Although Hurricane Sandy remains a Category 1 hurricane, as we have seen with previous storms such as Hurricane Ike in 2008, large storms with a lower ranking on the Saffir Simpson Scale can nonetheless push a large surge of water inland.
In this post, I want to briefly lay out the surge threat to New York and Connecticut. For the purposes of this post, let’s assume that Sandy makes a landfall along the central New Jersey coast.
(Note: In its recent run the respected European forecast model brought Sandy inland further south, and the National Hurricane Center’s official forecast calls for a landfall in southern New Jersey. This would benefit the New York metro area. However, any point to the north would get progressively worse for the Big Apple.)
Now let’s take a look at the Wavewatch III model, which demonstrates nicely why there’s concern about flooding from Sandy in New York and Connecticut. This model shows the combined height of wind, waves and swells.
Combined wind, waves and swell height at 7 p.m. CT Monday. (WeatherBell)
The critical aspect to note is that the direction of the highest waves from Sandy are being pushed directly into Long Island, Lower Bay and Long Island Sound.
Accordingly, the odds of a fairly large storm surge in parts of the New York metro area are rising. The following map shows the chance of a storm surge greater than 8 feet due to Hurricane Sandy in this area.
Chances of a surge greater than 8 feet. (NOAA)
As you can see some areas have a 40 percent or greater chance of such a surge. Simply put, if you live in an area 8 feet or less below sea level in these areas, there will be water in your home.
For the New York area a landfall further south will be most beneficial. We will have to see whether that happens as time for Sandy to make a significant track shift is slipping away.