Hook echo
Videos
A hook echo is a pendant or hook-shaped weather radar signature as part of some supercell thunderstorms. It is found in the lower portions of a storm as air and precipitation flow into a mesocyclone,
A hook echo present on a radar image of the May 22, 2011 Joplin EF5 tornado. The signature, along with a debris ball, is present on the bottom-left portion of the supercell that produced the tornado.
Tornado vortex signature
Videos
A tornadic vortex signature, abbreviated TVS, is a Pulse-Doppler radar weather radar detected rotation algorithm that indicates the likely presence of a strong mesocyclone that is in some stage of tor
Hook echo
…one of the classic hallmarks of tornado-producing supercells. The National Weather Service may consider the presence of a hook echo coinciding with a tornado vortex signature as sufficient to justify issuing a tornado warning. Because of the unpredictable and potentially catastrophic nature of tornadoes, the possibility of…
Typical display of a tornado vortex signature (the downward-pointing triangle near the mesocyclone) on a National Weather Service Doppler weather radar display (here the case of the 1999 Bridge Creek-Moore tornado).