SANTA CRUZ, Calif.: On Friday, utility crews in northern California worked to restore power to tens of thousands of homes after two days of fierce winds and torrential rain, even as the region braced for more stormy weather over the weekend.
The National Weather Service (NWS) predicted that the next round of heavy rain and gusty winds would hit the northwest corner of California late Friday and spread southward into the San Francisco Bay Area and central coast on Saturday and Sunday. Southern Oregon was also expected to be affected.
The approaching storm, described by the NWS as an "atmospheric river" of dense moisture flowing in from the Pacific, is expected to dump several inches (about 10 cm) of rain on a region already saturated from repeated downpours since late December, renewing risks of flash flooding and mudslides.
Forecasters warn that hillsides and canyons stripped bare of vegetation by previous wildfires are especially vulnerable to rock and mudslides. In addition to heavy rains, up to 2 feet (60 cm) of snow was expected to fall in higher elevations of the Sierras over the weekend, where accumulations of a foot to 18 inches (46 cm) or more were measured earlier this week.
Forecasters urged residents to prepare for the deluge and stay off roads in flood-prone areas on Friday, as much of the northern two-thirds of California, the most populous state in the United States, were under flood watches, gale-force wind advisories, and winter storm warnings.
The ominous forecast comes from a massive Pacific storm that wreaked havoc on California for two days with hurricane-force wind gusts, pounding surf, soaking rains, and heavy snow. The northern part of the state was hit the hardest.
Some 60,000 homes and businesses remain without electricity in northern California because of high winds and heavy rain. Flash floods and rock slides also disrupted road travel.
Howling winds uprooted trees that had been weakened by prolonged drought and were poorly anchored in soil, causing power lines to fall.
High surf and runoff from heavy rains combined to flood several blocks in Santa Cruz, and heavy waves ripped up wooden piers in the neighbouring town of Capitola and nearby Seacliff State Beach.
Further north, pounding waves flooded the ground-floor museum of the historic Point Cabrillo lighthouse in Mendocino County, according to the Mendocino Voice newspaper.
A massive atmospheric stream of moisture from the tropical Pacific and a sprawling, hurricane-scale low-pressure system known as a bomb cyclone powered the two-day storm, which ended Thursday night.
Since early last week, it has been California's third and strongest atmospheric river. According to research, such rainstorms will occur more frequently and with greater intensity, breaking up long stretches of extreme drought.
Since New Year's weekend, at least six people have perished in the severe weather, including a toddler who was killed when a redwood tree in northern California's Yosemite National Park fell and crushed a mobile home.
According to the NWS, the city of San Francisco experienced its wettest 10-day period in more than 150 years, since 1871, when a quick succession of storms dumped 10.3 inches (26 cm) of rain there between December 26 and January 4. The city's downtown saw 14.37 inches (36.5 cm) of rain in total over the course of 10 days, a record that the NWS predicted would likely hold through the impending downpours.
Although the storms have brought much-needed replenishments to the Sierra Nevada snowpack, which is a vital source of water for California, experts predict that much more snow will need to fall throughout the winter in order to significantly alleviate the state's dire drought situation.
For better or worse, the weather service forecast that yet another atmospheric river storm, this time "likely stronger," was "on the horizon for Monday" as a part of a larger pattern that is likely to last at least through the middle of January, according to forecasters.