Nor'easters

Winter can bring big storms and heavy seas to Maine. Please obey all posted signs and closures and always stay away from strong surf.  NPSPhoto.

The forces of erosion continuously shape the Acadia environment. Seemingly soft forces such as wind and water shape rocks and ecosystems over time. Strong storms and crashing waves have shaped Acadia's coastal environment since the beginning of time.

 

Weather

Nor'easters

Hurricanes get a lot of attention, but there’s another kind of storm that is more common and damaging for Acadia: Nor’easters.

Like a hurricane, Nor’esters occur in the North Atlantic Ocean, are characterized by strong winds and large waves, are typically accompanied by heavy precipitation, and can cause substantial coastal erosion. But there are key differences:

• where hurricanes are warm water driven, nor'easters are cold water driven and often have multiple low pressure centers instead of a single eye like a hurricane,
• hurricanes originate in the tropics and move northwest, nor'easters originate in the mid-Atlantic and move northeast
• hurricanes are typically short-lived (6-8 hours) and weaken over time, nor'easters are longer lived and can last 12-48 hours, strengthening over time,
• hurricane wind speeds can reach up to 150 mph, while nor'easter's winds typically ranger from 13-45 mph,
• hurricanes typically happen in a certain area only once a year or once a lifetime, while nor'easters are frequent in the northeast average up to 30 per year,
• serious damage from hurricanes are typically concentrated to less than 300 miles, while nor'easters typically range up to 1,000 miles, and
• hurricanes typically occur from June-Oct in the United States, while nor'easters are frequent from October to April.

Nor’easters are driven by a temperature difference between the cold air over land and relatively warmer air over the sea, and these temperatures have been changing. Warmer air holds more moisture, and northeast winds blow this warm, moisture-laden air into New England, leading to heavy rain and snow and winds.

While we don’t know if this trend will continue, we do know that storms will have a more severe impact because the sea is rising. (As evidence for higher seas, normal high tides are causing flooding more often. In 2019, this “sunny day” flooding occurred six days in Acadia, the January and March 2018 nor’easters set records for the highest and third-highest tides in history, respectively. Higher water levels means storm waves and flooding also reach farther inland. Waves and storm surge collide with the shoreline, wash over dunes and beaches, and flood low-lying areas. Nor’easters cause erosion of beaches and dunes, and damage visitor infrastructure such as roads, trails, and docks. Though usually weaker than hurricanes, Nor’easters cause more coastal erosion because they occur more often and, because of their slow movement, can affect the coast for days rather than hours, encompassing multiple high tides. They can bring significant rain and/or snow and ice, and cold temperatures that can complicate clean-up and rescue efforts.

Despite the damage they cause, Nor’easters are not well studied. Different storms means we need different models, computer simulations of ocean-atmosphere-land interactions, to understand and anticipate impacts from future storms. Acadia National Park, Cape Cod National Seashore, and Boston Harbor Islands National Recreation Area are working together on a joint research project. Climate change is threatening Acadia's coastline by increasing the frequency and severity of nor'easters.

 

Duration:

2 minutes, 52 seconds

Nor'easters are large storms that batter the coast of Acadia National Park, Boston Harbor Islands National Recreation Area, and Cape Cod National Seashore. Discover how these storms influence these parks and how climate change is influencing the intensity and damage of Nor'easters.

 

About the Nor'easter Research Project

Isaac Ginis of the University of Rhode Island developed new models of the track and intensity of Nor’easters making landfall in New England. Ginis combined computer models of wind, waves, and storm surge developed for hurricane studies used by NOAA and the Navy for operational forecasting and the Department of Homeland Security (DHS) Coastal Resilience Center of Excellence. Ginis worked closely with Peter Stempel, an architect with Rhode Island School of Design and now at Penn State, who created three-dimensional visualizations of the model results.

With these models, the team can show impacts to the coast at resolutions as close as 10 meters, compared to most current models that have a ~300 meter resolution (referred to as the “computational mesh size”). But higher resolution requires greater computational resources [how long to run the model], so researchers have to be selective about where to apply high-resolution analysis. Staff from each park provided input on areas of concern, and worked closely with Stempel to ensure the visualizations closely approximate reality; for example, a “tree library” for Acadia (showing or describing the collaborative process used to generate the visualizations may increase perceptions of their legitimacy).

All three parks are a patchwork of public and private, natural and cultural land and sea scapes. Ginis tested the model using historic storms, which can be drawn upon to show threat of Nor’easters. Recent storms can also be modeled by Ginis to provide corresponding data and graphics.

How Nor'easters Damage Acadia

Nor'easter cause significant damage to Acadia National Park every year in the following ways:

• Public health and safety: Danger to people attempting to witness/photograph storms; potential for water and waste water systems to be inundated; wells impacted by sea water intrusion. In stormy conditions, campgrounds, trails, and shoreline roads must be closed.
• Low-lying roads and bridges and other infrastructure: Otter Cove, Seawall, Schoodic Point, Thompson Island Picnic Area, Seawall, Sand Beach Cultural heritage: Eroding shell middens, carriage road and trail washouts.
• Natural heritage: Eroding beaches, marshes, wind damage to forests.