Kelvin-Helmholtz near San Francisco
October 06, 2006
The above photo showing a classic display of silhouetted Kelvin Helmholz wave clouds was taken this past winter near San Francisco, California. I was about to leave for home from work and couldn't help but notice this amazing sky. The Sun had just dipped behind these well formed instability clouds off the Pacific coast. Such "breaking" wave clouds likely result form vertical wind shear -- a significant difference in wind speed across their vertical thickness.