Tuesday, June 13, 2006

check the odds

Today's Houston Chronicle features an article with the grim title:
It withstood destruction before, but can it weather a hurricane?South Padre: A vulnerable isle

Go ahead and
read it if you must, but let me warn you, this is not a cheery way to start your day. Sample quote:

A major storm could easily produce a 23-foot wall of water. That's something South Padre may not be able to withstand, (building director Jay) Mitchim says. ''In that situation, all bets are off."


So reading this caused me wonder -- just what are the odds, anyway?

Higher than you might think. A google search led me to this page where people who supposedly know these things posted the following table:

Probabilities for all U.S. cities experiencing hurricane-force winds
        •        New Orleans, La. 29.30 % in 2006, 12.74 % average
        •        Mobile, Ala. 22.23 % in 2006, 11.30 % average
        •        Myrtle Beach, S.C. 18.42 % in 2006, 12.12 % average
        •        Brownsville, Texas. 15.52 % in 2006, 18.06 % average
        •        Cape Hatteras, N.C. 13.84 % in 2006, 20.12 % average
        •        Savannah, Ga. 13.58 % in 2006, 10.32 % average
        •        Galveston, Texas. 13.55 % in 2006, 11.40 % average
        •        Corpus Christi, Texas. 7.93 % in 2006, 7.97 % average
        •        New York. 7.38 % in 2006, 4.36 % average
        •        Atlantic City, N.J., 6.12 % in 2006, 4.61 % average
        •        Ocean City, Md. 5.67 % in 2006, 5.69 % average
        •        Cape Cod, Mass. 2.26 % in 2006, 7.22 percent average


So why are Brownsville's odds so much higher than the rest of the Texas coast -- and double those of Corpus? It seems neither right nor fair!

Of course, these are the same nattering nabobs of negativity who tell us we are already experiencing global warming, so I guess we are free to be skeptical about just how accurate a prediction those odds are... right?

5 Comments:

Blogger MLeahy said...

Well let's look at it this way, the odds are less than average unlike most of the Gulf Region and East Coast. There is something positive in everything. Enjoy the beautiful weather I see on the live cams. Wish I were there. MLeahy

1:49 PM  
Blogger Sam said...

Hi Mike - were's my Mike-a-Rita?

Now as to those statistics, you have to be careful. It is like a weather forecast for rain: is it a 20% change that it will rain or that maybe 20% of the local area could see measurable rain? Is it both? When it is 100% chance of rain why on Earth doesn't it rain at my house?

If there is a 15% chance of a hurricane does it mean that of an expected 16 storms, 2.4 would nail South Padre Island? I just don't think so. Nope, I think they're talking about a complicated trajectory analysis using a GIS and some fancy-schmancy probability statistics (N-P!).

To go back to what Cliff Rowell the Fire Chief was saying, a 23-foot "wall of water" could indeed wash the Island like a tsunami. With all due respect, it just don't happen that way. Nope, dude, during a surge the water rises like the tide and starts slowly rising. Any slop over 5-7 feet comes onto Gulf Blvd. High tide with the surge and waves can be a bitch.

And, that is what happened on the Florida coast today down south of Tallahasee, from TS Alberto. Could we get a chance of a Super Category 4-5 here? Yes, but those chances are like one in 500 years.

Oh and Mike, speaking of positives and blessings, TS Alberto saved a multi-million dollar ag crop in the Florida Panhandle, which has been in drought and burning up lately.

6:12 PM  
Anonymous Anonymous said...

First a tip of the hat to Sam for pointing out that Stats can be confusing and not always what they seem.
As for the 23 ft surge, I don't think it matters too much whether its a tsunami or just a high tide thing. ( ok, it matters but... ) The main thing is that all of the island other than a few condos would be under water and large parts would stay that way for a long time. That is what happened to Biloxi who had I think 22 ft. Have you been flooded out before ever?? Even after a day you are looking at ripping down all sheet rocked walls, mold gets extreme etc. Wouldn't end the town, some would build back but would be a big hurt and take years to recover.

As for the global warming, hurricanes come every year. The worst years may ( may ) have come during the years of the spanish armadas. Locally didn't the island get hit three times in one year back around 1941??? Seems like I read something like that though I could certainly be wrong as to the year. Still, thats before "global warming". Also thanks to Sam for mentioning that Alberto may have saved the orange crop and put out some drought related grass fires. ( a study of the 1998 dreaded el nino period showed that even though their were more storms ( some Cal flooding)and some areas of drought related to the el nino, and even though their was at least 4 billion in direct loses....the benifits to other parts of the country that got more than avg rain, had a longer growing season and plain ol folk who got to use less heating oil, caused a positive benefit of 19 billion, or a net plus of about 15 billion.) No, I am not hoping for a huricane here cause it might somehow help a different part of the country might need the rain. But, since Sandy mentioned the global warming thing I couldnt resist adding things aren't always as they seem whether its hurricane stats, or el nino, or global warming or whatever.

7:14 AM  
Anonymous Anonymous said...

Florida and the Sippi gulf coast have a very shallow tidal shelf that extends miles out to sea. This allows the back side of a hurricane to push up lots of surge. Thankfully south Texas has deep water just a few miles out.

Just my 2 cents worth.

Relax, Have a Homebrew!

Tha Beerman

8:18 AM  
Blogger Sam said...

Yeah, and we've got this nice barrier Island to slow down the wave energy as storms head to Brownsville and Harlingen! Those condos do come in handy sometimes...

I just read a NY Times article that the real problem was about one billion dollars in fraudulent FEMA claims by individuals. About one in five bucks spend went to things like nice hotel rooms in Hawaii, Girls Gone Wild videos, and football tickets. The article didn't even venture into commercial fraud, all those contractors cleaning up the mess. I say add another Bill.

9:22 AM  

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