A massive dust storm blew over southwestern Saudi Arabia in late March, 2014. The dense dust stretches from north of Mecca to Yemen - more 650 mi (1,046 km) - with the thickest dust forming an opaque airborne river east of the Asir Mountains. A moderate layer of sand stretches inland. Although the skies to the west of the tall escarpment appear clear, it is only relatively clear air. Viewing the scene at higher resolution reveals a fine veil of dust covering Saudi Arabia's western shore and blowing across the Red Sea.
Dust storms are common in this region, especially at the time of year when strong winds, known as shamal drive huge quantities of dust high into the air. Such storms can quickly reduce visibility to zero, close airports, drive residents indoors, and stop shipping. While winds can whip up a sandstorm at almost any time, most occur during the two shamal seasons – the first roughly from late spring to summer, and the second from late fall to early winter. Early spring dust storms, like this one, are less common.
The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra satellite captured this true-color image on March 27, 2014.