Extratropical cyclones, like tropical cyclones, cause water to rise offshore. However, extratropical cyclones, in contrast to most storm surges brought on by tropical cyclones, can, depending on the system, raise water levels over a large area for longer periods of time.
Extratropical storm surges can occur on the Pacific and Alaskan coasts in North America, and north of 31 degrees North on the Atlantic Coast. Extratropical storm surges may be possible further south for the Gulf coast, mostly during the winter, when extratropical cyclones affect the coast, such as the 1993 Storm of the Century. Coasts with sea ice may experience an “ice tsunami” that causes significant damage inland.
When Hurricane Ida’s remnants became a nor’easter off the southeast coast of the United States, November 9-13, 2009 marked a significant extratropical storm surge event on the east coast. For a number of days during the event, easterly winds were present along the northern periphery of the low-pressure center, pushing water into places like Chesapeake Bay.
As water was constantly built up inside the estuary from the onshore winds and freshwater rains flowing into the bay, water levels rose significantly and remained as high as 8 feet (2.4 meters) above normal in numerous locations throughout the Chesapeake for a number of days. By only 0.1 feet (3 cm), water levels in many places were below previous records.