“How wet is it up there?” I asked.

“Wet enough that I’m on Facebook at 11 AM on a Tuesday in October,” said Duane Hoff, proprietor of Fantesca Estate on the slopes of Spring Mountain in Napa.

I reached out to Duane when I saw him online earlier this week just to see how he and his fellow Napa winemakers are handling the recent deluge and follow up drizzle that is making for what by many accounts is a “challenging” harvest up and down the West Coast of the U.S.

Whenever it rains during harvest, journalists begin buzzing with rumors and allegations, speculation and prognostication. I’ve seen at least two arguments on twitter about whether or not this harvest is going to be a disaster.

Like with most things, the truth is complicated.

Providing a blanket statement on how harvest is going in California is as futile as trying to generalize about politicians. There’s bad, there’s good, there’s mixes of bad and good, and everything in between.

How harvest ends up, and the quality of the vintage depends on an incredible number of factors: the micro climates of individual vineyards; the variety of grapes grown in those vineyards; how the vines are trained; the farming practices; hell, even the rootstock can affect how well the grapes are weathering this… weather.

Certainly in many parts of California, Oregon, and Washington, the 2011 vintage can be fairly well characterized as cool (with an especially cool spring that saw rain for many folks right around the time the grapes were flowering. Overall, summer had fewer heat spikes than normal, and now as we’re in mid-harvest, there’s this big storm (followed by a smaller one) that has swept across the west coast, bringing earlier-than-usual rains in larger-than-normal amounts.

Despite this, however, the overall rainfall for the year is lower than in 2010 by a significant amount (at least here in California).

But whenever a significant amount of moisture, along with unseasonably cooler weather corresponds with harvest time, there are definitely some consequences.

Perhaps some of the most significant impacts are being felt in the coolest areas, where in some cases, vineyards will likely not even get ripe enough. Duncan Meyers, the winemaker at Arnot-Roberts (whose Clary Ranch Syrah I reviewed last week) told me via e-mail that it’s not clear to him whether that vineyard will make it this year. “We’re sitting at around 17 brix,” he said, “last year we were harvesting on November 23rd at 20 brix.”

That is the fear of many in Oregon’s Willamette Valley, which has seen one of the coldest years in several decades. While the true verdict is still out, some have used words like “disaster” to characterize the possibility that many vineyards may not ripen.

Back in California, I spoke with Andy Peay of Peay Vineyards earlier this evening, whose vineyards sit on sea-facing ridges at the far western expanse of the Sonoma Coast appellation. It was clear that the Peays were scrambling to get the majority of their fruit in over the next couple days now that it has warmed up a little, but that they won’t escape unscathed. “No estate Roussanne this year,” he said wistfully, “the skins just burst, so it ain’t going to happen.”

Peay’s real concern, however, is his Pinot Noir crop, whose skins he and his brother and their winemaker Vanessa are watching carefully, hoping that they don’t degrade, and hoping that some dry warm weather will stave off the prime enemies of anyone growing Pinot Noir this year: mildew and rot.

Pinot Noir offers a particular challenge to growers in a year with a wet cold harvest. The thin skinned, tightly packed bunches of berries tend to trap water, which is a fertile breeding ground for mildew, which essentially attacks the grape clusters from the inside out. Chardonnay likewise tends to suffer from Botrytis rot, for many of the same reasons.

Winemaker Jamie Kutch, whose continual quest to produce lower alcohol, higher acidity Pinot Noirs meant that most of his fruit was harvested before the rains was doubly glad this year. “I was just out in Anderson Valley today,” he told me on Monday, “and I’m starting to see Botrytis. And man, you don’t want that stuff on your grapes. One day its in one cluster, the next day it’s in 100 clusters, and the day after that it’s in 10,000. It multiplies massively, exponentially.”

Other grape varieties like Syrah and Cabernet tend to have much looser clusters of grapes and fare better in this weather.

Paul Roberts of Bond Estate in Napa, like many of the folks in Napa I spoke to was fairly unconcerned with the weather.

“It’s definitely been a cooler year,” he said to me earlier this evening when I cornered him at a wine tasting event, “and that cold rain in June left us with crop levels in some of our vineyards that are forty or even fifty percent lower than normal.”

But Bond has harvested only about 5 percent of its grapes so far, and expects to begin bringing in fruit over the next couple of days as the warmer, drier weather brings sugar levels up to typical picking range in the grapes (23-25 brix, for Bond) and pulls some of the water out of the berries.

Duane Hoff of Fantesca was equally unruffled. “We’ll put a few more people on the sorting table than usual,” he told me as we chatted on Facebook, “to make sure we don’t get any rotten or moldy clusters in there.” He noted that despite similar weather during harvest last year (admittedly without quite the same deluge that they received this past weekend) the wines turned out fantastic.

Indeed, many winemakers I’ve talked to over the last week are delighted with what has been a generally cool summer without any of the heat spikes that made 2010 a roller coaster of a vintage. A slow and steady, cooler summer in California, Oregon, and Washington has meant that the grapes are retaining higher acidity levels, which can often translate into fresher, brighter flavors, not to mention longer-lived wines.

Those growing grapes in warmer climes of California are looking at generally reduced yields, but many are quite optimistic about quality for the same reasons. Jason Haas of Tablas Creek Vineyards on California’s Central Coast reported to the Associated Press that while in some cases his yields are down 80%, the quality will be very high.

In short, it seems like America’s West Coast is having a very European vintage, as we struggle with some of the weather conditions that regularly plague the cooler areas of Burgundy and Bordeaux in France, and the Mosel Valley in Germany. And as for these Europeans? Well, let’s just say they’re having a particularly European vintage themselves, replete with hail and rain and more.

But even as I write this, the forecast for the next few days here in Northern California is for dramatically warming days, and lots of sun. If that ends up being true, those who listen carefully may hear many collective sighs of relief from wine country. We can only hope our brethren elsewhere get their share in time to make a difference in their wine harvests.

Even if it ends up being a “challenging” vintage for many regions, that doesn’t necessarily end up being a bad thing.

In the most perfect of vintages, the wine all but makes itself. In more challenging vintages, that’s when good vineyard managers and winemakers end up making the difference between decent, and excellent wine. And in the most challenging vintages, good talent can mean the difference between excellent wine and a total disaster.

As Hoff put it before he signed off: “Winemaking is like flying. The reason you have a great pilot isn’t to fly the plane. It isn’t even to land it. You and I could do that if we had to. The reason to have a great pilot is so that when things go wrong, a Captain Scully can land your plane on a river and not lose a single life. That is too dramatic, but that is the peace of mind that a great winemaker and farmer give you.”

Good luck out there, all of you!