[Deo volente]

near Acton, yesterday:

[thecodont]

Ken Hively / Los Angeles Times

"A pyrocumulus cloud rises from the Station fire burning north of Los Angeles." More Photos

http://latimesblogs.latimes.com/lanow/2009/08/fire-burns-105000-acres-with-no-control-in-sight.html

I'd never before heard of a "pyrocumulus" cloud.