Both hurricanes and tornadoes are pressure-driven vortices: air rushes inward toward a low-pressure core, and the Coriolis/angular-momentum effect spins it into a rotating funnel. Wind speed depends on the pressure gradient across the storm's radius.
v_tangential(r) ≈ sqrt(ΔP / ρ) · f(r / R_max)
Saffir-Simpson category ≈ f(v_max)
angular momentum conserved as r shrinks → v increases near the eye
- Central pressure drop — the pressure deficit driving the storm; a bigger drop means faster winds and a higher category.
- Storm radius — how wide the vortex is (hurricanes: broad; tornadoes: narrow and tall).
- Ambient wind speed — background steering wind that advects the whole vortex sideways.
- Particle count — number of tracer parcels used to visualize the wind field.
- Hurricane / Tornado toggle — switches vortex geometry between a flat wide hurricane and a tall narrow tornado funnel, since the underlying physics (pressure-driven rotation) is the same at very different scales.
This is why hurricane categories (Saffir-Simpson) and tornado ratings (Enhanced Fujita) are both fundamentally wind-speed scales derived from the same pressure-gradient-to-rotation physics, just at vastly different sizes and durations.