A nearly ideal axisymmetric  basin formed by the impact of a meteorite about 49,000 years ago on the Colorado plateau close to Flagstaff, Arizona. Today, the bowl-shaped crater is about 1.2 km wide and 175 m deep. The crater rim extends about 30-50 m above the surrounding plain and is unbroken by any major saddles or passes. This near-ideal topographic basin provides perfect conditions to study mesoscale atmospheric structures and processes.

Experiments conducted at Meteor Crater in October 2006, revealed that occasional unusual meteorological events (downslope-windstorm-type flows, warm air intrusion, likely hydraulic jumps) occurred within the crater on clear, light-background-wind nights. As the configuration in 2006 was not designed to fully explain the observations, another field experiment was conducted at the crater in October 2013 within the framework of a follow-up project (METCRAX II) initiated by the University of Utah and funded by the US National Science Foundation. Besides the University of Utah, IMK-TRO, the National Center for Atmospheric Research (NCAR), the University of Basel and the Ruhr-University Bochum participated in the field experiment. IMK-TRO installed several meteorological instruments (wind lidar, tethersonde, sodar, scintillometer, mobile turbulence towers) during the month-long campaign.

The participation of IMK-TRO in METCRAX II is funded by the international bureau of BMBF.