Bay Area's December dry spell expected to reach an end

"An end to a lengthy dry spell that has made this December one empty of rain in the Bay Area but heavy with tule fog more common for the Central Valley is about at hand, according to the National Weather Service. The bigger impact on the month-long pattern is not expected to hit heavily until later in the week, if then."

""We're probably going to have some occasional light precipitation late (Monday) into (Tuesday) and then later in the week," NWS meteorologist Rick Canepa said. "The much better chance for a more impactful system is next week. There's a large-scale trough setting up over the Northeastern Pacific. Now if that large-scale pattern backs up a little bit and retrogrades, it might not be as wet. We'll have to wait and see how that goes.""

A lengthy dry spell has left December nearly rainless in the Bay Area while producing persistent tule fog more typical of the Central Valley. Light precipitation is possible late Monday into Tuesday and sporadically later in the week, with most measurable rain expected in the North Bay and totals not exceeding about a quarter-inch. Temperatures will remain cold with overnight lows in the 30s and 40s and dense fog advisories affecting interior valleys, shoreline and bay areas. Visibility has been reduced to under a mile at some airports. A large-scale trough over the Northeastern Pacific raises the chance of a more impactful system next week, though retrograding could reduce its moisture.

Read at The Mercury News