A storm destined to bring a swath of heavy snow from Minneapolis and Chicago to Washington, D.C., will cause problems at the coast from wind, beach erosion and coastal flooding.
While the storm will not nearly be as intense as Sandy, the Blizzard of '93, the Perfect Storm (Halloween Storm of '91), or the Ash Wednesday Storm of '62, it will cause problems for some interests along the coast.
Northeast winds can become strong enough to cause sporadic power outages from the Delmarva Peninsula to New Jersey. A few gusts to 60 mph are possible Wednesday into Thursday. Well inland less wind is in store, but the amount of wet snow adhering to trees will cause power outages as well.
The shape of the coast and wind direction determine which areas are most susceptible to flooding from rising ocean and bay water levels. The duration and strength of the onshore wind determines the severity of the water rise.
The exposed amount of uninterrupted wind over the water, known as fetch, will lead to above-normal tides starting Wednesday in many areas.
From the Delmarva Peninsula to New Jersey Wednesday and Thursday, we project water levels to average 2 to perhaps 4 feet above normal (published) values. This can be enough to cause coastal flooding at times of high tide. However, some flooding can also occur along the north shore of Long Island. Some water may back up over the western end of Long Island Sound, Raritan Bay, Delaware Bay and the Chesapeake Bay with water levels running about 2 feet above published values.
Offshore waves can reach 30 feet with the storm. While the size of the waves diminishes substantially near the coast, frequent breakers and over wash can do a job on the beaches.
The worst coastal effects for Cape Cod, the Islands, the east coast of Massachusetts and offshore interests may be Thursday into Friday, if the storm strengthens and jogs farther north, rather than taking a more easterly path. If this ends up being the case, then water levels of 2 to 4 feet above normal will then swing toward the east coast of New England. With strong winds, coastal flooding and beach erosion.
Lingering Coastal Problems into the Weekend
Regardless of any shifts in storm track Thursday to Friday, the storm will become large and powerful (bomb out) by Friday and will linger nearby offshore. As a result, it will act like a giant plunger and pinwheel, driving waves and winds along the mid-Atlantic and New England coast into the weekend.
While winds will not be as strong in most areas by Saturday, they will still have an onshore component in many areas. While these will not be strong enough to cause damage over interior areas, they will continue to play a role along the coast. Minor to moderate beach erosion may continue due to the rough surf conditions from eastern New England to northeastern North Carolina. Water levels may continue to average 1 to 2 feet above published values.
The storm and its lingering aftermath may add to repair bills for some beach communities in the wake of Sandy or undo some of the repairs already made.
The shape of the coast and wind direction determine which areas are most susceptible to coastal flooding. The duration and strength of the onshore wind determines the severity of the water rise. Areas with a northerly or northeasterly exposure as well as some of the back bays will take on the most water in this situation.
Fortunately, astronomical impact around the time of the storm be minimal with significant distance between the new and full moon phases.
The storm should abate before the approach of the new moon on March 11, 2013.