How Big Is Hurricane Dean

Chris Mooney says it's huge and part of a trend:

Dean was officially the most powerful hurricane that we’ve seen globally so far in 2007, and was by far the strongest at landfall. It was also the first Category 5 Atlantic hurricane seen in the since the record-setting Hurricane Wilma of October 2005. In fact, Dean set some records of its own. Its pressure was the ninth lowest ever measured in the Atlantic, and the third lowest at landfall. Indeed, there hasn’t been a full Category 5 landfall in our part of the world since 1992’s Hurricane Andrew. Dean was in all respects a terrifying storm, and we can only hope that the damage will somehow be less than expected as it tears across the peninsula and then, after crossing the Bay of Campeche, moves on to a presumed second Mexican landfall. [...]

Well, first of all, Dean now takes its rank among the top ten most intense Atlantic hurricanes. If you look at that list you’ll see that six of the strongest (Wilma, Rita, Katrina, Mitch, Dean, and Ivan) have been in the past ten years. That’s not the kind of statistic that’s easy to overlook. According to these data we are getting stronger storms in the Atlantic basin now than we ever have before.

Is global warming to blame? You'll need to read Chris' book Storm World to get a sense for the science in detail, but there's a rough consensus that a warming planet should lead to more intense storms, albeit a lot of disagreement as to how strong that effect is.

Comments

I am very skeptical about data quality.

There is no good data on hurricane intensity before the 1960s, i.e. no direct observation from the air, satellite or weather baloon.

The 1940s hurricanes were particularly frequent and intense, and were not well measured.

Posted by p | August 21, 2007 8:24 AM

Long story short: sea surface temperature (SST) fuels hurricane intensity, but SSTs aren't the only factor. In fact, increases in SSTs may stoke factors that inhibit hurricane development. That said, if 2005 is any indication when all the factors align, it's lights out, hurricane-wise.

Posted by Jeffrey Davis | August 21, 2007 8:39 AM

Some market evidence that most folks feel the hurricane threat is overstated: Last year this time, I bought one of Berkshire Hathaway's b-shares so I could get a discount on GEICO car insurance (bought a few more this past spring). At the time, the b-shares were trading at about $3200 per share. Apparently, investors were worried about the effect of hurricanes on Berkshire's earnings (Berkshire is essentially an insurance company that uses its float to invest in stocks and buy operating companies), particularly now that we were living in a post-Katrina, post-"An Inconvenient Truth" world.

As it started becoming clear that the '06 hurricane season was fairly mild, Berkshire's stock price started to go up. See the 1-year chart. What's happening this year? Same thing, essentially, except now the stock is starting to appreciate in August, instead of September, which means investors are probably less worried about hurricanes this year than they were last year.

Posted by Fred | August 21, 2007 8:45 AM

It's only since they started giving hurricanes guys names that they became "bigger" (if you know what I mean)

Posted by Ethel-to-Tilly | August 21, 2007 8:51 AM

If anything is to blame, it's liberal Hollywood.

Posted by Bill | August 21, 2007 8:58 AM

So I guess that as soon as we can predict the movement of stock prices we'll also be able to predict hurricanes. Great! I'm sure we'll have a handle on that in no time!

What's even more awesome is that we don't even need to understand weather or climate at all. All the information anyone could possibly need about anything at all is right there in the price of stocks! From now on I'm gonna throw out the entire newspaper except the stock listings pages. Hell, I'm off to burn down my local library right now!

Posted by DMonteith | August 21, 2007 9:19 AM

Mooney:

In fact, Dean set some records of its own. Its pressure was the ninth lowest ever measured in the Atlantic, and the third lowest at landfall.

Um, this is a pretty odd definition of "record," isn't it? There's a tendency to speak of climate change issues as if records and extremes are the real story -- witness the recent absurd to-do the wingnutosphere over whether 1998 was the hottest US temp or not -- when it's of course the long term trends that tell the story. (And it's a frightening one.) I fear Chris is falling prey to that mentality here.

Posted by Glenn | August 21, 2007 9:20 AM

Dean is also the first Atlantic hurricane of 2007 and typically are stronger then those that occur in other regions of the world.

Posted by Trent | August 21, 2007 9:50 AM

See also Art Bell's seminal The Coming Global Superstorm.

Posted by Dave in IL | August 21, 2007 9:59 AM

Dave,

That's not the same Art Bell from Coast-to-Coast AM, is it?

Posted by Fred | August 21, 2007 10:05 AM

Yeah, same Art Bell. Just funnin'. But it's a great title.

Posted by Dave in IL | August 21, 2007 10:21 AM

Yeah, but it was below zero here in Minneapolis last January, so I don't believe in global warming.

Posted by Gus | August 21, 2007 3:11 PM

Another flaw is the failure to take into account the fact that hurricanes seem to come in cycles, and that there is a period of relative dormancy followed by 25 years of greater activity. Andrew marked the start of one such 25 year period, which means we're in for quite a few more hurricanes between now and 2017. So part of the reason there have more intense hurricanes in the last decade is that there were fewer hurricanes overall in the preceding decades.
And there were several monster storms, such as the one that hit Long Island and New England in 1938, and the Labor Day Hurricane, which are definitely not part of the modern count.
Also, intensity is not the only guide to how much damage a storm can do. Speed of passage, point of landfall and geographic extent are just as important. Andrew was fast, compact and made landfall on the southern edge of a metropolitan area. Had it made landfall thirty miles north, had a wider windfield, or moved more slowly, the damage it inflicted could have easily been three or four times the actual amount. Wilma did massive damage in Florida while it was fading into a Category 1 storm, well down from its peak intensity.

(Having experienced Andrew, Wilma, Katrina, and several other hurricanes directly, this question is a bit more personal for me than some others.)

Posted by kishnevi | August 21, 2007 11:05 PM