When the massive dust cloud rolled in from Tucson-Oro Valley, I heard a neighbor screaming at the kids outside, “Go inside, the rain is coming!” A “humbug” is an imposter, meant to deceive, and for a time, I’ll bet many folks, like my neighbor, thought a good rain was coming along with the darkening sky (composed mainly of….”Altostratus cumulonimbogenitus”–kind of a silly name, some with areas of virga). There were also dark-looking Altocumulus opacus clouds, and Cumulus humilis at the bottom of the As here and there (e.g., see second photo). So, it was a threatening sky to be sure!
Go here to see dust storm roar through Tucson, courtesy of your University of Arizona Wildcats Weather Department. Very exciting! Plus you will see all the cloud movement that was going on before the dust hit.
Below are a few shots from yesterday’s dramatic dust cloud as it rolled and roiled northwestward out of the Tucson metro area and up the Oro Valley. First, a cloud shot that showed truly remarkable Cumulus-Cumulonimbus development east of the Catalinas just after 7 AM AST yesterday. You knew at this point, it was going to be an interesting day with so much so early.