New Paper: Normalized Hurricane Damage in the U.S.

[wxman57]

Here's an excellent paper by Pielke, Jr., R. A., Gratz, J., Landsea, C. W., Collins, D., Saunders, M.,and Musulin, R. The paper normalizes all hurricanes between 1900-2005 to 2005 dollars and accounts for coastal development over the last 106 years.

And the winner is ...

1. Great Miami Hurricane 1926 -- $157 billion
2. Galveston 1900 -- $99 billion
3. Katrina 2005 -- $81 billion
4. Galveston 1915 -- $68 billion

I think the cost for Katrina is probably a good bit higher than that $81 billion estimate.

Here's the link to the paper:

http://sciencepolicy.colorado.edu/publi ... _paper.pdf

[Jim Cantore]

Good stuff

However, I find it very hard to believe that this would cause only $13.7 billion

[wxman57]

Good stuff

However, I find it very hard to believe that this would cause only $13.7 billion
http://weather.unisys.com/hurricane/atl ... /track.gif

Take a look here. Search on Cat 3-4 hurricanes within 65nm of Miami for 1947. You can zoom in on the track:

http://maps.csc.noaa.gov/hurricanes/viewer.html

Although no data are provided on the wind field structure of the 1947 hurricane, that hurricane passed 30-40 miles north of Miami, so the strongest wind would have missed the most populated area as it tracked to the west to west-southwest across south Florida. The 1926 hurricane was likely larger and more powerful, striking just south of Miami it would have put Miami in the right-front quadrant.

[MGC]

It won't be long before the Miami area overtakes Katrina's real damage numbers. Heck, a pool enclosure in Miami Beach most likely costs more than the typical house in the lower 9th ward in New Orleans. Yep, the damage costs will be off the scale with the next 1926 type hurricane in south Florida.......MGC

[Jim Cantore]

Worst Possible storm I can think of is Miami, around to Tampa, then up the coast to NYC, imagine THOSE numbers.

[wxman57]

Worst Possible storm I can think of is Miami, around to Tampa, then up the coast to NYC, imagine THOSE numbers.

Physical dollar damage is one thing, but long-term damage to our nation's economy is another. A worst-case scenario may be a direct hit on Houston-Galveston. Note the almost 4 million people living here, making it the most populous coastal area likely to be hit by a major hurricane (it was hit 5 times between 1900-1950 by a Cat 3-4 hurricane). For those of you not familiar with the area, it's the home of a tremendous number of oil refineries, a much greater concentration than southeast Louisiana. A direct hit could knock out as much as 30-40% of the U.S. refining capacity for months

[StormWarning1]

The Galveston 1915 storm was larger and more intense than the Galveston 1900 storm, it should be listed as number 2.

Storm surge was actually higher in 1915 than 1900 in Galveston.

If the South Florida real estate market keeps tanking the Miami 1926 hurricane might slip a few notches on the list.

[wxman57]

The Galveston 1915 storm was larger and more intense than the Galveston 1900 storm, it should be listed as number 2.

Storm surge was actually higher in 1915 than 1900 in Galveston.

If the South Florida real estate market keeps tanking the Miami 1926 hurricane might slip a few notches on the list.

Taking a look at the tracks of each of the Cat 4 hurricanes, the 1900 hurricane moved ashore just a little up the coast of the 1915 hurricane:

http://myweb.cableone.net/nolasue/gls.gif

But that shouldn't have accounted for a $30 billion difference in damage estimates. I think you've found an error in their calculations. Take a look at their equations. One of the main factors in calculating today's dollar damage is the damage that occurred the year the storm hit. The big problem with the two GLS hurricanes is that there was no seawall protecting GLS in 1900 so the island was nearly destroyed. In 1915, the newly-constructed seawall prevented the surge from washing over the island. So the damage from the 1915 hurricane was far less than from the 1900 hurricane. In order to get the 1900 hurriacne "right", the authors would have to estimate the 1900 damage had a seawall been in place.

Good catch.

[MiamiensisWx]

I'm sorry, but I don't believe this storm would cause just $3.1 billion in damages roughly...



The overall housing expenses in the Tarpon Springs/St. Petersburg/Tampa Bay/Sarasota/Bradenton region, along with the expanding size of such a storm and synoptic setup and the angle of approach (allowing a significant surge), would surely result in much higher damage totals even when normalized. Also, despite the Unisys data, this was a Category Three at Florida landfall per NOAA.

[wxman57]

I'm sorry, but I don't believe this storm would cause just $3.1 billion in damages roughly...

http://weather.unisys.com/hurricane/atl ... /track.gif

The overall housing expenses in the Tarpon Springs/St. Petersburg/Tampa Bay/Sarasota/Bradenton region, along with the expanding size of such a storm and synoptic setup and the angle of approach (allowing a significant surge), would surely result in much higher damage totals even when normalized. Also, despite the Unisys data, this was a Category Three at Florida landfall per NOAA.

That storm was a lower-end Cat 2 with 95-100 mph winds at landfall. It struck the coast north of Clearwater almost to Tarpon Springs. Now just because it wsa a Cat 2 doesn't mean that it had Cat 2 winds all around the center. Such a hurricane might only have produced a few pockets of hurricane-force winds in the Tampa Bay area, as inland winds will typically be 1-2 categories lower than max sustained winds offshore. Surge height would have depended upon the expanse of the stronger wind field. As we saw with Charley in 2004, a small hurricane produces a small storm surge. Without details on this hurricane's wind field, I don't think that you could conclude such a storm would cause a lot more damage than $3 billion. I agree that a large and powerful hurricane could put much of Tampa underwater, causing considerably more damage than $3 billion.

I was just looking through the tracks from 1851 at Coastal Services Center using their excellent viewer:

http://maps.csc.noaa.gov/hurricanes/viewer.html

Interesting that Tampa Bay has never been hit by a hurricane stronger than Cat 2.

[Derek Ortt]

I believe the 1921 storm was reanalyzed to 110KT at landfall (though I have little confidence in those findings as the value was derived using a standard pressure to wind relation, not an October GOM one

[wxman57]

I believe the 1921 storm was reanalyzed to 110KT at landfall (though I have little confidence in those findings as the value was derived using a standard pressure to wind relation, not an October GOM one

Right, there's no precise relationship between central pressure and max winds. It all depends on the size of the hurricane. Such an estimate based solely on central pressure could be 20-30 kts off.

[MiamiensisWx]

I believe the 1921 storm was reanalyzed to 110KT at landfall (though I have little confidence in those findings as the value was derived using a standard pressure to wind relation, not an October GOM one

Right, there's no precise relationship between central pressure and max winds. It all depends on the size of the hurricane. Such an estimate based solely on central pressure could be 20-30 kts off.

True, but I was just stating that a recent NOAA reanalysis has reclassified the October 1921 hurricane as a 105KT to 110KT Category Three at it's landfall in the vicinity of Clearwater and Tarpon Springs, as Ortt mentioned. It is still possible the storm was a still a marginal (lower-end) major hurricane at Florida landfall, as based on land friction and wind readings in the Tampa Bay region taken during the storm's approach, and I believe that this supports a pressure gradient for that storm that would still support an intensity of around 105KT (120MPH) at Florida landfall per the one-minute average. Also, those Category Three winds were likely restricted to a small area between Clearwater and Tarpon Springs (sparsely inhabited at the time) along the immediate shoreline.

[Deputy Van Halen]

Taking a look at the tracks of each of the Cat 4 hurricanes, the 1900 hurricane moved ashore just a little up the coast of the 1915 hurricane:

http://myweb.cableone.net/nolasue/gls.gif

But that shouldn't have accounted for a $30 billion difference in damage estimates. I think you've found an error in their calculations. Take a look at their equations. One of the main factors in calculating today's dollar damage is the damage that occurred the year the storm hit. The big problem with the two GLS hurricanes is that there was no seawall protecting GLS in 1900 so the island was nearly destroyed. In 1915, the newly-constructed seawall prevented the surge from washing over the island. So the damage from the 1915 hurricane was far less than from the 1900 hurricane. In order to get the 1900 hurriacne "right", the authors would have to estimate the 1900 damage had a seawall been in place.

Good catch.

What's even more important than the seawall when talking about huge storms is that they also raised the elevation of the city of Galveston between 1900 and 1915 (by 12 feet, I think). The storm surge from a Cat 4 could overtop the seawall, and if not it could at least get around the seawall by filling in the unprotected parts of the island first. But once the surge comes in that 12 feet makes all the difference in the world.

If the study were to start making adjustments for seawalls and levees and elevations and whatnot, then it becomes purely an estimate of "what if this storm hit today?". Was that what they intended? If so, maybe they should drastically scale back the Katrina estimate. Because aren't the levees in New Orleans "supposed to" be able to withstand another Katrina? (or soon will if they follow through on the plans?).

[wxman57]

Taking a look at the tracks of each of the Cat 4 hurricanes, the 1900 hurricane moved ashore just a little up the coast of the 1915 hurricane:

http://myweb.cableone.net/nolasue/gls.gif

But that shouldn't have accounted for a $30 billion difference in damage estimates. I think you've found an error in their calculations. Take a look at their equations. One of the main factors in calculating today's dollar damage is the damage that occurred the year the storm hit. The big problem with the two GLS hurricanes is that there was no seawall protecting GLS in 1900 so the island was nearly destroyed. In 1915, the newly-constructed seawall prevented the surge from washing over the island. So the damage from the 1915 hurricane was far less than from the 1900 hurricane. In order to get the 1900 hurriacne "right", the authors would have to estimate the 1900 damage had a seawall been in place.

Good catch.

What's even more important than the seawall when talking about huge storms is that they also raised the elevation of the city of Galveston between 1900 and 1915 (by 12 feet, I think). The storm surge from a Cat 4 could overtop the seawall, and if not it could at least get around the seawall by filling in the unprotected parts of the island first. But once the surge comes in that 12 feet makes all the difference in the world.

If the study were to start making adjustments for seawalls and levees and elevations and whatnot, then it becomes purely an estimate of "what if this storm hit today?". Was that what they intended? If so, maybe they should drastically scale back the Katrina estimate. Because aren't the levees in New Orleans "supposed to" be able to withstand another Katrina? (or soon will if they follow through on the plans?).

Yes, every structure on Galveston Island was raised between 10 and 15 feet behind the seawall. The seawall is actually about 15.8 feet high and the ground slopes up across Seawall Blvd. by about 3-5 feet. The study is meant to represent what kind of damage would occur today should the same storm hit the same area. Obviously, it would be a lot more work to account for changes in levee structures, topographical changes, etc. As for the Katrina number, it's the 2005 figure - there was no conversion factor as the study is in 2005 dollars. However, the estimate from earlier New Orleans hurricanes would have to be scaled back because the levees were raised after Betsy in 1965.

[Jim Cantore]

Good stuff

However, I find it very hard to believe that this would cause only $13.7 billion
http://weather.unisys.com/hurricane/atl ... /track.gif

Take a look here. Search on Cat 3-4 hurricanes within 65nm of Miami for 1947. You can zoom in on the track:

http://maps.csc.noaa.gov/hurricanes/viewer.html

Although no data are provided on the wind field structure of the 1947 hurricane, that hurricane passed 30-40 miles north of Miami, so the strongest wind would have missed the most populated area as it tracked to the west to west-southwest across south Florida. The 1926 hurricane was likely larger and more powerful, striking just south of Miami it would have put Miami in the right-front quadrant.

I was talking more about it's second landfall.

[wxman57]

Good stuff

However, I find it very hard to believe that this would cause only $13.7 billion
http://weather.unisys.com/hurricane/atl ... /track.gif

Take a look here. Search on Cat 3-4 hurricanes within 65nm of Miami for 1947. You can zoom in on the track:

http://maps.csc.noaa.gov/hurricanes/viewer.html

Although no data are provided on the wind field structure of the 1947 hurricane, that hurricane passed 30-40 miles north of Miami, so the strongest wind would have missed the most populated area as it tracked to the west to west-southwest across south Florida. The 1926 hurricane was likely larger and more powerful, striking just south of Miami it would have put Miami in the right-front quadrant.

I was talking more about it's second landfall.

The 2nd landfall into SE LA was as a minimal Cat 1 hurricane. The direction of approach wouldn't be too much of a problem. Such a hurricane might only produce damage in the millions, maybe not even tens of millions. Mainly power outages and minor flooding.

[Derek Ortt]

only 1 year has 2 in the top 15

2005

[Jim Cantore]

Good stuff

However, I find it very hard to believe that this would cause only $13.7 billion
http://weather.unisys.com/hurricane/atl ... /track.gif

Take a look here. Search on Cat 3-4 hurricanes within 65nm of Miami for 1947. You can zoom in on the track:

http://maps.csc.noaa.gov/hurricanes/viewer.html

Although no data are provided on the wind field structure of the 1947 hurricane, that hurricane passed 30-40 miles north of Miami, so the strongest wind would have missed the most populated area as it tracked to the west to west-southwest across south Florida. The 1926 hurricane was likely larger and more powerful, striking just south of Miami it would have put Miami in the right-front quadrant.

I was talking more about it's second landfall.

The 2nd landfall into SE LA was as a minimal Cat 1 hurricane. The direction of approach wouldn't be too much of a problem. Such a hurricane might only produce damage in the millions, maybe not even tens of millions. Mainly power outages and minor flooding.

I got ya.

What is the absolute worst angle of attack for New Orleans?

[Derek Ortt]

Now, the 47 hurricane would probably only cause damage in the tens of millions

Before Katrina, more, as evidenced by Cindy. The highrises would have suffered and that angle would not produce as much weakening before reaching NO as Cindy underwent