After years of anguish over short crops and low demand for grapes, Sonoma County growers are holding their breath and hoping for something that has eluded them for years: a normal harvest.

They won't have to wait much longer to find out.

Grapes across the North Coast are ripening as the temperatures rise. Clusters of red varietals are showing signs of veraison, the telltale sign that harvest is near, when grape skins soften and globes transition from tangy green to luscious ruby red.

Harvest for grapes used in sparkling wines will likely begin in mid-August, and growers will start plucking grapes for still wine off the vines around Labor Day, they said. And if the weather continues to cooperate, the crop size should return to normal, around 200,000 tons.

"So far, so good. I think it's been about ideal," said Nick Frey, president of the Sonoma County Winegrape Commission. "After two years of not very cooperative weather, of course it's still early, but we've gotten this far, and things look good."

Temperatures throughout the week are expected to hover in the mid-80s, which is ideal for developing the sugars within the grapes, Frey said.

"Harvest is coming pretty darn quick, a lot quicker than the last two years," said Jim Murphy, owner of Murphy Vineyards, based in Alexander Valley. "We have, over the last week, a tremendous color showing up in a lot of the red varietals, including the cabernet."

Crews have been out in the fields in preparation for harvest. Vineyard workers are thinning plump clusters that could grow too crowded, to stave off bunch rot, and cutting out clusters that have been slow to ripen, to cultivate a consistent crop. But labor supply has been tight, and that may become a bigger issue when harvest swings into full gear in just a few short weeks.

"We've got chardonnay in Dry Creek Valley where the berries are starting to soften up," said Duff Bevill, founder of Bevill Vineyard Management. Chardonnay in Alexander Valley and the northern reaches of Russian River Valley around Healdsburg also are beginning to ripen, indicating that harvest could begin early enough to pull the crop from the vines before fall rains, he said.

Prices continue to be strong for Sonoma County grapes, with most grapes already contracted to wineries.

"It's nice, because the last two years haven't been fun," Bevill said.

Although growers have been able to get the field work done so far, fewer hands have made for slower work, several said. As a result, more growers may turn to mechanical harvesting, he said.

"We'll see what happens when harvest comes," Frey said.

"I know there's a big concern at some of the bigger management companies about getting some of their work done, because the labor just isn't there," Murphy said.

While it's still early to determine the size of the crop, growers expect it to be larger than last year, when the crop was 17 percent below normal. Sonoma County crushed 166,070 tons in 2011, a 13 percent drop from 2010, another year with low yields.

"I feel like almost everything is average to above average," said Chris Bowen, vineyard manager at Hunter Farms, which cultivates 100 acres in Sonoma Valley. "In the blocks that we farm, certainly the pinot noir looks to be the best that I've seen in at least three years, maybe more. Chardonnay looks good, too. . . . There's so much fruit that we think we're going to have trouble getting it all ripe."

Most growers are reporting normal production levels, a welcome improvement over the past few years, Bevill said.

"This is a pleasant change. People are feeling good," Frey said. "We're optimistic, and anxious to get on with harvest before we get any fall rains this year."

You can reach Staff Writer Cathy Bussewitz at 521-5276 or cathy. bussewitz@pressdemocrat.com.