As one of nature’s most unpredictable manifestations, tornadoes can be sudden, violent, and devastating. More than 1,000 tornadoes occur on average each year in the United States. Most occur in the late spring and early summer months, typically in the early evening into the overnight hours. Know these signs of an impending or actual tornado:
- Green or Yellow-Tinged Sky. While a sky with a green or yellow tinge doesn’t necessarily mean a tornado is looming, it is often a strong sign to take cover. In the least, these clouds often carry hail, which commonly accompanies the tornadic activity.
- Wall Cloud. A convective cloud, such as a wall cloud, is formed when the atmosphere is unstable. These clouds may stand vertically, rather than holding their usual horizontal stature, or may have vertical wisps. Funnel clouds often originate from these clouds.
- Funnel Clouds. Funnel clouds can form slowly or quickly. If you happen to see one or just think you do, find shelter immediately. Once a funnel cloud hits the ground, it’s a tornado.
- Cloud of Debris. Tornadoes aren’t always the dark, tightly knit twisters portrayed in the movies. If you see objects rotating in the air, find cover. A tornado’s dark color is mostly due to the dirt accumulated in the rotation. Just because a tornado (or technically, a funnel cloud) hasn’t hit the ground doesn’t mean it’s not dangerous. Most deaths and injuries attributed to tornadoes are due to flying
- Roaring Noise. Tornadoes can have a whistling or a roaring sound, sort of like a train. By the time you hear it, though, it may be too late. Don’t use sound as your cue to find cover.
Tornado Ratings
|
Category |
Wind Velocity Range |
Typical Damage |
|
F0 |
40-72 mph |
Minimal: Broken tree branches |
|
F1 |
73-112 mph |
Moderate: Mobile homes tipped over. Automobiles pushed off roads. |
|
F2 |
113-157 mph |
Significant: Roofs torn off houses, some large trees are uprooted. |
|
F3 |
158-206 mph |
Extreme: Roofs, walls torn off, trains tipped over, most trees are uprooted. |
|
F4 |
207-260 mph |
Catastrophic: Houses leveled, structures blown apart, cars thrown and large debris moved. |
|
F5 |
261-318 mph |
Incredible: Houses lifted off foundations, automobile-sized projectiles thrown in excess of 100 mph. |
Understand Weather Alerts
Watch – While a watch is usually a simple alert to be aware, tornadoes demand extra attention. Due to the abrupt nature of a tornado, remaining outdoors during a tornado watch is not a good idea. Also, avoid driving long distances, particularly in rural areas, during a tornado watch.
Warning – Danger is imminent. The very moment you hear the warning, take action to protect property and life. Spotters (either people or radar) have verified at least one tornado in your area.
Remember the majority of tornadic activity occurs in the Midwest and lower plains states. But, surprising to some, tornadoes have occurred in every state. Because tornadoes can appear instantaneously, even tornado watches should be taken very seriously. Pay continued attention to weather forecasts during a tornado watch and listen to your weather radio.