A strong winter storm brought strong winds and high elevation snow to West Coast over the weekend, leaving more than 350 000 homes and causing flash floods and mudslides. Several more waves of heavy rain, gusty winds and high elevation snow are expected before the end of the week.
Wind gusts in excess of 96 km/h (60 mph) downed trees and power lines, leaving more than 300 000 customers without power in Washington (the majority in King, Pierce and Thurston counties) and tens of thousands in California on January 5 and 6, 2019. By early Monday, January 7 (UTC), the number of customers without power stood at 77 372 in Washington and 56 203 in California.
“Strong winds picked up virtually instantaneously across Oregon and Washington and gusted as high as 84 mph on Abernathy Mountain in Washington and 79 mph in Mount Hebo in Oregon,” AccuWeather meteorologist Faith Eherts writes.
The winds have subsided in the Pacific Northwest by early morning January 6 (LT), but authorities still urged residents to use extreme caution to avoid coming into contact with active power lines.
Heavy overnight rain in California forced authorities to issue flood warnings and advisories in the Los Angeles area.
Mudslides and flooding there closed several roads and caught up several cars in debris. There were no deaths or injuries reported.
The storm dumped more than 76.2 mm (3 inches) of rain in Marin County, triggering flooding along San Francisco’s Great Highway.
The NWS weather station in Kentfield registered 98 mm (3.86 inches) of rain, San Rafael registered 84.3 mm (3.32 inches), Napa 59.9 mm (2.36 inches), Mt Diablo 33 mm (1.3 inches), Oakland 32.5 mm (1.28 inches) and San Francisco 27.4 mm (1.08 inches).
Near white-blizzard conditions were reported in the Sierra, disrupting traffic and forcing authorities to issue an avalanche warning for the Lake Tahoe area, south into the Sierra along the California-Nevada line, valid from 12:00 LT, January 6 to 07:00 LT, January 7.
At least 60 cm (2 feet) of snow was reported at Mammoth Mountain and more than 30 cm (1 foot) in the upper elevations around Tahoe.
This severe weather event is now mostly over. Some rain and mountain snows are expected to continue across parts of the Intermountain West and the Rockies on January 7.
The next round of precipitation is likely to arrive on the West Coast by Tuesday, January 8 as a deep low pressure system moves into the eastern Pacific.
Locally heavy rainfall is possible in the lower elevations of northern California and the Pacific Northwest, with snow in the higher elevations of the Cascades and mountains of northern California.
Featured image credit: Caltrans