The slow-moving cloud — known as a haboob — hit parts of Phoenix and Arizona City, 60 miles to the southeast, late Monday afternoon, at one point leaving 15,000 energy customers in the dark. The number still without power Tuesday morning was more than 5,000, according to Poweroutage.us, mostly in Maricopa County.

The haboob was followed by severe thunderstorms that ripped through Phoenix, leaving behind downed trees, wind damage and widespread power outages.