Storm-surge probabilities from the National Hurricane Center
Irene's winds diminished somewhat overnight and are expected to weaken further, according to the National Hurricane Center. However, its predicted path over roughly the center of Long Island will create havoc for the East End.
As with most hurricanes and tropical storm, most damage comes not from wind but from water. Irene will charge into the region early Sunday, coinciding with an above-normal new-moon tide cycle. Factoring in this with its strong east-to-north-east sustained wind of up to 80 miles per hour with higher gusts and the surge of water associated with such storms, and the likelihood of flooding and extreme damage from high waves is great.
Typically, the highest surges associated with hurricanes have been experienced in narrowing estuaries and river mouths. A graphic on the National Hurricane Center Web site can be searched for estimates of the base surge, that is, how high the water will come without factoring in waves and wind. As of Saturday morning, it showed the greater probability of surges in excess of three feet in the northern and western portions of Gardiner's and Peconic Bays, as well as Long Island Sound.
It is important to point out that the surge described above is merely the amount that sea level is expected to rise as the storm passes overhead; the National Weather Service is forecasting waves up to nine feet in Long Island Sound by Sunday afternoon.