A Marine Heatwave is a prolonged period of abnormally high sea surface temperatures in a specific region. While heatwaves are common on land, MHWs can last for months or years, devastating coral reefs, shifting fish migrations, and—critically for forecasters—dramatically increasing the moisture and energy available for coastal storms.
In 2026, MHWs in the Gulf of Mexico are a top search for tropical meteorologists. When a hurricane passes over an MHW, it doesn’t just grow; it “explodes” in intensity. Pros search for “Ocean Heat Content (OHC) anomalies” rather than just surface temperature, as the depth of the warm water in an MHW determines if a storm will churn up cold water or keep feeding on a deep reservoir of heat.
New for 2026, agencies like NOAA and the ECMWF have launched dedicated MHW forecast products. Professionals in the “Blue Economy” (fisheries and aquaculture) search for “MHW duration probability maps” to decide when to harvest shellfish or move floating salmon pens before the water becomes too warm for the animals to survive.
The “Blob” was a massive MHW that fundamentally changed the West Coast weather for years. In 2026, researchers search for “MHW recurrence intervals” to determine if these events are becoming the “new normal.” They are also looking at how MHWs “talk” to the atmosphere to create “Ridges of Doom”—persistent high-pressure systems that cause multi-year droughts on land.