North Bay saw most rain during weekend storm; more expected Wednesday

A wet weather front that arrived over the weekend and dropped more than 3 inches of rain on parts of Sonoma County - topping Bay Area rainfall totals - is set to deliver another gusty punch on Wednesday with strong rain and winds forecast for the North Bay.

The first prolonged storm of the rainy season tapered off Sunday after dropping just under an inch of rain in Santa Rosa, while a little more than 3 inches fell in the hills west of Healdsburg, said Mark Strudley, a National Weather Service hydrologist. It left in its wake a period of high surf, prompting authorities to issue a warning for the North Bay coastline that will last until Tuesday morning. Swells were forecast at 15 to 18 feet and the Weather Service warned of sneaker waves - large swells that crash ashore after a long, mild lull.

Rainfall over the weekend pushed Santa Rosa’s total to 1.79 inches so far this month, the wettest period since February, when 4.20 inches fell in a span of four days.

The overall total this season for Santa Rosa, 3.36 inches since the start of October, still lags far behind the seasonal average of 7.64 inches to this point. Last year by this time, the city had recorded 6.75 inches of rain.

But more wet weather is forecast for the area starting Wednesday, when the coastal mountains in Sonoma County will likely get up to 2 inches of rain, while the rest of the county will see about an inch, Strudley said.

“It looks to be some intense rain early in the North Bay, early in the storm,” he said.

Diana Henderson, a forecaster with the service, said the storm will bring sustained winds of 10 to 20 mph, with gusts up to 25 mph. She cautioned Monday that it was still early in the week and that outlook could change.

The big question posed by this series of storms is whether the state has entered the much-anticipated El Niño pattern, signaling a turn into a wetter winter that could help alleviate the state’s four-year drought.

That’s hard to know exactly, Strudley said.

The current storm track is coming down from Alaska, the source of most of the North Coast’s heavier storms. During an El Niño year, such rainfall can be heavier and more frequent due to warmer-than-usual ocean temperatures, which then contribute to more moisture in the air.

Strudley said that it’s difficult to say whether this weekend’s storm was El Niño-related, but that the strongest storms in an El Niño year typically arrive in January.

You can reach Staff Writer Christi Warren at 521-5205 or christi.warren@pressdemocrat.com. On Twitter @SeaWarren.