Coordinated polarization lidar, Ku-band radar and dual-channel microwave radiometer observations of a deep orographic cloud system were collected from a mountain-base site in northwestern Colorado as part of the Colorado Orographic Seeding Experiment (COSE) research effort. The remote sensing observations are presented for three distinct storm stages, corresponding to a pre-frontal altostratus cloud layer, a local orographically-induced cloud development, and a peak in storm activity accompanying the passage of a weak cold front.