Dust Storm — Northwest Pinal County, Arizona

2024-07-21 · Northwest Pinal County, Arizona

Event narrative

Visibility down to 1/4 mile reported in the area of SR-347 near the Gila River crossing. No accidents nor injuries were reported.

Wider weather episode

With the subtropical high pressure centered near Las Vegas, Nevada, the overall steering flow was from the north to northeast. Strong daytime heating in combination with PWAT values of 1.5+ inches resulted in MLCAPE values in excess of 1000 J/KG and DCAPE values in excess of 1500 J/KG. In addition, in the upper-levels, there was a disturbance that helped with the vertical ascent. As a result, the environment was primed for the development of strong to severe thunderstorms. Strong thunderstorm activity developed across the Mogollon Rim during the late morning into the early afternoon hours and was steered southwestward towards south-central AZ. A deep, long traveling outflow boundary developed and surged well ahead of the activity and traversed the entire Phoenix metro area with strong winds as well as areas of blowing dust during the mid to late afternoon hours. The outflow boundary as it continued to migrate southward sparked additional thunderstorm activity across portions of northwest Pinal and southwest Maricopa Counties.

Source: NOAA Storm Events Database, event_id 1202250. Narrative written by the NWS forecast office that issued the report.