A tornado is not just "strong wind" — it is a tight, angular-momentum-conserving vortex that forms when the rear-flank downdraft of a supercell squeezes a broad, slowly rotating mesocyclone into a narrow column. Because angular momentum is conserved as the column's radius shrinks, its rotation rate must increase — the same physics that makes a figure skater spin faster by pulling in their arms. This simulation models the resulting wind field as a real Rankine combined vortex and derives the funnel's pressure deficit from cyclostrophic balance.
L = ω₀·R₀² is fixed by the mesocyclone spin slider at a broad reference radius. Shrinking the core radius (vortex stretching) automatically raises the core's angular velocity as ω = L / r_core² — momentum conservation in action.v = ω·r); outside it, tangential speed falls off as v = ω·r_core²/r, conserving angular momentum — together the classic two-layer Rankine combined vortex.dP/dr = ρv²/r, integrated to give the funnel's characteristic bowl-shaped pressure deficit, deepest at the core center.Measured central pressure deficits inside strong tornadoes can exceed 100 hectopascals — roughly ten times the pressure drop found in the eye of an intense hurricane — packed into a core just tens of metres wide instead of tens of kilometres.
A Rankine combined vortex tornado core spins up as its radius shrinks, conserving angular momentum exactly like a figure skater pulling in their arms — with tracer particles and a live cyclostrophic pressure-deficit field.
Vortex stretching, angular momentum conservation, the Rankine combined vortex wind profile, and the cyclostrophic pressure balance that produces a tornado's characteristic funnel and destructive core winds.
Set the mesocyclone's baseline spin, then shrink the vortex stretching (core radius) slider and watch tangential speed and pressure deficit rise automatically, following real momentum conservation.
Central pressure deficits inside strong tornadoes can exceed 100 hectopascals, roughly ten times the drop found in a hurricane's eye — packed into a core just tens of metres wide.