I just got back from another trip to Napa Valley a couple weeks ago and wanted to chime in on how things are looking. Damp. In Oakville, there were many vineyards that had standing water and even some of the hillside and mountain vineyards of Stags Leap District and Howell Mountain have been getting soaked. We drove past Lake Hennessey about a dozen times, and the water is HIGH.
Some vineyards with good drainage still suffered from washout, the topsoil being cleared away from the fast traveling draining water. But I would suspect that hillside vineyards still did fairly better than those on the valley floor. Waterlogged soil can affect later vintages for the vine health and loss of topsoil through the highly erosive downpour has it's own affects as nutrients and protection for the root ball are washed away. The waterlogging prevents the vines from being able to get much needed nitrogen, and can cause chlorosis (leaves start to wilt and lose their color), the canopy is compromised. This will greatly affect later ripening conditions.
Damaged vines and washed out soil might hurt some valley-floor production for years to come, but there is a silver lining to these rain clouds. The precipitation will help growth and a less-stressful time for winemakers as they can stockpile water storage for the valley, in preparation for the next unforeseen stint of dry years. Even if one dry farms, water is needed for daily operations, frost protection, cleaning and so forth.
So what does this mean for the 2017 vintages and thereafter? Best outcome, we sacrifice the 2017 and maybe the 2018 vintages (keep our fingers crossed) to the grape gods for better vintages in the future. To actually have this much water again in Napa is a long term good thing, as low yields from dry years have been driving grape prices up. With that said, I'd highly suggest you stock up while you can on up to 2016 vintages. We'll most likely have those boring or flawed vintages incoming from mid-level producers. Top-tier producers might sell off inferior juice and keep the best for themselves or their buddies.
I'll be back out there in early May and give an update. Hopefully things clear up a bit and the healing begins.
Zach Cherry, Wine Director & Certified Sommelier
Lukas Wine & Spirits Superstore, Overland Park, KS