New study about wind damage in Houston from Hurricane

[vbhoutex]

SE TX and especially Houston area residents need to check this out.
http://www.chron.com/news/houston-texas/article/New-study-highlights-region-s-extreme-wind-3605028.php#src=fb

[ROCK]

good stuff.....but I always though that an approach on the west end of Galveston would be worst case scenario not right up the ship channel ala IKE....that would put much of Houston in the NW quad...

[vbhoutex]

Alicia took a very similar track to that shown in the article. However her windfield was smaller that Ikes, as was her eye. The eye came in right over our location in the Spring Branch area of W Houston. To say the very least it was intense, but Ike was worse due to the windfield size and the fact that we were never in the eye at our location in SB. We were in the West eyewall for almost 6 hours though. The graphic pretty much confirms what I thought our winds would be at each category. I'm not sure I will stay around at my house(major trees)for 130 mph sustained even though they say hide from the wind, run from the water.

[ROCK]

yeah 130 would be a little high for me to stay around... that would be insane....

[Ptarmigan]

The strong +130 mph winds would be incredibly loud. I read hurricane wind decibel can go as high as 160 dB! That's about loud as thunder and is constant.

[beoumont]

The strong +130 mph winds would be incredibly loud. I read hurricane wind decibel can go as high as 160 dB! That's about loud as thunder and is constant.

I recall during Hurricane Andrew: I was in a house, under a table in the middle bedroom, very near the window which was covered with plywood; in a location 2 miles from the edge of the northern edge of the eye. Studies afterward indicated sustained winds at my location were 145 mph, with gusts to 175 mph. It literally sounded like a commercial jet engine was running just outside. A friend was sitting right next to me and when I screamed words at the top of my lungs, not a foot from their ear, my words could hardly be distinguished.
These cars below were about 65 feet from me, and I did not hear them flipping:

[ROCK]

I put this over in the ENSO thread but thought it was better suited for this SE Texas specific thread.

http://www.srh.noaa.gov/topics/attach/html/ssd97-37.htm

[MGC]

Trees are not the greatest worry. I had five trees land on my house in Dimondhead MS after Katrina. They did some damage but not major damage. Actually, I think the trees acted as a wind break. Several houses down the road that had much greater wind exposure had partial roof failure and had the winds been just a little stronger would have compromised the structural integrity of the house. Of course, it is your call to evacuate. I sat throught Hurricane Betsy in the French Quarter on the third floor of a house and the structure was moving a good bit....enough to make my Mom cry in fear.....MGC

[jasons2k]

I posted this on Eric's blog:

I seriously question the results of this tool if based on the Civil Tech study, and here is why. I almost could not believe what I saw from the maps published in Sunday’s paper. The maps depicted a Cat 2,3, or 4 moving NW at 10mph with a nearly linear windfield adjacent to the storm, on the left (wrong) side. If you follow me – the result shown on the Cat 4 maps is Cat 4 winds in Hempstead and Cat 3 winds (lower) in Baytown for a storm moving NW at 10mph. That’s impossible; it’s totally flawed.

The highest winds will be in the right quadrant, closest to the coast, and will drop-off quickly as you move inland. An accurate map of this would show curved (not straight) lines as contours. A more accurate set up maps can be pulled here: http://www.nhc.noaa.gov/aboutmeow.shtml. Here is a Category 5 at 12 knots: http://www.nhc.noaa.gov/gifs/GC13512.GIF. The highest wind threat hugs the coast and quickly drops as you move inland.

Those maps in this study simply cannot be relied upon for anything other than a hypothetical fantasy of real Cat 4 winds in Katy. It concerns me that there is so much focus on winds, and while they are a real threat, we are more likely to be impacted by inland flooding.

[vbhoutex]

After going into the site the COH has generated for this it became clear very quickly how flawed this study is. Whoever was in charge of gathering and assimilating the data for this apparently has no idea how a tropical cyclone works. It showed areas that would have 130mph sustained with higher gusts having less than a 25% chance of any structural damage. That is just plain ludicrous. IMO, it is also very dangerous to publish such a flawed tool to the public and tell them to use it to make life or death decisions. I told them that in the survey that they ask you to fill out after viewing the site.

[CrazyC83]

I posted this on Eric's blog:

I seriously question the results of this tool if based on the Civil Tech study, and here is why. I almost could not believe what I saw from the maps published in Sunday’s paper. The maps depicted a Cat 2,3, or 4 moving NW at 10mph with a nearly linear windfield adjacent to the storm, on the left (wrong) side. If you follow me – the result shown on the Cat 4 maps is Cat 4 winds in Hempstead and Cat 3 winds (lower) in Baytown for a storm moving NW at 10mph. That’s impossible; it’s totally flawed.

The highest winds will be in the right quadrant, closest to the coast, and will drop-off quickly as you move inland. An accurate map of this would show curved (not straight) lines as contours. A more accurate set up maps can be pulled here: http://www.nhc.noaa.gov/aboutmeow.shtml. Here is a Category 5 at 12 knots: http://www.nhc.noaa.gov/gifs/GC13512.GIF. The highest wind threat hugs the coast and quickly drops as you move inland.

Those maps in this study simply cannot be relied upon for anything other than a hypothetical fantasy of real Cat 4 winds in Katy. It concerns me that there is so much focus on winds, and while they are a real threat, we are more likely to be impacted by inland flooding.

Winds drop most significantly the first few miles from the coast. If the immediate coast sees Category 4 conditions, a few miles inland it will likely drop to Category 2 conditions (which are still extremely dangerous). After that, the drop-off is slow - most inland areas would see Category 1-2 conditions for quite a while.

Still, Category 2 winds will likely cause significant roof damage, destroy mobile homes, surely would knock most trees down and power would be lost to well over 95% of customers, likely 98-100%.

[Ptarmigan]

Winds drop most significantly the first few miles from the coast. If the immediate coast sees Category 4 conditions, a few miles inland it will likely drop to Category 2 conditions (which are still extremely dangerous). After that, the drop-off is slow - most inland areas would see Category 1-2 conditions for quite a while.

Still, Category 2 winds will likely cause significant roof damage, destroy mobile homes, surely would knock most trees down and power would be lost to well over 95% of customers, likely 98-100%.

I consider gusts more dangerous than sustained winds. For example, if an area has sustained winds of 100 mph, gusts can go as high as 140 mph. Gusts is usually what does the damage.

[Ptarmigan]

I posted this on Eric's blog:

I seriously question the results of this tool if based on the Civil Tech study, and here is why. I almost could not believe what I saw from the maps published in Sunday’s paper. The maps depicted a Cat 2,3, or 4 moving NW at 10mph with a nearly linear windfield adjacent to the storm, on the left (wrong) side. If you follow me – the result shown on the Cat 4 maps is Cat 4 winds in Hempstead and Cat 3 winds (lower) in Baytown for a storm moving NW at 10mph. That’s impossible; it’s totally flawed.

The highest winds will be in the right quadrant, closest to the coast, and will drop-off quickly as you move inland. An accurate map of this would show curved (not straight) lines as contours. A more accurate set up maps can be pulled here: http://www.nhc.noaa.gov/aboutmeow.shtml. Here is a Category 5 at 12 knots: http://www.nhc.noaa.gov/gifs/GC13512.GIF. The highest wind threat hugs the coast and quickly drops as you move inland.

Those maps in this study simply cannot be relied upon for anything other than a hypothetical fantasy of real Cat 4 winds in Katy. It concerns me that there is so much focus on winds, and while they are a real threat, we are more likely to be impacted by inland flooding.

I agree inland flooding is most dangerous. It is what kills most people in hurricanes, like Mitch, Floyd, and Irene. Also, storm surge is very dangerous as well. It killed most people in Great Galveston Hurricane and Katrina.

[CrazyC83]

Pure wind hurricanes like Andrew, Dean and Charley have had fairly low death tolls in comparison, despite being high category storms.

[vbhoutex]

Winds drop most significantly the first few miles from the coast. If the immediate coast sees Category 4 conditions, a few miles inland it will likely drop to Category 2 conditions (which are still extremely dangerous). After that, the drop-off is slow - most inland areas would see Category 1-2 conditions for quite a while.

Still, Category 2 winds will likely cause significant roof damage, destroy mobile homes, surely would knock most trees down and power would be lost to well over 95% of customers, likely 98-100%.

I consider gusts more dangerous than sustained winds. For example, if an area has sustained winds of 100 mph, gusts can go as high as 140 mph. Gusts is usually what does the damage.

I think you are correct in this assessment. that is what scares me about this software that the report was about. If we are getting 130 mph sustained we could be getting 150+ in gusts, yet the software showed a less than 25% chance of any damage to structures!! I did address my concerns with the people who developed it while I was at the Hurricane Workshop here in Houston, as were others who had the same concerns I did. Hopefully they will listen and revisit their results.

[jasons2k]

After going into the site the COH has generated for this it became clear very quickly how flawed this study is. Whoever was in charge of gathering and assimilating the data for this apparently has no idea how a tropical cyclone works. It showed areas that would have 130mph sustained with higher gusts having less than a 25% chance of any structural damage. That is just plain ludicrous. IMO, it is also very dangerous to publish such a flawed tool to the public and tell them to use it to make life or death decisions. I told them that in the survey that they ask you to fill out after viewing the site.

Great point and the more I think about this, it really disturbs me. Those maps were on the front page of the Sunday Houston Chronicle - it was a special section for goodness sakes! I'm surprised Eric Berger endorsed this. I generally respect him but this is just so flawed.

[ROCK]

I have seen what EF1-2 tornados can do and they are in a range of 130 sustained (well close enough) but you guys get my point. Damage would be substantial and not 25%....more like significant structural failure of homes when you throw in the gusts.....I think it was a tactic to get more people to buy the paper more than anything.

[MississippiHurricane]

Thanks so much for that link! I got back from Houston Tx last week and they had that story on the news on khou I think went to their site and could find the link or the story!

[CrazyC83]

I have seen what EF1-2 tornados can do and they are in a range of 130 sustained (well close enough) but you guys get my point. Damage would be substantial and not 25%....more like significant structural failure of homes when you throw in the gusts.....I think it was a tactic to get more people to buy the paper more than anything.

Not to mention in the tornadoes, the winds last for a MUCH shorter period - only seconds, or on rare occasions minutes, as opposed to 1-3 hours in the eyewall of a hurricane.