Bryan Berenguer, Brian Skahill,* and Manfred Stoll
*Chemeketa Community College, Northwest Wine Studies Center, 215 Doaks Ferry Rd NW, Salem, OR, 97304 (bskahill@my.chemeketa.edu)

This analysis is a follow-up to a recent study that examined the ripening potential of Pinot noir in Oregon’s Willamette Valley (WV) American Viticultural Area (AVA). The study involved computations of the growing season average temperature (GST) viticulture climate classification index on a mean decadal basis from the 1950s to the 2090s using coupled model intercomparison project phase 5 (CMIP5) RCP4.5 and RCP8.5 projections of minimum and maximum daily surface air temperature. It considered the complete archive of the 32 CMIP5 daily localized constructed analogs downscaled historic data sets and their observational data that were used for downscaling and bias corrections to develop a weighted ensemble that optimized calculation of the GST index throughout the WV AVA. Using the GST index value range from 14.0 to 16.0°C for optimum suitability of Pinot noir (Vitis vinifera L.), the study results showed a progressive trend of decreasing area to support Pinot noir in the WV AVA for each RCP-emission scenario, which was more pronounced for the RCP8.5 scenario projections. This study applies the temperature-based GST bioclimatic index calculations that were developed for the WV AVA and the individual optimal GST index value ranges proposed by Greg Jones in 2006 for 20 other Vitis vinifera L. varieties, to evaluate alternative varieties that may be more suitable for ripening in the WV AVA due to climate change.

Funding Support: NA