By Guest Blogger, Rodney Gagnon, Winemaker and Founder of Glasshaus Wines
By all accounts, the quality of the 2013 vintage rivals that of 2012.
VINTAGE WEATHER REPORT
The weather throughout the Petaluma Gap region during the 2013 growing season (Apr-Oct) was slightly warmer and sunnier with higher humidity, compared to the previous 10 year average (2003-2012).
Regional temperatures exceeded 10 year averages with the only “typical” temperatures in April, July and October. Even 2012 and 2009’s warmer than average conditions were surpassed by 2013 temperatures. Solar radiation exceeded historical averages as well as levels seen in 2011 but trailed 2012 and 2009. Only October experienced greater sunlight than 2012 and 2009.
Humidity levels were higher than average through most of the growing season with the exceptions of April, May and October. The increased humidity due to the marine layers during the height of the growing season surpassed those seen in 2012 and 2009. Wind conditions in our otherwise windy region were slightly diminished as compared with previous averages. This, combined with increased humidity levels during the summer, required diligent canopy management.
The following detailed comparisons attempt to place September 2013’s weather conditions in context with historical averages.
The Petaluma Gap experienced mean daily temperatures that effectively echoed historical norms during the month of October. In contrast, however, high temperatures exceeded averages during the month by 4.9˚F while low temperatures trailed averages by -2.5˚F creating diurnal temperature variations that were 7.4˚F greater than average.
During the entire growing season, mean daily temperatures mildly exceeded both historical and 2012 norms by 0.4˚F and 1.0˚F, respectively. While minimum temperatures remained average, the slightly higher maximum temperatures created greater diurnal temperature variations throughout the growing season by 0.9˚F.
Solar radiation levels of 358 Ly/Day were 66.5 Ly/Day or 22.8% higher than average for the month of October. The clouds that carry fall rains and obscure the sun failed to appear in significant quantities in October, allowing more sunlight to reach the vines.
2013 was a considerably sunnier year as compared to the previous 10 year average by 18.6 Ly/Day or 3.6%. Even though we experienced higher than historical averages, 2012 was even sunnier than 2013 by 10.0 Ly/Day or 1.8%.
Wind speeds in October were lower than 2012 and the previous 10 year average by 5.9% and 16.2%, respectively. The diminished airflow throughout the region proved not to be a concern due to the overall sunnier, warmer and drier conditions. Identical to 2012, 2013's growing season's wind conditions lagged historical averages by 4.3%.
October was a considerably dry month with average relative humidity 13.3% lower than 2012 and historical averages. The lower average humidity was primarily due to lower minimum levels as maximum humidity levels were on par with 2012 and the previous 10 year average.
Similar to 2012, 2013's growing season was a modest 1.4% drier than the previous 10 year average. Unlike 2012 however, 2013's overall drier conditions were due to lower minimum levels as maximum levels were actually higher than average.
Although of supreme importance, weather, in and of itself, is only a single variable in a wine growing season. The resulting fruit quality when it arrives at the winery is determined by a myriad conditions such as timing of weather events, site micro-climates, geography/orientation, training/trellising, fruit set, canopy management, etc etc etc.
This report is based on Petaluma Gap regional weather data obtained from the California Irrigation Management Information System (CIMIS) Petaluma East Station (144) and is meant to characterize general growing conditions for the region. It should not, in any way, be construed to represent the growing conditions for any one particular vineyard site.
Find Glasshaus Wines' 2013 Sonoma Coast Chardonnay on www.cellarangels.com and help raise funds for charity with proceeds.