Hook Echoes on Radar: Signature of a Mesocyclone

 Below: Two Supercell Hooks in Oklahoma on 3 May 1999.

The eastern-most storm has a very strong mesocyclone and, at the time of the image, was producing an F4 tornado in southeastern Oklahoma City. (Please note: the hook is NOT a signature of the tornado, but of the mesocyclone that eventually "gave birth" to the smaller, much more intense vortex).


 Doppler Radar Also Allows Visualization of Motion to and from Radar

The radar acually can be used to measure the speed of motion of precipitation (dust and large debris) being carried by the wind towards the radar or away from the radar. Thus, Doppler radar can be used to actually spot the true motions in mesocyclones. In addition, when storms are particularly close to the radar site, the radar can detect the smaller scale motion of the developing tornado: the Tornado Vortex Signature.