The entire Bay Area is once again under a Flood Watch starting on Saturday, as two more storm systems head into the region, and low-lying areas along the Russian River are now under evacuation warnings.

On Thursday evening, the Sonoma County Operational Area Emergency Operations Center issued an evacuation warning for "all residents living near the Russian River floodway and its tributaries from Healdsburg to Jenner." That represents a significant part of the northwest quadrant of the county, and it reflects a forecast that the Russian River will crest at around 40 feet by Sunday or Monday — eight feet above flood stage for places like downtown Guerneville.

"For your safety, prepare to leave the areas below the 40 foot flood level in the Russian River area," county officials said.

While there was concern about the Russian River flooding in Wednesday's storm, rainfall totals turned out to be less extreme than on Saturday. But the accumulating water and runoff are expected to take the river above flood stage by some point on Sunday, the National Weather Service predicts.

And water levels along the river near Guerneville and Monte Rio are already at seasonal highs, as seen in the Thursday video from the Sonoma County Sheriff's Office below.

The first storm system this weekend is expected to hit the North Bay starting Friday night and extending to Sunday. As the Press Democrat reports, the first round of rain is expected to bring totals as high as 3.25 inches to the area — with 4 inches accumulating at lower elevations by Tuesday, and up to 8 inches in the coastal mountains.

According to the evacuation order, "The current forecast predicts the river will reach 32 feet on Sunday night. The Russian River is expected to possibly surpass 39 feet Tuesday night after 7pm."

Residents of Guerneville know that while 32 feet is considered flood stage, things start to get hairy at around 38 feet — and peoples' memories are still fresh from February 2019, when the Russian River crested around 46 feet and much of the town flooded, including the R3 Resort and its pool.

Flood watches and advisories are also likely to be issued for other parts of the Bay Area, and East Bay creeks and rivers have already been reaching flood stage during the last two storms in this atmospheric river parade.

Photo: Sonoma Co. Sheriff/Twitter