There is nothing that scares us more than the shrieking winds and powerful force of a tornado. It’s one of nature’s ways of reminding us of its awesome power.
Tornadoes form when warm, moist air gets trapped under a layer of cold, drier air, creating an unstable situation. The instability grows when the warm layer underneath gets pushed up into the atmosphere either by heating up near the ground or an influx of cold air.
When the warm, moist air rises it cools and forms large clouds and thunderstorms. If conditions are just right, that rapidly rising air will start to spin and can exceed over 250mph. The spinning causes the signature funnel-spout-shaped cloud, and at the moment it touches land, the swirling air mass officially becomes a tornado.
Here are ten facts about tornadoes we seem to ask ourselves again and again as these destructive funnel clouds strike...
1. Just how many tornadoes hit the U.S. yearly?
Calculating an exact average is difficult as the ability to track and record severe weather events such as tornadoes has changed a lot over the years. As of 2011, the average was believed to be around 1300 per year, but with numbers on the rise. It’s worth noting that already in 2013, 370 tornadoes have been reported. Three out of every four tornadoes on Earth occur in the United States.
2. What is the deadliest tornado to hit the U.S.?
March 18, 1925, saw a tornado so large and powerful it covered areas in Missouri, Illinois and Indiana. The so-called Tri-State tornado accounted for 695 deaths. Texas on the other hand, is the State plagued with the most tornadoes.
3. What U.S. city has had the most reported tornadoes?
Poor Oklahoma City seems to be situated in prime tornado territory. The city has 100 known tornado strikes, though it is believed to be more as of this writing. Texas, on the other hand, is the state plagued with the most tornadoes.
4. What was the biggest U.S. tornado?
Hallam, Nebraska saw a tornado touch down on May 22, 2004 which had a peak width of nearly 2.5 miles. That’s close to the maximum size a tornado can reach.
5. When are tornadoes most likely to form?
Tornadoes can form any time of the year, provided the atmospheric masses clashing with each other can make the clouds spin. That said, tornadoes tend to form in the springtime. In southern states in the U.S. they seem to form most frequently between March and May and in the northern states they most often touch down in June through August. Interestingly, many tornadoes seem to appear between the hours of 3:00pm to 9:00pm, but be aware they can form at any time.
6. What’s the strongest wind speed recorded in a tornado?
Unfortunately, tornado wind speeds are difficult to measure because the strength of their winds can often damage recording equipment. However, the highest wind speed that was able to be recorded clocked in at 302mph in Bridge Creek, OK in 1999.
7. Which states make up “Tornado Alley?”
The flat plains areas of Nebraska, South Dakota, Oklahoma, Texas and Kansas are a veritable playground for tornadoes, with regular touchdowns in the spring and summer.
8. What is a waterspout?
Waterspouts, or weak tornadoes that form over warm water, generally occur in late fall or late winter in the U.S., and you might see several form at the same time. If they do move inland, they can become full-fledged tornadoes.
9. How long do tornadoes last?
Funnel clouds usually last less than 10 minutes, though often they touch down for mere seconds. Some unusual cases have lasted for over an hour.
10. How do tornadoes move?
Many twisters travel from southwest to northeast; some can move in the opposite direction for discreet periods of time. The one thing that can cause a tornado to backtrack is if it runs into the powerful winds from the eye of a thunderstorm.