“Generational Bomb Cyclone” Storm Éowyn intensified over unusually warm ocean temperatures heated by climate change

A rare Red Weather Warning was issued for Northern Ireland and parts of Scotland ahead of expected destructive winds exceeding 130–160 km/h (80–100 mph). These exceptionally strong winds were fueled by the collision of cold air and unusually warm ocean temperatures, which enabled the storm to intensify significantly as it developed. According to the Climate Shift Index: Ocean, these elevated sea surface temperatures were made at least 40 to 100 times more likely by human-caused climate change.

Storm Éowyn, the low-pressure system that recently caused rare snowfall along the Gulf Coast of the United States, was propelled toward the region by an exceptionally strong jet stream, with wind speeds exceeding 386 km/h (240 mph). This enhanced jet stream, combined with bombogenesis, was forecast to produce a potentially dangerous "sting jet"—a narrow corridor of extreme winds—capable of causing significant damage to homes and buildings, widespread power outages, and hazardous travel conditions.

Bombogenesis occurs when a storm system rapidly intensifies, characterized by a drop in its central barometric pressure of at least 24 millibars (24 hectopascals) within a 24-hour period. The resulting, significantly more intense system is commonly referred to as a bomb cyclone. In Éowyn’s case, the anomalously warm Atlantic Ocean helped fuel this process of explosive cyclogenesis, contributing to potential wave heights of up to 50 feet. 

This Climate Shift Index: Ocean Ocean analysis is based on OSTIA, the Copernicus-based high-resolution SST data product.

What do experts say?

Shel Winkley, Meteorologist at Climate Central, said: 

“Climate change clearly warmed the waters that fueled Storm Éowyn’s development, making this storm much more dangerous. Fossil fuel pollution is amplifying this threat.”

To request an interview with a Climate Central scientist, please contact Abbie Veitch at aveitch@climatecentral.com. 

How do we know climate change is influencing this ocean heat?

The Climate Shift Index: Ocean is grounded in peer-reviewed methodology and high-quality data. It quantifies the influence of climate change on sea surface temperatures.

The Ocean CSI indicates how human-caused climate change has influenced the likelihood of daily sea surface temperatures occurring at nearly any location around the world’s oceans.