Posted on July 13th, 2026 in Regional Ocean Forecasts
The experimental seasonal outlook for the Northwest Atlantic Ocean continues to predict widespread warm surface conditions this summer and fall, with even stronger warming in winter and spring in the tropical North Atlantic and Gulf of St. Lawrence driven by the Pacific El Niño. Along the Northeast U.S. continental shelf, cooler than normal bottom temperatures will continue to persist in the deep Western Gulf of Maine.
Warmer than average surface conditions, indicated by positive sea surface temperature (SST) anomalies, are expected to continue across the central portion of the Northwest Atlantic region in the next 6 months. Heading into the winter and spring, the tropical North Atlantic and Gulf of St. Lawrence areas are predicted to be more than 2 °C above average, while near average conditions are predicted in the central Northwest Atlantic. This pattern is a well-known imprint of the winter Pacific El Niño on the spring Northwest Atlantic. GFDL’s SPEAR model, which provides the atmospheric forcing for the regional MOM6 model, is predicting a strong El Niño this coming winter.
Focusing on the Northeast U.S. shelf region, cooler than usual bottom waters have been persisting in the western Gulf of Maine for a number of months and are predicted to continue but gradually diminish over the next year. Only moderately warmer than normal anomalies are predicted next winter and spring, though prediction skill is lower at this long lead time.
Here we show predicted bottom temperature probabilities along the full U.S. coastline in the Northwest Atlantic model. These plots show whether bottom temperatures have at least a 50% chance of being in the lower third of historical values (cooler than average), in the middle third (near average), or in the higher third (warmer than average). Areas where none of these three categories exceed 50% likelihood are marked uncertain. As shown in the previous figure, bottom temperatures in the western Gulf of Maine are likely to be cooler than average in the summer and fall before turning towards near average in the winter. Along the Southeast U.S., Gulf of America, and Caribbean, areas of warmer than normal conditions are predicted in summer and fall. As prediction skill decreases at longer lead times, the forecast for these areas in winter and spring tends towards uncertain.
These figures show data from GFDL’s regional ocean model of the Northwest Atlantic, MOM6-NWA12. This model is based on the Modular Ocean Model version 6 (MOM6) and features 1/12° resolution. To produce year-long seasonal forecasts, MOM6-NWA12 is run using atmospheric forcing fields from GFDL’s SPEAR global prediction system. An ensemble of 10 simulations is run, using a different ensemble member from SPEAR for each, and the results are averaged for the figures shown here. New seasonal forecasts are run four times per year, in January, April, July, and October. Note that these experimental predictions are not official NOAA forecasts.