What is a haboob? The science behind the dust blob that swallowed Phoenix

What is a haboob?

Haboobs are dense walls of dust kicked up by thunderstorms, and can be several miles long and several thousand feet high. Haboobs can travel hundreds of miles depending on the area’s geographic terrain. 

“A haboob is a dust storm, but not all dust storms are categorized as haboobs,” says Sean Benedict, lead meteorologist at National Weather Service in Phoenix. Benedict says most of the dust storms in the southwestern U.S. are haboobs. They differ from other dust storms by their trigger, appearance, and duration. The name “haboob” comes from the Arabian word ‘hab’, meaning ‘to blow’ and has been used by the meteorological community for almost 100 years.

Haboobs are common during the North American monsoon, a seasonal high-pressure pattern that forms when summer temperatures cause a shift in wind patterns that draw in moisture from the Pacific Ocean and the Gulf of California. This moisture helps fuel thunderstorms in the area that then trigger dust storms like haboobs. 

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“With the high pressure in place, the storms go up and they usually don’t move much,” says Benedict. “Eventually, they collapse and produce downbursts, or microbursts.”