As though the weird quality of the fantastic landscape of South Dakota Badlands was not enough, huge rolling clouds (or rather very dense fog) descended to advance majestically over surreal rock formations... The fog front left in the wake of a severe Rapid City storm, rising above in an impossible crested wave:
Similar weather phenomenon, according to witnesses, happened in England (Penzance, Cornwall) - perfectly defined, very slow moving wall of the densest fog ever seen. Here is another bank of thick rolling fog - this time at Rock Mills Rd. in Rappahannock County, Virginia:
Don't miss other recent storm hunting by Mike Hollingshead. Here are some examples of extremely low-hanging shelf clouds, created by a monster supercell off Yankton, South Dakota. (it spawned a tornado, too) See more on this page.