20-05-2025
Enhanced Fujita Scale; how National Weather Service ranks tornadoes
The Brief
Tornadoes are rated on the Enhance Fujita Scale.
The rating does not have anything to do with the size of the tornado.
Ratings go from EF-U to EF-5.
MILWAUKEE - Tornadoes are categorized on what is called the Enhanced Fujita Scale or EF Scale.
What we know
The Enhanced Fujita Scale became operational on February 1, 2007. It was designed to rate tornadoes based on estimated wind speeds and related damage. The strength of a tornado has nothing to do with the size of it.
When a tornado is surveyed, it is compared to a list of Damage Indicators and Degrees of Damage which help estimate the range of wind speeds the tornado produced to damage specific structures and/or materials.
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It is important to note that the EF Scale is a set of wind estimates, not measurements based on damage. It uses a three-second gust estimate at the point of damage. Estimates vary with height and exposure.
Dig deeper
Wisconsin has had tornadoes that are rated EF-U, standing for EF-Unknown. The National Weather Service rates a tornado an EF-U when the tornado's intensity can not be determined due to the lack of visible damage to buildings, trees, or other structures in order to assess the wind speed needed to classify a tornado.
Typically, Wisconsin experiences an average of 23 tornadoes per year with the peak months being May through June.
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It has been an active season across portions of the Ohio and Mississippi River valleys and the south. Wisconsin has a preliminary count of 20 tornadoes so far in 2025.
Meanwhile, offers a variety of extremely useful weather tools to help you navigate the stormy season. They include the following:
FOX6 Storm Center app
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FOX LOCAL Mobile app
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FOX Weather app
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We have a host of maps and radars on the FOX6 Weather page that are updating regularly — to provide you the most accurate assessment of the weather. From a county-by-county view to the Midwest regional radar and a national view — it's all there.
When the weather gets a little dicey, schools and businesses may shut down. Monitor the latest list of closings, cancellations, and delays reported in southeast Wisconsin.
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The Source
Information in this report is from the FOX6 Weather Experts and National Weather Service.
The Source
Information in this report is from the FOX6 Weather Experts and National Weather in this report is from the FOX6 Weather Experts and National Weather Service.
