Snow by Saturday? It's 50-50

  
By Joe Rodriguez, San Jose Mercury News
02.22.11

Break out the mittens. Charge up the digital camera. Practice your throw.

It hasn't snowed on the valley floor, at least deep enough to provide ammunition for snowball fights, in 35 years -- since Feb. 5, 1976, to be exact. But we just might make winter history again this weekend.

Another Alaska cold front due here Thursday afternoon has the potential to drop some winter delight on Bay Area sidewalks and backyards by Saturday morning.

"It has to be a cascade of all the right things adding up together," said Jan Null, a consulting meteorologist at Golden Gate Weather Services.

He said the Alaska cold front bearing down on us isn't yet carrying enough rain for a good snow dump when it gets here, but it might pick up more moisture as it loops over the ocean off the Pacific Northwest before arriving.

"There's a 50-50 chance that will happen," said Null, who still remembers driving happily home that February morning 35 years ago. "It's really a rare thing for it to snow at sea level in the Bay Area."

Even if that doesn't happen, Null said, this storm is sure to drop snow on the region's tallest peaks and on the eastern foothills down to about 1,000 feet. Mount Hamilton above San Jose will become even whiter than it has been the past few days.

"It's a sure thing," Null said.

The National Weather Service station in Monterey was watching the same cold front approach, too, but forecasters there weren't giving odds on  palm trees.

"I'm not going to say it's impossible," forecaster Diana Henderson said. "We are going to get a good blast of Arctic air."

Like Null, she said the right snow-building ingredients have to fall in place. However, she said, Friday night and early Saturday morning are shaping up as the coldest hours of this storm. That would be the time for a dramatic snowfall at lower elevations, maybe even sea level.

The first rain showers and colder temperatures should hit the Bay Area on Thursday afternoon, with overnight temperatures in downtown San Jose dipping to the mid- to high 30s and midday temperatures in the 50s. The weather service expects a low of 33 degrees Saturday morning before the storm clears out of the region by Monday.snow falling on palm trees.
"Other than that," Henderson said, "it's a cakewalk."