SAN FRANCISCO (KGO) -- An atmospheric river pummeled the Bay Area early Tuesday morning causing widespread flooding on roadways and downed trees and branches.
This is the first of several storms that are expected to hit California this week bringing gusty winds, rain and snow to parts of the state.
On Tuesday, Downtown San Francisco received more than an inch of rain and Mount Tamalpais had more than 4 inches before dawn.
Storm causes flash flooding, leaving cars stranded in North Bay
The atmospheric river that swept the Bay Area overnight brought bitter weather -- torrential rain, flash flooding -- making for a nasty commute across the North Bay.
Some cars were abandoned by their drivers, stuck in the middle of the road as massive flooding blanketed Highway 12 in Sonoma County.
A creek spilled over west of Windsor, at Mark West Station Road.
But all in all, the Level 3 storm didn't bring widespread damage that officials anticipated.
"From our standpoint this was a beneficial storm, typically when you're dealing with burn scars like the Glass Fire. We always get concerned with rainfall rates that have mudslides," said Paul Lowenthal, Santa Rosa Fire Marshal. "We've seen some of the effects from larger storms but with this storm, we didn't see any movement on the burn scar - just localized flooding across the city."
But for drivers on the road, the rain brought slow speeds, gloomy skies and a muddy commute.
"It is scary, make sure you have both hands on the wheel. And it can get you at any moment and that can be disastrous," Novato resident Briggs Macdonald said.
Residents are hopeful the next batch of storms looming into the new year will just bring much needed moisture, and not a widespread wipeout.
Heavy rain causes roof to collapse at East Bay store
In San Ramon, the rain likely caused the roof to collapse at the Big 5 Sporting Goods store located in the Crow Canyon Commons shopping plaza, just before 6 a.m. on Tuesday.
In a statement to ABC7 News, the City of San Ramon says a main beam in the center of the store broke, which caused the roof to collapse. That also took down the fire sprinklers. The city says the broken sprinklers and water from the roof flooded the RiteAid next door.
When the fire department arrived on scene, a big part of the store's roof was gone.
San Ramon Valley Fire Protection District Battalion Chief Eric Saybe says the buildings are decades old, but even still, it is rare for a roof to collapse. He adds, with a large amount of rain and a flat roof, water drainage may have been an issue.
"With a flat roof, rain, the impact would be the weight of the water. So, drainage is very important," explains Saybe. "Don't see it too often. I have been here 20 years now, and this is the first collapse I have seen."
Big 5 and the city are working to assess the structural damage. Yellow caution tape and red danger tape still block the front of the building, which has been red tagged by the city.
In Moraga, Moraga Road between Sky Hy Drive and St. Mary's Road is closed due to a large tree on power lines. PG&E crews responded to repair the pole and lines.
Residents were asked to use alternate routes.
Rogue waves in Peninsula
On Highway 1 in San Mateo County, a large tree fell blocking directions of the roadway around 4:30 a.m., just east of 280.
"Slow down, slow down, people like to drive fast on Highway 1, it's pretty dangerous," Rjay Dominia, a Pacifica resident said. "We see accidents all the time around here, especially closer towards Manor, all the time, just slow down, relax."
Pacifica, no exception to the heavy rain showers and problems all over the roads.
"Lots of trash blown across the street, and leaves and branches and things totally all over the place," Tristan Brosnan, a Pacifica resident said.
The storm spurred a high surf advisory into Wednesday morning on the coast, meaning large breaking waves between 18 and 25 feet tall.
"I haven't seen it quite this crazy in a while but it's fun to come day here and see it like oh my goodness," Brosnan said.
Dominia, a local of Pacifica, says no matter how tempting it might be to take a video near the pier, that means, you've got to watch out for rogue waves.
"When it comes to the high tide warnings, you really want to be careful because there's something called rogue waves, which you know it's calm one minute and then at any given moment, it will just come up and sweep you," he said. "So just never turn your back on the waves."
Power outages, road closures, flight cancellations in San Francisco
The stormy weather we've seen in San Francisco is nothing compared to the blizzard conditions in the Midwest and the East Coast.
Even so, because of a domino effect, we continue to see cancellations and delays here.
At SFO Tuesday, there were plenty of travelers, but not the crazy long lines seen in the past few days.
With some exceptions, most travelers are finally able to get to where they want to go.
On this Tuesday, there has been more than 70 canceled flights and 200 delayed flights at SFO. Even so, the SFO duty manager said operations are running much more smoothly thanks to the extra staff working.
As many people return from their Christmas breaks, the Bay Area has a little stormy weather of its own to reckon with.
Pounding rain and gusty winds in the overnight and early morning hours meant some streets were flooded.
The southbound lane of the Great Highway was closed for a while because of minor flooding.
Department of Public Works said that tree crews and arborists were on standby.
"We've had calls for trees in bike lanes and branches down. Those have been responded to very quickly," said Beth Rubenstein with SF Dept. of Public Works. "We had some issues around civic center. The PUC is on it, clearing those out."
"It all seems so mild to me. I'm from Chicago. It's probably good to be getting rain considering it's pretty dry here," said Morgan Wessel of San Francisco.
The heavy downpour that drenched San Francisco didn't seem to be much of a problem for public works crews.
Meanwhile, PG&E says at the peak about 400 customers in the city were without power. That number is now down to double digits.
Heavy snow, rain in the Sierra
The harsh winter storm is bringing several inches of snow and howling winds to the Lake Tahoe area.
Chains are required in both directions on I-80 and Highway 50 for those vehicles that aren't four-wheel drives and equipped with snow tires.
"For one second I felt like the winds was knocking me over. I was like, oh my gosh this place is just crazy but I love it," said Andrea Flores of Santa Rosa. Flores is talking about the winds she felt Monday night in the Sierra, winds that were throwing snow every which way at the Palisades Tahoe ski resort overnight into Tuesday; and winds that have impacted all the resorts including Boreal Mountain.
"We did not spin our lifts that go to the top of the ridgeline today but we did have a few other options down lower," said Tucker Norred of Boreal Mountain. "There are lifts that take you to our terrain park features as well as we have tubing available, we have ski and snowboard lessons that are down low."
Continued calls for Bay Area residents to conserve water despite winter storms
Despite all of the rain the Bay Area has already received and is forecast to receive, experts say it's critical to keep conserving water.
The storms the Bay Area has been faced with have not been easy to navigate, amid flooding and other hazards, PG&E says the wind has caused significant outages.
"We want our customers at home to prepare for any outages. Because this storm system is not the only one that we're going to see this week. There are several other storm systems coming," said PG&E spokesperson Mayra Tostado.
But even though the storms have been dangerous and damaging in some cases, experts say this storm and future ones are a good sign.
"It is exactly the kind of thing that we hope to get every winter," said Professor Alison Bridger from the Department of Meteorology and Climate Science. "It's exactly the kind of thing that we didn't get last year in January and February."
But Bridger says we still have to worry about long dry spells in the future, making it critical to continue conserving.
"If you've learned to conserve," she said, "Why change?"
A message echoed by Valley Water in Santa Clara County.
Even having just one year of above average rainfall is not going to get us out of the current situation that we're in," said Metra Richert, Valley Water's water supply planning and conservation manager. "Some data that kind of supports that is if you look at our reservoirs, they're still only at 19% full capacity."
Metra Richert says that reservoirs statewide are also lower than they should normally be at this time of year.
Right now she says Santa Clara County has been doing a good job with conservation, the hope is that residents keep it up, even if we have a better rain year.
Though we'll need more than the current storms to get us out of the drought, work is being done to capture as much rain as possible.
"We have multiple reservoirs all throughout the county," Richert said. "Their aim is to collect the water during the rainy season and to hold on to it so that we can use that water during the summer when it's most needed."
Local water agencies including Valley Water offer water saving tools and landscape rebate programs to help conservation efforts.
More information can be found here.
For now, experts continue to look at the current storms with optimism.
"I think after about New Years, people will be tired of (the rain)," said Bridger, "But too bad, they need the rain."
ABC7 News reporters Zach Fuentes, Anser Hassan, Lena Howland, Suzanne Phan, Stephanie Sierra and J.R. Stone contributed to this story.
The Associated Press and Bay City News Service also contributed to this story.
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