Stratus clouds are low-level
cloud characterized by horizontal layering with a uniform base, as opposed to convective or
cumuliform clouds that are formed by rising
thermals. More specifically, the term
stratus is used to describe flat, hazy, featureless clouds of low altitude varying in color from dark gray to nearly white. The word "stratus" comes from the
Latin prefix "strato-", meaning "layer". Stratus clouds may produce a light drizzle or a small amount of snow. These clouds are essentially above-ground
fog formed either through the lifting of morning fog or through cold air moving at low altitudes over a region. Some call these clouds "high fog" for the fog-like cloud. While light rain may fall, this cloud does not indicate much meteorological activity.