Howard Rice has sailed and hiked in a few windy places. It a recent adventure in Tierra Del Fuego, he faced his "day of days" and survived. In his account of the ordeal, he describes what he, for lack of another word, termed "cyclonic winds".
http://www.mysailing.com.au/cruising/howard-rice-the-end-of-the-south-american-adventure-comes-in-dramatic-fashion
"Unfortunately the winds were only getting worse now and it was clear he was in trouble. It was about this time he first heard the screaming. Not a voice, or noise in the rigging, but a sound, he says, emanating entirely from some sort of a rotating wind phenomena he described as “cyclonic.” These visible wind formations were suddenly swirling wildly around him—dozens of them—lifting kelp off the beach and ripping rivers of white froth across the sea....
Howard says he was mesmerized. Transfixed. He couldn’t believe his eyes."
Now, Howard has certainly seen his share of "mere" williwaws, so this must have been something a bit different. From what I can intuit, it seems that they may be a sort of localized, very powerful chaotic, closely spaced eddies driven by katabatic winds. A special little sub-phenomenon spun off, if you will, by the joys of the williwaw. Has anyone else first hand experience with these "cyclonic wind" beasts?