Dust Storm in Northwest Valley, Arizona

Visibility less than 1/4 mile along Loop 303 just south of Surprise in blowing dust from thunderstorm outflow. No accidents or injuries were reported.

Abundant moisture (PWATs 1.75-2.00 inches) and instability (MLCAPE 1000+ J/KG) combined with an approaching upper-level trough to result in an environment favorable for strong convective activity. Thunderstorms first developed across the Mogollon Rim and White Mountains during the early to mid afternoon hours and then slowly drifted southwestward towards south-central Arizona. Activity affected portions of Gila County, where significant water flow was observed along the Russell Gulch area. Additional activity moved from the higher terrain down into western portions of the Phoenix metro during the early evening hours, where damaging winds and blowing dust were observed.