A powerful thunderstorm moving in from the west caused power outages, lightning in downtown Sonora and the evacuation of the Tuolumne County Administration Center Thursday afternoon.

The storm hit about 2:30 p.m., snarling traffic where lights were not working and stopping business on a large part of Washington Street in downtown Sonora.

PG&E reported 2,187 customers in downtown Sonora lost power at 2:42 p.m. The number grew to 2.249 before power was restored to most by 4 p.m.

National Weather Service representative Hannah Chandler said that over a 24 hour period ending at 5:30 p.m., 0.47 inches of precipitation fell in the Sonora area.

Bright flashes of white light consumed downtown Sonora, preceding by mere seconds a reverberating roar of thunder. Buildings throughout downtown Sonora absorbed the tumultuous boom, from the South Washington Street taqueria all the way to the tin roofs of the Sierra Building at the Mother Lode Fairgrounds.

Maryanne Wright was crossing Washington Street at Linoberg when she saw lightning flash.

“It blinded me for a second,” she said. “It sounded like a gunshot. The traffic stopped.”

During the subsequent confusion following the loss of power, an employee at Hot Shotz Bar and Grill said following the flash of lighting and the rumble of the thunder, people emerged from surrounding buildings, hands over the hearts, all asking what had happened.

A few blocks north at the county office building, employees stood outside as firefighters cleared the building after a report of black smoke on the roof.

Barbi Plowman, who was standing outside the county building, said, “It sounded like a bomb going off. It blew out the phones, and the generators kicked in.”

Fire Capt. Kurt Rhoades said the smoke was likely from a generator starting. During the firefighter’s investigation of the roof of the building, he added, there was no evidence found of a lighting strike.

Tuolumne County Undersheriff Bill Pooley said, “No fire…the generator let off black smoke on top of the building.”

People were allowed back inside after a few minutes just as rain started falling.

Lightning strikes were reported at Sanguinetti Road at Mono Way, which knocked out a transformer, setting power lines on fire.

The Tuolumne County Sheriff said several fire crews, sheriff’s deputies and PG&E responded.

“Deputies have notified nearby homes of the fire,” the Sheriff’s Office said in a Facebook post. “No mandatory evacuations are needed at this time.”

The storm struck minutes before schools were about to send students home for the day. Power was out at Sonora Elementary, which cancelled its third grade play scheduled for Thursday night.

Kristin Svum, manager of Mountain Home Gifts, said, “It was so bright. it was a flash of light and the thunder was a quarter or a second after. The windows really moved. The boom of the thunder moved the windows quite a bit.”

The Union Democrat and the buildings nearby lost power for 3-4 seconds.

Buildings at the Mother Lode Fairgrounds, where dozens of people were attending a job fair, also lost power for a few seconds.

Sonora Police Lt. Turu Vanderwiel said the police station lost power as well.

Traffic lights were out at a number of intersections, including the busy Greenley and Mono Way and Mono Way and Restano.

The downed lights caused a backup of traffic on Mono Way leading onto the Eastbound Highway 108 onramp. In the rainy confusion, many vehicles slowly passed through the blinking red light, leading to long lines of vehicles in each intersection.

Some of the same weather events may be expected to hit Sonora tomorrow as well.

“There is a slight chance of thunderstorms late morning to tomorrow afternoon,” said Chandler.

Between a 24 hour period starting at 6 p.m. Thursday evening and ending Friday, an additional 1 inches to 1.5 inches of rain are expected to fall, she said.

Thunder and lighting may accompany the rainfall, she added, but that will not be clear until Friday.

Additionally around 4 p.m., the railroad barriers on Seco Street in Jamestown were down said California Highway Patrol PIO Faustino Pulido. He was not sure if issues with the railroad crossing were the result of the storm.