The Phoenix metropolitan area experienced two intense dust storms, known as haboobs, within a single week. Scientists have described these events as among the most severe to impact the region in years and unprecedented in recent records.
Haboobs occur in the U.S. Southwest when powerful downdrafts from thunderstorms pick up loose dust and dirt, carrying it forward in a wall of debris. These storms can significantly reduce visibility, posing hazards to drivers, and can also affect air quality.
The most recent storm occurred early Thursday, just three days after a similar event on Monday. While both storms reduced visibility to approximately half a mile, they largely occurred during nighttime hours, minimizing potential traffic impacts, according to the National Weather Service.
Researchers at Arizona State University, which contributed to the development of a new dust storm severity scale, classified both storms as Category 5 events. This scale, introduced this year and based on data since 2010, defines the most extreme dust storms. The two recent occurrences mark only the fifth and sixth Category 5 dust storms recorded in the last 16 years, according to Randall Cerveny, a professor at Arizona State. "To have Class 5 dust storms occur one right after another a few days apart is unprecedented in our records," Cerveny stated.
Scientists noted that the Phoenix region has experienced drier-than-normal conditions, which can lead to increased dust availability. Climate change has been cited as a factor that can increase the likelihood of both severe droughts and heavier storms, potentially contributing to more frequent and intense dust storms in the future.