Because they do not produce severe weather and are typically ignored by climate change scientists, mid-level, non-precipitating clouds are the forgotten clouds of the atmospheric science community. To fill this research void, the DoD Center for Geosciences and Atmospheric Research (CG/AR) at CIRA-CSU is sponsoring an ongoing field program, the Cloud Layer EXperiment (CLEX). The CLEX addresses a better physical understanding of mixed-phase non-precipitating clouds in the middle troposphere. In particular, the CLEX strives to document the microphysical, dynamical, and radiative properties of these clouds with the goal of improving their forecasting, modeling and remote detection.