A storm is technically an atmospheric disturbance that includes one or more of the following: hail, lightning, rain, sleet, snow, and/or thunder. Some storms typically combine precipitation and wind, such as thunderstorms, hurricanes, and cyclones. Other storms, such as dust storms and sandstorms, have wind but no precipitation. Dust storms are caused by forceful winds passing over loose particles of dust.
Dust may develop on the surface of the Earth due to drought or dry conditions that are less harsh, but still leave the soil parched. Soil erosion, overgrazing of grasslands, and desertification contribute as well. Dust can be lifted to about 3.8 miles (6.1 km) above the Earth by a storm. The problems caused by such storms include reduced visibility and breathing troubles, and the dust coats everything, which may be damaging to equipment and machinery.
Dust storms occur in many parts of the world. During a drought that took place in the 1930s in the United States and Canada, agricultural workers by the hundreds of thousands were displaced by massive storms. Periods of drought have also occurred in the 1950s, the '70s, and from the end of the '80s into the '90s. In 2007, a dust storm in Texas caused severe damage, sending people to the hospital with respiratory issues and delaying many flights at the Dallas-Forth Worth Airport.
Australia is another area that is prone to dust storms, though they are less frequent there than thunderstorms. In November 1902 during a period of drought, a storm referred to as “The Great Dust-Up” began in South Australia and spread northwards to Victoria and portions of New South Wales, even reaching Sydney. This particular weather disturbance was accompanied by an unusual phenomenon: reported “balls of fire” that are thought to have been formed by static electricity caused by the movement of the dust particles. They both showered sparks from the sky and also set some buildings on fire.
In the last few years, notable dust storms have struck in the Kingdom of Bahrain in 2008 and in Karachi, Pakistan in 2007. Great storms originating in Inner Mongolia can travel far enough to cause pollution in Beijing, as one did in 2006. Seven days after it began, the dust reached the United States’ West Coast.