The weather is broken. The Rossby effect, which should be bringing winter storms down the coast, seems to be stalled. We have had a persistent ridge of high pressure over the North Coast since November, which broke down once early in December. Since then we have had an unremitting string of dry days, cool nights and record daytime highs.
I’m worried, like I have not been in 30 years. I track rainfall accumulation from November 1 to October 31, and since Nov. 1, 2013 we have received just 1.85 inches of precipitation at our vineyard. This is barely 16% of the average to-date since 11/1/1997 (11.24 inches). Just for giggles, here’s the 2014 accumulation to date compared to the next driest winters in my records:
It’s dry, drier than 2012, which USDA described as “…the most severe and extensive drought in 25 years.” This bodes ill for urban water restrictions and availability of irrigation water for the most populous and agriculturally productive State in the country.
It has me worried for our vineyard as well. The UC Davis Cooperative Extension — Fresno County December 2013 newsletter discusses a possible consequence of a very dry winter: Delayed Spring Growth (DSG). Symptoms include: poor and uneven bud break, stunted growth, smaller flower clusters or complete abortion of clusters, failure and ultimately death of individual buds, and excessive sucker growth at the base or head of the vine. So we will be irrigating soon.
Another concern is that the warm daytime temperatures will wake the vines up early. There is still the possibility of us having a sufficiently wet end of winter-start of spring to make up for the current drought, but if the vines wake up due to warming in the shallow root zone, the weak shoots will be more prone to late frost and to spring Botrytis.
I love farming grapes, and we have had a couple of easy vintages. But I’m planning for a hard time in 2014.