Gigantic Cumulus Clouds

Veering off the topic of gardening, an unusually massive, majestic cumulonimbus cloud - and based on a little research, probably a calvus-type cumulonimbus - formed just east of my neighborhood, probably east of the crest line of the Santa Ana Mountains. The weather has been unusually hot - in the high 90's - for over a week, with building humidity. This was one of the larger, higher altitude thunderheads that I've seen in years so close to home. Incoming jetliners on approach to John Wayne Airport were definitely diverting around this cell, in an unorthodox landing pattern. Interestingly, it completely disappated within two hours of taking this photo.


Additionally, very large Pyrocumulus clouds have been forming over the immense Station Fire in the San Gabriel Mountains. A pyrocumulus cloud is essentially a very unstable, violent thunderhead that forms as super heated air and convection from wildfires or volcanic eruption rises, collecting moisture and blooming as it hits colder air. The term Ppyrocumulus also applies to the so-called "mushroom cloud" formed by atmospheric nuclear detonation. This photo (copied from wikipedia), shows the pyrocumulus from the Station Fire towering over downtown L.A.



At one point on September 2nd, I'd estimate the top of the pyrocumulus was well over 20,000 feet - it was incredible, dwarfing the 10,000 foot summit of Mt. San Antonio to the south. Evidently, these pyrocumulus clouds can form rain heavy enough to douse the flames that are feeding it, however in the instance of the Station Fire, the fire was much too large for this to have occurred. Another weird fact is that a pyrocumulus cloud can contain such violent weather that temperatures within upper pockets of the cloud can plummet well below freezing, despite the scorching heat that produces the cloud in the first place.