Mother Nature may deliver one last gut punch to grape growers before this historically dismal season comes to an end.
Wet weather is bearing down on Sonoma County, and the rain expected to start Friday could deliver a fatal blow to grapes still hanging on the vine.
Growers reacted Monday by kicking harvest into overdrive.
"We are going to be beyond max capacity until the rain starts," said Glenn Alexander, owner of Bacchus Vineyard Management. "We'll basically be going around the clock."
Any moisture at this point brings the threat of a mold outbreak, and with the harvest season already delayed by a cool summer, some growers have decided now is the time to bring it all in.
"Grapes aren't going to ripen much more in this weather," Alexander said. "A lot of growers are saying, &‘Let's end this thing.'"
On Monday, vineyard managers across the county were calling around to see if anyone might have an extra tractor, or an unused forklift, or even an entire crew to help them finish picking before the rain arrives. But with the harvest only about two-thirds complete, few vineyards had resources to spare.
The rain's impact depends on several factors, not least of which is the amount of precipitation that actually falls.
Ken Clark, senior meteorologist with AccuWeather.com, forecast a light sprinkling on either Thursday night or Friday morning.
"It's not going to be a big rain event," he said. "Let's not overplay it."
His model showed a light drizzle lasting only a couple hours, and he forecast not much more than a tenth of an inch of rain.
"Then there is definitely going to be a dry day on Saturday and probably on Sunday," he said.
More rain might arrive Sunday night or Monday morning, and this time it could be wetter, he said. Or wet weather could miss Sonoma County all together.
"There are a lot of things that could happen between now and then. It could be a fictitious storm," he said. "But if it comes, it would be a wetter system."
Other forecasts are not so promising. The Weather Channel is predicting a 40 percent chance of rain on Friday and Saturday, and then a 60 percent chance of rain Monday through Wednesday.
Sonoma County usually receives just under a couple inches of rain in October, with most of that in the second half of the month. So far only .28 of an inch has fallen.
Growers appear to be planning for the worst, which seems prudent after their string of bad luck this season.
The unusually foggy summer resulted in an outbreak of mold and also slowed the development of grapes. A sudden explosion of heat in August set record temperatures and turned an estimated 20 percent of the county's crop into sun-fried raisins.
To deal with those challenges, farmers spent more time and money managing their fields. At the same time, they will likely receive considerably less money for this year's crop.
The county's total harvest is expected to be about 20 percent below average, yet the weak economy has resulted in little demand for extra grapes. Farmers who have unsold grapes are receiving offers that in most cases don't cover their costs - if they receive any offers at all.
"It is has been the most difficult season in my 24 years of growing," said Steve Dutton, a grape grower whose family farms about 1,100 acres of vineyards. "This is just one more thing to deal with."
Dutton Ranch had harvested about 75 percent of its estimated 4,000 tons of chardonnay by Monday afternoon. But 300 tons will likely remain on the vine when the rain arrives Friday, Dutton said.
"We don't have enough man power and the wineries don't have enough capacity to harvest everything by then," he said. "We'll have to wait and see what the weather does."
The rain's impact will vary from vineyard to vineyard, as both soil type and grape varietal play a role in determining just how destructive moisture can be.
Soils that don't drain well, such as clay, could result in vines sucking up extra water that dilutes sugar levels in the grapes and further delays the fruit from ripening. And grapes such as petite syrah, chardonnay and zinfandel are more susceptible to mold.
"It's either pick it or lose it," said Dan Barwick, wine making consultant at Paradise Ridge. "This is farming. That is what we have to deal with."
Barwick described this season as "the worst in a lifetime."
Growers are now watching closely to see if Mother Nature will really deliver another calamity. Paul Sloan, owner of Small Vines Viticulture, which manages 120 acres, is waiting until the last minute to decide whether to pick his remaining crop before Friday.
"I'm going to be tracking about 5 different weather sources," Sloan said. "We're trying to have all the information we possibly can."
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