Signs are pointing to a cold and wet week in Sonoma and Napa counties, with the potential for three more storms following the weekend rains, according to the National Weather Service.
The most recent storm, which began Saturday, had already dropped about 1.7 inches in the coastal mountain ranges, with varying totals of between 0.2 to nearly an inch in the Sonoma County valleys and between 0.1 to 0.4 in Napa County valleys of 5 p.m. Sunday, according to weather service data. Showers from this system are expected to continue off-and-on through Monday morning, providing a short break before yet another rainstorm, weather service meteorologist Dial Hoang said.
The second system is set to bring another 1/2 to 1 inch into the Sonoma and Napa County valleys between Monday night and Wednesday morning. Some flooding concerns exist mid-week but are expected to mostly be minor, Hoang said, with some creeks and streams north and west of Santa Rosa potentially rising to flooding levels. Fortunately, a lack of rain in the last month has allowed the Russian River to lower and for soils to dry up, meaning fewer chances for dangerous flooding.
A coastal flood advisory is in effect through 3 p.m. Tuesday in an area including portions of Marin, Napa and Sonoma counties, mostly in the valleys. Some lots, parks and roads could flood and some isolated road closures could occur during this time.
As the storms pass through, temperatures overnight could drop to near freezing or freezing levels. From Tuesday through Thursday night, there is the potential for low-30-degree temperatures in the interior valleys, and Santa Rosa specifically could see lows between 31 and 32, Hoang said.
Residents should be mindful of people, pets, plants and pipes overnight, Hoang added.
Slight thunderstorm chances are present early in the week and fade through Tuesday.
Yet another “quick shot of rain” is set to arrive Wednesday night and last into Thursday morning, with lingering showers expected into the afternoon. Up to 1/2 of an inch is expected for most areas across the North Bay, though the coastal mountain ranges could get up to 1 inch.
The final storm is on tap for the weekend. Forecasters are still refining the predictions for this fourth rain, Hoang said.