Page:Handbook of Meteorology.djvu/97

Rh Tradition has made the long, flat cloud-streak near the horizon the type form of stratus cloud. But if that same cloud-streak were overhead it would appear merely as a low cloud covering more or less of the sky. When a fog lifts, it forms a stratus cloud; and if it floats away toward the observer’s horizon it becomes a long gray cloud streak. In the first case one is looking at the under side of the surface; in the second, at the edge. The components of a stratus cloud may be fog, smoke or dust—or even all three.

Qualifying Descriptive Terms.—Usage in the matter of descriptive terms is not uniform. The following have been suggested.

Recording Cloud Conditions.—The International Cloud Committee recommends the following instructions for the guidance of observers: