An assessment of winter 2021-22 after our wettest December since 2004

It seemed like a good omen for this winter when we got several inches of rain in late October. Typically, winters where there's significant early rain (like 2004-05, 2009-10, or 2016-17) end up being drought-breakers, the sorts of years where you replenish aquifers and set your vineyard up for at least a couple of vintages. But then we had an almost-entirely-dry November, which combined with the moderate la nina conditions in place this year, suggested below-average rain. So it was with relief that the storm door opened the second week of December and directed a series of weather systems at the California coast. We got measurable rain twelve of the final nineteen days of the month for a total of 11.06 inches. That puts us at something like 175% of normal rainfall to date:

With the storm door closed at the moment, it seemed like a good time to step back and take a look at what this rain means for the winter, and more relevantly this upcoming harvest's prospects. After two dry years, it's wonderful to see how incredibly green the vineyard is, grass growing fast now that the sun is out:

After moving them to shelter during the biggest storm, both for their own safety and so they didn't compress the wet soil too much, the sheep are back in the vineyard enjoying all the new grass:

The early rain, and the cover crop growth it produced, allowed us to make a full rotation through the vineyard already. It's pretty cool walking through vineyard blocks and seeing the sheep manure from just a few weeks ago already nearly obscured by regrown grass:

The water we received, despite its volume, nearly all soaked in and saturated the absorbent limestone clay layers, with only a tiny fraction percolating into our watershed. Las Tablas Creek is flowing, but it's hardly a raging torrent:

Evidence of the abundance of moisture at the surface is provided by new growth of water-loving plants like mushrooms (left) and miner's lettuce (right):

A little break of sun is welcome at this point. It will give the recent rain a chance to penetrate deeply and will super-charge the growth of the cover crop. We're hoping to get the sheep through two more full rotations through the vineyard before we have to move them out for budbreak, and it seems likely we'll be able to given the abundance of food.

Even better, this moisture came without any significant negative impacts. Because of the absorbency of our soils, we don't worry much about erosion in the vineyard. But I was pleased to see the impact of the erosion mitigation measures  we took to keep our roads in good shape. The photo below shows one of these: straw bales that we put in drainage areas to divert the water into the vineyard, where it could soak in, rather than continuing down roadsides:

Overall, I'm feeling like we've gotten the beginning of winter we all were hoping for. We're ahead of schedule for water, already having exceeded the full-winter totals we've seen in recent years like 2013-14, 2014-5, and (most importantly) 2020-21, with more than half the rainy season still to come. We've already booked 13 below-freezing nights, which means that the vineyard is fully and truly dormant. The cover crops look like they're in for an outstanding year. 

What would an ideal second half of winter look like? A few weeks of sun, then a resumption of more rain in the second half of January. Continued periodic storms and frosty nights in February and March. And come early April, a smooth transition to more benign weather with no more frost, so budbreak can proceed uninterrupted. Can we do it? Time will tell. But we're off to a great start.