The J-SCOPE forecast system for Washington and Oregon coastal waters presents preliminary results for the 2021 upwelling season. The CFS forecast indicates the current La Nina (ENSO-negative) conditions are likely to persist through the Northern hemisphere winter (95% chance) but may transition to ENSO-neutral conditions during spring of 2021 (~55% chance), but forecasts of ENSO beyond the spring are more uncertain and consistent with the spring predictability barrier. In comparison to the climatological data, coastal waters in the J-SCOPE domain during the summer upwelling season (May - August) are forecast to have near climatological sea surface temperatures (SST) until summer (July-August) when they become warmer mostly offshore, and these warm anomalies do not extend to subsurface habitats. In fact, the subsurface anomalies along 47°N and 44°N are cooler than climatology. Bottom oxygen is forecast to be lower over the Washington and Oregon continental shelves early in the upwelling season with the Oregon shelf trending toward near climatological values later in the upwelling season with high disagreement between ensemble members during the upwelling season. Chlorophyll concentrations vary spatially and temporally but are forecast to be lower than climatological values early in the upwelling season, especially on the Oregon continental shelf, but trending toward near climatological values over the shelves later in the upwelling season, and the region associated with the Juan de Fuca Eddy with higher than average chlorophyll. Bottom Ω is forecast to be undersaturated throughout the upwelling season, with the exception of supersaturated conditions for nearshore regions within the Olympic Coast National Marine Sanctuary and some coastal embayments on the Washington shelf. Surface Ω is forecast to be supersaturated throughout the upwelling season (though August) for all coastal areas.

The forecast system predicts the timing of the spring transition from downwelling to upwelling, the cumulative upwelling index, sea-surface temperature (SST), primary production, chlorophyll stock, dissolved oxygen, and sardine habitat. The forecast for 2021 is composed of three model runs that make up an ensemble. Each model run is initialized at a different time (January 5, January 15, January 25), and has complementary forcing files from the large scale model, CFS. The details of the wind forcing for each model run can be found on the California Current Indicators tab. For each of the predicted quantities listed above, we report the ensemble average anomaly as well as the relative uncertainty within the ensemble, which is defined as the standard deviation of the ensemble divided by the mean of the ensemble and is reported as a percentage of the mean. All of these quantities are reported as monthly averaged anomalies from our new January-initialized reforecast climatology, which spans 2009 - 2017. An anomaly is an indication of how different conditions are to what they have been in the past. For more information about anomalies, please see the NANOOS Climatology App. These predicted quantities are key indicators for the California Current Integrated Ecosystem Assessment report.