Update On Riverside County Power Outages, Statewide Flex Alert

RIVERSIDE COUNTY, CA — With temperatures soaring in Riverside County and beyond, a statewide Flex Alert remains in place, which calls on residents to voluntarily cut their power use in hopes of reducing strain on the state's power grid.

According to the California Independent System Operator, which manages the state's power grid, the Flex Alert was initially announced for 5 to 10 p.m. Thursday but was extended through Friday to relieve stress on electric grids due to the ongoing heat wave.

A Flex Alert is a call for voluntary energy conservation, essentially a plea for residents across the state to cut their power use to reduce overall demand and lower the risk of outages.

Around 3:30 p.m. Thursday, Cal-ISO announced plans for the extended Flex Alert.

According to Cal-ISO, residents are urged to take steps prior to the alert taking effect, such as pre-cooling their homes, using major appliances and closing window coverings to preserve cool air indoors. Once the alert takes effect, residents should set their thermostats to 78 degrees or higher, avoid using major appliances and turn off all unnecessary lights.

The Flex Alert comes as an abnormally strong ridge of heat has been bearing down on the region, bringing temperatures as high as 119 degrees to the California interior that could last until the weekend. Because of the extreme heat and high overnight temperatures, the state's electric grid will be straining to meet evening demand when air conditioners are in heavy use and solar energy generation is waning.

If the demand becomes too great, rotating outages (Stage 3 CAISO Emergencies) would be necessary, according to providers. Learn more about rotating outages here.

Southern California Edison customers in Riverside County and the Southland have been experiencing outages amid the heatwave. The utility has mostly attributed the shutdowns to equipment problems. Keep up on SCE outages here.

To stay current with forecasted supply and demand conditions, and monitor grid alerts, warnings, and emergencies, visit the ISO's Today's Outlook at www.caiso.com, or download the free ISO Today mobile app. And you can sign up for Flex Alerts and find other conservation tips at flexalert.org.

SCE reminded customers they should be prepared in case of power outages. Learn more here.

Temperature records were shattered Wednesday in two Riverside County cities for the second consecutive day amid a sweltering heat wave.

The mercury hit 107 in San Jacinto, breaking the previous record of 103 for June 16 that was set in 1985, according to the National Weather Service. San Jacinto also reached 107 on Tuesday, besting that day's record that was set in 1961. Records have been kept consistently there since 1948, according to forecasters.

The high in Idyllwild was 104 on Wednesday, breaking its record for June 16, which was 97 in 1961. The mountain community reached 99 on Tuesday, also breaking that day's record from 1961. The weather service has kept records in Idyllwild consistently since 1943.

The heat let up slightly Wednesday in portions of Riverside County, especially in the Coachella Valley, but forecasters said Thursday will be much hotter.

Wednesday's highs countywide also included 90 in Corona, 96 in Riverside, 109 in Palm Springs and 101 in Lake Elsinore.

An excessive heat warning began Monday morning and will continue through 9 p.m. Sunday in the Coachella Valley and the San Gorgonio Pass near Banning.

The warning also includes the Riverside metropolitan area and the Riverside County mountains that began Tuesday and will last through 9 p.m. Saturday.

The weather service said the extreme heat will significantly increase the potential for heat-related illnesses, particularly for those working or participating in outdoor activities.

People should be prepared to drink plenty of fluids, stay in an air-conditioned room, stay out of the sun and check up on relatives and neighbors.

While young children and pets should never be left unattended in vehicles under any circumstances, the weather service said that's especially true during warm or hot weather -- when car interiors can reach lethal temperatures in a matter of minutes.

The county recently opened cooling centers in multiple locations, where residents who don't have access to air-conditioning can stay during the heat of the day. A complete list of options is available at www.capriverside.org/cool-centers.

The hot weather will begin weakening on Sunday, when temperatures are expected to begin subsiding, according to the National Weather Service.

—City News Service contributed to this report.