A haboob (or dust storm) can sweep Arizona’s desert landscape anytime but most often occurs during the monsoon season, which typically lasts from June through September. There are dust storms that can be miles long and thousands of feet high. Haboobs can occur in arid and semiarid regions of North America and any dry region; however, they are particularly frequent in Arizona.

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What is a Haboob

During a thunderstorm, winds move opposite the storm, coming from all directions as a storm collapses and begins to release precipitation; wind directions then reverse, gusting outward from the storm and generally most potent in the storm’s direction.

As this downdraft of cold air reaches the ground, it blows dust up from the desert, creating a wall of airborne sediment that precedes the storm cloud; dust walls can be up to 62 miles wide. Haboob winds typically travel at 22–62 mph and may approach without warning.

There are times when rain does not fall at ground level due to evaporation in the hot air (a phenomenon known as virga). Evaporation cools the rushing air further and accelerates it.

Preparing for a Haboob

In seconds, dust storms can reduce visibility to near zero, resulting in deadly, multi-vehicle accidents. Early in the monsoon, near agricultural areas and Willcox Playa in Cochise County are their most common occurrence. When thunderstorms are nearby, use caution in these areas.

To identify dust storm hazards, familiarize yourself with these terms:

• “Dust Storm Watch” lets you know when and where dust storms are likely to occur. Watch the sky and stay tuned to your radio, television, or smartphone for information.
• “Dust Storm Warning” is issued when visibility is less than 1/2 mile due to blowing dust or sand and winds exceeding 30 mph.

If you have a smartphone, you can turn on your emergency alert settings to alert you when either of these warnings is in effect.

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What to do if you’re caught in a haboob while driving

Do your best to avoid driving when there is a haboob watch or warning. Haboobs plus cars are a deadly combination. However, if you can’t avoid it, here’s what to do:

• Immediately check traffic around your vehicle and begin slowing down.
• Do not wait until poor visibility makes it difficult to pull off the roadway safely — do it as soon as possible. Then, completely exit the highway if you can.
• Do not stop on the road or in an emergency lane. Instead, safely pull completely off the paved portion of the roadway.
• Put your vehicle in park, take your foot off the brake (so your brake lights do not illuminate), and turn off your headlights and taillights. Other motorists may follow taillights during dust storms and strike you from behind.
• Keep your seatbelts buckled and wait until the storm passes.
• Drivers of high-profile vehicles should be especially aware of changing weather conditions and travel at reduced speeds.

A dust storm usually lasts a few minutes to an hour at most. Until the dust storm passes, stay put. After a Haboob passes, follow instructions from the National Weather Service about additional hazardous conditions that may be expected.

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