Updated June 28, 2011 at 5:30 p.m.
The nearly half an inch of rain that has fallen across the Bay Area Tuesday has pushed this month into record-breaking territory: It's now the rainiest June on record in Oakland and at San Francisco International Airport.
It is also the rainiest June 28 on record in downtown San Francisco, downtown Oakland and at the Oakland and San Francisco airports, according to Chris Stumpf, a meteorologist with the National Weather Service.
At SFO, 0.52 inches had fallen by 4 p.m. The previous mark for this date was set on June 28, 1992, when 0.14 inches fell there, according to National Weather Service meteorologist Steve Anderson.
By noon, downtown San Francisco had received 0.37 inches of rain, breaking a record set for the same date in 1952, when 0.22 inches fell on the city, Anderson said. By 4 p.m., San Francisco had received 0.78 inches of rain.
The day's precipitation won't likely break downtown San Francisco's June record of 2.57 inches, set in 1884, Stumpf said. As of 4 p.m., downtown had received 1.99 inches in the month of June. But the city is beating out notoriously rainy Seattle, which has received 1.42 inches of rain so far this month.
The storm system came from the Gulf of Alaska and should clear up Tuesday evening, Stumpf said, with a potential for scattered showers overnight.
Lightning struck in Concord Tuesday, he added, and the warm temperatures and nature of the system make conditions ripe for more lightning Wednesday.
“Since there’s still so much moisture and we’re in the summer months, there’s a possibility of thunderstorms,” Stumpf said.
But the June gloom won't last for long. By Friday, the weather should be warmer and sunnier, with temperatures predicted in the 70s for San Francisco.
This isn’t the first wetter-than-normal month of 2011.
Deke Arndt, the chief of the climate monitoring branch at the National Oceanic and Atmospheric Administration’s National Data Center, said this year was among the top 11 rainiest springs in Northern California since the agency began monitoring in 1895.
While the numbers are out of the ordinary, experts say it’s difficult to connect them to any greater climate trends.
“It's tough to link up a rogue precipitation event late in the season to climate phenomena,” said John Abatzoglou, a meteorologist with the Desert Research Institute. “We don't have any well-established ways to explain connections between events like today’s rainfall and facets of climate variability. So I guess I'll say this is weather being weather.”