Hurricane Irene: Thinking the unthinkable

Nate Silver isn't afraid of numbers.

His fascinating FiveThirtyEight blog on the New York Times, after all, is designed to help readers "cut through the clutter of this data-rich world."

Silver's work is "devoted to rigorous analysis of politics, polling, public affairs, sports, science and culture, largely through statistical means," he says.

So when Nate crunches some numbers, it's usually a good idea to listen closely.

He's turned his attention today to the unthinkable: 

What would really happen if Hurricane Irene slammed directly into New York City, the most populous city in the United States and the teeming capital of finance, media, art, fashion and other important commercial and cultural things?

To find out, Silver looked back at 20 big storms that hit above the Mason-Dixon line since 1900.

He then got busy with the regression analysis:

"The procedure I have used to estimate economic damage — this is going to get a tiny bit technical — is to regress the logarithm of economic damage on three independent variables," he writes. "The first two variables are the storm’s wind speed, and the distance of the storm from New York City, at its closest approach to Manhattan. The third variable is how many fatalities the storm caused in the Southern United States (these were significant in the cases of Hurricane Donna in 1960, Hurricane Agnes in 1972, and Hurricane Floyd in 1999), which is used as a proxy to segregate out damages caused in the South from those in the Northeast in the case of storms that made multiple distinct landfalls."

Here's the bad news, according to Nate:

"According the model, a hurricane with wind speeds of about 100 miles per hour — making it a “weak” Category 2 storm — might cause on the order of $35 billion in damage if it were to pass directly over Manhattan. Such a storm would probably flood New York’s subway system as well as acres upon acres of prime real estate in neighborhoods like the East Village, the Financial District, TriBeCa, Coney Island, Red Hook, Dumbo, as well as parts of Staten Island and most of the Rockaways.

Although far from the most likely scenario, this may represent a reasonable-worst-case estimate of what could happen if Hurricane Irene took exactly the wrong turn at exactly the wrong time."

Here's the latest on what promises to be a very wet, and very wild, weekend on the East Coast.