Palm Desert Under Flash Flood Watch Until Late Thursday: NWS

PALM DESERT , CA - A thunderstorm producing heavy rain prompted the National Weather Service Thursday to issue a flash flood warning for southeastern Palm Springs, Cathedral City, Palm Desert and Rancho Mirage, as well as parts of state Route 74.

Just before 3 a.m., the NWS reported that about an inch of rain had fallen within an hour, causing a threat of flooding in Borrego Palm Canyon, prompting the flash flood warning. The NWS also issued a flash flood advisory just after 3 a.m. for Riverside, Moreno Valley, Perris, western Beaumont, Woodcrest and March Air Force Base. According to the NWS, heavy rain could cause flooding of small creeks and streams, urban areas, highway, streets and underpasses, as well as other drainage areas and low lying spots.

Storms remain most active in the SD and Riverside County Mtns, though they are starting to shift toward Borrego Springs.
— NWS San Diego (@NWSSanDiego) August 3, 2017

Both warnings were originally set to expire early Thursday morning, but were extended until 10 p.m.

Thursday is expected to be the last day of rain and thunderstorms in the region following days of road closures from the wet summer storms. The humid conditions caused by recent monsoonal moisture will continue throughout the day, but drier air will move in from the southwest by Friday, bringing humidity levels down and making thunderstorms much less likely Friday and heading into the weekend.

Radar image at 11:54 AM showing thunderstorms over the San Diego and Riverside Cnty mountains. #cawx pic.twitter.com/YTtTKMOqDj
— NWS San Diego (@NWSSanDiego) August 3, 2017

On Wednesday, heavy rain caused water and mud to submerge the junction of state Routes 79 and 371, prompting the California Highway Patrol to close both highways at the location. The storm cell dumped a large amount of rain about 1 p.m., leaving the junction flooded.

Some vehicles became stuck in the flood zone, but no one was injured.

In the Coachella Valley, lightning strikes led to outages in Palm Springs, Cathedral City and Desert Hot Springs, though power was mostly restored by Thursday morning. Some roadways in Palm Springs were also flooded, including South Araby Drive between Anza Trail and Stagecoach Road, which was closed for about four hours before reopening just after 7:30 a.m.

On Tuesday, heavy downpours triggered flooding, mud and debris flows throughout Lake Elsinore, Meadowbrook, Perris, Temecula and surrounding locations. A number of intersections were closed, but those closures were lifted Tuesday night and early Wednesday morning.

— Image: A view of the storm clouds on Thursday from Palm Springs International Airport / Credit: Renee Schiavone / By City News Service