What the work claims
The Fujita scale claims to rate tornado intensity by mapping observed damage to a theoretical scale spanning from calm (F0, ~Beaufort 8) to supersonic flow (F12, Mach 1.0), with F1 at Beaufort 12.
How it was done
Ted Fujita introduced the scale in 1971 with Allen Pearson. It was derived as a theoretical 13-level (F0–F12) linkage between the Beaufort and Mach scales. Official ratings rely on post-event damage surveys — ground or aerial — and may include radar data, witness accounts, and photogrammetry.
What holds up
The F0–F5 categories hold up as a standardised, observation-driven framework for comparing tornado damage severity. Its reliance on structural and vegetation damage remains operationally robust and widely adopted.
What does not
The wind speed estimates were never verified. They were later found to be overestimated, especially above F5. The scale is not a direct measurement of wind; it is damage-based, and its theoretical upper levels (F6–F12) were never intended for operational use.
Why it matters beyond the lab
It created the first systematic, field-deployable language for tornado severity — enabling consistent reporting, risk communication, and infrastructure standards — even though its wind-speed anchors are unverified.
Is it worth your time
Yes. It remains foundational for tornado assessment in the US and shaped how meteorologists link observable damage to physical intensity — but only if you treat it as a classification tool, not a wind-speed meter.