And a nor’easter is exactly what’s in the forecast for the Northeast over the next three days.
Two low-pressure systems are inching closer to each other this week, destined to unite just off the Mid-Atlantic coast by Friday. Farther north, cold high pressure is building over Greenland and eastern Canada, which will compress the storm and cause it to intensify on its north and west sides.
Wind gusts to 60 mph would be damaging and would certainly lead to power outages from the Mid-Atlantic to New England. Torrential rain will increase the risk for river and stream flooding. The rain may turn to heavy wet snow in some areas, which will cause even more travel disruption.
The National Weather Service in Boston is warning that moderate-to-major coastal flooding could cause property damage. Significant beach erosion, they say, is “almost a sure bet.” Unfortunately, part of this storm will coincide with high tide for the region, which will exacerbate the impact.
Starting Thursday, this nor’easter has the potential to produce a storm surge of three to four feet above high tide. In addition, coastal areas will need to factor in waves, which will raise the water level. Wave heights are expected to reach 30 feet offshore.
“If these values verify major coastal flooding would occur,” the Weather Service wrote Wednesday, “and this includes large break waves resulting in structural damage including seawalls.”
“Major” coastal flooding isn’t just a superlative — it has a specific meaning. In flooding designated as “major,” shoreline roads are flooded with up to three feet of water. Needless to say, many roads will be impassable. Large debris will be washed ashore. Basements will flood, sea walls could be damaged and beaches will be severely eroded, according to the National Weather Service.
In other words, the impact from this storm will be similar to what the region experienced during the “bomb cyclone” in early January, though this storm will consist more of rain than snow.
The phrase “storm surge” is usually associated with hurricanes, but physically it’s water being pushed onshore by wind. It can happen anytime winds are pointed toward the shore. The stronger the wind, the larger the storm surge will be.
There is a tendency to misinterpret the worst effects of a nor’easter. They are usually associated with heavy snow that can shut down major interstates, ground flights and reduce visibility to near nothing. Those effects are certainly crippling, but much of the lasting damage is along the coast, where entire beaches wash away and hundreds — maybe thousands — of homes flood.
The Rutgers study found that, although Superstorm Sandy was the largest storm surge on record at the Battery in New York City, storms like nor’easters caused 88 of the top 100 storm surges at the location.