The rain is still coming as California's typical rainy season is winding down, and rainfall totals show an above-average season for parts of the Bay Area, which is great news for mitigating the drought.

After last night's bit of rain, there is more to come on Friday and Saturday, with what might be the season's last atmospheric river storm. Rain is expected to begin in San Francisco around 6 am Friday, and it will continue into the evening, tapering off around midnight. Scattered thunderstorms are possible Saturday morning and afternoon, with the weather clearing by evening.

Up in Tahoe, they're expecting five to ten more inches of snow, but it won't be a blizzard like they saw earlier this month. The majority of the snow from this storm system is going to hit the Southern Sierra, as the Chronicle's meteorology team explains — and that's a good thing, because while the Northern Sierra currently sits at 116% of average with its snowpack, the Southern Sierra is still at 92%.

The New York Times' California Today column discusses this season's rain in the state, noting that SoCal was — as the El Nino pattern tends to do — hit the hardest with rainfall. Los Angeles has received 140% of its average annual rainfall so far this year, with more rain headed their way this weekend.

And the entire state could be in for more rain in April, which would not be strange. But the Times talks about the "end of the rainy season" being March 31, in terms of typical patterns of November-to-March rains.

Climate scientist Daniel Swain discussed California's rainy season in his recent "office hours" broadcast, saying that the "above average" snowpack in the Northern Sierra was notable because we are "in an era where 'average' is not too accurate a descriptor of what happens most of the time."

As for talking about future rainfall trends, "It'll be everything but the mean that matters," Swain added, explaining that mean trends become meaningless if California starts swinging between extremes from year to year.

Nonetheless, San Francisco has already basically seen all of the rain it usually gets for its "rain year," which goes from July 1 to June 30. As this chart shows us, Downtown San Francisco is at 113% of average for rainfall by March 27, with 22.73 inches so far, and at 99% of normal for the entire rain year.

Other places, though, like Sacramento are at 92% of average for this point in the year, and the figure for Oakland Airport is also low, at 86%, which could be attributable to the Bay's microclimates. San Jose is at 128% of average rainfall for this time of year.

Photo: Jeremy Bishop