Different features in satellite images and products

Sometimes foehn events are detected in satellite imagery by distinctive cloud formations. The foehn wall is an orographic cloud band that forms along the ridge summit of mountain ranges due to condensation of moisture as the air is lifted up the windward slopes. The foehn arch is an extensive layer of altostratus clouds that forms downwind of the mountains in the rising portion of a lee mountain wave. The foehn gap is a band of clear air that can be observed between the wall and the arch. In this case study, the foehn event occurs with mainly dry air at different levels, making foehn identification difficult in satellite images. Moreover, the cloudy downwind that could indicate the presence of a lee mountain wave was absent.