Sunday, August 28, 2011

Hurricanes Irene and Before

Now that Hurricane Irene has hit New York city as only a tropical storm (not to minimize the great damage such a storm can do -- it landed in North Carolina and then New Jersey as a legitimate (Cat 1) hurricane), I wonder if Bill McKibben will rethink his recent column that blamed global warming for Hurricane Irene. Remember, it's hardly unprecedented for a major hurricane to hit that area -- this is from Wikipedia:

  • "The Great September Gale of 1815 (the term hurricane was not yet common in the American vernacular), which hit New York City directly as a Category 3 hurricane, caused extensive damage and created an inlet that separated the Long Island resort towns of the Rockaways and Long Beach into two separate barrier islands.
  • "The 1821 Norfolk and Long Island Hurricane, a Category 4 storm which made four separate landfalls in Virginia, New Jersey, New York and southern New England. The storm created the highest recorded storm surge in Manhattan of nearly 13 feet and severely impacted the farming regions of Long Island and southern New England.
  • "The 1869 Saxby Gale affected areas in Northern New England, decimating the Maine coastline and the Canadian Outer Banks. It was the last major hurricane to affect New England until the 1938 storm.
  • "The 1893 New York hurricane, a Category 2 storm, directly hit the city itself, causing a great storm surge that pummeled the coastline, completely removing the Long Island resort town of Hog Island."
  • The Great Hurricane of 1938, which made landfall as a Category 3 hurricane and killed upwards of 800 people with $41 billion (2011 dollars) in damage.
Again, I'm not minimizing this hurricane, which as I write this has killed 22 people (16 in the U.S.) with $7 B in damage. But, storms happen.

PS: Thanks to commenter Steve Bloom for mentioning Kerry Emanuel's Power Dissipation Index as an alternative to Accumulated Cyclone Energy. (Also see Steve's comment here.) PDI essentially adds up the cube of a storm's velocity, while ACE adds up the square. Emanuel has a reason for this (details here), which I'm still trying to understand. It's not intuitively obvious to me that that's a better measure; it does, though, track sea surface temperatures:

This graph is from Emanuel's 2007 paper in Journal of Climate.


Larry Hogue said...

Now that's more like it.

Steve Bloom said...

David, after carefully re-reading McKibben's column, I really don't see the problem. Your main objection (the unprecedentedness or lack thereof) is addressed in his third and fourth paragraphs via extensive quotes from hurricane expert Jeff Masters.

As Masters says, what's really unusual are the high SSTs all the way north to NYC, high enough to support lots of Cat. 3 hurricanes if they stay that way. The increasing North Atlantic SST trend, BTW, has been scientifically pinned to AGW.

Of note, the end of the Masters quote emphasized the rainfall threat, which was the aspect of Irene that wasn't subject to disruption by shear winds. And indeed, it came to pass just as predicted. NYC dodged a bullet on the wind and storm surge, but if those SSTs stay up that won't last.

The Croquist said...

Serious post here:

Good for you David. I hadn’t been here in a while so I missed your first post on this. Calling out McKibben when he’s basically supporting your side shows class. Now that the storm has turned out to be a pretty typical hurricane McKibben has egg on his face.

Done being serious:
I’m calling this your “Sister Sojourn” moment. Have you considered a run for the White House?

Back to being serious:

I’ve had at least two friends impacted by the storm. The first is Debbi on Long Island. (She’s a babe even if she is a grandmother)* She lost power for about 30 hours. Ironically her daughter just bought and moved into a house about 2 miles from the south shore and didn’t lose power.

My friend Larry summers in Newcomb NY. You can look up Newcomb up if you want but as a hint, it’s probably the closest equivalent to “Big Foot” land on the east coast. He pulled a boat out of Lake Harris for flooding concerns. It proved to be a good move because it helped break the fall of the tree that landed on the boat and trailer in his driveway. It was just the top of the tree so he doesn’t think there was significant damage but the irony is priceless. He was out of power for about 6 hours.

Both sides use individual weather events to further their agenda. Thanks for not being one.

* God I’m getting old.

Steve Bloom said...

And above it all stands The Croquist.

BTW, TC, you missed the main way in which Irene was *not* a typical hurricane.

The Croquist said...

In what way was Irene *not* a typical hurricane?