San Luis Obispo County’s grape harvest is under way, and so far, this year’s crop looks like a good one thanks to a little help from Mother Nature.

“Overall, quality looks excellent,” said Neil Roberts of Roberts Vineyard Services, a vineyard management company in Templeton.

“Whites have been coming in beautifully,” he continued. “We are starting to pick the red varieties now with cabernet two to three weeks out. Weather has been cooperative with warm days and cool nights, which are excellent for grape maturity and quality.”

Vineyard managers and growers say it’s a welcome change from previous years that brought challenging weather conditions.

“Wine grapes don’t like temperature extremes,” said Dana Merrill of Mesa Vineyard Management in Templeton. “Nice, even temperatures make great wine.”

Growers predict that this year’s grape crop will increase from last year, to about 3.7 million tons, up from 3.3 million in 2011, said Heidi Scheid, spokeswoman for the California Association of Winegrape Growers. Last year, grapes did not get off to a good start because of hard rains and freezing conditions, she said. That meant a late start to the harvest.

This time, there were “no real low dips and heat spikes,” she said. “We had a warm spring and a warm, enjoyable summer. And the weather seems to be holding right now. If we make it through Thanksgiving with no rain, we’ll be very happy.”

The favorable weather has resulted in overall good yields with strong quality, she added.

“When you get those things simultaneously, it’s grape-grower heaven right there.”

Audra Cooper, the North Coast grape broker for Novato-based Turrentine Brokerage, said the Paso Robles area and parts of Santa Barbara are not expected to bring in as large a crop as some other areas, such as Lodi. But she, too, believes that the overall grape harvest is looking better than last year, and that this year’s crop will be larger than anticipated.

So far, the majority of what has been harvested are white varietals such as chardonnay, pinot blanc and pinot grigio.

“They have come in at expectations, with a few slightly above,” she said. “Some of the early red varieties have come in at expectations or below, such as the syrah, merlot and zinfandel. We still have a long way to go before we have a good handle on the red varietals.”

As for demand for wine grapes, Cooper said she has noticed a slowdown in demand compared with the previous six months, which means an easing in price.

The slowdown in demand is due to a larger than anticipated wine-grape crop in California.

“It’s not necessarily true for the Central Coast, but it will impact the market here on the Central Coast,” she said.

Overall, it has been a “fantastic year on the Central Coast for the market, with a lot of buyers buying grapes,” she said.

The same holds true for consumers, Cooper added.

“Ultimately for 2012, consumers will have a choice of some great wines at good price points,” she said. “For the consumer, that’s always a good thing.”