Tornado Strength

Lesson Plan - Get It!

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Can a tornado toss a truck or flip over a house?

Yes, and more! A thunderstorm has strong winds called updrafts.

An updraft is a powerful wind gust that comes straight up from the ground, sometimes carrying objects (or people!) with it. In a tornado, updrafts can sometimes exceed 150 mph.

If an item is lofted up into the main storm, it can be carried an extremely far distance.

This happened during a 1915 tornado in Great Bend, Kansas. Debris rained down over 80 miles from the town, including a sack of flour that traveled over 110 miles and a canceled check from the Great Bend bank that was found 305 miles away in Nebraska.

The picture below shows a waterspout, a weak tornado that forms over water.

Waterspouts have been known to pick up and transfer fish and other water creatures such as frogs, jellyfish, worms, or alligators. But not sharks. Sorry, Sharknado fans.

Even people have been thrown by tornadoes!

In 2006, Matt Suter was thrown the furthest by a tornado, traveling 1,307 feet. Read Tornado Throws Man Four Football Fields to learn about his amazing flight.

How is tornado strength measured?

Tornadoes produce a lot of debris, as you can see in this scene from Twister below.

Since it is tough to measure wind speeds while tornadoes are happening, they are categorized based on how much they eat or destroy.

Tornadoes are given a score from the Fujita scale, created by Ted Fujita in 1971. In 2007, the Fujita scale was enhanced and renamed, appropriately, the Enhanced Fujita scale.

Both scales are fairly similar to each other. The Enhanced Fujita scale (EF Scale) was created based on how much destruction happens when the winds are at a certain speed.

Meteorologists, engineers, and tornado evaluators inspect the area hit by a tornado. They may inspect from the ground, from the air during an aerial survey, or both.

To determine the EF level, all available information is used. Ground-swirl patterns, photos of the tornado or resulting destruction, weather data, radar, and witness testimonies are used to determine the EF scale.

The greater the destruction, the higher the winds in the tornado were, so a higher EF rating is used. Once the EF scale rating has been determined, there is a good idea of how fast the tornado winds traveled.

If you'd like to see exactly which factors are considered when determining the strength of a tornado, check out The Enhanced Fujita Scale (EF Scale). If you'd prefer significantly more reading (and who wouldn't?!), you can read the original Recommendation for an Enhanced Fujita Scale (EF-Scale) that was submitted in June 2004.

To better understand, watch the video below.

How big do tornadoes get?

Usually, the higher the EF rating, the larger the tornado. However, this is not always true.

Smaller tornadoes have caused as much significant damage as an EF4 or EF5, and there are occasionally larger tornadoes that cause relatively minor damage.

Watch the following video.

How much damage do tornadoes cause?

Watch the next video to see damage from an EF0 to EF5.

Maximum tornado wind speed is determined based on the damage caused by the tornado. Each EF level causes a specific severity level of damage. Examine each below.

How strong was the first tornado in Twister?

The opening scene of Twister takes place in 1969 when a family finds themselves in a dangerous thunderstorm.

• Did you hear the father say that the tornado coming was considered an F5? Notice anything…off…with this?

The Fujita scale wasn't developed until two years later!

Scientists have reviewed historical documents to rate past tornadoes, but there would not have been a Fujita rating in 1969.

There are roughly 2,000 tornadoes reported annually, most of which occur in the United States and Europe. However, only about 70 F5 tornadoes have been recorded since 1950.

Some experts disagree with this number. It is tough to distinguish between an F5 and an F4 tornado because buildings are destroyed in each scenario.

Watch the tornado chasers discuss the Fujita scale and what an F5 would be like in this scene from Twister.

One of the largest F5 tornadoes in recent history occurred in Joplin, Missouri, in the late afternoon of May 22, 2011.

Sirens were sounded 20 minutes before the tornado hit, but many people initially ignored them. The tornado killed 158 people and injured over 1,100 others. It was the deadliest tornado since 1947, and insurance payouts totaled over $2.8 billion.

Although the hospital in the last photo still stood after the 2011 tornado, it had to be demolished later because the tornado winds shifted the hospital off its foundation.

When fully versed in Fujita levels, move on to the Got it? section to see if you can figure out what level tornado caused the damage in each picture before taking a quiz to see which tornado level you are!