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Debris Flow — San Bernardino, California
September 12, 2022 · NOAA Storm Events record
Event narrative (NOAA)
Heavy thunderstorms associated with remnant moisture from post-tropical cyclone Kay produced torrential rain over the Apple and El Dorado burn scars on the afternoon of September 12. Multiple debris flows occurred following torrential one-hour rainfall rates exceeding debris flow guidance from the USGS and CAGS. Two of the debris flows traveled several miles including the Banning Canyon wash showing debris logs and ash water. The most impactful debris flow occurred in Forest Falls and Oak Glen, where the flow traveled at least 3 miles down Oakland Road with 4 foot boulders, logs over-topping the road with several feet of mud, with several power poles destroyed. Another highly impactful debris flow formed in Forest Falls on Prospect Road, where large boulders, black water and logs took out
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Source: NOAA/NCEI Storm Events Database. Deaths and injuries are those NOAA classifies as direct. Damage is the reporting office's estimate at the time and is not inflation-adjusted. This is a catalogue record, not a forecast.