UPDATED: Flash Flood Warning Issued In Idyllwild, Other Mountain Fire Areas

UPDATE AT 9:59 P.M. JULY 22, 2013: The flash flood warnings for local burn areas were canceled late Monday afternoon, but the county decided to open evacuation shelters for those threatened by the water. Here is a news release from the Riverside County Executive Office that explains the reason for the shelters:

An evacuation center has been established at Idyllwild Elementary School after heavy monsoon rains in the area of the Mountain Fire created the potential for flash floods and debris flows in several locations. 

Residents of Apple Canyon Road, north of Bonita Vista Road, were given precautionary evacuation warnings just after 1 p.m. Monday. The evacuation center opened at the school, 26700 Highway 243, around 5 p.m. for residents who feel threatened by the rain and potential flood and debris flows. By 6 p.m. Monday, no residents had taken advantage of the shelter being open. The evacuation warning is expected to remain in place until after conditions improve and the center, staffed by the American Red Cross, will remain open at least through Tuesday morning. Residents with questions about the shelter can call (855) 891-7325 overnight.

Trees, rocks and other debris can easily be washed downstream when rain follows a fire. Debris in canyons south of Palm Canyon may contain significant debris that shifts water flows away from normal paths. Residents along S. Palm Canyon Drive south of Bogert Trail should pay particular attention and take precautions to avoid potential flood waters and debris flows. Residents should not try to halt or divert debris carried by flood waters.

UPDATE AT 11:55 A.M. JULY 22, 2013: The National Weather Service has upgraded its flood "watch" to a flood "warning" in areas impacted by the Mountain Fire. (Click here for an update on the blaze.)

The NWS reports that thunderstorms are now developing over the burn area, including but not limited to San Jacininto Peak, Idyllwild, and Pine Cove.

Pine Cove and Lake Hemet are particularly susceptible to flash floods and debris flows from this rainstorm, according to the NWS.

Residents and motorists in and below recently burned areas should be alert to heavy mud and debris flows that may block roads and culverts, the NWS reported.

The heaviest rainfalls are expected this afternoon.

ORIGINAL POST JULY 22, 2013: A monsoonal air mass remains over Southern California today, and thunderstorms are expected to develop over parts of Riverside County bringing locally heavy rainfall with a high potential for flash flooding, the National Weather Service advised Monday morning.

A flash flood watch is in effect in the county mountains and Coachella Valley through this evening, the NWS reported.

Flash flood guidance values are three tenths of an inch of rainfall in 30 minutes or half an inch in an hour for the new burn areas.

Any thunderstorms in the burn areas could produce this amount of rainfall, and mud and debris flows are likely, the NWS warned.

A flash flood watch means that conditions may develop that lead to flash flooding, which is very dangerous, according to the NWS.

Check back for updates.