November 25, 2007
The photo above, appearing to show stairsteps in the clouds, was taken from the grounds of the University of Texas at El Paso on June 20, 2007 at approximately 2:00 p.m. local time. These are classic wave clouds. On this afternoon, westerly winds over a primarily north/south mountain ridge were just the right strength, with just the right moisture content (vertically) and stability (temperature change with height) to initiate this curious cloud formation. These clouds form a series of up/down wave couplets that are uniformly spaced horizontally instead of being vertically stacked. Wave clouds tend to be more common in fall and spring when winds speeds are generally higher than they are during the summer. Ocotillo cacti are in the foreground.
Photo details: Samsung Automatic 38-80 mm camera, 400 Fuji color negative film.