UPDATED: Flash Flood Watch Canceled for Riverside County Valleys; Tropical Storm Ivo Leaves 3 Dead in Its Wake

UPDATE 6:28 p.m. Aug. 26:

A flash flood watch that was expected to remain in effect through Tuesday for Riverside County valleys has been canceled by the National Weather Service.

"Widespread cloud cover inhibited much development over the area today," NWS stated in a message just after 6 p.m. Monday. "And with daytime heating no longer at its peak...thunderstorms west of the [Santa Ana] mountains are no longer expected for the rest of the day."

However, the flash flood watch remained in effect through Tuesday evening for the deserts and mountains of Riverside, San Bernardino and San Diego counties, according to the weather service.

A 20 percent chance of rain and thunderstorms was still forecast Monday evening for Murrieta.

ORIGINAL POST 12:51 p.m. Aug. 26:

The ominous clouds covering Murrieta may bring a 30 percent chance of thunderstorms and showers Monday afternoon and evening as a flash flood watch remains in effect for much of Riverside County and San Bernardino counties today, including areas still recovering from the aftermath of heavy weekend rains.

The flash flood watch means that isolated flash flooding may occur in the Inland Empire and Riverside County valleys. The watch was expected to remain in effect through Tuesday evening, according to the National Weather Service.

The weather stems from Tropical Storm Ivo, which has the potential to bring more heavy rain over the mountains and deserts of San Bernardino and Riverside counties, as well as parts of the Inland Empire, as remnants of the storm system continued tracking north and further west over southwest California.

The weather has been more troublesome—fatal in some cases—for areas east and north of Murrieta.

Two people died Saturday in a multi-vehicle pile up during a dust storm on Interstate 40, according to the San Bernardino County coroner.

And U.S. 95 was closed from Interstate 40 to the Nevada state line for mud and debris removal. A woman was found dead in a wash Sunday near the 95 west of Needles, according to the coroner.

In the Coachella Valley, Palm Springs police advised motorists to avoid East Vista Chino and North Gene Autry Trail at the wash; they were closed due to flooding caused by the storm Sunday afternoon.

In Desert Center, Caltrans crews were working to restore roads and Southern California Edison workers were repairing the damage from a Saturday microburst that downed 55 power poles and powerlines on Kaiser Road, according to Riverside County fire spokeswoman Jody Hagemann.

Downed poles and powerlines made Kaiser Road near Powerline Road impassible north and southbound, Hagemann said.

About 20 employees of First Solar are sheltering in place at the solar plant until roadways are cleared nd they can leave the area, she said.

The Edison website indicated up to 150 customers in the Palm Desert area remain without power from outages.

A portable generator was installed to restore water service to about 150 Lake Tamarisk residents and a cooling center was opened at the Lake Tamarisk Community Center, Hagemann said.

"Monsoonal moisture and moisture from the remnants of Tropical Storm Ivo will continue to increase today and spread slightly farther west into portions of the inland valleys," according to an NWS statement. "Daytime heating will lead to thunderstorms with heavy rainfall and flash flooding, especially in mountains and deserts with isolated thunderstorms in the inland valleys.

"Heavy rainfall in burn areas of the past few years will likely lead to mud and debris flows near and below those burns areas," the NWS said.

The agency advised residents to have a plan of action ready to shelter in place or move to higher ground in the event they get caught up in a flash flood. 

—City News Service and Patch staff contributed to this report.