The Doppler velocity pattern of a mesocyclone within a severe thunderstorm. In a storm-relative reference frame, the idealized signature is symmetric about the radar viewing direction with marked azimuthal shear across the core region between peak Doppler velocity values of opposite sign. Typical signatures consist of Doppler velocity differences of 25– 75 m s⁻¹ across core diameters of 2–8 km, with resulting azimuthal shear values of 5 × 10⁻³ s⁻¹ to 2 × 10⁻² s⁻¹.