Bay Area storm ‘opening the door’ for wet new year, forecasters say

As the Bay Area absorbs an atmospheric river soaking the region, forecasters say multiple storm systems following closely behind means the year will end — and the new year will begin — with a torrent of wet weather.

Residents were put on alert Tuesday after the National Weather Service anticipated winds upward of 40 mph throughout the greater Bay Area, and a flood watch was issued based on predictions of 2 to 4 inches of rain for coastal ranges, 2 to 3 inches for interior areas, and between 1.5 and 2 inches for the region’s valleys.

The flood watch was accompanied by a flood advisory, which is less severe, for more inland areas, but major incidents failed to materialize, though commuters and roadside crews did grapple with minor flooding caused by middling drainage.

The storm’s biggest impact will be in paving the way for more to come, said NWS Meteorologist Cindy Palmer.

“This first one is opening the storm door for us,” Palmer said.

The latest storm moved in from Guam and matches the characteristics of a “Pineapple Express,” in which rain and winds will spare the area from freezing, keeping temperatures in a moderate range spanning the low 40s and upper 50s.

Palmer said the storm moved in faster than expected, which will result in a respite in the first half of Wednesday before a new storm system arrives in the evening. Steady rain is forecasted for Thursday and Friday, and yet another system is predicted to arrive between Saturday and Sunday.

“We are looking at wet weather continuing on New Year’s Day,” Palmer said. “We have several systems lined up.”

The Weather Service said that heavy rain was reported throughout the region Tuesday morning, ranging between 1 and 2 inches overnight, with 1 and 1.5 inches more expected. Raw data from the National Oceanographic and Atmospheric Administration taken at 11 a.m. Tuesday showed 24-hour rainfall estimates of nearly 2 inches at Oakland International Airport, 1.85 inches at Mount Diablo, 1.82 inches in San Francisco and two-thirds of an inch in San Jose.

Palmer added that because of the consecutive storm systems, the water falling in the Bay Area has a chance to help alleviate water shortages: “At this point in time, we’re looking at good beneficial rain.”

San Jose and the surrounding region, coastal cities in San Mateo and Santa Cruz counties, and San Francisco anticipated some flooding, but the most notable flooding involved creeks in Sonoma County. Those rises had mostly eased by late Tuesday morning.

“Other flooding we’ve seen has been the CHP reporting at onramps and offramps, anywhere storm drains were clogged,” Palmer said. “Thankfully it’s been minor flooding, nuisance flooding.”

Traffic delays were not widespread in the Tuesday-morning commute, though that was likely influenced by lower overall commute volume typically seen between Christmas and New Year’s Day.

Heavy snowfall of between 3 and 10 inches was predicted for the Lake Tahoe region, but in areas above 7,000 feet, the yield could reach 1 to 2 feet. A winter storm warning was in effect through at least late Wednesday morning, and road travel to the area was expected to see chain controls, delays, and possible route closures.

The Tahoe Daily Snow report on OpenSnow parallels Palmer’s rain prediction in the Bay Area, with “strong winds and heavy rain and snow Tuesday morning becoming all snow on the mountains through the day and to lake level by Tuesday night,” with a break Wednesday, storms through the weekend, and into next week.

Delays were also expected to continue for air travelers trying to leave and arrive in the Bay Area,  with the latest figures from FlightAware showing that more than 3,000 flights across the United States were cancelled as of Tuesday morning. Mineta San Jose International Airport was the only local airport approaching the national top 10 for cancellations for the day with over 150 affected inbound and outbound flights; Oakland was hovering around 20th with more than 120.

Those airports’ cancellation figures were largely influenced by Southwest Airlines, which account for virtually all of the nixed flights. Nationally, the carrier had cancelled more than 2,500 flights Tuesday morning, or 63% of its total flights for the day. Airline staffing shortages were also causing massive delays, with carriers scrambling to find essential personnel to staff flights and avoid additional cancellations.

Check back later for updates to this story. Staff writer Scooty Nickerson contributed to this report.