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For Students · Tornado Vortex

Tornado Vortex for a humidity index

Built for students learning it for a class or exam. See the concept move instead of memorizing formulas — and check your homework intuition. Simulate a humidity index live below — adjust the inputs and watch it respond, right in your browser.

Tornado Vortex (Rankine)Live

wind speed vs radius

Controls

Speed1×

Presets

Core radius (m)

Max wind (m/s)

A tornado's winds follow the Rankine vortex model: inside the core the air spins like a solid disk, with speed rising straight out to a peak at the core edge; outside, the wind falls off as 1/r. The fastest, most destructive winds ring the core, not the very center — which is why the eye of a vortex is deceptively calm.

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Data Inspector

Peak wind70 m/s

Peak (mph)157 mph

EF ratingEF3

Peak atr = 50 m

Governing equation

v_{θ} = Ω r (r \leq 50), v_{θ} = \frac{Ω R ^{2}}{r} (r > 50), Ω = 1.40 s^{- 1}

Reading this result: The peak 70 m/s wind (EF3) rides the edge of the 50 m core; the calm eye at the center is deceptive.

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Frequently asked questions

Is this good for students?: Yes — this version of "Tornado Vortex for a humidity index" is framed for students learning it for a class or exam. See the concept move instead of memorizing formulas — and check your homework intuition.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.