SMFR Analysis incorrect with Rita and Katrina?

[Valkhorn]

I heard from someone that SMFR data could possibly be as much as 20 knots off with landfalling systems of 100 knots or more. Apparantly there was a study done in 2004 by NOAA which showed that sea spray and shallow water can cause large errors with major landfalling storms.

I'm trying to find the source for this, so if anyone has heard this too let me know.

Seeing as how Microwave readings could be effected by that, this kind of would make sense to me - and could shed some light on supposed SMFR data of Rita and Katrina that does appear to conflict with actual wind damage and recon reports of the storm up until land fall.

If anyone knows where I could look, let me know. This does sound plausible to me.

[Derek Ortt]

thats news to me. I'll ask the scientist at HRD who works with the SFMR. However, it did register 112KT for Jeanne

And again, wind damage does not measure wind speed

[Valkhorn]

How does wind damage not measure wind speed???

Besides, the only reason to point to the hurricane being much weaker than the NHC had said is SMFR data, and yet all other signs point to something else.

So I'd rather believe what actually happened and what I can see with my own two eyes from the damage and recon reports than an experimental product that hasn't been proven to be 100% accurate yet.

[Derek Ortt]

wind damage is a function of far more than just speed

dropsondes and oppler radar confirmed the SFMR results for Katrina. Give it up, it was not as strong as it initially seemed. I was wrong at real time as well

[facemane]

How does wind damage not measure wind speed???

Poorly constructed buildings will generally fail regardless of a Hurricanes
category strength. To give you an example, my Uncles fish camp
survived the NE quadrant of Camille, yet was completely leveled by
the Western edge of Frederick. No one is debating that Camille was
by far the most powerful storm of the 2.

[curtadams]

I've yet to see any picture of damage above Cat 3 anywhere in Katrina, and very few pictures that even suggest Cat 3. Even right on the MS coast you see fields of roofs with little damage and tall pines still standing. Go look at pictures and damage assessments and compare them to Charley. Not even close. Katrina's spectacular damage was overwhelmingly from surge - gutted buildings with intact roofs, barges dropped intact on top of 2 story buildings, NO largely underwater, etc.

[Valkhorn]

dropsondes and oppler radar confirmed the SFMR results for Katrina. Give it up, it was not as strong as it initially seemed. I was wrong at real time as well

Sources?

[Valkhorn]

I've yet to see any picture of damage above Cat 3 anywhere in Katrina, and very few pictures that even suggest Cat 3. Even right on the MS coast you see fields of roofs with little damage and tall pines still standing. Go look at pictures and damage assessments and compare them to Charley. Not even close. Katrina's spectacular damage was overwhelmingly from surge - gutted buildings with intact roofs, barges dropped intact on top of 2 story buildings, NO largely underwater, etc.

Really?

From:
http://www.nhc.noaa.gov/aboutsshs.shtml

Category Three Hurricane:
Winds 111-130 mph (96-113 kt or 178-209 km/hr). Storm surge generally 9-12 ft above normal. Some structural damage to small residences and utility buildings with a minor amount of curtainwall failures. Damage to shrubbery and trees with foliage blown off trees and large trees blown down. Mobile homes and poorly constructed signs are destroyed. Low-lying escape routes are cut by rising water 3-5 hours before arrival of the center of the hurricane. Flooding near the coast destroys smaller structures with larger structures damaged by battering from floating debris. Terrain continuously lower than 5 ft above mean sea level may be flooded inland 8 miles (13 km) or more. Evacuation of low-lying residences with several blocks of the shoreline may be required. Hurricanes Jeanne and Ivan of 2004 were Category Three hurricanes when they made landfall in Florida and in Alabama, respectively.

There is no question that that occurred. What about 4?

Category Four Hurricane:
Winds 131-155 mph (114-135 kt or 210-249 km/hr). Storm surge generally 13-18 ft above normal. More extensive curtainwall failures with some complete roof structure failures on small residences. Shrubs, trees, and all signs are blown down. Complete destruction of mobile homes. Extensive damage to doors and windows. Low-lying escape routes may be cut by rising water 3-5 hours before arrival of the center of the hurricane. Major damage to lower floors of structures near the shore. Terrain lower than 10 ft above sea level may be flooded requiring massive evacuation of residential areas as far inland as 6 miles (10 km). Hurricane Charley of 2004 was a Category Four hurricane made landfall in Charlotte County, Florida with winds of 150 mph. Hurricane Dennis of 2005 struck the island of Cuba as a Category Four hurricane.

Also in Hattiesburg, you might want to realize that something similar to this description happened:

Considerable damage: Roofs torn off frame houses; mobile homes demolished; frame houses with weak foundations lifted and moved; boxcars pushed over; large trees snapped or uprooted; light-object missiles generated.

And as you can see from http://www.ncdc.noaa.gov/oa/satellite/s ... ujita.html
this is equivalent to an F2 tornado.

And if you look at the damage and the assessment from the NWS in Jackson, MS on this page

http://www.srh.noaa.gov/jan/katrina/forrest_ms.htm

You'll see the following quotes:

Roof totally blown off of a veterinary clinic in Hattiesburg. Winds between 125 and 150 mph were likely needed to produce this damage.

Pictures from two heavily damaged neighborhoods in Hattiesburg. Again, damage such as this is common in strong tornadoes. With Katrina, damage of this intensity was widespread throughout the city.

And frankly Derrik, you haven't really posted any sources of reaserch as to why we should believe SMFR compared to the dropsondes yet.

I mean according to the NHC it was a Cat 3 in MS and a Cat 4 in LA. The NWS here says it was a category three well inland.

So, I'd rather believe the pros that have been out here surveying the damage rather than someone 1200 miles away who has not been here personally, and has really only looked at one or two SMFR graphs and this supposed dropsonde data which you haven't correlated it for us.

And have you yet looked at the possibility of a 20kt error with SMFR?[/quote]

[senorpepr]

...and has really only looked at one or two SMFR graphs and this supposed dropsonde data which you haven't correlated it for us.

And have you yet looked at the possibility of a 20kt error with SMFR?

Derek has posted the SMFR charts. The dropsondes have been posted in here as well in recon threads. Both match up along with radar. If three products are in close agreement in a wind speed, the accuracy is pretty high and would cancel out the "possibility of a 20kt error".

[curtadams]

I really appreciate somebody posting pictures. I respect people who back up their claims with evidence, and I think it's sad we've been having this discussion for a month now and this is the first time I've seen somebody post a pic or a trackable quote supporting high wind damage.

That said, there's nothing here that supports > Cat 3 or really even demands Cat 3. Partially peeled roofs, downed trees, and damaged signs don't require Cat 3 winds (except possibly the roofs). It's not comparable to Charley. Charley did things like this: http://www.bocabeacon.com/gallery/pages/IMG_3835.htm Also, that's not F2 damage. F2 damage is like this: http://www.srh.noaa.gov/lzk/html/pics022401ay-nf.htm It doesn't take remarkable winds to destroy structures in an economical sense. Even F1 winds of 73 mph are supposed to be able to peel roofs according to the (uncalibrated) Fujita scale. http://en.wikipedia.org/wiki/Fujita_scale

Anybody who says "that kind of damage requires 125 -150 mph winds" doesn't know what he's talking about. Nobody's ever put a wide range of structures into a high-speed wind tunnel to see what takes them out. Estimates of damage due to x winds in tornados or hurricanes are just rough estimates, nothing more. Tornado wind measurements are very poor. Hurricane measures are good for the storm as a whole but the correlation to a particular structure's experience on the ground is poor.

Weren't there some tornados in MS too?

[artist]

great post curtadams!

[f5]

its amazing to have a CAT 3 with a 927mb pressure

[john potter]

CurtAdams, helicopter surveys of Homestead, Florida City, Cutler Ridge and other areas in the cone of Andrew's cat 5 winds show well constructed houses relatively unscathed, retaining roofs -- amid the absolute litter of below-spec structures. Andrew revealed very localized patterns of extreme damage -- as I believe NASA's photographic overalays of Katrina's damage -- as far north as hattiesburg -- are beginning to show. Katrina was a low-end cat 5 six hours before landfall (according to Weatherunderground's Steve Gregory) and a solid cat 3 windstorm on the MS shore -- continually gusting to 125-130-140 mph for over 4 hours -- together with the cat 5 surge of 20-30 feet across a 50 mile stretch. Katrina was truly extraordinary and will be remembered as a legendary hurricane.

[john potter]

oops, I meant NOAA's overlays. Sorry.

[brunota2003]

Subject: D5) How does the damage that hurricanes cause increase as a function of wind speed?
Or to rephrase the question: Would a minimal 74 mph hurricane cause one half of the damage that a major hurricane with 148 mph winds? No, the amount of damage (at least experienced along the U.S. mainland) does not increase linearly with the wind speed. Instead, the damage produced increases exponentially with the winds. The 148 mph hurricane (a category 4 on the Saffir-Simpson Scale) may produce - on average - up to 250 times the damage of a minimal category 1 hurricane!

If You Dont Believe That, then this is where I got it from: http://www.aoml.noaa.gov/hrd/tcfaq/D5.html That is straight from the NHC, so evidently, you dont need a Cat 4 to produce Cat 4 damage, plus whatever is in the air could strike and damage the building, causing it to weaken... All it takes is one window, or two or three, to blow out, and, BOOM, there goes your roof...

[dhweather]

I really appreciate somebody posting pictures. I respect people who back up their claims with evidence, and I think it's sad we've been having this discussion for a month now and this is the first time I've seen somebody post a pic or a trackable quote supporting high wind damage.

That said, there's nothing here that supports > Cat 3 or really even demands Cat 3. Partially peeled roofs, downed trees, and damaged signs don't require Cat 3 winds (except possibly the roofs). It's not comparable to Charley. Charley did things like this: http://www.bocabeacon.com/gallery/pages/IMG_3835.htm Also, that's not F2 damage. F2 damage is like this: http://www.srh.noaa.gov/lzk/html/pics022401ay-nf.htm It doesn't take remarkable winds to destroy structures in an economical sense. Even F1 winds of 73 mph are supposed to be able to peel roofs according to the (uncalibrated) Fujita scale. http://en.wikipedia.org/wiki/Fujita_scale

Anybody who says "that kind of damage requires 125 -150 mph winds" doesn't know what he's talking about. Nobody's ever put a wide range of structures into a high-speed wind tunnel to see what takes them out. Estimates of damage due to x winds in tornados or hurricanes are just rough estimates, nothing more. Tornado wind measurements are very poor. Hurricane measures are good for the storm as a whole but the correlation to a particular structure's experience on the ground is poor.

Weren't there some tornados in MS too?

Here's some pure wind damage from Katrina - please help me understand
how this is different than the photo from Charley that you referred to.

<img src="http://www.datasync.com/~magee/wind3.jpg">

[TS Zack]

Thats inland unlike the one for Charley...


Oh well, we will see what the NHC says.

[timNms]

May as well give it up guys. Until those who are skeptical actually GO to the places and look at the damage themselves, they'll not believe. Pictures really don't show the true scope of the damage. Also, there aren't that many pictures from Mississippi as the media was focused on the disaster that was unfolding in New Orleans.

Chris Landsea of NHC emailed me and told me they'd probably have the final analysis of the data posted on the NHC site in NOV or DEC. Regardless of what the mets on S2K say (and the amateurs as well), NHC is the final authority.

And Curtadams, if you'll go back thru the Katrina threads, you'll find that I posted a link to the Jackson NWS office that discussed the damage done in southern Mississippi.

[tornadochaser86]

either way that hurricane was very destructive cat 3 or cat 4