Sandstorms are caused by strong winds blowing over loose soil and sand, picking up so much of that material that visibility is reduced. In desert regions at certain times of the year, sandstorms become more frequent because the strong heating of the air over the desert causes the lower atmosphere to become unstable. This instability mixes higher winds in the middle troposphere downward, producing stronger winds at the surface. Sandstorms can go on for as much as days and as least as minutes. There is no set time to how long it will last it just occurs.

Interesting facts: THE DUST BOWL; There was a prolonged drought in the great plains of the United States in the 1930's. This led to vast areas of exposed dirt, which helped feed dust storms. It is not known what caused this event, but it is believe that poor land use practices by farmers made the situation worse that it would have otherwise been, by plowing up relatively dry grassland to plant wheat. The dust bowl, which made life even more misearble for many during the Great Depression occuring at this time, was highlighted in John Steinbeck's novel "The Grapes of Wrath"