The strongest, wettest storm system of the new winter season kept pounding the Mother Lode on Thursday, dumping near-record volumes of rain, unleashing damaging winds, bringing down trees, prompting power outages and snarling or blocking traffic in low-lying, flood-prone areas.

As of 5 p.m. Thursday, staff with Pacific Gas & Electric reported outages in towns including Copperopolis, Angels Camp, Sonora, Mi-Wuk Village, Chinese Camp, and outside Groveland and Coulterville. People in the Vallecito area reported outages late Wednesday and the power came back on before midnight.

Kim MacFarlane, assistant director of public works for the Tuolumne County community resources agency, said Thursday afternoon there were multiple county crews out in the heavy rains and in snow responding to downed trees on Lyons Bald Mountain Road, in Cedar Springs and Mi-Wuk Village, and she received another report of a downed tree in Twain Harte as she spoke to The Union Democrat.

“Our crews are going from one incident to another,” MacFarlane said. “We have flooding on Tuolumne Road, folks are trying to clear ditches and culverts. We have road crews prepared with equipment in place and chained up, because it’s snowing up the hill.”

Multiple downed trees due to high winds had been reported, MacFarlane said. She said she’d had no reports of property damage or injuries as of Thursday afternoon.

“We hope everyone is really patient and we’ll try to get the next problems as they happen,” MacFarlane said. “We’ll have staff on call overnight and we’ll try to get the roads clear and plowed as soon as possible.”

Overnight from Wednesday into Thursday, winds gusting to more than 25 miles per hour coincided with heavy rains to bring down weakened trees, limbs, needles, leaves and other storm debris in wind-vulnerable locations of Tuolumne County, public works staff said Thursday morning.

Continuing storm activity was expected to bring more rain, snow and winds, and potential for thunderstorms to Calaveras and Tuolumne counties through Thursday night. A break is expected Friday followed by more rain and snow again Friday night into Saturday.

As of 11 a.m. Thursday, public works and public resources agency crews were clearing storm debris from culverts and ditches, in Columbia, Crystal Falls, Sugarpine and Mi-Wuk Village.

County workers and others were also assessing and clearing downed trees from Corcoran Gray Road and Degnan Road in the Big Oak Flat and Groveland areas, and from Evergreen Road off Highway 120 on the way to Hetch Hetchy.

In addition, county roads workers and other workers were beginning to plow roads off Highway 108 up in the Cold Springs and Strawberry area, Tuolumne County public works staff said Thursday morning. Caltrans was handling the plowing of Highway 108. National Weather Service data for 24 hours before 10 a.m. Thursday showed maximum wind gusts of 26 mph up around Twain Harte, 20 mph east of Groveland and 20 mph south of Hetch Hetchy.

Wet weather that began last week has boosted precipitation totals for Mother Lode watersheds and the rest of the Central Sierra by more than 5 inches, from eight-tenths of one inch to 5.9 inches so far this water year. A seven-week dry spell left the Stanislaus River and Tuolumne River watersheds at just 16 percent of average precipitation, and storms that began the day before Thanksgiving have raised that to 89 percent of average as of Thursday morning.

This week’s storms, from Tuesday morning before rain and snow began falling through 10 a.m. Thursday, brought .95 inch to San Andreas, 1.15 inches to Angels Camp, 1.17 inches to Murphys, 1.6 inches to Arnold, 1.85 inches to Calaveras Big Trees, 1.36 inches at New Melones Dam, 1.26 inches to Columbia, 1.19 inches to Sonora, 1.68 inches to Twain Harte and Strawberry, 2.01 inches at Pinecrest, 1.22 inches at Moccasin and 1.35 inches at Groveland, said Cindy Matthews, a forecaster and hydrologist with the National Weather Service in Sacramento.

Forecasters estimate Thursday’s storms could bring an additional 1 to 2 inches of rain to the Sonora area by Thursday night, and 2 to 3 more inches to Yosemite Valley. Another storm system predicted Friday night to Saturday evening could bring a half-inch to 1 inch more to Sonora and Yosemite.

Jason Terry with the Tuolumne County Office of Emergency Services said Thursday there is sand available for sandbags at Tuolumne Road Yard, 18870 Birch Street, at Jamestown Road Yard, 18188 7th Ave., at Big Oak Flat/Groveland Road Yard, 11240 Wards Ferry Road, and at Columbia Airport, 10723 Airport Road. People who need to fill up sandbags need to bring their own bags and shovels, Terry said.

From 5 p.m. Wednesday through noon Thursday, Cal Fire Tuolumne-Calaveras Unit personnel responded to 10 medical calls, one over-sized debris fire in the Mountain Ranch area, one false alarm for a fire, and a house fire with no injuries on Harrison Drive in Sonora, reported at 6:09 a.m. Thursday, said Lindy Shoff with Cal Fire TCU communications.

Ebbetts Pass on Highway 4, Sonora Pass on Highway 108, and Tioga Pass on Highway 120 are now closed for the winter.

Contact Guy McCarthy at gmccarthy@uniondemocrat.com or 588-4585. Follow him on Twitter at @GuyMcCarthy.

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