Ivan Advisories

[Pebbles]

This had got to be fantastic for hurricane research...to be following such and obvious eyewall replacement cycle!

[Cape Verde]

The current Canadian model run doesn't give residents of Houston any comfort.

http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... =Animation

[Brent]

Man that outer eyewall is shrinking fast!

Is this good news...does it mean it's weakening?

Nope. Means it'll probably strengthen again and could be stronger than it's ever been.

[Brent]

Let's just say if a Cat 3 or stronger ever hits New Orleans head-on, it would be the worst catastrophe in U.S. history. The entire city would be devastated.

[Innotech]

this storm is undergoing a ton of eyewall replacements. How many is that now?

[Sanibel]

Ivan has probably missed the trough. His low-tracking tendency has verified in this south of track persistence.

He is heading right towards Cancun now like Gilbert. I have to allow for some credibility to NHC's consideration of the trough pulling it up, so a clean pass through the Yucatan Channel looks likely. This should bring an unhindered Ivan right into the Gulf. Time for NHC to chuck all the previous models and refigure this one from here.

Looks like my "gut" prediction of 200 miles west of Sanibel and into the Gulf played out.

[JTD]

Man that outer eyewall is shrinking fast!

Is this good news...does it mean it's weakening?

Nope. Means it'll probably strengthen again and could be stronger than it's ever been.

You are the purveyor of bad news, my friend.

[patsmsg]

Is this good news...does it mean it's weakening?

Heck...I thought this would indicate strengthening. Shows how much I know...

[mobilebay]

Is there any doubt now that the track will be shifted west.
Lets recap the 12Z runs.
1. ETA= Mississippi Gulf Coast
2. GFs=Panama City
3. GFDl= Pensacola (6Z)
4. NOGAPS=New orleans
5. EURO=Alabama,Florida Border (00Z)
The threat is increasing along the northern gulf Coast including the greater New Orleans area.
Oh yea. I forgot.
6. Canadian= Louisiana
7. UKMET=Mobile

[MBryant]

has anybody been keeping track of the frequency of ERCs?

[JTD]

Is this good news...does it mean it's weakening?

Heck...I thought this would indicate strengthening. Shows how much I know...

Sorry about that...I was wrong...apparently this is a very bad sign.

[LCfromFL]

Man that outer eyewall is shrinking fast!

Is this good news...does it mean it's weakening?

No Jason, just the opposite. Generally the smaller the eyewall, the faster the spin - think of an ice skater...when his/her arms are stretched out as they spin, they spin fairly slowly...but when they pull their arms inwards, they spin faster. Same generally goes with hurricanes. In an eyewall replacement cycle, the storm will form a 'secondary' eye - larger in diameter than the 'original' eye. The inner eye becomes raggedy and eventually collapses (the pressure usually goes up and the winds slow down a bit) - then the outer eyewall becomes the 'new' eye....which then shrinks and the pressure drops and the winds pick up again.

[rainstorm]

i am surprised the nhc track is so far east

[patsmsg]

[quote="SouthFLTropics"]It seems that Ivan has continued to defy the models, moving more southerly and westerly than what has been forecasted...<cut>...I mentioned in an earlier post last evening about the lack of research and data in such monsters since they are such rare events. Could this possibly be leading to model data that is slightly incorrect?quote]

I think you make an excellent point. There just isn't enough information on this more powerful storms. IMO, it seems likely that it would take more to influence a larger storm than a smaller one. Just makes sense to me, but I don't really know.

[southerngale]

Although I don't believe this model is correct since it's a left outlier, if the ridge is eroding, what is it seeing to cause such a westward shift? The NHC seems fairly confident in their track.
(note: I don't know how to read everything on that map...yet. lol )

[Shullate]

Sorry about that...I was wrong...apparently this is a very bad sign.

Think of a figure skater pulling her arms in.

[JTD]

Man that outer eyewall is shrinking fast!

Is this good news...does it mean it's weakening?

No Jason, just the opposite. Generally the smaller the eyewall, the faster the spin - think of an ice skater...when his/her arms are stretched out as they spin, they spin fairly slowly...but when they pull their arms inwards, they spin faster. Same generally goes with hurricanes. In an eyewall replacement cycle, the storm will form a 'secondary' eye - larger in diameter than the 'original' eye. The inner eye becomes raggedy and eventually collapses (the pressure usually goes up and the winds slow down a bit) - then the outer eyewall becomes the 'new' eye....which then shrinks and the pressure drops and the winds pick up again.

LC...that is an excellent explanation...thanks!

[BigO]

Cat 3 might do it. A Cat 4 would.

Getting more and more nervous about this. At thtis point, if they called a NOLA landfall (or anything 100 miles either side), it would be a matter of just getting out alive. Forget boarding up...the trouble will be getting out of town at all.

[rainstorm]

i agree. i am puzzled the nhc keeps it so far east

[southerngale]

No Jason, just the opposite. Generally the smaller the eyewall, the faster the spin - think of an ice skater...when his/her arms are stretched out as they spin, they spin fairly slowly...but when they pull their arms inwards, they spin faster. Same generally goes with hurricanes. In an eyewall replacement cycle, the storm will form a 'secondary' eye - larger in diameter than the 'original' eye. The inner eye becomes raggedy and eventually collapses (the pressure usually goes up and the winds slow down a bit) - then the outer eyewall becomes the 'new' eye....which then shrinks and the pressure drops and the winds pick up again.

Good explanation...thanks.