Aug 3, 2014
An upper-level low from Baja cut underneath a large area of seasonably strong high pressure aloft, tapping into lingering monsoonal moisture to produce showers and thunderstorms over the mountains and deserts, as well as a few along the coastal areas, with heavy rain at times. The activity on the 2nd consisted of elevated thunderstorms with lightning along the coast during the morning and a few thunderstorms over the San Bernardino County mountains. Rain and rapid cooling in one of these storms
Source: NOAA National Weather Service Storm Events Database (event 539354). Narrative written by NWS staff at the time of the event.
This event is one of many recorded floods in San Bernardino County. See the full FEMA flood zone map, NFIP claim totals, and disaster history for the area.