In arid regions like the deserts of Arizona wild duststorms can form. You can see dustdevils all over the landscape of Arizona. But when you see a Haboob you need to get to shelter. When a thunderstorm forms the winds will move in other directions being pulled into the storm. Then when the storm reaches the point of producing rain it caves in on it self. This pushes the wind out away from the storm known now as a downdraft. As the wind hits the desert floor it causes the sand to blow out forming a wall of debrie ahead of the storm. They can be as wide as 60 miles with severe damaging winds. The following picture

is of one that hit Eloy Arizona August 18th 2011. Homes were damaged, billboard signs were scattered over the highway. We were lucky to make it through this storm. We will share more photos soon. Toby was not to happy about being caught in this Haboob.
Midland Consumer Radio WR-120B NOAA Weather Alert All Hazard Public Alert Certified Radio with SAME, Trilingual Display and Alarm Clock – Gift Box(White)