Twister Injury & Frequency replace: ‘No upward trends in normalized tornado losses or in major tornado incidence’ – ‘A clear decrease in major tornado incidence’

https://rogerpielkejr.substack.com/p/tornado-damage-and-frequency-an-update

BY ROGER PIELKE JR.

Excerpt: Today, I share the latest data on normalized U.S. tornado losses since 1954 and a time series of the incidence of the strongest tornadoes since 1975. I doubt you’ll come across these data anywhere else.

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The time series shows a significant decrease in annual normalized losses.The 1954–1963 decade averaged $4.8 billion per year; the 2015–2025 decade averaged $1.9 billion per year.

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… tornado data is strongly suggestive of an overall decline in the incidence of the strongest tornadoes. The figure below shows the annual count of F3/EF3 and stronger tornadoes from 1975 through 2024, the period over which data quality is most consistent.

The time series shows a clear decrease in major tornado incidence. The 1975–1984 decade averaged 49 F/EF3+ tornadoes per year; the 2015–2024 decade averaged 26 per year — a decline of roughly 46 percent. Note that data available back to 1954 makes this decrease look much larger, but is accompanied by questions of data quality.

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