A night to remember: Thunderstorm shatters records THUNDERSTORM Rain, 750 lightning strikes shatter Bay Area records

A lightning bolt strikes the Transamerica tower in downtown San Francisco on Thursday night. A lightning bolt strikes the Transamerica tower in downtown San Francisco on Thursday night. Photo: CBS San Francisco Photo: CBS San Francisco Image 1 of / 9 Caption Close A night to remember: Thunderstorm shatters records 1 / 9 Back to Gallery

The thunderstorm that blew through the Bay Area on Thursday night was one for the books - it shattered rainfall records in four cities and produced more lightning strikes than any storm in years.

All that rain pushed local precipitation totals closer to seasonal averages, percentage-wise, than they've been since a bone-dry December. It was accompanied by 750 lightning strikes across the Bay Area between 8 p.m. and midnight, said Chris Stumpf, a National Weather Service forecaster.

"That's quite a bit more than we've almost ever had, at least in recent memory," he said. "It's nice to mix things up."

Bolts hit the Transamerica Pyramid, towers on the Bay Bridge and Golden Gate Bridge, the giant container cranes at the Port of Oakland and an airplane that had just taken off from San Francisco International Airport for London. The plane turned back without incident.

The blustery storm gave way to blue skies and puffy white clouds by the time the Giants took the field for their home opener at AT&T Park. No rain is on the horizon until Tuesday, and even then, the chance of a shower is slight.

Thunderstorms are uncommon in the Bay Area, but when they do strike, it's usually in the spring and fall. That's when warm air blowing in from the central Pacific mixes with frigid air from the Gulf of Alaska, said Jan Null, a meteorologist for Golden Gate Weather Services.

As the warm air races upward through the cold, it builds an electric charge. That charge is released as the bolts of lightning and rumbling thunder that captivated people throughout the Bay Area Thursday night.

"The greater the difference (in air temperature), the stronger a storm you are going to have," Null said.

The uppermost layer of air in Thursday's storm hovered around 40 degrees below zero, while the lower air was about 50 degrees, Null said.

All that electricity in the air was a little too much for Pacific Gas and Electric Co., which lost service to 6,500 customers at the storm's peak.

PG&E recorded 162 lightning strikes in San Mateo County alone, said Joe Molica, a spokesman for the utility. Each bolt of lightning is 1 billion volts, and most PG&E equipment is designed to carry between 4,000 and 12,000 volts, Molica said.

"You're talking about a lot of energy going into our system, which can cause some damage," Molica said.

The storm also did damage to rainfall records. The 1.24 inches that fell in downtown San Francisco on Thursday broke the April 12 record of 0.92 of an inch, set in 2003, the National Weather Service said.

A weather station in downtown Oakland recorded 1.26 inches, more than double the previous record for the date of 0.59 set in 2003. Mountain View and San Jose also recorded new records for the date.

As late as the end of February, after a winter of sporadic showers, San Francisco's rainfall for the season beginning July 1 was just one-third of average. That's changed substantially since the onset of spring. The latest storm boosted the city's total to 15.26 inches - about two-thirds of normal.

Despite the leaps and bounds, weather service meteorologist Diana Henderson said, San Francisco probably won't reach 100 percent of average by June 30.

But who knows?

"My guess right off the top of my head is probably not, but then again, at the beginning of the month, we were well below normal - below 50 percent," she said. "It's anybody's guess, really."