Many find storms to be interesting and even thrilling, but they are dangerous creatures that deserve our respect. By definition, thunderstorms contain lightning, the underrated killer. Thunderstorms also produce damaging winds, hail, flooding and tornadoes. For a storm to be considered “severe”, it must contain at least one of the following criteria:
- Wind gusts of 58 MPH or greater
- Hail of 1 inch in diameter or greater
- A tornado
Although lightning can be deadly, the National Weather Service doesn’t use it to define a severe thunderstorm. If it did, every thunderstorm would be severe, by definition. Also, excessive rainfall may lead to deadly flash flooding, but heavy rain is not considered severe. Flood threats are handled through a separate set of watches and warnings from the NWS Birmingham. And there are tornadoes... yes these do make a thunderstorm severe, but they will be upgraded to a tornado warning by the NWS if that happens.
One event that can cause damage and injuries during severe thunderstorms are straight line winds. Damaging winds occur much more frequently than tornadoes and can be just as damaging. They can exceed 100 mph. Trees and power lines can be knocked down, mobile homes can be overturned, and well built homes and buildings damaged.
Another event that can cause damage and injuries during severe thunderstorms is hail. Hail is most common in the spring in Alabama, when atmospheric conditions make it most likely that the ice can reach the ground. Hail can cause severe damage to automobile and even to buildings, damaging roofs and windows. Hail injuries are rare, but do happen. Hail can also cause deaths, as happened on March 28, 2000 when a man in Fort Worth, Texas was struck by a baseball sized hailstone. There have been five recorded hail fatalities in U.S. history. So while it is not a frequent killer, it can still be deadly. To be safe, just don’t get caught outside in a thunderstorm.
Tornadoes are another event that can happen during severe thunderstorms. We’ll cover in another Weather Safety 101 post.
The primary safety rule for dealing with thunderstorms is to be in a well built structure, away from windows. This will protect you from the hail and non-tornadic winds. Also avoid any electrical equipment. If you are caught outside, find shelter immediately.
Stay tuned for another Weather Safety 101 post soon.