Northern California could be in for a new atmospheric river storm by the end of the week, potentially blasting the Bay Area with substantial rain, and the Sierra with even more heavy snow, but likely not as fierce as the wet storms that wreaked damage across the region at the start of the year, forecasters say.
Storm-lashed California may not get much relief soon: The cold and rain could be here to stay for at least the next two weeks, according to weather experts.
The weather outlook for Northern California for March 8 through March 14 leans toward colder and rainier (or snowier) conditions than usual, per an outlook issued Tuesday from the National Weather Service’s Climate Prediction Center — though mid-range forecasts are notoriously finicky.
A successive series of powerful atmospheric river storms poses a growing threat to California as the ground becomes more saturated, river levels rise and heavy winds threaten the power infrastructure. This week’s storms are expected to dump intense levels of rain in a fairly short period of time. The greatest potential for disaster is in Northern California, which has already been battered by several destructive storms — including one this weekend that caused a deadly levee breach.
After three years of drought, California is beginning 2023 with more snow on the ground than at any start to a year in a decade. State water officials trekked into the Sierra Nevada to conduct the first snow survey of the winter season on Tuesday, reporting 174% of average statewide snowpack for the date.
California, particularly Northern California, was walloped by a major winter rain and snow storm last week and meteorologists expect that high levels of precipitation will continue for at least another week. Despite some damage and at least one death from local flooding and tree-toppling high winds, the storm and the predictions of more to come are welcome relief from what had appeared to be a prolonged drought.
Bay Area residents would do well to keep their gloves handy, as they’ll be fighting a parade of storms that started on Boxing Day. Monday’s contender brought light showers and winds that evolved into heavy rainfall and intense winds by the Tuesday morning rush hour. In parts of the East Bay hills, Peninsula and North Bay highlands, winds gusted over 50 mph and were accompanied by intense rainfall across the region, where totals exceeded an inch and a quarter at both official downtown San Francisco and Oakland weather stations. More torrential downpours came down over the Santa Cruz Mountains and North Bay highlands, where stations like Felton and Mt. Tam exceeded 4 inches of rain.
Two atmospheric rivers (ARs) are forecast to make landfall along the US West Coast on 9 Dec and 12 Dec. The first AR is forecast to bring a short period of AR 1 conditions (based on the Ralph et al. 2019 AR Scale) to coastal Southern Oregon. The deterministic GFS and ECMWF have drastically different solutions for a developing area of low-pressure associated with the second AR, making it difficult to pinpoint the timing, IVT intensity, and landfall location.
A line of storms that ushered in a chilly, soggy start to December should continue to move across Northern California early this week, offering more chances for rain in the Bay Area and a fresh coat of powder over the Sierra Nevada. One-third to a half-inch of rain could still fall over lower-lying portions of the Bay Area from Sunday through Tuesday morning — further boosting already healthy rainfall totals over the past several days.
Many Californians will wake up this morning to a relatively rare phenomenon: Rain. Today, the freezing-cold temperatures and high-powered winds that have gripped much of the state this week are set to give way to a good old-fashioned winter storm: Both Northern and Southern California are expecting rain, strong winds and heavy mountain snow, with an avalanche warning in effect through Friday for backcountry areas in the Sierra Nevada.
Most Californians don’t expect to see anything like a white Christmas, but this year, even a damp Christmas is looking unlikely. An update to the Climate Prediction Center’s official winter forecast shows a hot and dry season ahead for much of the Golden State.
