I first flew this event about twenty years ago. That afternoon it
formed off the beach and closer to launch, though it angled off-shore more. It
was formed about 500' off the water and the top was around 1200' with a very
slow rotation from the seaward side up over the top. The one I flew Sunday
afternoon was of similar dimension and characteristics, however, there were
multiple "tongues" extending into several of the local valleys.
I've seen others and photographed some over the years but it is such a dynamic
event that you just have to be there at the right time. My flight lasted only an
hour and fifteen minutes and in that time the cloud developed, changed
characteristics and dissipated. By the time I was driving home, it was gone. It
is good "head-scratcher" and there have been lots of theories about what causes
the "block" as most refer to it (I prefer shear), but no scientific explanations
backed by solid meteorology - just conjecture. There is a lot going on with it,
but I don't want to bore you with a lot of detail.
