LAKE COUNTY, Calif. – Unusual cloud formations and vivid rainbow colors in the sky got the attention of many county residents on Tuesday.

A picture taken by Joe Steiner was posted by friend Shannon Kimbell-Auth on Facebook Tuesday. It showed a mass of clouds with an explosion of color.

Pictures Lakeport resident Russell Bishop posted on his Facebook page also showed the colors against an unusual cloud column.

Lake County News asked Alan Buis, a spokesman for the National Aeronautics and Space Administration's Jet Propulsion Laboratory at the California Institute of Technology in Pasadena, about the cloud formations and what they were.

Buis consulted with a number of scientists, and Steve LaDochy, a meteorologist at California State University, Los Angeles, and a Jet Propulsion Lab employee, offered the scientific explanation of what Lake County residents witnessed.

In Steiner's photo, what's seen is cloud iridescence, which is diffraction of sunlight by different sized cloud droplets. The typical clouds associated with cloud iridescence are cirrocumulus and altocumulus, LaDochy explained in an email.

Regarding the cloud shown in Bishop's photo, LaDochy notes in his email response, “I’ve seen these in Canada, but not quite like this down here. It is called a circumzenithal arc and is associated with ice crystals (often in thin cirrus clouds at very cold temperatures).”

He said the ice crystals cause a refraction of sunlight that enters the top of plate-like crystals and exits out one of its sides. It requires a fairly low sun, at less than 32 degrees, to accomplish it.

“A more common refraction is a halo around the sun due to ice crustals or sundogs, where the halo is brightest on the sides of the halo making it look like 3 suns. Romans thought this brought good luck,” LaDochy said.

The ice crystals that give rise to the optical wonders come from cirrus clouds high in the atmosphere, where temperatures are below -20 degrees Fahrenheit, LaDochy explained.

“They are not rain clouds, but can cause some pretty optical effects when the sun shines through them. Sometimes contrails will get a bit of these effects, but not often,” He said.

LaDochy added, “People should look up more often.”

Email Elizabeth Larson at This email address is being protected from spambots. You need JavaScript enabled to view it. .