Those of you who have been following California's recurring struggles with fire won't be surprised to hear that it's been dry. Record low relative humidity has been a major contributing factor to the wildfires that have raged in both northern and southern California. Here in Paso Robles, we haven't seen the same high winds that fueled this year's terrible fire season, and one somewhat comforting fact is that those sorts of wind events are quite rare here, as the Santa Ana winds that affect southern California don't often make it this far north, while the Diablo winds that affect northern California don't typically make it this far south. Still, it's been really dry, with no rain yet, relative humidity dropping into the mid-single digits the last few days, and the lowest dew point I can ever remember seeing (-3°F) on Halloween. There have been several mornings over the last couple of weeks where I've gone out to my car in the morning, had it be below freezing, and yet have no frost on the windshield because it's just been too dry.
What may not be so obvious from the news coverage is that it's been quite cold so far as we've transitioned from fall to winter. We've already had several frost nights in our lower-lying spots, and the vines are mostly in dormancy. Check out the difference in the look of one of our old Roussanne blocks from a month ago:
And we haven't even been the coldest spot in Paso Robles. If you look at the Paso Robles Wine Country Alliance's weather summary for October 31st (the day with the amazingly low dew point) you can see that there were several local weather stations that measured lows around 20°F and one that even dropped into the teens. And yes, even on this day with some very cold mornings, we had warm afternoons. The diurnal temperature swings, always big here in Paso Robles, reach extreme (50+°F) levels during this season:
Even with the cold nights, the hilltops are still showing nice fall colors, and are likely to until we see a hard freeze. This photo, of one of our Syrah blocks, is just up the hill from the Roussanne block I photographed above:
How unusual is all this, and what does it mean for our prospects for a wet winter? Not particularly, and not much. We see our first rainfall of the winter by the end of October about three-quarters of the time. The rest of the years, which have included 1996, 1999, 2003, 2005, and 2017, it's been dry into November. A lack of early rainfall has not particularly impacted what the rest of the winter has looked like; those five years have averaged 22.5 inches of winter rainfall, only about an inch and a half different from the 24.2 inch 20-year average. As the 1.5 inch difference is exactly what we've averaged in our last twenty Octobers, there's essentially no correlation between a dry October and a dry winter. That's a reassuring thought.
While we'd like it wet, the cold is a good thing, as it forces the vines into dormancy and keeps them from expending extra energy at a time of year when there's no fruit to ripen. And we'll take what we can get, while we wait for the long-term forecast to show some hope for rain. We'd like to get our cover crop growing, so our sheep have something to eat. And rain would put to bed any lingering worries about this year's wildfire season. There no rain forecast for the next two weeks: more dry weather, with sunny, warm days in the upper 70s and low 80s, with chilly nights dropping to around freezing. But while our vines would like to usher in the rainy season, that sounds like pretty ideal weather for people. If you're coming to Paso Robles between now and Thanksgiving, it sounds like you can expect conditions to be pretty great.
Meanwhile, we'll look forward to the greens, yellows, and oranges of the harvest season transitioning to the softer browns of fall, like the Mourvedre block below. It may not have autumn's drama, but it's beautiful in its own right.