historic? 22z July 28th GOM SST 85 - 95F!!!

[drezee]

Opal. Or was that September?

October, no cookie for you

[drezee]

Andrew, do I get my cookie, lol


this weakening rule only applies to strong cat 4 or 5 storms moving to the northern GOM. Won't work for the mouth of the MS River though due to the eddy

however, the NGOM can sustain a cat 3 storm, which as Dennis and Ivan showed, is more than bad enough for the area

Why did Andrew weaken before Landfall with LA? Water Temps? The NHC says different...

Code: Select all

When Andrew reached the north-central Gulf of Mexico, the high pressure system to its northeast weakened and a strong mid-latitude trough approached the area from the northwest.

[drezee]

The interesting thing is that, we don't have tons of August hurricanes in the GOM...September is much busier for the GOM

[Tampa Bay Hurricane]

Derecho-
alright I take what I said back
no hard feelings

[drezee]

Another interesting point, the deepest water buoy in the GOM (42002-Water depth~3,200.0 m) has recorded a SST of 92.0F this month.

42002 ENE 2.0 3.0 0.5 5 4.5 SSE 1013.0 -1.3 30.6 33.3 23.8 - - -

[baygirl_1]

this weakening rule only applies to strong cat 4 or 5 storms moving to the northern GOM. Won't work for the mouth of the MS River though due to the eddy
however, the NGOM can sustain a cat 3 storm, which as Dennis and Ivan showed, is more than bad enough for the area

Derek, I agree that Dennis, Ivan, and even Opal in '95 weakened before landfall. However, Camille, Frederic, and the hurricane of 1906 all hit the North Central Gulf Coast and all were at least Cat. 4 hurricanes. In fact, it looks to my very amateur eyes that those storms were at least maintaining their strength (if not strengthening) at landfall.
Therefore, my questions are:
--Were those storms anomalies?
--Or is this situation (North Gulf SSTs are high but lower water levels are significantly cooler) a recent phenomena?

It's all very interesting. Thanks in advance for your answers.

[Stormcenter]

All I got to say is BOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOM go's any tropical depression that moves into that area.

I've seen plenty of years where the GOM is hot and there's no tropical activity at all there.

More to life than SSTs.

And actually the GOM really isn't egregiously warmer than normal. It's normal for GOM SSTs to be extremely hot in late July, August, and September EVERY year; oddly, every year, people seem to be surprised by this.

I have never seen 95.2F though. I have seen 94 though.

You are correct there have never been temperatures that warm in the GOM or even the Carribean at this time of the season.

[wxmann_91]

IMO SST's are only important to sustain hurricanes.

What matters most is shear and dry air. Let me demonstrate.

-Dennis strengthened rapidly right in the GOM despite moving, actually according to some people here at Storm2k, a cool eddy. That's because its outflow was enhanced by an approaching midlatitude trough, but once the trough encountered Dennis, Dennis was sheared. This wasn't the most important thing, though, because the shear brought in dry air from the southwest that was obviously entrained into Dennis' southern quadrant at landfall.

-Lili and Opal both strengthened to powerful Cat 4's then weakened suddenly back down. Again, both were because of an approaching midlatitude trough that first strengthened the storms then came in for the kill (though of course they weren't killed by the trough, the trough just came in, land killed them actually )

-Frederic and the hurricane of 1906 were both weakening, not strengthening, at landfall. Besides, records in 1906 were primative at best.

-Camille was probably a special case where the midlatitude trough stalled or something so that it only enhanced outflow but never had time for "the kill". Still, I think that it too was weakening at landfall, and only came in as a marginal Cat 5.

-The best example of a trough strengthening a hurricane at landfall instead of weakening would be Charley. It suddenly strengthened to Cat 4 because of good ventilation. Another good example would be Ivan (right before landfall), where a trough helped Ivan become quite beautiful in the GOM (IMO) then weakening it afterwards. Like Dennis, dry air entrained into Ivan.

Location is everything. Any hurricane that makes landfall north of 28 degrees N on the Gulf Coast has a less chance of making landfall as a Cat 4 or 5 because of these midlatitude troughs and possibly more importantly, dry continental air wrapping into their circulations.

And don't forget about the east coast. Isabel and Floyd made landfall as weakening Cat 2's, approaching troughs wrapped dry air into their circulations.

But I'd have to bet that many of these hurricanes would've weakened faster in cooler waters with the same upper-level environment, so if you ask me if SST's were important, I'd say yes.

[baygirl_1]

Thanks for your thoughts, wxmann_91.

Any hurricane that makes landfall north of 28 degrees N on the Gulf Coast has a less chance of making landfall as a Cat 4 or 5 because of these midlatitude troughs and possibly more importantly, dry continental air wrapping into their circulations.

As a resident of the northern Gulf Coast (above 28N), I sincerely hope this idea is a fact! It sounds probable. It's kind of a given that SSTs are needed to sustain a storm. I think what those of us around the Gulf are most concerned about is a scenario in which an already existing/developing storm enters the Gulf. These high (if not abnormally high) SSTs would provide an enormous amount of fuel for the storm. If there is no trough or dry air to "protect" us, it is possible a monster Cat 4 or 5 could come a-knockin'. But, here's hoping not!
Thanks, again.

[Huckster]

I think I understand fairly well the idea that hurricanes, especially strong ones, need a relatively deep layer of warm water to maintain themselves, and just like it has been mentioned in a posts earlier, it does no good just to have a thin layer of 90 degree water if the waters just below that are chilly. Also, I know there seems to sometimes be a controversy over north Gulf hurricanes weakening before they make landfall. Definitely, in recent years, there's been a trend for major hurricanes to weaken in the northeastern Gulf (possibly, probably) due to the lack of heat content in the water. Here's something else I've noticed that supports this idea. According to the reanalysis work so far completed, of the four landfalling Cat. 4 hurricanes in the Gulf from 1851-1910, two struck Texas (1886, 1900) and two struck Louisiana (1856, 1893). Also, during the same period, most of the landfalling strong cat. 3 hurricanes in the Gulf (let's say 105 to 110 kts) struck Texas (1880) or Louisiana (1855, 1860, 1879, 1886, 1909). Mississippi was hit by two of these storms after they crossed Louisiana (1855, 1860) and they were weakening. Only one such hurricane (105 kts or greater) directly hit the area from Alabama to roughly Cedar Key, and that hurricane (1896) was being swept up by a strong coldfront and moving NNE at 32 mph at landfall.

I know right now the re-analysis work is being reviewed for the rest of the 1910's and 1920's, but I imagine most of the changes will probably not be revolutionary; there will be no cat. 4's discovered in the NE Gulf at landfall, and I know at least one hurricane (Oct. 1916) is being at landfall reduced from its current Cat. 3 designation. My guess is that we'll see the following for major hurricanes in the north Gulf (roughly southern Texas to Tampa/Cedar Key area is how I am defining it) when this work is done...

1915 Cat. 4, TX
1915, Cat. 3, LA
1916, Cat. 3, MS
1916, Cat. 3, TX
1917, Cat. 3, FL
1918, Cat. 3, LA
1919, Cat. 4, TX
1921, Cat. 3 FL
1926, Cat. 3, LA
1928, Cat. 3, FL/AL

If that's correct, that yields seven of those ten major hurricanes as Texas to Mississippi storms. Both Cat. 4's hit Texas. I don't know of any hurricane in the northeastern Gulf from 1930 to the present that stands any chance at being revised up to a Cat. 4 at landfall, while Carla and Audrey were Cat. 4's for sure, and possibly Betsy as well. Camille was not really a northeastern Gulf hurricane either, as far as I am concerned, but more of a north central Gulf storm. I would say that the general principle is that the area of the eastern half of the north central Gulf (let's say Alabama and the western Panhandle) to Tampa or northeastern Gulf is far less likely to see landfalling cat. 4's and 5's than is the area from Brownsville to Pascagoula. From 1851-present, at least nine Cat. 4's or 5's (1856, 1886, 1893, 1900, 1915, 1919, 1957, 1961, 1969) struck the northwest Gulf area while NONE struck the northeast Gulf. These are numbers, and weighty numbers at that, not feeling or opinion. This is, of course, contingent upon the Re-analysis yielding the results that I expect for those northwest Gulf storms, but there still will not be found, as far as I can tell, any storms in the northeast Gulf that will dispute this idea. Even if one or two such storms are discovered, the reasoning still stands. Again, I am not trying to say that it is always impossible for such a storm in the northeastern Gulf to make landfall, just that it definitely seems less likely.

My guess is that this is related to TCHP and also to the weather patterns prevalent in the northeast Gulf when large hurricanes are passing through that area, which often include shear and dry air, since many of the major hurricanes in that area occur in latter September and October. Here's one thing maybe you can help me on. When I look at TCHP maps, I see it drop off to zero along practically every spot along the Gulf, including the areas of Texas and Louisiana where many Cat. 3's and even strong Cat. 4's have made landfall. How did these storms maintain their intensity and in some cases intensify right up to landfall? It seems like the TCHP drops off to zero right where the ocean gets shallower. Is it possible that near TX and LA, this is the reason why the TCHP seems to drop, but since the water is shallow, the very warm waters go all the way to the bottom, eliminating the problem of upwelling colder waters that may happen near the FL Panhandle? Just a guess. I do not know much about that, so anyone who can offer some input on that in a cordial, constructive, friendly way, please feel encouraged to do so!

[drezee]

-Frederic and the hurricane of 1906 were both weakening, not strengthening, at landfall. Besides, records in 1906 were primative at best.

-Camille was probably a special case where the midlatitude trough stalled or something so that it only enhanced outflow but never had time for "the kill". Still, I think that it too was weakening at landfall, and only came in as a marginal Cat 5.

Come on:

Frederic:
59 28.40 -87.70 09/12/18Z 115 950 HURRICANE-4
60 29.70 -88.00 09/13/00Z 115 946 HURRICANE-4
Pressure dropped to 942 before landfall (hmmmmm)

Camille:
11 26.00 -87.70 08/17/06Z 155 - HURRICANE-5
12 27.00 -88.20 08/17/12Z 160 - HURRICANE-5
13 28.30 -88.70 08/17/18Z 165 - HURRICANE-5
14 29.40 -89.10 08/18/00Z 165 909 HURRICANE-5
winds increased up to the coast ( no one would fly into it: fear!)

[wobblehead]

This morning the weather buoy 70m south of Dauphin Island Al. reports a water temp of 87 f. You don't have to boil shrimp up here you just net'm and their ready to eat.

[AussieMark]

IMO SST's are only important to sustain hurricanes.

-Frederic and the hurricane of 1906 were both weakening, not strengthening, at landfall. Besides, records in 1906 were primative at best.

What Frederic was weakening at landfall. I may not know as much as others around here but I was certain that Frederic was intensifing at landfall.

[Derek Ortt]

Frederic was only a cat 3. It entered the NGOM already on an intensification trend and as a marginal 3, so it was able to do better, kind of like Erin in 1995. It's when the really big storms move toward the NGOM where the problems lie. Also, this doesn't seem to work west of Mississippi

[AussieMark]

Frederic was only a cat 3. It entered the NGOM already on an intensification trend and as a marginal 3, so it was able to do better, kind of like Erin in 1995. It's when the really big storms move toward the NGOM where the problems lie. Also, this doesn't seem to work west of Mississippi

Is this why Upper Texas Coast, Louisiana and Western part of the Florida Peninsula have had more strikes from category 4's compared to Mississippi- Florida Panhandle

[drezee]

Frederic was only a cat 3. It entered the NGOM already on an intensification trend and as a marginal 3, so it was able to do better, kind of like Erin in 1995. It's when the really big storms move toward the NGOM where the problems lie. Also, this doesn't seem to work west of Mississippi

Frederic was more likely a Cat 4 at landfall. Pressure at Dauphin lsland at landfall was 943 mb. Dauphin island bridge reported winds of 145 mph. Recon observed 138 kts at flight level just prior to landfall (~143mph est. Surface Winds).

Futhermore, the NHC classified it as a Cat 4 at landfall. 135 mph sustained

[Derek Ortt]

it was classified as a cat 3 with 115KT winds. 115KT can be either a cat 3 or a cat 4, they chose the cat 3 designation instead, though the recon does lead to 120KT winds, if it can be confirmed to have eben from the 700mb flight level. If it was at 850mb, then we are closer to 110-115KT

[Stormcenter]

Frederic was only a cat 3. It entered the NGOM already on an intensification trend and as a marginal 3, so it was able to do better, kind of like Erin in 1995. It's when the really big storms move toward the NGOM where the problems lie. Also, this doesn't seem to work west of Mississippi

Frederic was more likely a Cat 4 at landfall. Pressure at Dauphin lsland at landfall was 943 mb. Dauphin island bridge reported winds of 145 mph. Recon observed 138 kts at flight level just prior to landfall (~143mph est. Surface Winds).

Futhermore, the NHC classified it as a Cat 4 at landfall. 135 mph sustained

Frederic was a monster.

[Innotech]

KALAMASHIGGYSHIGGYBOOOOOOOM!!

High SSTs might not cause tropical activity but its scary to see such high ones

[BamaMan]

I know one thing . . . . No matter what Frederic was, it devastated us her in Mobile and Dauphin Island.
I was 19 at the time, and as far as this area is concerned nothing had come close before, or has since here in Mobile