Wine harvesters are rumbling through vineyards in the central San Joaquin Valley in California.

Grapes are ripening earlier than usual, growers are receiving more money than in recent years and wineries are scrambling to find certain varieties.

"Demand exceeds available supply this year," said Nat DiBuduo, who heads Allied Grape Growers in Fresno.

He said varieties coming up short this year could include chardonnay, pinot noir and pinot gris. And demand has even stepped up for merlot, a variety that was left to rot in some vineyards just two years ago.

One reason for the shortfall, DiBuduo said, is that 150,000 acres of grapes were removed in the past 10 years as a glut forced prices down.

Frosts -- mostly in the north but also in South Valley foothills -- also cut the size of this year's crop. And hot weather, along with drought conditions, pared yields.

DiBuduo said yields could be 10 percent below average in the Valley. The crop is estimated to be 20 percent smaller than last year and a third less than in 2005 in such prime wine regions as Napa and Sonoma counties and the Santa Rita hills near Solvang.

Madera County grower Steve Schafer said he is picking some red varieties -- including cabernet sauvignon -- earlier than ever before, in some cases a month earlier.

"The wineries can only handle so much," he said. "Right now, the harvest is running 110 percent. There's a traffic jam."

Most of the harvesting takes place at night because of the lower temperatures, said Carson Smith, president of the San Joaquin Valley Winegrowers Association, which formed this year to promote the region's wine.

Despite higher prices that growers are receiving, DiBuduo said, profits are diminished by significantly higher costs for fuel, fertilizer, herbicides and metal for trellises.

"It's nearly double in some cases," he said.

Prices paid to growers are up between 25 percent to 50 percent, DiBuduo said. Some examples: Thompson seedless grapes that sold at $150 per ton last year are expected to be in the $225 range, chardonnay that was $250 is $350 to $450 and cabernet sauvignon that was $250 is $300 to $350 this year.

"One that has not changed is white zinfandel. It's at $225 this year and last," DiBuduo said.

DiBuduo said he does not expect that shoppers will pay higher prices.

"Wineries may make adjustments. There will always be the super-value wines," he said.

The expected smaller crop comes when demand for domestic wine is growing by 3 percent to 5 percent a year and the market for wines in the $12-to-$20 range is soaring by 18 percent, said Rob McMillan, who heads the wine-industry lending business at the St. Helena of Silicon Valley Bank.

McMillan said the shortfall could translate to fewer bargains on wine shelves in stores.

He said the state's roughly $19 billion wine industry typically is at its most profitable when there is a slight grape deficit.

McMillan and others in the industry believe the state could be at the start of a sustained grape shortage. Even if growers rush to plant new vineyards in the spring, it will be years before those new plantings would produce any quantity of grapes.

DiBuduo said the shortage "could and should spur more plantings, but it has to be the proper varieties with winery contracts."

Schafer said there are still "competing crops we're getting good margins on," including almonds.

"I pulled out a vineyard and made as much on corn as on some grape varieties," he said.

Both Schafer and DiBuduo said a major cloud on the horizon for grape growers is a continuing drought and concern over how much water will be available for irrigation.