This is a cloud, all right—a dust cloud, and a fast-moving, dense, nasty one that stymied traffic west of Tucson, as it caught indirect sunset light reflected off clouds to the west. It also was a fascinating manifestation of fluid flow. The outflow that caused this blew a well-defined haboob through Tucson itself, briefly and directly sunlit, before crossing some small mountain ranges that redirected the wind off into various channels and directions. One of those currents focused onto a patch of desert a short distance to my southeast and lofted a strikingly dense dust bomb rapidly skyward for hundreds of feet, moving leftward (northward) and perpendicular to the westward aim of the haboob as a whole.
4 WSW Three Points AZ (10 Jul 21) Looking SE
32.0624, -111.3851