Aug 7, 2011
Favorable positioning of the monsoon high pressure system over New Mexico allowed for a surge of moisture into southern Arizona. An upper level disturbance rotating around the high was the focus for thunderstorm development across the region. Some of the storms produced damaging winds, heavy rainfall, and flooding.
Source: NOAA National Weather Service Storm Events Database (event 340172). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Pima County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.