How to Compute Tornado Strength

Tornadoes are measured in strength from F0 to F5. F0 is the weakest form of a tornado, while F5 is the strongest. They can also be measured using the Parson's scale. Computing tornado strength is an important way to know how dangerous an approaching tornado is, which lets people know how they should prepare for the approaching weather event.

Instructions

Difficulty: Moderate

Things You’ll Need:

• Fujita scale
• Weather information

1. Decide which scale you would like to use. The Fujita Scale uses the F0-F6 system. The Parson's Scale is used to measure the amount of space that the tornado's path affects. Typically, the Fujita Scale is used today. The standard scale is known as being F0-F5. An F6 category does exist, but it very rarely, if ever, is used.
2. Check the speed of the tornado. Checking the speed of a tornado can be dangerous business. Unless you're trained in measuring the speed of a tornado, you shouldn't attempt to do it by yourself. Instead, you should consult a weather service that will tell you the speed at which the tornado's wind is moving.
3. Familiarize yourself with the different categories in the Fujita Scale.
4. Consult the Fujita Scale. You will find that the scale breaks down the wind speeds into the following categories: under 116 kilometers per hour (F0), between 117 km/h and 180 km/h (F1), 181 km/h to 253 km/h (F2), 254 km/h to 331 km/h (F3), 332 km/h to 448 km/h (F4), 419 km/h to 512 km/h (F5), and more than 512 km/h (F6).
5. Locate the wind speed of the tornado on the Fujita Scale, and find the corresponding level.

Tips & Warnings

• Have a copy of the Fujita Scale handy so that you can use it easily.
• Strong tornadoes can cause a lot of damage. If there's one heading your way, you may need to evacuate the area.