The J-SCOPE forecast system for Washington and Oregon coastal waters presents preliminary results for the 2025 upwelling season. La Niña conditions are expected from the CFS forecast to persist through February-April 2025 (59% chance), with a transition to ENSO-neutral likely during March-May 2025 (60% chance). In comparison to the climatological data, during the summer upwelling season (May - June), coastal regions are forecasted to have near or cooler than climatological sea surface temperatures (SST) with the warm anomalies developing by the end of the season (July - August). Subsurface anomalies, colder than climatological, extend subsurface mid-shelf with bottom temperatures over much of the shelf cooler than climatological along both 47°N and 44°N. Bottom oxygen is forecasted to be lower over both the Washington Oregon shelves with high disagreement between ensemble members resulting in high uncertainty in late summer surrounding this forecast throughout the region. Subsurface oxygen anomalies extend down the slope regions. Hypoxia is forecasted earlier than climatological (in late May, early June) at both CEO42 and NH-10, with an earlier onset at NH-10. Ćháʔba· also develops hypoxia in July, which is not typically observed at this location. Chlorophyll concentrations vary spatially but are forecasted to be lower over the upwelling season. Bottom Ω is forecasted to be undersaturated throughout the upwelling season, with the exception of supersaturated conditions on shallow nearshore Washington shelves. Surface Ω is forecasted to be supersaturated throughout the upwelling season 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 2025 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 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.