One large storm or a series of smaller storms can cause significant beach and dune erosion. Storm erosion follows a similar but more rapid pattern than seasonal erosion. Damaging storms, such as nor'easters, usually occur in the fall, winter, or early spring months when the "seasonal" beach profile is already relatively narrow. Storn-induced changes lower the beach profile and result in extensive loss of the berm. In addition, storm damage usually causes significant dune erosion, scarping, or complete loss of the dune.

Storm recovery follows a similar process to that of the seasonal beach, with offshore sandbars providing protection, and slow, gradual increase of the berm in response to smaller waves. This can occur over one season, but may take a year or more. Dune recovery is a much slower process. Dunes rebuild by re-established dune vegetation trapping windblown sand. It can take several seasons or even many years for a dune to recover naturally from a large storm event.

Almost all of Connecticut’s beaches are moving landward in response to coastal storms and gradual sea level rise. Over the past century sea level in Long Island Sound has risen approximately 10 inches. The landward migration of the beach and dune system is like the motion of a tank tread; the beach migrates over itself in response to storms and sea level rise, but only in locations where glacial deposits are available to replenish the sand supply and infrastructure does not impede natural movement of the beach. The barrier spit at Bluff Point State Park offers an example of beach migration. (See the Changing Beach at Bluff Point State Park) Because the barrier beach at Bluff Point State Park is not affected by infrastructure, the beach migrates in response to storm events and sea level rise.