SAN FRANCISCO (KRON) — The latest in a series of atmospheric rivers arriving in the Bay Area Monday evening is expected to bring significant rainfall, according to the National Weather Service. Scattered showers are possible throughout the day Monday with heavy rain expected to arrive overnight, according to KRON4 Meteorologist John Shrable.

Along with what the NWS calls a “moderate to high potential for rain,” the atmospheric river is expected to raise the possibility of flooding and road closures.

Graphic: Kyla Grogan

Bay Area rain forecast this week

“We are once again bracing for the impacts of an atmospheric river that is unfortunately coming at a time when our ground is already thoroughly saturated and our rivers, creeks and streams are already sitting at high levels,” said KRON4 Meteorologist Kyla Grogan. “The result will be a very dangerous early morning on Tuesday as these heavier rains hit their crescendo bringing high runoff rates leading to flooding.”

Expected rainfall around the North Bay mountains and valleys could be in the range of two or more inches, the NWS said. That’s enough to cause rivers, streams and creeks to flood, trigger shallow landslides and cause roadway flooding and closures.

“Given our drought conditions in California, rain is usually welcome but the problem with this system is the timing,” said Grogan. “Our soils, our rivers, creeks and streams – they just can’t take any additional rain right now and I am very concerned that we will see flash flooding on Tuesday and the potential for debris flow meaning the earth starts moving under the weight of the rain that has been absorbed.”

Graphic: Kyla Grogan

Storm to impact Tuesday commute

“It’s really important that people heed the advice to stay clear of any water in roadways where they can’t tell how deep it is. My advice is that if you can’t see the lines on the road, don’t drive through it,” Grogan added.

Higher elevations like the Santa Cruz Mountains and higher North Bay mountains could get four or more inches of rain, the NWS said. Rain will likely remain heavy into Tuesday morning, complicating the morning commute and bringing potential flooding.

According to forecasts, the brunt of the rainfall hits Monday night and early Tuesday.

“The worst of the rain will be falling overnight and into the early morning hours on Tuesday. If you have the option to stay off of the roads Tuesday morning, I’d exercise that option,” Grogan said. “If you must travel, make sure that you’re giving yourself extra time and obeying any road closures or detours as they are there to keep you safe.” 

Graphic: Kyla Grogan

When will the rain stop?

Unlike recent storms that have stretched out over several days, this weather system is expected to move through quickly.

“I do have some good news to share in that we are drying out Wednesday and Thursday which will be a chance to reset and allow some of the water levels to recede,” said Grogan. “I’ll be timing out the storm today so tune in if you need info.”