Way off the coast of Ecuador, past the Galapagos Islands, spreading along the equator into the South Pacific is a stretch of deep sea that can make or break wine vintages around the world.
When that body of water rises in temperature a measly 1˚ F above average for 7 months straight, an "El Niño" is declared by the National Oceanic and Atmospheric Administration (NOAA), and we in Lodi experience more rainfall than normal.
Conversely, when the water temperature drops 1˚ F, "La Niña" becomes the dominant influence, bringing us dry conditions.
The last major El Niño ran from April 1997 to June 1998 and scored a big +2.5 in NOAA's book. (Even weather geeks - myself included - love scores, though these scores are completely objective, unlike wine!)
The 1998 El Niño was immediately followed by a pretty significant La Niña, scoring -1.6, that didn't end until July 2000, creating a whipsaw of soggy soils and cooling that dramatically slowed down vines. It seems this rapid succession of a strong El Niño and a strong La Niña is a recipe for potentially disappointing wines.
Indeed, grapes struggled to ripen throughout the state in 1998, particularly affecting the late-ripening Cabernet Sauvignon. James Laube of Wine Spectator called those Cabernets, "the most difficult group of young wines I've tasted in more than a decade."
With Zinfandel, the 1998 vintage was neither stellar nor a complete wash-out. Wine Spectator rated both Napa and Sonoma 83 out of 100 points, their lowest scores over 15 years of vintages, only slightly better than 81 points for Napa and 83 for Sonoma in 2000.
Respected wine critic Robert Parker, on the other hand, gave California North Coast Zins a decent 86 points for 1998.
Our latest El Niño ended in May after tweaking our weather for 12 months, nearly ruining anything left on the vine after the disastrous harvest rains of October 13.
And so far in 2010, we haven't had our normal helping of warmth. By mid-June at the main weather station in Stockton, we accumulated 759 "degree days" of heat necessary for grape vines to grow. That's dead-on what we had at the same time during another El Niño year, 2003, which is 82% of normal heat from the 10-year average of 921 degree days.
Further, the two El Niño's were somewhat similar, with the 2010 El Niño officially scoring +1.8 compared to 2003's +1.5. 2003, with its long, cool growing season could therefore be a very good predictor for what will happen this year.
What does all of this mean for Lodi's growing batch of 2010 wines?
The 2003 vintage Zins all together scored a decent 86 points from Wine Spectator, while Robert Parker felt the Northern California Zins were on the whole outstanding, giving them his best Zin score to date of 93 points. So if 2003 is any indicator, there is great potential for 2010.
This season affords Lodi an opportunity to really step up to the plate and make home-run-hitting wines, because cool weather tends to give winemakers a bigger window of optimally ripe harvest dates, preserving acidity and tannins to balance Lodi's bountiful fruit flavors.
The cool weather also means that Lodi winegrape growers are going to seriously need to consider cutting off green grapes and yanking leaves multiple times during the season to ensure that the few remaining grapes can achieve that perfect ripeness.
If our passionate growers are willing to continue to sacrifice some profits in tonnage, 2010 could very well be a vintage that firmly elevates Lodi into world class territory.