The strange spectacle is formed when "shear winds" blowing past each other roll a cloud into a log of sushi, or a ghostly passenger train, maybe some kind of tunnel through the fourth dimension.

Many people constantly report seeing the strange cloud formation.

Did you see something that looked like bubble clouds with Monday's storms? These unusual formations are known as mammatus clouds.

Real video of rare 'fallstreak hole' cloud formation? Fallstreak holes, also called cavum, sometimes occur when airplanes fly through certain clouds high in the atmosphere.

Strange cloud formation April 29 stretched from Gulf Shores to Butler County Published: May. 18, 2009, 2:45 p.m.