Posted by Tom Falley on November 26, 2014 at 5:05 PM
Most likely a roll cloud at the front of a microburst from a mature thunderstorm. A down rushing column of cold air spreads outward as it nears the ground. Most likely some strong and gusty winds to arrive at your location in a short time!
Discussion
3 replies:)
Picture taked by Oscar Covarrubias (IPhone)