This week’s dust storms that enveloped the Phoenix area in a dense haze were among the most severe the region has seen in years, scientists reported on Thursday.
These storms, known as haboobs, occur across the U.S. Southwest when strong downdrafts from thunderstorms stir up loose dust and dirt, propelling it ahead of the storm.
These storms can create massive walls of dust and debris, impairing visibility for drivers and posing health risks.
The latest storm arrived early Thursday morning, just three days after another similar event. Although there were no significant impacts reported, both storms reduced visibility to half a mile (0.8 kilometers).
“Fortunately, they both occurred later at night, resulting in less road traffic,” explained Matt Salerno, a meteorologist with the National Weather Service in Phoenix.
Classified as extreme Category 5 events on a dust storm severity scale, these storms featured large dust concentrations and wind speeds around 50 mph, according to Arizona State University researchers who helped develop the scale.
This scale, introduced this year, was created using data from as far back as 2010.
“Experiencing Class 5 dust storms in quick succession is unprecedented in our records,” stated Randall Cerveny, a professor in the School of Geographical Sciences and Urban Planning at Arizona State. “Such occurrences are rare.”
According to Cerveny, these were only the fifth and sixth dust storms in the last 16 years to reach Category 5, as he mentioned in a phone interview with The Associated Press.
He also noted that the Phoenix area has been experiencing drier conditions than usual, which can lead to more dust being stirred up. Scientists have indicated that human-induced climate change increases the odds of more severe droughts and heavier storms, potentially leading to more intense dust storms in the future.

