Flash Flood Warnings Issued for Southern California Counties

LOS ANGELES, Calif. — A flash flood warning was issued Friday for Los Angeles, San Bernardino, and Riverside counties. The warning took effect around 3 p.m. and will remain in place until 6 p.m. Rainfall rates of 0.5 to 1 inch per hour are expected, posing risks of life-threatening flash flooding, debris flows, and landslides.

Doppler radar showed thunderstorms developing in San Bernardino County at 4 p.m., with estimated rainfall of 0.25 inches expected within an hour. The flash flood warning for San Bernardino is active until 4:45 p.m. Riverside County also issued a warning at approximately 3:37 p.m. Key areas at risk include Highway 74 between Mountain Center and Anza, and Lake Hemet.

An advisory for flooding was also issued for Los Angeles and San Bernardino counties. The National Weather Service (NWS) reported that unusual weather patterns for July are increasing the chance of dry lightning and scattered showers across Southern California this weekend.

According to the NWS, early monsoonal moisture brought diverse showers and storms to Orange County and the Inland Empire from late Thursday to early Friday. By Friday afternoon, the weather system was moving towards the mountains of Los Angeles, Ventura, and San Bernardino counties.

Thunderstorms are mainly predicted for the San Gabriel Mountains and the foothills of Los Angeles County, as well as the San Bernardino Mountains and nearby high desert regions. Areas such as Lake Arrowhead, Big Bear Lake, and Arrowbear are under alerts for potential flash flooding of creeks, urban areas, highways, and underpasses.

“Turn around, don’t drown when encountering flooded roads,” urges Joe Sirard, a meteorologist at the Oxnard office of the NWS. He warns about the risks posed by heavy rain in hilly terrains, where low water crossings could become dangerous.

Sirard emphasized the possibility of wildfires due to dry lightning. “Sometimes you might get a rain shaft with lightning, but the lightning can occur and strike outside of the rain shaft,” he said. This rare weather phenomenon is not typical for summer, driven instead by a low-pressure system in northern Mexico.

As of Friday afternoon, localized flooding and strong winds were possible in other areas. Regions affected by previous wildfires, notably those of 2024 near Wrightwood, are at a higher risk of debris flows. Sirard noted, “We’re going to keep a close eye on things.”