High tide in New York brings flooding

Winds from the 2007 Nor'easter have pushed a two foot storm surge on top of an unusually high "Spring Tide" into the New York City area at the time of this evening's 7:30pm EDT high tide,(Figure 1). Battering waves on top of the storm surge have undoubtedly caused significant coastal erosion, and possibly damage to some structures along the coast. It could have been worse for New York City, as the peak storm surge of 2.5 feet occurred during the afternoon before high tide. Sustained winds of tropical storm force have been observed most of the day south of Long Island at Ambrose Light, and in Long Island Sound. The situation is worse along the western shores of Long Island Sound, where strong winds have already generated a 3-foot storm surge, which was still increasing in height as of 7:30pm EDT. High tide at King's Point is not until 9:30pm EDT tonight; Long Island Sound may see a destructive 4-foot storm surge at that time (Figure 2).

The Nor'easter is moving slower that expected, and is still centered over North Carolina at 7pm EDT. Central pressure continues to fall rapidly, and is down to 981 mb. The storm is expected to continue to intensify down to 973 mb, and track NNE up the New Jersey coast and over New York City. By 8am EDT Monday, the storm will peak in intensity over Connecticut and stall.


Figure 1. Tidal levels observed at The Battery in New York City as of 7:30pm EDT Sunday April 15. Note that water levels peaked at 2.5 feet above normal during the afternoon, but fell to 2 feet above normal at the time of high tide.

The storm surge from today's storm will rival some of the largest ones ever observed in New York, such as during the "Perfect Storm" of October 31, 1991, and the March 13, 1993 Storm of the Century. The worst coastal flooding in recent years in New York City occurred during the December 11-12 1992 Nor'easter, which damaged as many as 20,000 homes and forced almost 2,000 people to take refuge in emergency storm shelters. Storm surges of 4 feet were recorded near New York City, and 5.5 feet in western Long Island Sound. It is possible that the flooding levels seen in the December 1992 Nor'easter will be exceeded in western Long Island Sound tonight.


Figure 2. Tidal levels observed at King's Point in western Long Island Sound on April 15, 2007.

There is too much other remarkable weather to cover in detail. The entire Northeast coast will see an extended period of storm surge flooding, battering waves, and high winds that will likely cause hundreds of millions of dollars in damage. Heavy rains of over four inches have already fallen at New York's Central Park, a tornado from the storm has caused extensive damage in South Carolina that killed one person, and near blizzard conditions are affecting some mountainous regions of New England.

Mount Washington weather
It's a night to hunker down and stay inside at the Mount Washington observatory in New Hampshire. Winds at 8pm EDT were sustained at 70 mph, gusting to 77, and steadily rising. Keep an eye on the history page for Mount Washington to follow the remarkable weather conditions there.

I'll edit this blog tonight to update the water levels and winds, and have a full new blog Monday morning, and there will also be a separate update on the East Coast Winter Storm blog.

Jeff Masters