👀 Dual roll clouds seen in Fenwick Island, Delaware Via National Oceanic and Atmospheric Administration (NOAA): A low, horizontal tube-shaped arcus cloud associated with a thunderstorm gust 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. | WBRZ Chief Meteorologist Dr. Josh Eachus

Arcus cloud, Roll clouds Shelf clouds - menacing thundercloud moving over trees in stormy summer day with hot weather. Visible thunderstorm with wind and rain.