Aug 23, 2012
A large convective complex formed over south central Arizona during the early morning hours on August 23rd, a result of a weather disturbance acting on a very humid and unstable airmass. The complex of thunderstorms produced locally heavy rain across much of south central Arizona, including the greater Phoenix metropolitan area, beginning shortly after midnight and persisting through sunrise. Peak rainfall rates were between 3 and 4 inches per hour, and the heavy rain led to episodes of flooding
Source: NOAA National Weather Service Storm Events Database (event 403103). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Maricopa County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.