We monitor ocean surface temperatures from space and can see extremes develop in real time.  Several factors may cause MHWs in the ocean, and these mechanisms influence the timescales of the predictions of these events. On top of all is global warming, which has already added more than 1 deg Celsius to the temperature above pre-industrial levels, It is projected to rise between 1.5 to 4C above pre-industrial levels by 2100.

Water temperatures throughout the Gulf of Mexico and in the Caribbean Sea were anywhere from 1-2.5˚C (~2-4.5˚F) warmer than normal in July and early August of 2023. Temperature anomalies like this aren’t unprecedented, but they are concerning while in the thick of the Atlantic hurricane season (June – November) with the tropical North Atlantic already warm. Developing storms that pass into the region during a marine heatwave or with above average sea surface temperatures can be fueled by the warm waters as a result. Additionally, over time it will impact the different species of animals that call the ocean home.

The Gulf of Mexico marine heatwave began around November or December of 2022.

Our experimental marine heatwave forecasts indicate a 70-80% chance that extreme ocean temperatures will persist in the southern Gulf of Mexico and Caribbean through October 2023. That being said, our historical forecast skill in this region at 3.5 month leads is lower (though still better than random guessing).

Exposure to extreme temperature for long periods of time causes a breakdown in the relationship between coral and the algae that lives inside of them. The coral is left pale or white, i.e., bleached. The lack of food from the algae can lead to the death of the coral, subsequent erosion of the habitat, and ultimately a loss of the ecosystem services that we rely on including fishing and food, storm protection, tourism, and biodiversity. We are seeing instances of coral bleaching in the Miami area. Severe bleaching and significant mortality is also likely if the marine heatwave persists.

When corals are stressed by changes in conditions, such as extreme temperatures or reduced light penetration, they may expel the symbiotic algae living in their tissues, causing them to turn completely white in a process known as bleaching. Without the algae, they lose their major source of food and can become weak, potentially leading to death. However, if the conditions return to within optimal range for the corals (i.e. sea surface temperatures returning to average range), then the coral can become host again to the symbiotic algae and recover from the bleaching event. 

To learn more about coral bleaching: https://oceanservice.noaa.gov/facts/coral_bleach.html

When a coral bleaches, it is not dead. Corals can survive a bleaching event if waters cool down and other sources of nutrition are available, but they are under more stress and ultimately susceptible to mortality. The rise in marine heatwaves can cause an unprecedented increase in coral mortality within coral reefs and damage ecosystem services. However, with the help of marine heat wave forecasting, we can anticipate the temperature rises and monitor coral reefs to learn more about their threats and how we can help support marine ecosystems. 

To learn more about the marine heat wave forecast: https://psl.noaa.gov/marine-heatwaves/

For corals, the temperature is important but so is the amount of time that corals are stressed by the heat. The longer this stress persists, the more likely corals are to bleach. Bleaching does not always lead to death. But, again, if there is no relief from the heat, then corals don’t have time to recover from the stress, and they will eventually die. Corals are food and habitat for other marine organisms and if the corals die, this has a cascading effect on all the other life supported by the reef.

There are more isolated marine heatwave conditions off the Northeast US coast, along the Gulf Stream. We have also been monitoring a large marine heatwave in the Northeast Pacific (in the Gulf of Alaska) that has been sitting offshore for the past few months. There is some concern that it will spread along the US west coast as the current El Niño develops.

We monitor ocean surface temperatures from space and can see extremes develop in real time.  Several factors may cause MHWs in the ocean, and these mechanisms influence the timescales of the predictions of these events. On top of all is global warming, which has already added more than 1 deg Celsius to the temperature above pre-industrial levels, It is projected to rise between 1.5 to 4C above pre-industrial levels by 2100.

Water temperatures throughout the Gulf of Mexico and in the Caribbean Sea were anywhere from 1-2.5˚C (~2-4.5˚F) warmer than normal in July and early August of 2023. Temperature anomalies like this aren’t unprecedented, but they are concerning while in the thick of the Atlantic hurricane season (June – November) with the tropical North Atlantic already warm. Developing storms that pass into the region during a marine heatwave or with above average sea surface temperatures can be fueled by the warm waters as a result. Additionally, over time it will impact the different species of animals that call the ocean home.

The Gulf of Mexico marine heatwave began around November or December of 2022.

Our experimental marine heatwave forecasts indicate a 70-80% chance that extreme ocean temperatures will persist in the southern Gulf of Mexico and Caribbean through October 2023. That being said, our historical forecast skill in this region at 3.5 month leads is lower (though still better than random guessing).

Exposure to extreme temperature for long periods of time causes a breakdown in the relationship between coral and the algae that lives inside of them. The coral is left pale or white, i.e., bleached. The lack of food from the algae can lead to the death of the coral, subsequent erosion of the habitat, and ultimately a loss of the ecosystem services that we rely on including fishing and food, storm protection, tourism, and biodiversity. We are seeing instances of coral bleaching in the Miami area. Severe bleaching and significant mortality is also likely if the marine heatwave persists.

When corals are stressed by changes in conditions, such as extreme temperatures or reduced light penetration, they may expel the symbiotic algae living in their tissues, causing them to turn completely white in a process known as bleaching. Without the algae, they lose their major source of food and can become weak, potentially leading to death. However, if the conditions return to within optimal range for the corals (i.e. sea surface temperatures returning to average range), then the coral can become host again to the symbiotic algae and recover from the bleaching event. 

To learn more about coral bleaching: https://oceanservice.noaa.gov/facts/coral_bleach.html

When a coral bleaches, it is not dead. Corals can survive a bleaching event if waters cool down and other sources of nutrition are available, but they are under more stress and ultimately susceptible to mortality. The rise in marine heatwaves can cause an unprecedented increase in coral mortality within coral reefs and damage ecosystem services. However, with the help of marine heat wave forecasting, we can anticipate the temperature rises and monitor coral reefs to learn more about their threats and how we can help support marine ecosystems. 

To learn more about the marine heat wave forecast: https://psl.noaa.gov/marine-heatwaves/

For corals, the temperature is important but so is the amount of time that corals are stressed by the heat. The longer this stress persists, the more likely corals are to bleach. Bleaching does not always lead to death. But, again, if there is no relief from the heat, then corals don’t have time to recover from the stress, and they will eventually die. Corals are food and habitat for other marine organisms and if the corals die, this has a cascading effect on all the other life supported by the reef.

There are more isolated marine heatwave conditions off the Northeast US coast, along the Gulf Stream. We have also been monitoring a large marine heatwave in the Northeast Pacific (in the Gulf of Alaska) that has been sitting offshore for the past few months. There is some concern that it will spread along the US west coast as the current El Niño develops.