A powerful winter storm lashed through Southern California on Friday, blasting the mountains around Los Angeles with high winds and heavy snow, drenching the coasts with heavy rain, shutting down miles of major highways and even dusting the Hollywood Hills for the first time in decades.
In the higher elevations, forecasters said, the storm was a true blizzard, with warnings in place until late Saturday afternoon.
The storm on Thursday walloped Portland, Ore., with snow and low temperatures that contributed to the death of a child after an ambulance was delayed in its response to a medical call because of ice on the roads, officials said.
In Southern California on Friday afternoon, the storm was raising concerns among meteorologists and officials as they assessed multiple threats that would last through the weekend: several feet of snow in the mountains, where roads are heavily traveled; pounding rain in lower elevations that could flood roadways; and thunderstorms that could produce hail and tornadoes.
“It’s a rare storm considering how cold it is — and how wet it is,” Ryan Kittell, a meteorologist with the Weather Service in Los Angeles, said on Friday. “The biggest thing is a lot of road closures.”
While the rarity of the snowstorm prompted some anticipation among Californians unaccustomed to a phrase like “blizzard conditions,” there was still an entire weekend of dangers to look out for, including blizzard warnings for the mountains of Los Angeles, Ventura, Santa Barbara and San Bernardino Counties through Saturday afternoon.
Mark Pestrella, the director of the Department of Public Works for Los Angeles County, said that beginning on Friday afternoon, residents should avoid travel, especially in parts that will be pounded by the blizzard, a wintertime weather event in which winds exceed 35 miles an hour, considerable snowfall occurs and visibility is drastically reduced.
On Friday, the blizzard conditions were brewing in elevations 4,500 feet above sea level, with strong winds intensifying up to 80 miles per hour, reducing visibility and creating “treacherous” whiteout conditions, said Eric Boldt, a Weather Service meteorologist in Oxnard.
Up to five inches of rain were expected to fall along the coasts and valleys, and the heaviest snow, up to seven feet, was forecast to accumulate in areas of high elevation. Areas between 2,500 and 4,500 feet were expected to receive up to a foot of snow, and wind gusts of 80 miles per hour were expected.
By late Friday afternoon, a little less than 100,000 customers in California, mostly in the northern part of the state, were without power, according to PowerOutage.us.
Millions of people in the West, mainly in California and Nevada, were under winter weather alerts. Officials in Ventura County issued evacuation warnings for some inland communities, including around Ojai, through Saturday morning because of “anticipated flooding and debris flows.”
As some Californians marveled at the unlikely white landscape, many were trying to put a name to what they were seeing: Was it rain, snow, sleet, hail or graupel? The National Weather Service offered a vocabulary lesson for wintry mix beginners. Hail, or frozen precipitation of ice from thunderstorms, is hard and solid; graupel, or snowflakes that collect supercooled water droplets, is soft and wet.
The storm snarled major transportation arteries, causing road closures, high wind warnings and advisories for drivers to use chains on their tires on Friday.
Parts of Interstate 5, a major north-south route that runs from the border with Mexico to Canada, were shut down in areas in Siskiyou and Shasta Counties in the northern part of the state. The Grapevine, a 40-mile stretch of I-5 from northern Los Angeles County to Kern County, was shut down on Friday morning, and the authorities said there was no estimated time for when it might reopen.
“This is the coldest I’ve seen in a while,” said Joe Merriam, who has lived in Corona, about 50 miles southeast of Los Angeles, for 30 years. “This is very unusual — very crazy.”
On Thursday, the storm paralyzed parts of Oregon, trapping motorists for hours while others abandoned their vehicles on the side of the road. Travel disruptions persisted into Friday, with the Oregon Department of Transportation announcing closures along at least three highways.
Rick Graves, a spokesman for the Portland Fire Department, confirmed that a baby under the age of 1 in Portland died at a hospital after firefighters responded to a medical call of a child not breathing just after 6 a.m. on Thursday. The ambulance had been delayed, in part, because of poor conditions on the roads that were covered in two inches of “bulletproof ice,” Mr. Graves said.
The West Coast can be one of the hardest places in the country to predict weather because of the lack of observations over the Pacific Ocean, and the intensity of the storm caught many people — including forecasters — by surprise.
A person standing in downtown Los Angeles can see a 10,600-foot peak that will typically have snow on it, but by Saturday, that snow will extend much farther down the mountain, underscoring the strength of the storm, said Andrew Rorke, a forecaster for the Weather Service in Los Angeles.
Though the Hollywood sign was not likely to be lost in a snow-covered hillside, snow or graupel was seen falling Thursday morning near the sign, the Weather Service Office in Los Angeles confirmed. A brief flurry was again spotted there on Friday, the Weather Service said.
There is also a high risk for avalanches across the Sierra Nevada on Friday into Saturday morning, according to the Avalanche Forecast Center.
This will not be the last winter storm to hit the area; forecasters from all Weather Service offices in California are predicting another storm at the beginning of next week.
Reporting was contributed by Christine Hauser, Corina Knoll, Derrick Bryson Taylor and Remy Tumin.
