IDYLLWILD - More thunderstorms struck today over western Riverside County and the San Jacinto Mountains, dropping hail, downing utility lines, flooding valley roads and raising concerns about lightning-sparked wildfires.

A late-afternoon storm system moving about 5 mph southwest from Hemet over Homeland, Winchester, Menifee and Lake Elsinore was "capable of producing golf ball size hail" and "winds in excess of 60 miles per hour," the National Weather Service reported.

At 3:32 p.m., about 10 miles southeast of Perris, there were reports of three-quarter-inch hail, flooded streets and trees down, said Weather Service Meteorologist Dan Atkin.

By 4 p.m., a brush fire was burning in the Quail Valley and Canyon Lake area, utility lines were down in Homeland, and flooding had been reported on roads in Green Acres, Homeland, and on the Escondido (215) Freeway in Menifee, according to Riverside County fire officials and the California Highway Patrol.

There was a "high volume" of service interruptions for electricity customers in the Hemet, Perris, Menifee and Sun City areas this afternoon due to storm activity, Scott Andresen of Southern California Edison said just before 5 p.m.

The brush fire near Quail Valley was reported just after 3 p.m. and it charred about three acres at Goetz and Newport roads, but no homes were threatened, said fire department spokeswoman Cheri Patterson.

Earlier this afternoon during reports of multiple lightning strikes in the San Gorgonio Pass, a brush fire was reported on remote, steep terrain on Morongo Indian Reservation land in Potrero Canyon, northeast Banning, Patterson said.

Another fire in the Pass broke out at 1:36 p.m. at Sunset Avenue and Wilson Street in Banning, Patterson said.

Today's thunderstorm activity began shortly before 11 a.m., when a storm system over the San Gorgonio Wilderness and Yucaipa Ridge prompted flash flood warnings, and coincided with a front moving south toward Riverside Advertisement

[ Chatton and Associates ] County, said National Weather Service Meteorologist Noel Isla.

Multiple severe storm and flash flood warnings were issued throughout the day by the Weather Service for areas including northwest, central and southwest Riverside County.

One early warning was for the San Jacinto Mountains, including Lake Hemet near Mountain Center, and Anza on the south side of the mountain range.

Dark clouds formed over Idyllwild, but there were no lightning strikes or intense rainfall before 1 p.m., said Rhonda Andrewson of the Idyllwild Fire Protection District.

By 1 p.m., thunderheads more than 40,000 feet high were visible for miles.

"The highest tops of these storms are from 45,000 to 50,000 feet," said National Weather Service Meteorologist Philip Gonsalves.

"The heat is acting as a trigger, especially in the mountains, creating thermal updrafts and instability," Gonsalves said. "It can also generate rapid cooling in the storms. The humidity is is a major factor."

Triple-digit temperatures today punctuated what was expected to be the last day of the current heat wave in Riverside County.

As of 5 p.m., it was 105 degrees in Riverside, 108 in Hemet and 107 in Temecula, according to the National Weather Service.

Further east in the Coachella Valley, it was 110 in Palm Springs and 111 in Thermal.

But up in the San Jacinto Mountains, it was just 76 degrees in Idyllwild.

The threat of thunderstorm activity in west and central Riverside County was expected to continue through this evening as heat and humidity levels continued to rise, Isla said.

Towering thunderheads also wreaked havoc Wednesday in southwest Riverside County, igniting multiple lightning-strike fires and bringing down power poles and lines in a Lake Elsinore neighborhood, where about 110 homes and businesses remained without electricity today.

Edison crews hoped to have power restored on Pottery Street in Lake Elsinore by 6 p.m. Friday, Andresen said.