Some observations of the clearing of cumulus clouds downwind from snow-covered areas

Satellite images that illustrate the clearing of cumulus clouds downwind fr om snow-covered areas are presented. The cloud clearing resembles that occa sionally observed with lakes during warm advection, supporting the suggesti on that the thermal forcing associated with a uniform snow-covered area is comparable to that of a coldwater lake of similar size. Analysis of snow co ver patterns in the central United States suggests that the climatological probability for situations conducive to the cloud clearing is at most once per month.