new ivan landfall info... no cat 4

[Derek Ortt]

http://www.pensacolanewsjournal.com/new ... 7C93.shtml

[PTPatrick]

Umm... I was under the impression it was already classified at cat 3 at landfall.

[weatherlover427]

What the flip?

[Anonymous]

It was. 120-130 mph at landfall.

[Derek Ortt]

now it appears to be 115-120 m.p.h., maybe a category two hurricane

[Anonymous]

Not a category 2. 115 mph seems right.

[Brent]

The Florida Coastal Monitoring Project has concluded Ivan's sustained wind reached only Category 1 strength in the Pensacola area and "minimal" Category 2 strength at Perdido Key. The study states the storm surge was equal to that of a Category 3 hurricane.

That's hard to believe.

[Derek Ortt]

not really

what everyone is forgetting is that in a cat 1 or a cat 2, most of the area only receives tropical storm conditions, veryf ew receive cat 1 and in a cat 2, probably only less than 2% of the landfall zone get cat 2 winds. The winds rapidly decrease about a mile or so inland due to friction by about 20 percent

[weatherlover427]

You have to remember a lot of the sensors stop reporting in extreme conditions.

[mascpa]

Try and tell that to the folks who endured Ivan. Cat 1, minimum cat 2 ... thats bunk IMHO.

[Brent]

Look at the damage pictures. I've seen a lot of Cat 1 and Weak Cat 2 storms make landfall and Ivan's damage isn't even comparable to it.

[Derek Ortt]

as I've said before which you seem to be unwilling or unable to grasp brent is that in cat 1's and 2's, only 2 percent receives the cat 2 winds. Most only gets a TS

Ivan unraveled and the wind field expanded; thus, a large area, like in Opal, received cat 1 to cat 2 winds.

Most people have no idea of the force of hurricane winds as what they think are hurricane winds, are really moderate tropical storm winds.

the lesson of this is, take all hurricanes very seriously. It does not take a cat 4 or a 5 to cause this type of damage

[The Big Dog]

Also, most of those pictures -- and I could be wrong, because I haven't actually been there -- appear to be pretty close to the water, judging by the descriptions. Winds will be stronger, storm surge has a greater effect, thus more destruction.

There are probably going to be questions about the quality of the construction, as well, much like after Andrew. There is a 42-story condo on Singer Island that was torn up by Frances and Jeanne, which probably blew only Cat 1 winds on the coast in Palm Beach County.

[SouthernWx]

Well, if Ivan is rated as a cat-2 or "minimal" cat-3 at landfall....then NHC needs to downgrade Frederic and Opal as well, because the damage caused by wind is worse that what I observed in the field after Opal....and as bad as what I observed after Frederic.

Of course, by now.....everyone with a knowledge of past Atlantic hurricanes should realize the official NHC records on ranking hurricanes of the past are at best unreliable, and IMO a joke.(hopefully the current re-analysis project by AOML/HRD will correct the mistakes).

Case in point? Both Isabel (2003) and Floyd (1999) are rated as cat-2 landfalls for North Carolina....yet 1955 landfalling hurricanes Connie and Ione are both rated cat-3, but neither wind damage nor storm surge were higher than Isabel and Floyd. (and central pressures even higher than Floyd and Isabel at time of landfall).


PW

[Derek Ortt]

many so called cta 3's are being dropped significantly in the re-analysis. Gilbert also may be lowered somewhat

The wind data from recon from both Opal and Ivan are very much alike. I'm not sure about the frederikc recon data. However, Opal only had a small, single streak of cat 3 winds in an unpopulated area between Destin and Panama City. Ivan may have had multiple streaks and unfortunately in more populated areas

Not sure about the Frederic recon data, but the surface obs from Frederic are just ab bit suspicious of a 115KT storm. Something is wrong when Georges had higher winds reported (IMO, Georges may also have been a marginal 3 at landfall due to the multiple gusts over 120 m.p.h. that were reported over a large area, plus, the symmetric distribution in the eye wall)

[SouthernWx]

I agree Derek...there's no way IMO that Frederic had sustained 115 kt winds at landfall....it was more likely 110 kt (125 mph).

Based on flight level winds, I seriously doubt Gilbert's sustained winds were higher than 175-180 mph. John Hope and I discussed that once at TWC. John said there was no doubt in his mind that hurricanes Camille and Allen were both more intense regarding sustained winds than Gilbert. In 1989, I recieved a letter from veteran NHC forecaster Bob Case that said essentially the same thing (his personal estimate was 155 kt for Gilbert and 160 kt for Camille).

PW

[EmeraldCoast1]

Wait a second. Here's the deal in my opinion... Sustained winds and wind gusts can cause very different damage to different objects. Everyone that stayed here for Ivan has told me how much worse the winds were than Erin and Opal.

More detailed descriptions always include something like, "the wind sounded like a jet taking off and didn't stop for 2 or 3 hours". Well, when I hear those descriptions and compare them to my experience in Erin, it all makes sense. The "jet engine" sounds were with the gusts in Erin. The "jet engine" sounds were with the sustained winds during Ivan.

When you have a 90mph wind that is not gusting back and forth, but constantly putting pressure on all those trees and structures, eventually some stuff is going to give. My theory can be supported by looking at the thousands of pine trees that are not snapped by the gusts causing them to sway back and forth, but are literally bent over at mid trunk from being pushed relentlessly during the hours of sustained winds.

My point is that each hurricane cannot be measured simply with wind speed. There is a force factor that can only be measured by the destruction it causes. 90mph winds that are sustained for 2 minutes at a time will cause different damage than 90mph winds that are sustained for 14 minutes - or 1 hour. But the experts will still say that both storms were the same category.

Also, the storm surge was more like a cat 4 in many areas here. I like one man's description that Ivan was like a boat with a big wake. Just because the wind speeds decreased before landfall didn't mean that the cat 4 and cat 5 wake it had built up over the previous few days was going to instantly subside.

[Blown Away]

Ok Derek, I was in the eye of Jeanne and the storm was classified at 120mph at landfall, so the Ivan data may show
Ivan a little weaker the Jeanne at landfall? The damage
seemed alot worse with Ivan (beyond surge damage along the coast)? I'm no expert, but I respect your opinion, because I
never thought in a million years that NOGAPS track would confirm! Jeanne landed about 20 miles N of that NOGAPS WPB track! You felt that track would confirm and it did, on top of me! I would really like to get the official info from Frances/ Jeanne, because there was an obvious difference in the gusts
between Frances/ Jeanne! I'm thinking if Ivan is reclassified
to 115mph then Jeanne was more potent than Ivan?? I don't
know about that!

[donsutherland1]

I'd be very interested to see the methodology of this study. Radar imagery immediately prior to landfall suggested a Category 3 hurricane albeit a weakening one. Storm surge was also at Category 3 levels (which the study acknowledges) and I believe it needs to reconcile its differing conclusions between the radar data and storm surge.

At this time, I very much doubt that the National Hurricane Center will downgrade Ivan's landfall from Category 3 to Category 2.

[LAwxrgal]

The wind damage that I've seen is consistent with a Cat 3, the surge damage is consistent with a 3/4. There was structural failure on many homes, that Cat 1/2 winds don't cause.

On the other hand, someone mentioned Jeanne. Yes, granted, she was intensifying at landfall, unlike Ivan, which was weakening...