Aug 20, 2022
Favorable instability (MLCAPE 1,500-2,000 J/kg) and moisture (PWATs 1.3-1.6) for thunderstorm development were in place across eastern Riverside on the 20th. Daytime heating combined with orographic forcing aided in developing isolated thunderstorms across Joshua Tree National Park during the afternoon hours. Given the lack of steering flow, thunderstorms in the park had very little movement, causing heavy rainfall to occur over the same area and led to isolated flash flooding. No damage or inju
Source: NOAA National Weather Service Storm Events Database (event 1054612). 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.