An almost two-mile wall of dust, known as haboob, descended upon the Phoenix metro area yesterday, reducing visibility and causing flight delays at Phoenix Sky Harbor International Airport.

Haboob — which comes from the Arabic word for wind — happens when an intense downburst from a thunderstorm pushes damaging winds to the ground. It is the leading edge, or gust front, of an approaching storm, and usually occurs in Arizona during the summer months.

According to the National Weather Service, Phoenix Weather Forecast Office, yesterday's major dust storm had wind gusts of more than 50 mph. You can watch a time-lapse video of it here.

These storms strike with little warning and can cause multiple collisons, creating massive pileups. According to the Arizona Department of Transportation, seven people died and 90 were injured in 129 crashes caused by blowing dust, dirt and sand in Arizona last year.

Here are some way to stay safe:

  • Never stop on a roadway during a dust storm.
  • Pull your vehicle off the road as far as possible if you see dust approaching the road. Turn off your car's lights and take your foot off the brake after placing it in park. Stay there until the dust storm has passed.
  • Don't enter a dust storm if you can avoid it.
  • Can't pull off the roadway? Proceed at a speed suitable for visibility. Use the painted center line to guide you until you can find a safe place to pull off the road.

Did you know?

  • 60 mph winds: Can lift the rood off a carport.
  • 70 mph winds: Can turn an unanchored mobile home on its side.
  • 80 mph winds: Can lift the roof off a house.
  • 100 mph winds: Potential speed of a thunderstorm downburst, which is comparable to that produced by a tornado.

Have a weather question or a weather story idea? Send it to the Arizona Daily Star's "Thunderstruck" reporter Kori Rumore at