Flash Flood in La Paz County, Arizona

Photos from the La Paz County Public Works showed parts of Alamo Road washed out due to extensive flooding from overflowing washes that intersect the road. Timing estimated from radar. No injuries were reported.

The remnant mid-level circulation of what was Tropical Cyclone Kay was located over southern California. This led to southerly flow across Arizona, which helped increased moisture and instability with moisture values peaking at around 1.5 and MLCAPE values peaking at around 1000 J/KG. Strong to severe thunderstorms developed across southeast Arizona, near the Tucson area, during the late afternoon hours of the 11th and then progressed northward towards the Phoenix metro during the evening hours, resulting in widespread severe downburst winds and blowing dust as well as isolated flash flooding. The Phoenix Sky Harbor Airport reported a peak wind gust of 86 mph at 2053 MST. Additional storms then developed across western Maricopa County, extending into La Paz County, during the early morning hours of the 12th with heavy rainfall leading to flash flooding become the biggest threat.