Dust Storm — Central Deserts, Arizona

2012-07-21 · Central Deserts, Arizona

Event narrative

Scattered thunderstorms developed across southeast Arizona during the afternoon hours on July 21st. The storms produced strong outflow winds in excess of 40 mph which spread northwest across the deserts of northern Pinal county. The gusty winds picked up copious amounts of dust and dirt and generated dust storm conditions. At 4 pm a trained spotter near Arizola reported one eighth of a mile visibility in blowing dust; by 418 pm visibility dropped to zero mile and cars were pulled onto the side of the road. At 428 pm a spotter 7 miles east of Sacaton reported a dust storm with zero visibility and wind gusts to 35 mph. In addition, spotters in communities such as San Tan Valley and Apache Junction reported dust storm conditions with winds gusting as high as 50 mph.

Wider weather episode

Scattered thunderstorms developed over the higher terrain of southeast Arizona during the afternoon hours on July 21st. The storms produced strong outflow winds in excess of 40 mph which moved to the northwest and into the south central deserts during the late afternoon hours. The strong winds picked up substantial dust and dirt and created a massive dust storm which moved into the greater Phoenix metropolitan area after about 5 pm. Numerous weather spotters reported winds above 40 mph and visibilities below one quarter of a mile in a dust storm. The near zero visibilities created very hazardous driving conditions and led to some traffic accidents. No serious injuries or fatalities were reported.

Source: NOAA Storm Events Database, event_id 390007. Narrative written by the NWS forecast office that issued the report.