A crew of about 20 workers early Sunday rapidly snipped pinot noir grape clusters from vines, an effort duplicated throughout the region as the grape harvest moved into hyper-drive with rain on the way.
"It's a blur," said Tony Bugica, vineyard manager for Bacchus Vineyard Management, who was out with the crew off of Highway 116 near Graton. "Everybody's trying to get it done before the rain."
Weather forecasters said the first of two cool rain storms is expected to arrive in the North Bay by Monday afternoon, then tail off Tuesday with a second wet front blowing in on Wednesday.
Vineyard managers were expecting perhaps more than an inch of rain, prompting the flurry of activity over the weekend.
"This puts the accelerator down," said Nick Frey, president of the Sonoma County Winegrape Commission.
The grape harvest already is smaller and later than usual due to overall cooler, wetter weather. This week's forecast doesn't help.
Wet weather adds to concerns of additional botrytis, or bunch rot, and the cool temperatures and rain will impact all-important sugar levels. Wet weather also makes the vineyards muddy, preventing vehicles from moving effectively.
Frey estimated more than 20 percent of the county's overall grape crop is in. That leaves most of the $400 million crop still on the vine as the first storms of fall arrive.
While some of the thicker skinned grapes like cabernet and merlot can handle the rain, some grapes could suffer, such as zinfandel and chardonnay, said vineyard managers.
"A lot of zinfandel has been harvested, which is good," said Frey. "The chardonnay left in the field is vulnerable."