Our recent analysis shows that nor’easters are getting worse. Sometimes referred to as the Atlantic’s “perfect storms,” they present an ever-growing threat to coastal communities. When a hurricane or other powerful storm strikes, the damage—and disruption—can be immense. They happen when cold, dry air from the poles meets warm, moist air on the North American coastline, which leads to conditions perfect for severe storms. The research, published in the Proceedings of the National Academy of Sciences, examines nor’easter tracks between 1940 and 2025. It uncovers a sad truth underlying it all—these storms are getting worse and worse.
Nor’easters often develop and spin counterclockwise as they move rapidly to the northeast across the much warmer waters of the Gulf Stream. These storms are highly sensitive to different atmospheric conditions which can allow them to turn. They could either go out to sea or become directed to the Canadian Maritime provinces. As they travel over land, for example, they tend to weaken when their supply of warm, moist air is blocked. In the last 85 years, the strongest nor’easters have undergone a record setting upward trend in their peak wind gusts. These storms have very substantially raised their high end hourly precipitation rates.
The Dynamics of Nor’easter Formation
Nor’easters originate from a unique meteorological phenomenon. A cold polar airmass is moving down from the north. As it moves westward, it interacts with warm, moist air that is being transported northward along the coast. This unusual interaction between the two systems creates a distinct dynamic environment that can lead to the strengthening of particularly dangerous storms.
And like cyclones in general, as these systems move across the Atlantic’s warm waters, they continue to gain strength. Their storms spin opposite the Earth’s rotation, counterclockwise. Their strength is typically due to the large temperature gradient between the cold and warm air masses. Combined, these storms can create destructive winds and extreme precipitation, resulting in dangerous conditions throughout impacted areas.
This new analysis by researchers used a new cyclone tracking technique on a long-term and high-resolution dataset that covers 85 years. This comprehensive approach allows scientists to identify patterns in nor’easter activity and better understand how these storms have evolved over time.
Increasing Intensity and Impact
Study results reveal that significant nor’easters have become more severe over the last 60-70 years. These storms are characterized by minimum sea level pressures below a certain threshold sustained for a minimum of 24 hours and moving over 1,000 kilometers. Based on this analysis, researchers determined that strong nor’easters are defined as those above the 66th percentile in strength.
Kevin Chen and his colleagues noted, “Our analysis of nor’easter characteristics reveals that the strongest nor’easters are becoming stronger, with both the maximum wind speeds of the most intense (>66th percentile) nor’easters and hourly precipitation rates increasing since 1940.” This trend represents yet another worrying addition to coastal risk, especially in a warming world.
A few nor’easters are notorious enough to be well-remembered for their severity and effects. They’ve deservedly received monikers such as “Perfect Storm,” “Storm of the Century,” and “Snowmaggedon.” These storms have flooded homes and communities, killing hundreds and costing billions in damages. Yet they have led to severe injury and death. As the intensity of nor’easters increase, this creates a continued threat for coastal communities and emergency management professionals.
Implications for Coastal Communities
The strengthening of nor’easters specifically points to another potentially troubling trend, one which may have devastating consequences for the nation’s coastal communities. Through climate change, these hurricanes are getting stronger and their frequency is accelerating, threatening infrastructure, state economies and public safety.
Our coastal communities need to prepare for more frequent, intense storms. These disruptions are disruptive to the point of being life-altering and an often unbearable monetary weight. With billions of dollars already attributed to damages caused by past storms, local governments and emergency management agencies must prioritize resilience planning and invest in measures to mitigate potential impacts.