If you follow me on Twitter (and you should, since I post stuff there that is not quite right for stuff here) then you may have seen my picture of a lone lenticular cloud over Boulder the other day. Those are fairly common around here, and fascinating to watch. I love odd clouds, and so I was happy to see a whole bunch of them on a website called Moolf (which I found via Reddit). Some are really incredible. I've seen the sky full of mammatus clouds, and it's truly unearthly.