The following marine heatwave images were computed following the method in Hobday et al. (2016), slightly altered for the CCS, using both the WCOFS model output and forecast and the historical run of the West Coast ROMS. WCOFS is run by NOAA CO-OPS operationally. West Coast ROMS is run as a research model by the University of California Santa Cruz. The heatwave output is computed from the model surface temperature. Model output is used instead of satellite data because satellite data may have multiple gaps due to cloud cover. In addition, models can provide forecast information. The bottom part of the graph is the average heatwave index over the domain presented in the image. The heatwave index ranges from 0 (no heatwave) to 4 (extreme).