A low, horizontal tube-shaped arcus cloud associated with a thunderstorm gust front (or sometimes with a cold front ). Roll clouds are relatively rare; they are completely detached from the thunderstorm base or other cloud features, thus differentiating them from the more familiar shelf clouds . Roll clouds usually appear to be "rolling" about a horizontal axis, but should not be confused with funnel clouds .
ROLL CLOUD
Meaning of ROLL CLOUD in English
A comprehensive English glossary of weather. Полный английский глоссарий погоды. 2012