Great reply I got from Dr. Lyons todoy regarding katrina.

[seflcane]

I emailed him for his opinion on the northern Gulf and the factors it plays on hurricanes and this is his response.

The "official" intensity is all that matters. Whatever I might say would be meaningless since the NHC has the final decision on Katrina's intensity. It would appear to me that NHC would likely keep it a CAT 4 at first landfall and based on surge etc....possibly keep it a CAT 4 in MS. We will see.

Regards weakening near the Gulf coast....I am not a big SST or H2O content advocate. The Gulfmex is warm enough to sustain a CAT 5 anywhere during the peak months of hurricane season...so I say forget that. My opinion is that for slower movers land itself is likely disrupting the ciruclations a little so we would always expect weakening as any TC gets close to land. The westerlies often lie near the Gulf coast and that too is not good for strong TC's as shear and subsidence can affect them. Finally we have just been lucky the past 25 years...look back to earlier times you will see strengtheners near landfall in the Gulf.

Sincerely, Steve

[seflcane]

Also I find his heat content comment interesting too.

[Dean4Storms]

I tend to agree with him, a few degrees cannot make that much difference. Whereas land especially along the gulf coast begins a steady rise in elevation the further inland you go would have to be a bigger player along with the westerlies as he mentioned. We all saw how very flat and wet land across the southern tip of Florida did very little to disrupt Katrina, but look at how much Mitch weakened as he near the mountainous Honduran/Nicaraquan coasts. Even the thin strip of Cuba weakens most storms that are moving from south to north where heat content and the SST's are boiling.

[seflcane]

I tend to agree with him, a few degrees cannot make that much difference. Whereas land especially along the gulf coast begins a steady rise in elevation the further inland you go would have to be a bigger player along with the westerlies as he mentioned. We all saw how very flat and wet land across the southern tip of Florida did very little to disrupt Katrina, but look at how much Mitch weakened as he near the mountainous Honduran/Nicaraquan coasts. Even the thin strip of Cuba weakens most storms that are moving from south to north where heat content and the SST's are boiling.

He said the same thing during Ivan too. The SST in the gulf were boiling just of the LA coast.

[f5]

i think the reason why storms weaken in the northern gulf is beacuse of all that super dry air coming of the continent as compared to Flordia which has water on both sides.

[truballer#1]

i think the reason why storms weaken in the northern gulf is beacuse of all that super dry air coming of the continent as compared to Flordia which has water on both sides.

agree, but also the southern florida has warm swampy water

[Aslkahuna]

If you look at the drought monitor, you will also see an area of dryness NW of where Katrina hit so this meant that the air over land in that area was probably drier than normal. Land interaction is very important as well-watch typhoons as they approach Luzon, Taiwan or Japan when the circualtion starts coming over thos mountainous islands. Also watch storms that approach mainland China or NW Australia and you will see similar weakening so it's not just the Gulf Coast.

Steve

[truballer#1]

If you look at the drought monitor, you will also see an area of dryness NW of where Katrina hit so this meant that the air over land in that area was probably drier than normal. Land interaction is very important as well-watch typhoons as they approach Luzon, Taiwan or Japan when the circualtion starts coming over thos mountainous islands. Also watch storms that approach mainland China or NW Australia and you will see similar weakening so it's not just the Gulf Coast.

Steve

read somewhere that katrina weekend becasuse the dry air fron the northwest got in katrina and weakened it. if no dry air it would of stayed a strong cat5

[wxmann_91]

Shear maps right before landfall indicated that the upper-level anticyclone over Katrina had moved to the southwest, so instead of helping the storm, it induced some southwesterly shear. A band of strong westerlies from a shortwave trough did not budge across middle LA and MS. Shear was rapidly increasing all around Katrina.

The only thing I'm missing are the shear maps (should've saved them), but it was clear that Katrina was moving into a hostile environment, the anticyclone was restricting outflow on the southwestern, western, and southern side, and the westerlies from the shortwave brought in some dry continental air.

[johngaltfla]

Also I find his heat content comment interesting too.

As do I. I've seen lots of "the gulf is cooler so it's safer now" statements here and elsewhere (that's to paraphrase).

I think that we're not safe until it drops below 82 degrees, but then again, I'm just praying for snow in Tampa by September 20th now.

[mettski]

Also I find his heat content comment interesting too.

As do I. I've seen lots of "the gulf is cooler so it's safer now" statements here and elsewhere (that's to paraphrase).

I think that we're not safe until it drops below 82 degrees, but then again, I'm just praying for snow in Tampa by September 20th now.

Why is Tampa getting all the attention? - ophelia ? - my gf is in tampa so i'm particularly interested.

[seflcane]

Also I find his heat content comment interesting too.

As do I. I've seen lots of "the gulf is cooler so it's safer now" statements here and elsewhere (that's to paraphrase).

I think that we're not safe until it drops below 82 degrees, but then again, I'm just praying for snow in Tampa by September 20th now.

Im interested to see how all the runoff from draining New Orleans will effect the Heat content in the Gulf.

[NateFLA]

Could you forward me that email?

If so i'll PM you with my email address....

[seflcane]

Could you forward me that email?

If so i'll PM you with my email address....

The email is in the very first post of the thread.

[NateFLA]

Could you forward me that email?

If so i'll PM you with my email address....

The email is in the very first post of the thread.

I know... I am regarding the specific email itself...

[seflcane]

Could you forward me that email?

If so i'll PM you with my email address....

The email is in the very first post of the thread.

I know... I am regarding the specific email itself...

See Pm.