NOAA / SCIENCE SOURCE / SCIENCE PHOTO LIBRARY NOAA / SCIENCE SOURCE / SCIENCE PHOTO LIBRARY
Bats encountering supercell thunderstorm with hook echo indicative of tornado. Del Rio, Texas. March 19, 2006. The hook echo is one of the classical hallmarks of tornado-producing supercell thunderstorms as seen on a weather radar. The echo is produced by rain, hail, or even debris being wrapped around the supercell. The National Weather Service considers the presence of a hook echo as sufficient to justify issuing a tornado warning. A supercell is a thunderstorm that is characterized by the presence of a mesocyclone: a deep, continuously-rotating updraft.
Model release not required. Property release not required.