Iridescent Burst Over El Paso

Photographer: Chris Grohusko, Photographer
Summary Author: Chris Grohusko, Jim Foster

The photo above shows a wondrous burst of iridescence as seen from El Paso, Texas on the afternoon of June 13, 2008. It was about 100 F (38 C) on this early summer’s day. Hot even by El Paso standards! Looking to the sky for relief I noticed an altostratus cloud deck which often precedes rain and then observed these splendid iridescent clouds. The colors were unusually vibrant for iridescence, and the intensities changed as I watched. Iridescence occurs when sunlight is deflected by cloud droplets in the process of diffraction. Droplet size strongly affects the colors that result.