Roll Cloud or Shelf Cloud?
The complex of storms that moved across Green country Thursday produced some ominous looking clouds. After posting video of this cloud formation on Facebook I received some questions about how these clouds form. So I wanted to share the answer with you: This is a roll cloud which looks like a long tube and even appears like it is rolling. Although it looks like a tornado turned horizontal, it's not. You can see clearly this cloud is completely separated from the main storm. Typically roll clouds form when a storm is dying out. The outflow from a dissipating thunderstorm spreads outward and lifts what is left of the warm, moist air lingering at the surface. In Oklahoma, we see more shelf clouds than roll clouds-they do have similar characteristics but a shelf cloud is attached to the base of a parent cloud (towering thunderstorm). Video was taken by our Tulsa's Channel 8 Mobile Storm Team member Sequoyah Quinton.