NCAR meteorologist Hal Frank coordinates radar information at the operations center radar display terminal at Sunday Creek during the Cooperative Convective Precipitation Experiment (CCOPE). CCOPE brought some 200 U.S. and European participants to southeast Montana for the largest thunderstorm study ever undertaken. Led by Brant Foote and Charles Knight, CCOPE deployed 14 aircraft, 8 radars, and 130 automated surface weather stations. The coordinated measurements produce key insights into how air is entrained and mixed in clouds and how ice particle growth leads to giant hail in supercell storms.