Downpours triggered by thunderstorms rolling through the San Bernardino National Forest Thursday triggered flash floods, mudslides and other hazards around Idyllwild and surrounding mountain communities.
The inclement weather gained momentum early Thursday afternoon, originating from the Santa Rosa Mountains and farther south and east in San Diego and Imperial counties, according to the National Weather Service.
According to the California Highway Patrol, at about 2:30 p.m., a storm cell drenched the area around Ponderosa and Walters drives east of Highway 243, on the north end of Idyllwild, causing roadway flooding.
At least two vehicles became stuck due to muck on Ponderosa, the CHP stated.
The streets were shut down at 3 p.m., and Caltrans crews were requested to clear the mud and debris.
A similar hazard developed on Highway 243 at Foster Lake Road, about a half-mile south of Ponderosa, just after 3 p.m. The CHP stated rocks and debris flowed onto the highway amid rain bursts, disrupting traffic.
The highway remained open, with traffic moving through cautiously, but Caltrans was again summoned to clean up the mess.
A flood advisory was in effect Thursday afternoon for the entire San Gorgonio Pass, as well as the Anza Valley. The NWS issued a broader flood watch for the mountain communities and the Coachella Valley until 2 a.m. Friday.
Thursday evening, forecasters said a “strong thunderstorm” would impact San Bernardino and Riverside counties through 6 p.m., with wind gusts up to 50 mph and half-inch hail.
An airport weather warning was in effect for Palm Springs International Airport for cloud to ground lightning from 5:25 to 6 p.m. Those thunderstorms wee expected to move out of the area after 6 p.m.
Farther east, rain bursts from thunderstorms rolling through the Palo Verde Valley near Blythe caused major traffic flooding and prompted a Sigalert. The alert was issued around 3:30 p.m. Thursday for U.S. Highway 95 and Second Avenue, according to the California Highway Patrol.
CHP Lt. Steven Rusk said the alert was issued instead of a highway closure, calling it a precaution for motorists to drive safely in the area. It was unclear how long the Sigalert would remain in effect.