2005 Hurricane Season starting to piece together...

[BayouVenteux]

...But we must remember that the northern Gulf cannot support systems above marginal cat 3 due to the very shallow depth of the warm water

Derek, please explain/elaborate if you would, as I'm somewhat confused, what with the history of major storms (Cat 3,4,5) having made landfall across the SE Texas, Louisiana, Mississippi, Alabama , and NW Florida Gulf Coasts. Granted they are not a common occurence relative to the average person's lifetime, but there's no denying they do indeed happen. Are you referring specifically to their sustainability as major hurricanes over a relatively long time period?

[Huckster]

http://www.nhc.noaa.gov/NHC_TCD_final.txt

Here is one of the 5 days for Hurricane Isidore. Notice the obvious collapse of the storm as it nears Louisiana. This was never a threat to be even a landfalling category 4 hurricane. Yes, it had potential, just as Lili did. But we must remember that the northern Gulf cannot support systems above marginal cat 3 due to the very shallow depth of the warm water

I don't want to get into a heated debate, but what exactly do you mean by the northern Gulf not supporting systems above marginal cat 3? I think we might have discussed this before, but I can't remember.

[Anonymous]

Audrey-North Gulf- 145 mph
Betsy- North Gulf- 150 mph
Camille-North Gulf-190 mph
Frederic-North Gulf-130 mph

??? I don't quite understand...

[Derek Ortt]

lets look at many of these systems in the northern GOM

Betsy: Weakened from 150 to a category 3 at landfall (Andrew did likewise in the same area)

Carmen: Weakened from a 4 to a 2

Camielle: Word is it is going to be lowered significantly upon the reanalysis from 165KT. I would not expect it to be any more than Andrew's S fla winds as a hurricane is nearly in gradient wind balance. That equation does not support winds any higher

Elena: Weakened from 110 to 100KT

Andrew: see Betsy

Opal: 130-100KT

Lili: 125-80KT (actual winds may have been 90, recon did not sample the convective area in NW quad)

Ivan: 120-105KT

Bret: 125-100KT

The storms such as Frederic and Audrey did not become major hurricanes until reaching the northern GOM. The northern GOM does not have the heat content to allow for a mature cat 4 or 5 to survive, but it does have enough to allow for a cat 2 to intensify and there have been instances where these can under last minute RI, if the upper dynamics are there (such as an approaching trough). What is typical though is that everything seems to converge around the 100KT level for the north GOM (especially from Louisiana eastward)

[vacanechaser]

Good points Derek... I can see where you are coming from.. Pretty interesting... Makes sense to me.. Never did beleive the Camille numbers..


Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

[Scorpion]

I think the Camille numbers are quite reasonable for the amount of damage she did. They were recording 120 mph winds 100 miles inland.

[Brent]

I have ALWAYS noticed what Derek pointed out. I can remember Opal still very well to this day(we were in the eastern eyewall for awhile and 200 miles inland). It was still a solid Cat 1 sustained when it got here with gusts over 100 mph for several hours(between 11pm and 3am no less). That's with it being a marginal 3 at landfall. I shudder to think how bad it would have been had that come in as a 4 or 5.

[Anonymous]

I think Hurricane Camille was probably 170-180 mph. But not 190-200 mph.

[vacanechaser]

I agree Floyd, I was thinking near 170 sounds more reasonable..

As far as Lili goes, I was thinking about that whole situation, Lili may have had a better chance of being a much stronger hurricane at landfall, one due to the more compact size but two the water was plenty warm for her but Isidore really put a hurting on that being so large and basiclly churning the entire Gulf up. Lili passed right over the same area where Isidore's center passed once into the central Gulf and that heat content was gone plus overall cooler water left in Isidore's wake.. Lili COULD have been a big deal there IMO, but as they say, "I guess that is something we will never know."

Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

[Derek Ortt]

see the conference paper by Melecie Desflots for more info regarding why Lili weakened. Numerical model simulations showed a last minute shear increase, but only in the NW quadrant as the area-averaged shear was only borderline favorable/unfavorable

[Anonymous]

I have to disagree. Lili went from a Category 2 to a Category 4 over the same waters Isidore crossed a week before. I think it was the shear. There was not alot of shear, but Lili was so small, she imploded.

As for the examples of North Gulf Hurricanes that weaken as Derek pointed out, although I see your point on some, I think others are coincidental.

Carmen--Carmen was 150 mph right off the coast, but it scraped along the coast, and that weakened it:::


Opal--Eyewall Replacement Cycle

[Derek Ortt]

Opal was a candidate to make it as a cat 4 due to its fast motion; however, the other negative factor of the north gulf struck... shear. Shear increased to about 25KT at landfall

[Anonymous]

So far...the top four strongest US Hurricanes ever are:::

1. 1935 Labor Day Storm at Craig Key, FL - 185 mph/892 mb
2. 1969 Hurricane Camille at Pass Christian, MS - 185 mph/909 mb
3. 1992 Hurricane Andrew at Homestead, FL - 165 mph/922 mb
4. 1886 Indianola Hurricane at Indianola, TX - 155 mph/925 mb

[Javlin]

Well guys I have to disagree on the Camille issue I was here staying out at KAFB.We listened to reports over the radio in Dolan Hall win gust well over 200+.Now were the reports from the Pass or the Bay or the flight line out front on the Back Bay I can not say.I do know this was a fallout shelter and I never in my life saw steel doors shake so much.Then we have the wind gage on one the ships that was in Gulport harbour stuck and pegged at 190 mph.

[MSRobi911]

casper

I lived through Camille as many of my relatives did in Saucier which is up Hwy. 49 from Gulfport. We know what she was, I don't care what they want to do in there post assessment. Camille had 190+ mph winds and a 30 foot storm surge. Ask anyone who lived thru it!

Mary

[jann13]

I am not an avid weather forcaster, but do have an intrest in the Hurricane season. I became very interested last year after the 2004 season. Is it possible that 2005 could have the same effect on Florida as 2004 and I am starting to hear that the Bermuda High may be repositioning to direct Hurricanes to Florida again. Is this true? Sorry if I sound nieve.

[Derek Ortt]

the ship guages are not at 10m. The winds at 100m above the surface are significantly higher because within the boundary layer, the wind increases logrithmically with height. Those ship reports without the height of the anemometers are not very meaningful


Also, many of those wind reports on the radio are estimates and eye witness estimates are typically severe over-estimates. I was guilty of that myself during Hurricane Frances when I'd stand on the balcony for a few minutes at a time

[Javlin]

You are right about ship probably Derek forgot about the height and they were on shore at that time possibily.The hulls of the two cargo ships ended up on land and from the bottom of the hull to the gage easily 100ft.It would be interesting to get wind reports from KAFB that nite.It is always a little breezy out there hence the name Gulf Breeze Golf Coarse next to the flight line.With your knowledge of research and records could that be possible?
I wanted to add one of the things I always remembered the next morning.As we opened the doors on the second floor and looked out I could see were windows implode;explode on the rear of cars as far as I could see.Our old chevy was just fine it suffer the old atage"If you listen real closely on a warm summer night you can hear the rust crackling".Our old chevy had holes in the floorboards.

[Anonymous]

I am not an avid weather forcaster, but do have an intrest in the Hurricane season. I became very interested last year after the 2004 season. Is it possible that 2005 could have the same effect on Florida as 2004 and I am starting to hear that the Bermuda High may be repositioning to direct Hurricanes to Florida again. Is this true? Sorry if I sound nieve.

Yes, let's hope not, and things can change, but it is looking like the High may build like, or stronger than 2004.

[Derek Ortt]

with the height of the anamemoter, an exprapolation based upon a simple model could be possible; however, hurricanes are not a simple model and the BL varies from storm to storm. Some storms have BL reductions of about 30%, while for others its only 10-20% and these processes are not that well understood. Thus, those ship reports indicate either cat 4 or cat 5, from what you've told me alone, its inconclusive.

If we have 850 or 700mb FL data, then a more realistic surface wind estimate can be made