On Friday afternoon, the skies were mostly clear across the San Francisco Bay Area. The sunny weather made it hard to believe rain was in the forecast this evening, but at 1 p.m., meteorologists confirmed the storm is on the way.
"You can see it in the satellite images," said National Weather Service meteorologist Crystal Oudit of the cold front headed toward the Bay Area. "There are clouds all over Washington and Oregon right now, and it's going to push down and straight through our area."
The system is expected to impact the Bay Area on Friday night into Saturday. Rain totals are not expected to be impressive compared to winter, when a couple of inches of rain can fall in a single day. The forecast has generally trended drier as the system is not carrying quite as much moisture as originally expected. What's more, the storm will not provide enough moisture to significantly wet vegetation, and the weather service said in its forecast that "the rains on Friday and Saturday will not be fire season ending."
That said, any rain at this point is noteworthy in the Bay Area, which has seen little precipitation since the start of the wet season on Oct. 1. Last month, the downtown SF weather gauged recorded 0.11 inch of rain, in contrast to the October average of 0.94.
From Friday to Saturday, the North Bay is predicted to record 0.2 to 0.7 inch of rain, downtown San Francisco 0.25, the East Bay 0.2 to 0.44 and the South Bay 0.18, Oudit said.
The outlook shows the first showers arriving in the North Bay at 7 p.m. Friday, moving south of the Golden Gate between 8 p.m. and 9 p.m. and the South Bay by 9 p.m. or 10 p.m.
The heaviest rainfall is expected overnight, though rain rates are not predicted to be heavy, and will be light to moderate at best, Oudit said.
Dry, warm conditions are forecast to return Sunday, and offshore winds, those desiccating winds that blow warm inland air toward the coast, will pick up, the weather service said.
"Fire weather concerns will immediately increase Sunday," the agency warned.