down the Warning Categories

The base level warning remains consistent with traditional parameters, requiring quarter-sized hail (1.00 inch) and/or thunderstorm winds of 58 mph.

For considerable threats, conditions must include at least golf ball-sized hail (1.75 inches) and/or 70 mph winds, while destructive threats involve baseball-sized hail (2.75 inches) and/or 80 mph winds. Notably, destructive threat warnings will automatically trigger Wireless Emergency Alerts (WEA) on smartphones within the warned area.

Impact and Significance

The destructive thunderstorm category serves as an urgent call to action, indicating a life-threatening event that could cause substantial property damage. These severe warnings will trigger immediate mobile alerts to ensure public safety.

Statistics show that only 10 percent of severe thunderstorms nationwide reach the destructive category annually. These primarily consist of damaging wind events, such as derechos, and intense rotating thunderstorms known as ‘Supercell’ storms, which can produce extremely large hail.

The ultimate goal of this enhanced system is to increase survival chances by ensuring people know exactly what to do before, during, and after severe weather events.