Drought-stricken California got its first glimpse Friday of a big weekend storm system the likes of which, forecasters say, the state has not seen in more than a year.
The rain and snow, which began in the morning, is expected to be confined to Northern and Central California and continue through the weekend.
The northern San Francisco Bay Area could see as much as 9 inches of rain before the storm rolls out Monday morning, the National Weather Service said. In the Sierra, up to 4 feet of snow is expected at elevations above 7,000 feet.
"It's not a drought buster, but it's definitely more than a drop in the bucket," said Steve Anderson, a forecaster with the National Weather Service in Monterey.
The region will still remain well off its average annual precipitation numbers. San Francisco normally would have received 14.5 inches of rain this season by now. That figure is currently at a little more than 3 inches, with up to 3 more inches expected over the weekend.
Other parts of the region are in a similar deficit. The weekend storm is expected to be the first to bring more than an inch of rain to Sacramento in a 24-hour period since December 2012, said Johnnie Powell, another National Weather Service forecaster.
Forecasters also are hopeful the storm portends an end to the persistent dry weather that has plagued the state for months and contributed to its drought emergency. Light precipitation is forecast for Wednesday and Thursday and another storm is possible next weekend, although it's not yet clear how strong that would be, Anderson said.
The rain and snow expected over the weekend are part of warm, subtropical storm system known as a Pineapple Express that is strung across the Pacific Ocean to Hawaii, Anderson said.
Forecasters are warning of the possibility of road and stream flooding, as trash and debris that have not been washed away because of a lack of rainfall clog storm drains. Minor mud and rock slides also are possible.
Southern California was expected to be mostly dry. Forecasters said measureable rain over the weekend likely would not fall farther south than San Luis Obispo and northern Santa Barbara counties as a ridge of high pressure pushes up from the south.