Dust Storm — Central Deserts, Arizona

2016-07-18 · Central Deserts, Arizona

Event narrative

Strong thunderstorms developed across the higher terrain of east and southeast Arizona during the afternoon hours on July 18th and some of the stronger storms produced gusty outflow winds in excess of 40 mph. These winds spread towards the northwest, picking up large amounts of dust and dirt and creating dust storm conditions. A trained weather spotter 4 miles east of Casa Grande reported visibility down to around one quarter mile in dense blowing dust at 1652MST. A Blowing Dust Advisory was already in effect at this time and was soon upgraded to a Dust Storm Warning at 1711MST. The severely restricted visibilities resulted in very hazardous driving conditions during evening rush hour; fortunately no accidents were reported as a result of the dust storm.

Wider weather episode

A favorable monsoonal circulation was in place across the lower deserts of Arizona on July 18th, and this allowed scattered thunderstorms to develop across the higher terrain of eastern and southeastern Arizona during the afternoon hours. Gusty outflow winds were generated from the stronger storms across southeast Arizona and they picked up significant amounts of dust and dirt as they moved across northern portions of Pinal county creating dust storm conditions. Storm spotters in the vicinity of Casa Grande reported dense blowing dust along with wind gusts reaching 30 mph. The dense blowing dust and associated near zero visibility created very hazardous driving conditions during the afternoon rush hour.

Source: NOAA Storm Events Database, event_id 642746. Narrative written by the NWS forecast office that issued the report.