A flash flood warning is in effect for San Bernardino County until 6:30 p.m. Monday, with the National Weather Service in Las Vegas warning that thunderstorms have already produced between 0.5 and 1 inch of rain and could trigger life-threatening flooding across creeks, streams, highways and underpasses. Doppler radar showed the storms stretching between Searchlight in southern Nevada and Essex in California, and forecasters said flash flooding was either already underway or expected to begin shortly as the storms pushed eastward.
According to kesq.com, the warning specifically named Searchlight, Cal-Nev-Ari, Highway 95, Interstate 40 and Essex as locations likely to see flash flooding as the system moved through. The bulletin, issued by the National Weather Service in Las Vegas, described the hazard bluntly: life-threatening flash flooding driven by thunderstorms capable of dumping heavy rain in a short window. As the Sacramento Bee also reported, the warning covers urban areas as well as rural stretches of road where water can pool quickly.
Why Drivers Are Being Told to Turn Around
Forecasters were especially pointed about roadways. Per the warning, most flood deaths happen inside vehicles, and low-water crossings become especially dangerous once heavy rain starts falling. The guidance was simple: turn around rather than attempt to cross a flooded road, since rushing water can carry away most cars once it reaches about 12 inches deep, and moving water can knock a person off their feet with as little as 6 inches, per NWS.
The advisory also touched on hydroplaning, a hazard tied to vehicle speed, water depth and tire tread that causes uncontrollable sliding when water builds up ahead of a tire faster than it can be displaced. Drivers are advised to ease off the accelerator if it happens, avoid slamming the brakes, and let the tires reconnect with the road before straightening the wheel. General guidance for wet roads includes using headlights, driving in middle lanes, avoiding puddles, and keeping distance from large trucks or buses that can kick up spray and obscure visibility.
A Pattern of Flooding Across the County This Month
Monday's warning is not an isolated event for San Bernardino County this season. Just days earlier, heavy rain triggered a mudslide in an Inland Empire burn scar, closing Valley of the Falls Drive at Momyer Creek Trail along with Oak Glen Road and Potato Canyon Road, according to the Los Angeles Times. Radar estimates suggested the area above Oak Glen received roughly 2 inches of rainfall during that event, which struck ground still recovering from a 2020 wildfire — terrain the newspaper noted remains prone to debris flows downhill of the burn scar. The San Bernardino County Sheriff's Department said at the time there was no threat to homes or residents from that mudslide.
That same week, a separate flash flood warning covering Riverside and San Bernardino counties remained active until 7:30 p.m., with forecasters flagging Yucaipa, Forest Falls, western Mount San Gorgonio, Banning and Mountain Home Village as areas at risk, per forth.news. And back in July, the county saw an even heavier soaking: a National Weather Service warning in effect until 9:45 p.m. covered Needles and stretches of Interstate 40 and U.S. 95, with up to 3.5 inches of rain reported and flash flooding already underway near Needles, according to the Press-Enterprise.
The Bigger Picture Behind the Storms
The rain fueling these repeated warnings has been tied to a monsoon pattern moving through the region, the Los Angeles Times reported, rather than any tropical system. Other reporting on the broader storm activity noted that Twentynine Palms and Twentynine Palms Base were also forecast to see flash flooding in a related warning, according to CBS Los Angeles.
For now, the National Weather Service is urging anyone in flood-prone parts of San Bernardino County to seek higher ground and to never attempt to drive through flooded roadways. With the warning set to expire at 6:30 p.m. Monday, forecasters say the flash flooding threat could persist right up until then as storms continue tracking eastward across the region.
