Rain and snow, which began to fall in drought-stricken California on Friday, is expected to continue through the weekend in the biggest storm that the area has seen in more than a year.
Still, the big weekend storm is far from enough to break a drought which has prompted authorities to implement strict water saving measures across the state.
The San Francisco Bay Area has received only about 25 percent of the rain it has normally had by this time of year, said National Weather Service forecaster Diana Henderson.
Forecasters 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.
"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.
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.
Before the storm rolls out Monday morning, the northern San Francisco Bay Area could see as much as 9 inches of rain, the weather service said. In the Sierra, up to 4 feet of snow is expected at elevations above 7,000 feet.
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 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.
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 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.
Meanwhile, snowpack levels in nearby Oregon on Friday were less than half of normal, and the drought index was still severe to moderate.
Dozens of sites in Southern Oregon showed the lowest snowpack since the 1940s, when records were first kept.
The storm was expected to drop a foot or more of snow in mountainous parts of southern Oregon and 2 to 8 inches in western Oregon valleys that got slammed Thursday, the National Weather Service said.
The snow was expected to turn to freezing rain Friday night and Saturday in many areas. That will turn roadways icy and increase the possibility of downed power lines, forecasters warned.
The first storm dropped more than a foot of snow on parts of the Pacific Northwest and left one person dead in an Interstate 5 pileup in southwest Washington. It also closed schools and offices.
Mount Ashland Ski Area remained closed with just 6 inches of snow, but is high enough at 6,000 feet to expect to get snow even as the coming storms bring warmer temperatures.
The storm track wasn't carrying as much rain and snow into Washington, where the snowpack was better but not great.
Snowpack levels ranged from 32 percent of normal on the Olympic Peninsula, to 50 percent on the Lower Columbia, 65 percent in southern Puget Sound, to 63 percent on the northern Puget Sound.
The Yakima Basin ranged from 57 percent to 62 percent. Spokane was at 78 percent. And the Lower Snake was the highest at 86 percent.
The drought index was at moderate across most of Washington.
Al Jazeera and The Associated Press