The expected arrival of the nearly 600-mile-wide Hurricane Irene this weekend means that states of emergency have been declared along the length of the eastern seaboard. Dangerous Irene is an usually wet and large hurricane in its overall size with tropical storm force winds extending out nearly 300 miles from the center. Climate scientists studying hurricanes have documented a 35-year warming trend of 1 degree Fahrenheit in ocean surface temperature. That 1 degree rise in surface temperature increases atmospheric water vapor available to feed hurricanes, increasing the area of tropical storm force winds and total rainfall amounts.
Depending on numerous factors, it could take New York City “weeks or months” to return to normal if the densely-populated city suffers a direct hit from Hurricane Irene. Apart from the potential loss of life in the most densely populated part of the America, history suggests that the economic damage could run into the tens of billions of dollars, depending on the severity of the storm and how close it comes to the City of New York. Unlikely but theoretically plausible scenarios could have the damage entering the realm of the costliest natural disasters of all time, and perhaps being large enough to have a materially negative effect on the nation’s gross domestic product.
The storm is poised to hit New York at a time when high tides reach their highest levels, which could amplify flooding in the city built around bays and rivers. Some experts predict a storm surge of five feet or more. Lower Manhattan could see streets under a few feet of water.
"In many ways, a Category 2 or stronger storm hitting New York is a lot of people's nightmare, for a number of reasons," said Susan Cutter, director of the Hazards and Vulnerability Research Institute at the University of South Carolina.
Even if the winds aren't strong enough to damage buildings made largely of brick, concrete and steel, a lot of New York's subway system and power lines are underground. The city's airports are close to the water, too, and could be inundated, as could densely packed neighborhoods. Hospitals were told to make sure generators were ready.