Sep 2, 2009
Mid-level moisture in Easterly flow aloft and marginal instability produced several thunderstorms over the Inland Empire and San Diego County mountains and valleys on the afternoon of September 2nd. These storms produced heavy rain, flash flooding, gusty winds, and hail. Flash flooding was reported in Moreno Valley and Witch Creek. Several locations received over an inch of rain from the storms.
Source: NOAA National Weather Service Storm Events Database (event 197813). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in Riverside County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.