Real Estate Photographer in Jarrell, TX

This is the time of year, when Texas sees more severe thunderstorms that can spawn tornadoes, you might hear more about where a twister ranked on the Enhanced Fujita scale or its EF rating. Among the effects from climate change, weather researchers are seeing changes in where tornadoes appear and when — so is the current tornado rating system adequate for today’s storms?

How strong can tornadoes get?

Severe weather season in Texas, or when severe thunderstorm activity peaks between March and June, coincides with transitional weather patterns typical for spring. The jet stream’s position over Texas brings more cold fronts that interact with moisture-rich air from the Gulf of Mexico, all contributing to an unstable atmosphere, including storms capable of producing tornadoes.

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In 2024, nearly 1,800 tornadoes were reported nationwide, with Texas leading the country at 169 tornadoes. Each of these tornadoes were surveyed on the damage they caused and were given an EF rating of EF0 to EF5 by the National Weather Service.

As common as tornadoes are in Texas, the most violent and catastrophic ones — EF5 tornadoes with winds of at least 200 mph — are actually quite rare. The most recent EF5 tornado in Texas was the Jarrell tornado in Williamson County north of Austin on May 27, 1997, with peak winds of more than 260 mph. Meanwhile, the last EF5 tornado in the United States occurred nearly 12 years ago in Moore, Okla., on May 20, 2013, with top winds of about 210 mph.

However, some tornadoes have surpassed 300 mph, including two in Oklahoma: the 1999 Bridge Creek-Moore tornado, which reached 321 mph as measured by a mobile Doppler radar system, and the 2013 El Reno tornado, where winds exceeded 313 mph. With wind speeds surpassing the EF5 rating, some people have begun questioning whether a revised scale, or introducing an EF6 rating, might be considered in the future.

Is the current tornado scale adequate?

After a suspected tornado strike, weather service survey teams evaluate scenes of damage using a list of specific indicators to more accurately assess the strength of the tornado. They account for the types of buildings, infrastructure and trees that have been damaged, and use the indicators to determine degrees of damage. Once they estimate the wind speed that could’ve caused the damage, using ground reports and Doppler radar data, they can then establish an Enhanced Fujita scale rating for that tornado.

The ratings range from:

The Enhanced Fujita scale is already a 2007 revised version of the original Fujita Scale created in the 1970s, so should government weather authorities at the National Oceanic and Atmospheric Administration consider another revision?

Christopher Nowotarski, assistant professor of atmospheric science at Texas A&M University, doesn’t think that NOAA will introduce a new category. The transition to the EF scale adjusted how the damage ratings were surveyed as well as which wind thresholds led each category, he said.

“The idea of the EF5 rating is that your house sustained catastrophic damage,” Nowotarski explained. “At some point, your house is already knocked down with over 250-mph winds, so what’s the difference between going up to 350-mph winds.”

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He also said another reason you won’t see a higher rating level is because of continuity with climate records.

“When you’ve had five categories for the longest time, adding an extra category would add inconsistency to the historical records,” Nowotarski said. “You can’t go back to 1960 and ask if there were any EF6s, it would be hard to do that at this point.”

While he believes NOAA will not introduce another category to the tornado scale, he noted that a modification is likely. This update would aim to account for more natural damage indicators, as tornadoes do not always affect artificial structures. They are considering using other things like tree fall patterns in a tornado as well as how far trees were moved when they fell.

Global scale for tornadoes

Tornadoes are not only recorded in the United States, but they occur across the world, especially in Canada, Europe, parts of South America and South Asia.

In the summer of 2023, the European Severe Storms Laboratory adopted the International Fujita Scale because of the absence of a wind damage scale that could be easily applied in Europe. The original Fujita and TORRO scale, which is the United Kingdom’s version of the EF scale, give little guidance on how to rate damage and does not incorporate recent knowledge about the effects of wind damage on structures built outside of the United States.

Overall, this helps ensure consistent tracking of violent tornadoes worldwide. Outside of the United States, there have been eight tornadoes rated F5, EF5, T10+ or IF5 globally. These include two in France and Germany, and one each in Canada, Italy, Argentina, and Australia.

April 5, 2025

Newsroom Meteorologist

Mary Wasson is a newsroom meteorologist for the San Antonio Express-News. She can be reached at mary.wasson-triplett@express-news.net

Mary has been a meteorologist for more than 16 years. Since she and her family were forced to shelter from a tornado, she has been fascinated with how storms develop. Originally from Winchester, Ky., she earned a communications degree from Morehead State University and a Master of Science in Geoscience from Mississippi State University. She has worked in Rapid City, S.D., Lexington, Ky., Austin and Temple.