This was a great way to start a monsoonal chase day—after a delicious lunch with frozen custard in far southeast Tucson, while watching the towers develop. The biggest of those early convective piles became this young cumulonimbus, thrusting its sharp, symmetric, hat-shaped form into a crystal-blue southern Arizona sky, enticing and inviting closer inspection right down the highway. The remarkable little westward-moving storm briefly developed some midlevel rotation and a well-defined visual hail shaft near Patagonia, AZ, pelting my later location with hail near an inch in diameter for 15 minutes. It also was the anchor cell for a building, outflow-dominant line of convection that would hit Sonoita in its early stages, then produce a memorable haboob over and west of Tucson around sunset.
11 NNW Sonoita AZ (10 Jul 21) Looking S
31.8519, -110.6971