Not sure if 'anvil thunderheads' is a real meteorologic term, but we get much of our monsoon rain from these amazing cloud formations that grow an anvil-shaped topknot. They tend to be localized, growing from a few puffy clouds, then the anvil grows up and the rain falls down. Often lightning announces the impending rain, which may only cover a square mile or less. We saw about 15 of these today -- this being the most spectacular one. The dark gray area under the center of the 'topknot' is getting a nice downpour. The growing anvils may drift away as they form, taking our moisture to another town, full of people welcoming this gift of life.