The National Weather Service says there's a 50-50 chance that more thunder and lightning could arrive in Sacramento after 3 p.m. today, mimicking the prolonged light show that mesmerized the region this week.

But lightning storms – besides providing an awesome spectacle – come with some peril.

In Plumas County, a woman carrying an umbrella was hit by lightning and critically injured.

Plumas County Sheriff's Sgt. Ken Nelson said the lightning that knocked the woman down at 5 p.m. Wednesday at her home near Portola "burned off" all the fabric on her umbrella.

It knocked her to the ground and halted her breathing, according to sheriff's reports.

The woman, whose name was not available, was flown by helicopter to UC Davis Medical Center in Sacramento, where she was listed in critical condition Thursday.

Also on Wednesday, two people were killed and seven injured after the gusty electrical storm pounded the state with thunderstorms and lightning, igniting dozens of small wilderness fires.

The deaths and most of the injuries occurred Wednesday in San Bernardino County. Lightning killed a woman walking under a tree in Fontana, and in the San Bernardino Mountains, wind blew a tree onto a car and killed the driver during the storm.

In San Diego County, a man was hit by lightning as he worked outdoors. He was hospitalized in critical condition.

According to National Geographic, 3,696 deaths from lightning strikes were reported in the United States between 1959 and 2003.

It said 10 percent of those struck by lightning die, and 70 percent suffer long-term effects. National Geographic said the odds of being struck by lightning in the United States in any year are 1 in 700,000.

In Northern California, the National Weather Service reported the lightning strikes came in waves, beginning Wednesday afternoon and continuing into early Thursday. The storm set off car alarms, sent some dogs into near panic and knocked out power to thousands of electricity customers.

It also awakened plenty of people: They tweeted on Twitter in the middle of the night about the continuous lightning, put comments on Facebook, and sent digital photos to sacbee.com. To see the photos, go to sacbee.com, "Inside The Bee."

Citrus Heights resident Joe Cronin, who retired from the National Weather Service in Sacramento in 1993, worked for many years as a government meteorologist in Green Bay, Wis. He's seen his share of thunderstorms, but this storm was something to behold.

"It was the most impressive display of lightning I have ever seen," Cronin said. "That storm was unique – just so much lightning. Vivid displays. It was so extended. A lot of time in the Midwest you will have a cold frontal passage with good, strong thunderstorms with it. But they move through. There was more lightning last night than I have ever seen before."

The weather service attributed the thunderstorms to moisture from the Pacific, a rising low pressure system, and unstable air near higher elevations.

It said the thunderstorms will move slowly out of the region, and that cooler temperatures in the mid-70s are likely today and Saturday.

Still, this week's storm was unusual for its unrelenting intensity.

"There were periods when we didn't have a break between lightning flashes. That's pretty unusual for here," weather service meteorologist Mike Smith said.

He estimated hundreds of lightning strikes, but no large fires were reported.

In Davis and Marysville, where thousands of customers lost power, electricity was restored to most by noon, said a spokeswoman for Pacific Gas and Electric. In all, 23,000 PG&E customers lost power.

The Sacramento Municipal Utility District reported far fewer power failures.

Meteorologist Smith said the storm dropped nearly an inch of rain in downtown Sacramento and at higher elevations, perhaps preventing so-called dry lightning forest fires in the mountains.

"It certainly was not dry," said Smith. "Most of the storms contained a lot of rainfall. We got reports where they were getting a half an inch of rain in 15 minutes and over an inch of rain at times."

The half-dozen pooches who stayed overnight at Cha Cha's Doggie Daycare in east Sacramento took it all in stride.

Office manager Victoria Cox monitored the canines on a 24-hour doggie cam from her house.

"Nobody was stressed out," she said. "I was double-checking to make sure, because if anybody was stressed we would come back and take care of them. They have their blankets and their bones."

She had left the radio on a little higher at Cha Cha's to drown out the thunderclaps.

Call The Bee's Bill Lindelof, (916) 321-1079.