A weak tornado that was seen in Southeast Colorado.
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Courtesy of University Corporation for Atmospheric Research, Photo by Linda Lusk

Sizes of Tornadoes

Tornadoes come in three different sizes, each with different characteristics. The three sizes are: weak, strong, and violent. Their size is dependent not only on their physical width but is part of the Enhanced Fujita Scale that includes a smaller number of groups and their average duration.

Weak tornadoes make up 69% of all tornadoes. Less than 5% of the total deaths caused by tornadoes are from weak tornadoes. A weak tornado lasts from 1-10 minutes or maybe a little longer. Winds within this category of tornado are less than 100 mph (161 kph). The weak tornado category corresponds to an F0 or F1 on the Enhanced Fujita Scale. Only light or moderate damage occurs with this type of tornado. This damage could include, but is not limited to: breaking branches from trees, pushing over shallow rooted trees, peeling off the surface of roofs, and pushing houses off their foundations.

Strong tornadoes account for 29% of all tornadoes. Close to 30% of all tornado deaths are from a strong tornado. These tornadoes can last 20 minutes or at times even longer. The wind speed range for strong tornadoes is 110-205 mph (177-330 kph). According to the Enhanced Fujita Scale, strong tornadoes correlate with the F2 and F3 tornadoes. These tornadoes cause considerable to severe damage, including: tearing roofs off the frames of houses, demolishing mobile homes, overturning trains, and uprooting most trees in a forest.

Violent tornadoes are the least common and account for 2% of all tornadoes. These tornadoes cause 70% of tornado deaths. Their duration can be longer than an hour. Wind speeds for violent tornadoes are typically greater than 205 mph (330 kph). This type of tornado is a representation of F4 and F5 tornadoes on the Enhanced Fujita Scale. Devastating or incredible damage occurs in violent tornadoes. This damage includes: leveling well constructed houses, throwing cars, lifting strong frame houses off of their foundations and carrying them a great distance, and debarking trees.

Last modified June 11, 2008 by Vanessa Pearce.

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