That's what Mohave looks like when the wind switches to off-shore. The thermals will come down from the desert and as soon as they hit the water it will turn into a water-spout. Bunch of kiters have bin lofted that way ; some needed a helicopter ride to the hospital after it happened.
If i was flying a HG or a PG ; i'd go as Far away from a cloud formation like that as i could get ; that kind of lift can Kill Ya !! The higher the tops on the clouds, the more dangerous they become. At-least the cloud formation will give Ya a clue as to what's gonna happen ; the thermals at Mohave are Dry-air, so there won't be a puffy white cloud till the thermal hits the vaporization point, (usually 14K-ft) ie-- NO warning except the dust in the thermal at it's base.