Deep waters in the Gulf of Maine and the Mid-Atlantic Bight shelfbreak region are expected to remain cooler than in recent years. This prediction, a product of NOAA’s Changing Ecosystems and Fisheries Initiative, is from the first experimental seasonal ocean outlook released by NOAA scientists in April. It is a shift from previous patterns: From 2004 to 2013, sea surface temperatures in the Gulf of Maine warmed faster than anywhere else in the world.
Fisheries Data Supports Forecast
Conditions at the bottom of the ocean along much of the Northeast U.S. coast have been colder than normal in the first few months of 2025. Data collected in March 2025 by several surveys and the eMOLT program, a partnership between commercial fishermen and NOAA, showed:
- Bottom temperatures across much of the Gulf of Maine that were 0.5–2.0 °C (0.9–3.6 °F) below normal for March, though a few locations reported slightly warmer than normal conditions
- Cooler than normal conditions all along the edge of Georges Bank and deep along the Mid-Atlantic Bight shelf break and slope
- Patches of near to slightly above normal temperatures inshore around Long Island
The first experimental outlook was produced by an advanced integration of NOAA Research’s global seasonal forecast model with a newly developed high-resolution numerical ocean model. The outlook predicts that many of these patterns of above and below normal bottom temperatures will persist into the summer:
- Continued cold is predicted in the deep Gulf of Maine, while some shallow nearshore regions may see moderately above normal temperatures
- Colder than normal conditions are also forecast to persist deep along the Mid-Atlantic Bight shelf break and slope, but warmer than normal conditions are predicted to develop in much of the shallower Mid-Atlantic Bight
- Near the surface, moderately warmer than normal conditions (about 1 °C or 2 °F above average) are predicted throughout most of the region
Since releasing the outlook, NOAA scientists have continued monitoring conditions in the Northeast. Consistent with the forecast and data collected in March and April 2025, they are seeing cooler than normal bottom temperatures.
Are these changes part of a longer term shift?
The recent persistence of cooler than usual conditions in the Gulf of Maine is a marked departure from the last two decades. From 2004 to 2013, the Gulf of Maine sea surface temperature warmed faster than virtually anywhere else in the world. Strong marine heatwaves, or extended periods of substantially warmer than normal conditions, were observed in 2012 and 2016. This abrupt warming had impacts on a number of important fisheries, including cod and lobster.
NOAA’s Geophysical Fluid Dynamics Laboratory conducted experimental model predictions of the next 10 years in 2023. They suggest that the warming will pause over the next decade, with the temperature trend at the surface remaining flat or slightly cooling. In the model, this pause in the warming trend is associated with slow variability in the ocean and atmosphere that takes place over several years. This will ultimately result in a temporary southward displacement of the warm Gulf Stream current, which allows colder water into the Northeast U.S. region.
The cool water observed this winter and spring, its predicted continuation at depth this summer, and several cool pulses observed in 2024 point to this prediction being accurate so far. However, several additional years of data will be needed to confirm whether the warming trend has paused as predicted.
These ocean outlooks are based on advanced numerical models developed by NOAA Research. The Seamless System for Prediction and Earth System Research (SPEAR) model was developed at the Geophysical Fluid Dynamics Laboratory. It predicts how the ocean, atmosphere, land, and sea ice across the planet will evolve over the next 1 to 10 years. Through a process known as downscaling, predictions from the SPEAR global model are then fed into a much higher resolution regional model, built with NOAA’s Modular Ocean Model version 6 (MOM6). This high-resolution model also simulates coastal tides, plankton, and ocean chemistry.
Preparing for Changing Ecosystems and Fisheries
We will update the seasonal outlook for the U.S. East Coast—which includes the Caribbean and the Gulf of America (formerly the Gulf of Mexico)—every 3 months. We will also continue to regularly update our 10-year forecasts. Combined, these forecasts will provide actionable information about potential near-future ocean conditions. Coastal communities, industries, and resource managers can use this information to reduce the impacts of ocean changes.
Scientists at NOAA Fisheries are working closely with NOAA Research and university partners to understand how these predictions can be best incorporated into marine resource management. Changes such as the cooling of deep bottom waters are expected to be particularly impactful for groundfish species, such as cod and haddock, which live on or near the deep sea floor.
