Mid-level clouds appearing as gray or white patches or layers, often with shading, arranged in groups or lines between 6,500 and 20,000 feet altitude. These clouds indicate changing weather conditions and potential thunderstorm development.
From Latin 'altus' meaning 'high' and 'cumulus' meaning 'heap.' The term combines Luke Howard's 1803 cloud classification with altitude descriptors added later as meteorologists refined the system to include height categories.
Try Another Word