2020: The Year Climate Change Got Real for American Wine

As I write this, I'm staring out at a dim, yellow landscape, the indistinct sunlight filtered through a thick layer of atmospheric smoke. I have a sweatshirt on because the day has never really warmed up here in town. We had a couple of days this past week, prime ripening season in Paso Robles, where it barely made it out of the sixties. A photo, no filter applied:

We're not really complaining; as apocalyptic as it looks, the air has been cool and fresh at the surface, and we got a chance to catch up on harvesting after what was a scorching hot previous weekend. And plenty is ready. Pretty much all our Syrah. The Vermentino and Marsanne. Our first lots of Grenache Blanc. The smoke has reduced actual temperatures from model forecasts by some 20 degrees, and if we'd had the mid-90s weather that was forecast for this week, it's possible that new blocks would have ripened before we could get through the backlog that the last heat wave produced.

This smoke layer, driven by the fact that six of California ten largest fires ever are currently burning, is only the most recent of a series of unprecedented things we've seen in the 2020 growing season. A week ago, we had a heat wave that crested with back-to-back-to-back days that topped out at 109, 113, and 111. The Paso Robles Airport broke its all-time high with a 117 reading. And San Luis Obispo hit 120°F, which appears to be the highest temperature ever recorded in a coastal zone anywhere in North or South America.

Last month, we saw a trio of fires in the Central Coast produce so much smoke at the surface that we closed our tasting patio for four days because the air quality was so bad. On August 20th, San Luis Obispo had the worst air quality in the world. Those fires were sparked by a surge of tropical moisture, the remnants of Tropical Storm Fausto, that moved up the California coast and produced thousands of lighting strikes on August 14th and 15th. The fires lit by those lightning strikes were fueled by another heat wave that pushed temperatures over 105°F each day between August 15th and 18th.

Paso Robles is hot in the summer. Summer days over 100°F have never been rare here. But the increased number and distribution of these days, the fact that records are falling more often, the earlier and earlier beginnings to harvest (and the shorter durations between veraison and harvest), and finally the new, tropical-influenced rainfall patterns, are new. A few data points that I look at:

• Over our first 15 vintages, 1997-2011, we started our estate harvest in August 40% of the years. Since 2012, we have done so 78% of vintages. Similarly, in those first 15 years, there were six times we harvested into November, and another four that finished October 28th or later. Over the last 8 years, we haven't once harvested in November.
• It's not just harvest. This year's gap between veraison and harvest was just 35 days, breaking our record of 36, set in both 2016 and 2019. Before that, the record was 39, in 2015). 2013 was the first year that we saw 40 or fewer days between veraison and harvest. So, in less than a decade, we've seen this critical ripening period shrink by 15%. Crucial growing periods are getting hotter. 
• Our total growing season degree days, a rough measurement of the number of hours in which it's warm enough for grapevines to photosynthesize efficiently, shows that since 2000, our five warmest years have all come since 2012.

All those data points are indicative, but none of them are likely to on their own pose much of a threat to winemaking here in Paso Robles. But they feed into two phenomena that do: droughts and fires. I'll address droughts first. I wrote a 3-part blog series back in 2014 about our move toward dry farming as a part of being ready for what seems likely to be a drier future. In the research for that, I looked at EPA projections for rainfall showed that, depending on our success in reducing emissions, coastal California would see between 20% and 35% less precipitation annually by the end of the 21st Century:

That research has since been reinforced by studies of warming in the Pacific Ocean, which will have a complex series of consequences, including increased rainfall in places like northern Australia, the Amazon, and Southeast Asia, but less rainfall (and a later onset of the rainy season) in coastal California. This suggests that droughts, particularly the multi-year droughts like the one we saw between 2012 and 2016, will become more common.

Next, fires. It's not like California is a stranger to fires, but severe ones are definitely happening more often. I moved out here in 2002. The first time after that there was any smoke here was July 2008, when I wrote in a blog that two big fires to our north had burned some 73,000 acres in three weeks. (Note that that figure seems almost quaint now, with the horrific Creek Fire east of Fresno burning 160,000 acres in the first four days.) The second fire I noted in the blog was in 2016. Except for 2019, we've seen scary fires in California's wine country each year since then, and 2020 has already seen the most acres burned on record:

Just smashing records of all kind

Right on the heels of overtaking the record 1.9M acres burned in 2018, look at the cumulative #wildfire radiative power in 2020 with at least two months until we see any rain

source: @NOAA #CAfire #CreekFire pic.twitter.com/edBM8WZpTf

— Dave Marvin (@dmarvs) September 8, 2020

The fires are driven by a number of factors, including higher temperatures, lower humidities, poor utility maintenance, human encroachment into wildland areas, and accumulated fuel in the forests after a century of fire suppression. All of these encourage fires to be bigger, faster-growing, and more destructive than before. But what has set the worst ones off in recent years has been climate-related: either through dry winds spurring (and spreading) fires through downed power lines in periods before it has rained in California, or by tropical moisture that has sparked summer lightning.

The fires that impacted Northern California in 2017 and 2018 were produced by late-season (October and November) windstorms that spurred fires from an aging electrical grid. This is largely a governmental and regulatory failure. But while these windstorms aren't new, and don't particularly appear to be a function of climate change, thanks to climate change the time of year when these storms are common is more likely to still be summer-dry. That is why the climate change-driven later onset to the rainy season is a significant contributor to the number and severity of fires.

2020's fires in California have been different. The storms this summer that produced the first series of wildfires were driven by tropical moisture that was pulled into California. A warming climate produces more and larger tropical storms and hurricanes. 2020 has already seen so many tropical storms that I've begun to read articles about how NOAA might run out of names. The direct impacts of tropical storms and hurricanes on California are rare: minor compared to their impacts in the Atlantic or the Gulf of Mexico. But the more of these storms that form, the greater the chance that tropical moisture can end up in unexpected places. These occasionally produce enough moisture to provide some short-term fire risk reduction (such as the July 2015 storm that dropped more than two inches of rain on us) but more often produce extensive lightning with only limited moisture. These sorts of storms introduce extreme fire risk. 

The combination of warmer days, dryer (and later-beginning) winters, and more frequent incursions of summer tropical moisture has combined to produce drastically more days with very high fire risk.

Our new work on #ClimateChange & autumn wildfire risk in California, led by Michael Goss, is out today in (open-access) ERL. We find that climate change has already doubled the frequency of extreme fire weather days since 1980s.(1/6) #CAwx #CAfire #CAwater https://t.co/kei6rJSZQO pic.twitter.com/W8Y7xn0tkn

— Daniel Swain (@Weather_West) March 30, 2020

So, what to do? That's the hard part. Most of the response has to come at the governmental level. Investments need to be made to modernize utilities. Forest management practices could be improved to reduce the amount of fuel that builds up. Cities, counties, and states should adopt growth plans that reduce the human/wildland interface as much as possible, both to reduce the opportunities for fires to start and to minimize the loss of life and property when they do. But ultimately, if climate change itself goes unaddressed, all these initiatives (none of which are easy or likely to come without resistance) are likely to be overwhelmed by the growth in the number of extreme fire days and fast spread of fires that do start.

Here's where regenerative agriculture comes in. One of its tenets is that agriculture has an important and necessary role in the reduction of greenhouse gases (and especially Carbon Dioxide) in the atmosphere. And plants, after all, are the best engines we have in doing so, since photosynthesis uses CO2 as one of its inputs, turning that carbon into carbohydrates. But modern farming produces more emissions than the plants it grows consume. Some of that is the fertilizer, derived mostly from petrochemicals. Some of that is the fuel for the tractors and other machinery. And some of it is the processing of the agricultural products.

Regenerative agriculture leads the way toward building carbon content in the soil, through a combination of permaculture, cover crops, reduction in tillage, and the replacement of chemical inputs with natural ones like compost or manure. Soils with more carbon content also hold more moisture, which will help California wineries weather the droughts too. We showed in the application process for our new Regenerative Organic Certification that it was possible to increase our soil's carbon content while growing grapes even in a dry climate like Paso Robles.

Regenerative farming is not just for wineries. It's what all farms, from row crops to orchards to fibers to livestock, should be moving toward. But vineyards offer some of the lowest-hanging opportunities for better farming, because wine is a value-added product with the resources to invest, and the investments tend also to make higher-quality grapes and longer-lived vines, providing return on the investments.

I can't imagine how California, Oregon, or Washington wineries can live through the 2020 vintage without worrying about how climate change might impact their future. A small silver lining could be encouraging more of that community to move toward regenerative farming. Consumers have a role to play here too. Before this year, there wasn't an available standard for moving to, measuring, and being audited for being regenerative. Now, with the launch of Regenerative Organic Certification, there is. If your favorite wineries are not farming regeneratively, you should be asking them why not. It's one of the tools we as farmers have to take some control over what is likely to be an increasingly volatile and dangerous future that might look like last week a lot more often than any of us would want. 

Harvest 2020 Begins Slowly, After a Record-Short Interval from Veraison

Last week, we brought in our first two lots of Viognier and our first lot of Syrah. It wasn't a furious start to harvest, but it was still a beginning. The cellar smells like honeysuckle and nectarines from the Viognier, there's the energy that always comes from the beginning of the harvest season, and the harvest chalkboard is no longer a literal clean slate:

[Editor's note, congratulations to Senior Assistant Winemaker Chelsea Franchi and her husband Trevor on the arrival of their little girl Bohdi on our second day of harvest!!!]

We typically mark the beginning of harvest as the day the first fruit comes off the estate. So, in 2020 that meant the August 25th arrival of grapes from our oldest Viognier block. In my verasion post last month, I predicted a start time sometime between August 26th and September 5th. These dates are calculated by adding 36 to 48 days from our veraison date (the range we've seen over the last 15 years between first veraison and first harvest). 2020 produced an interval of just 35 days. If you've been following weather reports from California, you can probably guess why. After a moderate summer that had produced just three 100 degree days as of late July, the last month has seen ten days top the century mark and another ten top 90. Nighttime temperatures were warm too. In late July we hadn't had a single day all summer not drop into at least the 50s. Between August 15th and August 24th, we had nine of the ten nights get down only into the 60s.

Happily, the heat wave broke just as harvest was approaching, and since August 22nd we've seen an average high of 90 (with nothing higher than 95) and an average low of 55. The wildfire smoke we saw between August 19th and 22nd has cleared. And the picks we've done so far have been in ideal conditions. I love the photos that Viticulturist Jordan Lonborg took during that night pick, beginning 3am on August 25th. Here are two; you can see the rest on our Instagram feed:

Although we've started harvesting, it's important to remember that most of the vineyard is still some time off. The family of Rhone grapes is diverse enough that we typically figure a two-month stretch for harvest. In fact, there are some grapes that are still only in the middle of veraison (like this Counoise, below) as others are being picked:

Looking through our other red grapes shows the range of ripeness levels. Counoise is farthest out, likely six weeks or more, but others still have a ways to go. This Mourvedre is mostly red, but still likely won't be picked for more than a month:

Grenache is still as much pink as red, with the range of colors and jewel tones characteristic of this, our most beautiful grape. It too is at least a month out.

There are grapes that are getting close, most notably Syrah, already dark and starting to soften, and showing its classic conical cluster shape:

The other grape that is getting fairly close is Cinsaut. We're only on our second harvest, but one of the reasons why it is more planted than Counoise in France (despite that Counoise is more intense, and they serve similar roles in most blends) is that it ripens a month earlier, before or with Grenache instead of after:

Finally, Terret Noir, which looks fairly dark at this point but is still quite acidic, and on which we will wait another month or so:

On the white side, Viognier is obviously first in line. But there are others like Vermentino, Marsanne, and Grenache Blanc (pictured below) that are getting close. Vermentino might come as soon as the end of this week, and the other two should arrive sometime in the first half of September.

The weather is supposed to warm up again as we get to the end of this week, but seems unlikely to reach the heights of two weeks ago. That's fine. We're ready. Meanwhile, we'll enjoy the new sights and smells of the cellar as fermentations get going. This lone upright tank (filled with our first Syrah, picked Friday) will soon have plenty of new company.

Wineries -- and visitors -- should expect months of recurring periodic closures to tasting rooms

Yesterday, our tasting room was open all day for the first time since Thursday, August 13th. We're open again today, and conditions are lovely. Tomorrow looks pretty safe. After that, well, we'll have to see. At least the heat wave that forced us to close most of last week has moved on, but there are still big fires burning to our north, and whether we'll be able to open will depend on where that smoke goes. 

Welcome to 2020. Anyone waiting for things to go back to normal may be waiting quite a while. And I'm just not sure that wine lovers -- or wineries -- have fully realized that this uncertainty is likely to be the norm, rather than the exception, for tasting room operations over the next six months and more. For our part, I'm fully expecting that we'll have to be closed at least one day a week, on average, over the next six months. Why?

First, and most importantly, COVID, which has meant that wineries in California are restricted to outdoor service only. I agree that this is by far the safest way to open. In fact, even when we could have reopened indoors we restricted ourselves to outdoor service only, because the evidence is strong that the risk of COVID transmission is very low in distanced, outdoor settings, and higher in indoor spaces, even with distancing in place. Of course, being outside means you're at the mercy of the weather. But the virus itself is a source of uncertainty; we’ve already had a few instances locally of positive COVID cases at wineries, who have had to close for stretches to make sure their team and their spaces were safe.

It's not bad, most of the time, being outside in California. It's a big reason why people live here. And we got lucky that we had a moderate summer up until the last few weeks. But the climate that allows wine grapes to ripen is sunny and often hot. We do have some control; we installed extra shade, fans, and misters, and have found that with these measures we're able to lower the temperature roughly ten degrees. Plus, we're typically a little cooler than downtown or areas further east. And we do usually get a late afternoon breeze. But still, if it’s over 100, it’s not safe for our team or pleasant for guests. So, we close early and get people on their way before the heat of the day becomes blazing. We've had to do so eight days so far in August, including a six-day stretch between August 14th and 19th. Our average in Paso is a dozen 100+ days each summer. So expect at least a few more heat-related closures before fall.

The heat wave broke late last week. Unfortunately, we’ve got big fires throughout California, producing copious smoke. A few days ago we had the worst air quality in the world. At least with the heat, we could be open in the mornings. We typically took our last appointments at noon each day. That’s a little less than half our capacity, but it’s a lot better than nothing. But with air conditions unsafe, we couldn’t open at all August 20th, 21st, and 22nd. This dramatic satellite image shows the smoke blanketing much of California late last week:

Stunning view from space of the intense wildfires burning across Northern California covering the region in a sea of smoke. #LNULightningComplex #CZULightningComplex #SCULightningComplex #CAwx #CAfire pic.twitter.com/pr8NRRDSJw

— US StormWatch (@GreatWinter2017) August 21, 2020

The primary culprit for our smoke is the River Fire in Monterey County to our north, which has burned some 48,000 acres since it was started by a cluster of lightning strikes a week ago. But there are fires burning all over California right now, with other big ones in Sonoma, Napa, and Santa Cruz. And I think there’s every reason to expect these to be burning for months.

Typically, wildfires in California’s forests burn until they are put out by the onset of the rainy season in early winter. Our state’s remarkable firefighters are mostly tasked with protecting structures and making sure that the fires aren’t endangering communities. Once a big fire gets going, with the accumulated fuel from California’s winter growth and exceptionally low summer humidity, it’s just too much to ask to put a fire out. And that’s true even when there are only a few fires burning. With dozens of big ones spreading resources thin, there’s no chance.

These fires were mostly started by lightning strikes from a rare summer thunderstorm week-before-last. We seem to have dodged the potential for more dry lightning overnight. But we’ve still got months before winter rains will end our fire season. Remember all those terrible California wine country fires in 2017 and 2018? Those were in October and November. It's still August. We've got a very long way to go.

Until then? We’re expecting to make day-by-day calls, informed by the local air quality, as to whether we can open for tasters. Most other California wineries will be the same. So if you’re thinking of going wine tasting, plan to check conditions. We'll be posting updates on our website each morning. If it looks like this, we won't be open. We appreciate your flexibility and patience, and promise you wouldn't want to be tasting here anyway.

The kicker? Once fire and summer heat season are over, it will be because of rain. Gentle rain can be handled with umbrellas and heaters. A Pacific storm, with heavy rain and wind? Wineries will have to close for those too. So get used to thinking about a visit to go wine tasting as like a visit to the beach. Sure, make your plans. But also plan to check local conditions in the morning. Welcome to the new (2020) normal.

Veraison 2020 reflects our cool July and suggests a (gasp) normal start to harvest

The 2020 growing season has been a lovely antidote to all the chaos out in the world. Unlike many years, we've avoided both heat spikes and extended chilly periods. A graph of the daytime highs since May 1st gives a sense of how things have been distributed through July 22nd. You can see more 80s than 90s, plenty of 70s, and only three days (barely) in triple digits, one each month:

July has been particularly nice; our average high temperature so far this month has been 87.6°F. Compare that to the last three years, whose Julys averaged 91°F, 96.5°F, and 95.6°F. And remember, those are the high temperatures each day. Nights have been chilly, and it takes a while each morning for it to warm up. We haven't yet had a night this summer that didn't drop below 60°F, and our average nighttime low has been 47°F. That's kept the vineyard looking green and vibrant. The net result has been gradual progress by the vines and outstanding vine health.

Veraison, if you're unfamiliar with the term, is a physiological stage of grape evolution where the berry stops accumulating mass and starts accumulating sugar. More visibly, red grapes start their color change from green, while white grapes take on more of a yellow tint. Both red and white grapes start to soften. [For more about what's happening chemically, check out this veraison post from the archives.] This landmark comes roughly six weeks before the onset of harvest, and gives us our best estimate for when harvest will begin.

We didn't see any evidence of color in the vineyard until late last week, and it wasn't until this week that there was enough color change to be worth photographing. Now that it's started, I thought it would be fun to give you a visual tour. I'll start with Syrah, usually the first Rhone red to enter version and the fastest to change colors:

It's important to note that this cluster is somewhat more advanced than the average one. Even at the top of the hills, many of the Syrah clusters are green. At the bottom of the hills, there's very little color change to be found. And as for the other grapes, Mourvedre is the one where we're seeing significant color change. If you know that Mourvedre is almost always one of our last grapes to harvest, you might be surprised. But it isn't always last to enter veraison; it just takes a long time to go from first veraison to first harvest:

It took some significant searching by both Neil and me to find any color in Grenache. The best we could do is this one cluster, with a few red berries in a sea of green:

As for Counoise, it's still completely green. The cluster below is just one example; I could have pointed the camera just about anywhere and shown you more or less the same thing:

Although the veraison posts you're likely seeing from your favorite wineries may make it seem like veraison is a moment, like Christmas, it's probably better understood as a continuum, like winter, and first veraison is like first frost, or first snowfall. It will likely be a few weeks before even all the Syrah clusters are red, and probably six weeks until the last clusters of later grapes like Mourvedre and Counoise have finished coloring up. 

While six weeks is a good basic guide for the duration between veraison and harvest, it's not totally constant, and can be influenced by the weather that we get in the interim, as well as by the amount of fruit the vines are carrying and the inherent tendencies of the different varieties. For example, we noted first veraison on July 30th in both 2010 and 2019. In 2019, perfect ripening conditions (consistently very-warm-but-not-hot weather) in August and September gave us a short runup before our estate harvest began September 4th. In 2010 vintage, a very cool August delayed the start of harvest compared to 2019 by nearly two full weeks, to September 16th. The last decade is compiled in the chart below, with each year linked to my blog post about that year's veraison:

Year	First Veraison Noted	Estate Harvest Begins	# of Days
2010	July 30	September 16	48
2011	August 5	September 20	46
2012	July 25	September 5	42
2013	July 17	August 26	40
2014	July 9	August 23	45
2015	July 18	August 26	39
2016	July 13	August 18	36
2017	July 20	August 30	41
2018	July 29	September 10	43
2019	July 30	September 4	36
2020	July 21	?	?

Using the range of durations between first veraison and first harvest (36 to 48 days) we can have good confidence that we'll begin picking sometime between August 26th and September 7th. The weather between now and then will determine where in the range we'll fall. 

What's next for the vineyard? We'll watch the different grapes go through veraison. What starts like a trickle quickly becomes a flood, and the view in the vineyard changes daily. Grenache is sure to start to color up soon, and Counoise a bit later. White grapes too stretch out across a continuum; in fact, Viognier has already started veraison, although the visible changes are subtle enough that a photograph doesn't really show anything. Vermentino and Marsanne will move into veraison on the earlier side, Grenache Blanc and Picpoul in the middle, and Roussanne bringing up the rear, as usual. It's an exciting time. We'll be posting regular photos of veraison's progress on our Facebook, Twitter, and Instagram pages. In the cellar, we're bottling the last of our 2018 reds, refilling those barrels and foudres with our newly-blended 2019s, and starting the process of pulling out and cleaning all the tanks and equipment we'll be using once harvest begins.

So, while veraison doesn't mean we know exactly when we'll start to see fruit, it is the most useful signpost we have. And we know that the clock is ticking.

A last look back at the winter of 2019-20

This week, it finally feels like we've made the pivot from spring to summer. After several weeks of cool, wet weather, which delayed the spread of budbreak and encouraged an explosion of cover crop growth, this week it's sunny and warm. It's hit 82, 87, and 90 the last three days, quadrupling our total number of 80+ days in 2020. We're supposed to see another week or more of temperatures in the mid-to-upper 80s, and there's no rain on the horizon.

With that backdrop, I thought it would be a good time to look back on our most recent winter and see how it compares to other recent years. First, a look at rainfall by month:

You can see our late beginning to the rainy season (that November rainfall didn't start until the 26th), the wet December, a record-dry January and February, and the relatively wet last two months. Overall, with only limited prospects for additional precipitation, we're at 16.97" of rain for the winter, 71% of our 24-year average. That's lower than we'd like to see, of course, but with a wet winter last year, it's OK, and better than 10 of those 24 years:

In terms of temperature, we saw 30 below-freezing nights, with our first at the end of October and our last just two weeks ago, on April 7th. Over the last decade, we've averaged 34.5 below-freezing nights, so overall, this year was pretty normal. (If you're curious, our frostiest recent winter was 2011-12, with 57 below-freezing nights, and our least frosty was 2014-15, with just 13.) Our frostiest month was January, which, as you can see below, isn't always the case. Many years, it's too wet in January for it to drop below freezing. Compared to the rest of the last decade:

My sense that March and April were cooler than normal is reflected in the graph above, as well as in the fact that our average high temperatures in March (59.8°F) and April (65.5°F) were colder than the average highs in January (60°F) and February (68.3°F). I don't remember ever seeing that before!

The net result is a vineyard that's in excellent shape to attack the growing season with vigor. The cover crops are lush and deep, and Nathan is starting to cut and bale the sections that the flock couldn't get into in the last six or so weeks. You can see the height of the cover crops dramatically in the vineyard blocks where we've mowed every-other row, to give better air drainage and protect the new growth from frost:

So far, we've seen zero frost damage even from our couple of early-April below-freezing nights, as they affected only the lowest-lying areas, none of which had yet sprouted. The below Grenache block is in one of those lower areas, and it is healthy, vigorous, and doing its best to make up for lost time:  

This is one of my favorite times of year in the vineyard. Everything is still green, new growth is exploding out of the gnarled vine trunks, and the vineyard's patterns are starting to come into focus as we begin the long process of turning the cover crops under so they can decompose and provide nutrients to the vines' roots. It's going to be an even longer process than usual this year. The section in the valley in the below photo is Tannat that we turned under in late February, hoping to get a jump on the weeding process. It's already regrown. 

For scale, here's me in the Pinot Noir vineyard at my mom's house that is the source of the Tablas Creek Full Circle Pinot Noir. Not pictured: Sadie, who like the vines isn't tall enough to be visible in the high grass:

Overall, it's hard not to be optimistic. Wildflowers are everywhere, and the vineyard looks healthy and beautiful as we begin turning the cover crops under. If it's a little shaggier than normal for late April, well, it's not alone. We're all a bit overdue for a haircut.

Budbreak 2020: The World May Be Crazy, but the Vineyard is Right on Time

This winter has very much been one of phases. November was chilly but almost entirely dry, which got us into dormancy early but put us a bit behind in cover crop growth. December was very wet, with 6.66 inches of rain and 13 days with measurable precipitation. January and February stayed chilly (18 below-freezing nights) but saw very little precipitation. The sun and the saturated soil from our wet December produced a vineyard that grew greener by the day, but since wet soils hold temperature better than dry ones, raised the specter of very early bud break if we didn't get more rain soon. But then March turned wet and remained cold, dropping soil temperatures and keeping the vineyard in stasis for longer than I thought possible. The rainfall-by-month graph for the winter so far shows the whipsaw nature of what we've seen:

The vineyard's long period of dormancy is ending. The proliferation of California poppies are an indicator that the lengthening days and the warm sun will begin to wake up the vines:

Budbreak, as you probably guessed from the name, is the period when the grapevine buds swell and burst into leaf.  It is the first marker in the growing cycle, a point when we can compare the current season to past years.  Upcoming markers will include flowering, veraison, first harvest, and last harvest.  And like harvest, budbreak doesn't happen for every grape simultaneously. Early grapes like Viognier, Grenache Blanc, Grenache, and Vermentino tend to go first, followed by Syrah, Marsanne, Tannat, and Picpoul, and finally, often three weeks or more after the earliest grapes sprouted, Roussanne, Counoise, and Mourvedre. And it really is just starting. We only have budbreak in Viognier, the two Grenaches, and (bizarrely) the very top of one Mourvedre block. The below photo is Grenache:

This year is later than many years last decade, and a month later than our record-early 2016, but it's only about average for what we'd have expected historically. When we saw first budbreak the last dozen years gives a good overview:

2019: Late March
2018: Late March
2017: Mid-March
2016: Very end of February
2015: Second week of March
2014: Mid-March
2013: First week of April
2012: Mid-April
2011: First week of April
2010: Last week of March
2009: Second week of April
2008: Last week of March

It's important to note that the vast majority of the vineyard is still dormant. I was only able to find leaves in our earliest-sprouting grapes and only at the tops of the hills, which are warmer than the valleys, where cold air settles. And even where it's begun, with the exception of the earliest Grenache blocks, all there is to see is swollen buds like the one below, from the Haas Vineyard Pinot Noir:

It will be at least another few weeks before we see sprouting in late-emerging grapes like Counoise or Roussanne, or in low-lying areas. This Mourvedre block is one of many that show no signs of sprouting yet:

Why does budbreak happen when it does? It's mostly a question of soil temperatures. Grapevines (and all deciduous plants) are spurred by rising soil temperatures to come out of dormancy and begin their growing season. Evolutionarily, plants are trying to balance competing goals: to sprout early enough to achieve maximum carbohydrate generation from photosynthesis (i.e. ripen their fruit so animals eat it and distribute the seeds) while staying dormant long enough to avoid suffering damage to their reproductive prospects through frost.

Frost is on our minds. Before budbreak, the vines are safely dormant, and a freeze doesn't harm them. But once they sprout, the new growth is susceptible to frost damage. April frosts cost us roughly 40% of our production in both 2009 and 2011, and we don't feel truly safe until mid-May. So, we've still got more than a month to go before we can relax, and I'm thankful that it will be a few weeks before our later-sprouting varieties and our lower-lying (read: more frost-prone) areas are out enough to be at risk. 

You might think that earlier budbreaks increase your risks of frost. And yes, all other things being equal, having fewer nights where you have to worry about temperatures dropping below freezing is better than having more. But if you look at the two most recent frost years (2009 and 2011) both of those saw budbreak in April. Is it possible that the same conditions that keep a vineyard dormant longer in the spring raise the risks of frost damage once they finally do sprout? I think so. California weather patterns tend to be long-wave patterns, where conditions are more likely to be similar to what they are now in two weeks than to have changed entirely. That's unlike, say, Vermont, where I grew up, where it always seemed to me that each week's weather could just as easily have been generated by a random weather generator.

That said, looking at the long-term forecast offers some hope. We're supposed to get one more chilly late-winter storm next weekend, but it doesn't seem likely to be cold enough to damage the tops of our hills, and it doesn't seem like we will have progressed far enough for anything else to have sprouted. After that, we're expecting drier weather as the storm track shifts north. But there's a long way to go.

Meanwhile, we'll enjoy the rapid changes in the vineyard, and the hope that always comes with the emergence of new buds. Please join me in welcoming the 2020 vintage.

A Walk through the Vineyard, Poised between Winter and Spring

Even as we have implemented major changes to the business side of what we do, the vineyard continues its march through the seasons. The grapevines don't know that there's a shelter at home order. The cover crops aren't interested in quarantine details. Instead, they're paying attention to signals like soil temperature and hours of sun as their systems make the annual determination as to whether it's time to come out of dormancy yet.

We've finished the winter pruning work we needed to do, and we have six weeks or so before we're far enough into the growing season to need a large crew working on anything (the next big push will be shoot thinning). So, if we had to pick a time when it doesn't hurt us much to cut back on vineyard work and wait this out, this is a pretty good one.

I took a walk through the vineyard on Thursday to get a sense of where things were. After our nearly-entirely-dry January and February (just one storm, 1.11 inches total rainfall) it's clear that the rain we've received so far in March (4.16" across 13 different days) has made a significant difference. The ground is saturated. The cover crops have doubled in size. And the generally cool daytime temperatures (just 5 days this month that made it out of the low-60s, and only one in the last two weeks) and chilly nights (four have dropped below freezing) have delayed budbreak to a more-or-less normal time frame. Although it can't be long now, in my walk I didn't see anything that had pushed buds, even at the very tops of the hills and the very earliest varieties like Vermentino, Viognier, and Grenache Blanc.

What did I see? The wildflower season just beginning, with wild mustard the most precocious:

I took one shot (through our deer fence) of the sign pointing to our tasting room if you were to approach the vineyard on Adelaida Road from the north. If you are used to seeing Paso Robles in summertime when everything is golden and in sharp relief, the softer springtime contours can be surprising.

The dormant gray vines (Vermentino here) make for a great contrast this time of year with the green cover crop and the early wildflowers:

The day, like most of last week, saw a shower pass through. You can see the clouds hanging over the vineyard in this shot, looking down over our oldest Counoise block:

And finally, a shot looking up from more or less the middle of the vineyard over one of our Grenache blocks, a study in green, blue, and white:

If you'd like something more immersive than the still photos, I took a 20-second video in the middle of the vineyard too. I highly recommend turning on your volume.

Seems like most of us could use 20 seconds of spring vineyard breezes and birdsong right about now. Repeat as necessary. pic.twitter.com/EloZY8exiP

— Tablas Creek (@TablasCreek) March 20, 2020

Although we're not able to welcome you here in person right now, I'll look forward to sharing what the vineyard looks like more regularly over coming weeks. That way, you can follow along. And if there are things you particularly want to see or know more about, please leave a comment. Meanwhile, stay safe out there.

The Vineyard After a Wet December and a Sunny January is Impossibly Green

Last week, I commented on Twitter that we were entering the season where Paso Robles is absurdly beautiful everywhere you look. Don't believe me? Check it out for yourself.

December's rain and a mostly sunny January have combined to produce an explosion of cover crop growth, and everything is the intense yellow-green that winter in California produces, so different from the summer gold. There are clouds in the sky to provide contrast to the brilliant blues, the angle of the sun is lower, and you feel like you can hear the grasses growing, making the most of their brief time when moisture is readily available. This morning seemed like a good time to get out on a ramble through the vineyard to document how things look.

Our flock of sheep, if you visit this week, is hard to miss. They've been moving up the hillside behind the winery (which we call "Mount Mourvedre" because that's what's planted there), spending just a day or two in each long rectangular block before being moved up the hill to new (yes, greener) pastures. From just inside our front gate:

You may notice, looking past the solar panels, that there's a horizontal line a few rows below where the sheep are now. That's the boundary line between where the sheep were until this morning and the new section they just got into. We keep them in any one block no more than 48 hours, so they graze evenly but don't overgraze, and the grasses have a chance to regrow and build more organic matter this winter. Looking down the electric fence line makes it even clearer. The downhill section has been grazed already, while the flock is just getting started on the new uphill section they're in now:

The cover crop, in areas the sheep haven't gotten to yet, is a little behind where it often is at this time of year because of how late the rain first arrived. But it's making up for lost time quickly, and is about four inches think already. You can see it clearly in this shot, looking uphill through our oldest Grenache block toward some endposts that mark the beginning of a north-facing Marsanne section. When I walked up the hill, there was a turkey vulture on each post, every one basking in the morning sunshine:

Another view, focused on the vultures more than the green:

Turning around and looking down the hill, through the Grenache block and over the Counoise, Mourvedre, Tannat, Roussanne, and Grenache Blanc sections, gives you a sense of the patchwork of vineyard contours, as well as how green everything is. The more gray-green foliage of the olives stands out clearly.

While we needed this sunny January to get the cover crop growing and accumulating biomass, it has put us a bit behind where we'd hope we'd be in terms of rainfall. With the month almost over and no real signs of wet weather for the next couple of weeks, we're only at about 72% of normal rainfall to date. There's still plenty of winter to go, and plenty of moisture in the ground, but we're hoping for a wet February and March. For the winter so far:

Still, none of us are too worried. We've gotten enough rain to this point to have plenty of fodder for our sheep. There's lots more winter to come. And the sunsets? Those are a very nice reward.

I've said it before, but I'll say it again. If you haven't visited Paso Robles in the winter, you're missing out. We'll see you soon.

Six inches of rain in two weeks begins the vineyard's winter transformation

California, when it rains, is a paradise. The landscape transforms from stark browns and golds to something softer, with blurred edges. Green appears, seemingly overnight, as grasses and broadleaf seeds that have been waiting for moisture sprout and push leaves above the surface. Puffy white clouds appear in the sky, which has unbroken blue for months at a time in the summer. The images aren't the same as those that summertime visitors love, but for me, they're even better. I'll share a few of my favorites from a vineyard ramble this morning:

You can see that higher up in the vineyard, where this Counoise block is, we still have leaves on some of the vines. Although we've had several nights where our lower-lying areas have seen frost, we haven't had the hard freeze that will force the vineyard into dormancy top to bottom yet. This lower section is more representative. I particularly like the green that has already appeared:

The total lack of moisture in the summer has its own appeal, but the fog does give a better sense of distance, settling in the undulations of the hills:

The rain did us the favor of cleaning off our solar panels. Their modern regularity makes for a nice contrast with the sky and landscape:

The rain itself came in nearly ideal distribution. Up through November 25th we'd seen zero precipitation this winter. In the 13 days since, we've had measurable rainfall 12 of the 13. But it was generally modest. We only topped one inch once (1.47", on December 4th). Five other days saw between one-half and one inch. And very wet days tended to be followed by days with less rainfall, allowing everything to soak in:

So far, for the winter, we've totaled 5.88", which puts us at about 125% of normal at this point in the rainy season. Given where we were a month ago, that's pretty encouraging. It's also some validation to the research I did after that blog, which suggested that a dry beginning to the winter was only slightly correlated with a dry winter. 

What's next for us? A week, more or less, of sunny, dry weather. That's perfect, as it will give the new green cover crop a chance to get some growth in before the next rains come. After that, it's anyone's guess. Long-term predictions are still for a slightly drier than normal winter, but I feel a lot better about things given what we've banked already. As the mud on my boots suggests, there's plenty of moisture to work with, for now.

I'll leave you with my favorite photo of the morning, sun partially obscured by the fog, solar panels in the foreground, olive trees and vineyard truck in the middle ground, and vineyard sloping away down toward Las Tablas Creek in the background. The fog has since burned off, but I look forward to more moisture over the coming days.

Does a dry fall mean a dry winter season? Less than you might think.

Last week, I wrote about the dry, cool beginning to winter that we're seeing this year in Paso Robles. In my research for the piece, I made a surprising and reassuring discovery. It turned out that having a totally dry October, as we did this year, didn't have any predictive effect on our future rainfall for those winters. There were five such Octobers in the 23 years since we installed our weather station in 1996, and for the rest of the rain season (November-May) we averaged the same 22.2" of rain that we did in the 18 not-totally-dry Octobers. Yes, we missed out on the rain we didn't get that month (an average of 1.5") but it didn't appear that the conditions that produced these dry months lingered in any meaningful way later into the winter.

That got me wondering: was that true for future months? Did low rainfall in October and November mean we were likely to see a drier December-May? Did low rainfall October-December mean drier January-May? Or were the weather patterns truly independent, as my first-pass analysis last week suggested? It turned out that a dry month or months does have some predictive effect, but it's less than you might think. I'll present my findings below, but first a note on my methodology.

I decided first that using "totally dry" as my measuring point wouldn't be reasonable. We do of course have winter months without any rainfall, but after October they're rare. So, I decided that for a period to qualify as "dry", we'd need to have seen less than half of our annual average winter rainfall to date. So, for the period through October, "dry" meant less than 0.85" of total rainfall since July. For the period through November, "dry" meant less than 1.8" of rainfall since July. And for the period through December, "dry" meant less than 4.1" of rainfall since July. This does mean that the results are correlated, since this is a cumulative total, but it seemed better than counting a winter like 2009-10 as "dry" through November because we received less than 1/10" of rain in November, while ignoring that we received a nearly 10" storm in October.

So, what predictive effect does a dry early season have? About 15%, in my calculations. Here's a quick recap of the averages. At the bottom I've added in some graphs that highlight how the dry early seasons have played out.

Period	Avg Rain, Rest of Winter	Avg Rain (Dry Years)	Avg Rain (Wet Years)	# of Dry Years
Through October	22.49	20.84	24.28	12
Through November	20.49	16.92	22.05	7
Through December	16.04	14.31	16.52	5

As you might expect, the data is noisiest when you're looking at early-season results, both because there are more dry years (12) and you'd expect to have received a lower percentage of your total precipitation. In the below graph, I've marked years that met my definition of dry through October with orange columns. Wetter years are blue:

While the averages are still somewhat predictive, there are some very wet winters that followed dry early seasons, including last year. Looking at years that are dry through the end of November shows a more obvious correlation:

In the seven years where we had less than 50% of our average rainfall at the end of November, we only saw one year where we recovered to even hit our long-term average (2005-06). Some of that is the lower average future rainfall (23% less) but a lot of it is that we'd already gotten through enough of the rainy season that the difference between what we've banked in a dry year (1.2") and our average from our wet years (4.7") starts to become more significant. Looking at the data through the end of December doesn't change the picture that much:

It's probably unsurprising that when it's been dry through December, we're likely to be looking at a dry winter. But even more than in the previous chart, the biggest difference isn't in the future rainfall we'd expect (we received an average of 13% less rain January-June in those years that were drier through December) but in how much rain we've banked, or not. We'd normally expect to have received 8.17" of rain through the end of December, a little more than a third of our annual total. In the five notably dry years, we'd only accumulated an average of 2.7" to date, while in the other eighteen years we'd averaged nearly four times that already: 9.6".

What does this mean for us this winter? In practical terms, not much. Like always, we're at the mercy of the weather patterns, and what we've seen so far this fall has been consistently dry, with a persistent area of high pressure diverting storms well north of us. But for the first time, forecasts are starting to sound more hopeful, and it looks like there's a chance that this pattern will break down by the end of the month: 

Multi-model agreement that extremely dry pattern will continue across CA for next 7-10+ days (outside of poss. sprinkles in north). Ensembles suggesting about ~ 1 in 3 chance that Westerlies could break through ridge last week in Nov, bringing more widespread rain.#CAwx #CAfire pic.twitter.com/8dVNmVmYvN

— Daniel Swain (@Weather_West) November 11, 2019

For all that, I feel like the results of my digging into the weather details have done some good for my state of mind. Each week without rain at this time of year feels long. And as nice as it is to be able to go out and enjoy the beautiful sunny afternoons, I enjoy them less because of this nagging feeling that it's wrong, and we really need the rain. Knowing that the predictive effects of past early season dry spells have been modest, and that we have 90% of our rainy season in front of us (and fully two-thirds after January 1st) is a good reminder to be patient. Storms will be coming. Fingers crossed that they'll come soon.