Dust Storm in Northwest Pinal County, Arizona

Visibility of less than 1/4 mile along State Route 347 near Riggs Road due to dense blowing dust from thunderstorm outflow winds. No accidents or injuries reported.

Scattered to numerous thunderstorms developed over the northern half of AZ as well as near the International Border during the afternoon hours with more isolated activity developing across the foothills and higher terrain areas east of Phoenix. All of this activity was due to strong upper-level ascent associated with a low pressure system along the west coast and another upper-level disturbance over northern Mexico. Outflow boundaries from the aforementioned activity sparked new thunderstorm activity during the evening hours across much of the south-central AZ lower deserts, including the Phoenix area. The combination of MLCAPE values between 500-1000 J/kg and DCAPE values of around 1500 J/kg supported strong to locally severe downburst wind gusts. PWATs were also near 1.5, supporting an environment conducive to high rainfall rates with these thunderstorms and thus some flooding impacts.