Cloud Parade

The sky exhibited a beautiful mélange of clouds today. The indiscriminate showing was akin to a museum displaying an Albert Bierstadt painting next to a Jason Pollock canvas. From my position at Olmstead Point, I had a wonderful viewing spot of the varied art of the sky.

Iridescence%20over%20Olmstead.jpgTo the north, stretching from east to west, the sky birthed an array of stratus clouds; their lenticular, UFO-like shapes reminded me of my recent viewing of the movie, The War of the Worlds. I suppose Tuolumne would be the ideal place to be at the end of the world! Stratiform clouds are formed by wind; you can read about a stratus cloud unique to the Sierra Nevada, in my article “The Sierra Wave” at

To the south, cirrus clouds decorated the blue sky—wispy fibers with veins filled with ice. In the midst of one cirrus cloud, a band of color shimmered-a phenomena known as an iridescence. Directly above me, a halo encircled the sun, another optical phenomenon. Both the halo and the iridescence are cousins to the rainbow, and are caused by the refraction and diffraction of light respectively. In their wonderful book, The Rainbow Bridge: Rainbows in Art, Myth, and Science, authors Raymond Lee and Alistair Fraser tell of the Arab mathematician and physicist Alhazen musing in the eleventh century that “Now among things…which have given much perplexity of thought, are the two effects known as the halo and the rainbow.”

And lastly, in the southwest, a lone cumulus congestus cloud crept over the horizon, trying to assert its dominance as it rose beside Half Dome.