Overnight rain dampening the North Coast and its unpicked grapes won't dampen the spirits of grape growers, winemakers and winery owners buoyed by what they're calling the best harvest in years.

About one inch of rain is expected to fall, most of it coming this morning. Tuesday and Wednesday could have showers off and on coupled with cool afternoons and cold mornings.

Grape harvesters probably follow weather forecasts closer than they're following the Giants playoff games. Everyone with grape skin in the harvesting game knew last week that a cold storm was on the way.

But with the rain forecast bumped up from Tuesday to sometime after midnight Sunday, vineyard managers late last week hustled to add night and Sunday crews to the schedule.

"Everybody is scrambling to get something done," said vineyard manager Duff Bevill on Sunday. Crews would stay on the job "until the rains run us out of the fields."

By midnight Sunday, Sonoma County grape experts predicted about 80 percent of the year's overall crop would be picked.

What's left mostly will be cabernet sauvignon, a tougher grape that can handle a little rain, said Nick Frey, president of the Sonoma County Winegrape Commission.

"The impact should be fairly minimal," Frey said.

This storm is the first real rain expected so far this fall.

It's a cold storm too, with this afternoon in Santa Rosa expected to reach 60 degrees, compared with 73, which is the average high for Oct. 22 in Santa Rosa.

The low Sunday at the Charles M. Schulz-Sonoma County Airport was 39 degrees. Early morning grape pickers in some areas Sunday worked in temperatures dipping into the 30s.

The colder weather is preferable to picking in heat, said Roberto Mendoza of Windsor. Mendoza, a longtime supervisor for Bevill Vineyard Management, was working Sunday in northern Healdsburg with two crews of grape pickers.

They were at Dry Creek Vineyard in a section that rolls along a steep hillside overlooking Highway 101.

Wearing hats and sweatshirts or long-sleeved shirts, the 15 workers used curved knives to cut the stems of the clusters of deep-blue cabernet sauvignon grapes.

Moving quickly down the long rows, they repetitiously filled yellow boxes, then walked the boxes to a nearby large bin pulled by a tractor.

There were 43 tons to be picked.

They got about half of that done. Bevill expected a Sunday night crew would get the rest.

No talk of rain or cold could shake the upbeat feeling expressed Sunday by numerous people in the wine industry.

"This year is a wonderful harvest. It will go down in the books as one of the best harvests in a long time," said Kerry Damskey, a Geyserville winemaker and wine consultant.

Bevill called the harvest "uniquely perfect in a number of ways."

They described a 2012 harvest trifecta of sorts, with it's large, healthy crop, steady dry weather and high-quality grapes.

Memories of the last two year's small crops, ill-timed rainfall and spreading bunch rot was fading as this grape harvest heads for a close.

"Winemakers are happy, and growers are happy. It's been awhile since that happened," Frey said.

The down note was that the larger crop meant the county's many fermenting tanks can't handle the unexpected tonnage.

"Every tank at every winery is completely at capacity," said Guy Davis, winemaker and owner of Davis Family Vineyards.

Davis and others said they're being creative, using various containers they can find to move the winemaking process along.

After the past two years, no one seemed to be complaining.

"If you have to have problems to solve, may they always be too much, really great grapes at harvest," Davis said.

You can reach Staff Writer Randi Rossmann at 521-5412 or randi.rossmann@pressdemocrat.com.