Sep 30, 2018
Deep tropical moisture started to spread north and into far southeast California during the day on September 30th; the moisture spread into the area ahead of Hurricane Rosa and led to the development of isolated thunderstorms. Due to the tropical nature of the moisture, the storms that developed produced very heavy rain which led to an episode of flash flooding in eastern Riverside County, to the southwest of Joshua Tree National Park and just north of the Salton Sea. At 1925PST, the California
Source: NOAA National Weather Service Storm Events Database (event 779523). 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.