As the summer monsoon continues in the Desert southwest, we hear about both flash flooding and dust storms. Outflow from severe thunderstorms produce dust clouds that can rise thousands of feet in the air and reduce visibility to near zero. These storms, called Haboobs, are typical of very dry regions, such as the Sahara and the southwestern US, including Texas, New Mexico, and Arizona. Since haboobs combine both thunderstorms and dust, occasionally, conditions are just right and both elements mix. The resulting rain can have large quantities of dust. Some observers have even described the event as a mud storm!
Mary Knapp, Weather Data Library