Although it wasn’t intended as such, but Earth Day on April 22 makes this posting a happy coincidence.
I came across a link, Fantastic Wonders of Nature , on my monthly pronoia (yes, it is the opposite of paranoia) newsletter. It’s a link to a blog that contains photos of some pretty fascinating occurrences in nature. The pictures below are examples of Mammatus clouds. To quote
True to their ominous appearance, mammatus clouds are often harbingers of a coming storm or other extreme weather system. Typically composed primarily of ice, they can extend for hundreds of miles in each direction and individual formations can remain visibly static for ten to fifteen minutes at a time.