Abstract
The calendar date when cumulative GDD of relevant development thresholds was met were projected from 2031 to 2060 and compared to the 1950 to 2005 historic average. Projections of seed set were made using 14 GCCMs from a broader selection of models from the Coupled Model Intercomparison Project phase 5 (CMIP5). The 14 chosen models (Table 2) had previously been found to adequately capture characteristics of historical climate for the PNW (Abatzoglou and Brown 2012). Projections were made using two radioactive forcing scenarios: the representative concentration pathway (RCP) 4.5 and 8.5, corresponding to radioactive forcing of 4.5 and 8.5 W m-2 respectively. Models were further downscaled to a 4-km grid at daily scales using the Multivariate Adaptive Constructed Analogs (MACA) method (Abatzoglou and Brown 2012). MACA utilizes historic observations from weather data to adjust biases of the GCCMs and match spatial patterns to climate model outputs.