concentric eye

[Derek Ortt]

Looking at some zoomed in sat loops, it is apparant that Frances now has a concentric eye. This is likely the first of many eye wall replacements that will occur.

This is likely a 110KT hurricane at the present time

[Matthew5]

When it has the eye wall replacement. Then that new eye is going to tighten. Then it is going to bomb!

[Derek Ortt]

NO,

when it goes through a replacement, this thing will weaken up to 2 categories, justa s Floyd did in the bahamas, then quickly re-intensify

[NorthGaWeather]

It will probaley weaken down to a Cat 2 but nothing below that. Then bomb back out.

[B-Bear]

Wasn't this a pretty quick eye wall replacement, Derek? I mean, I don't recall one happening that soon after a hurricane formed before. Could just be I didn't notice.

[Derek Ortt]

we've also seen very rapid intensification and a very tight eye. This doesn't surprise me all that much since nearly every major hurricane undergoes this

[USAwx1]

When it has the eye wall replacement. Then that new eye is going to tighten. Then it is going to bomb!

it's not going to tighten. The eye is going to become much larger in diameter once the cycle is complete.

Concentric Eyewall cycles occur mostly in storms which attain cat 3 status or greater (w/ winds of AT LEAST 110 Kt). Spiral rainbands develop a complete or near-complete circle of convection around the eyewall--which cuts off the requited moisture and momentum, initiating a weakening process where minimum pressure rises, and wind speed decreases coincidently--while the diameter of the eyewall it's self increases. The outer eyewall then replaces the inner eyewall and becomes the primary one, at which time a rapid intensification may take place.

Frances may also become an Annular cane eventually
largesymmetric system with a large-diameter eyewall, and few outer rainbands. Recall Alex took on this structure over the NW Atlantic as a CAT 3 system.

[B-Bear]

we've also seen very rapid intensification and a very tight eye. This doesn't surprise me all that much since nearly every major hurricane undergoes this

Well, I guess that makes sense. You can only wind that sucker up so tight before you gotta wind it up again. I am just used to seeing the canes build for 2 or 3 days before cycling through an eye. But the rapid intensification explains it. How long do you think it will take it to get back up to speed after the cycle?

[Guest]

Isabel took on that shape too. hen it was a cat 5, it didnt have any bands. Just a monstrous donut.

[Pebbles]

I remember she also got the spoked wheeled look in her eye....Some stunning shots from her as well.

[USAwx1]

I remember she also got the spoked wheeled look in her eye....Some stunning shots from her as well.

those were actually mesovorticies rotating around within the eye it's self.

This is the best Image i have, but you should be able to see what im talking about by looking very closely at the eye.

[B-Bear]

I remember she also got the spoked wheeled look in her eye....Some stunning shots from her as well.

those were actually mesovorticies rotating around within the eye it's self.

This is the best Image i have, but you should be able to see what im talking about by looking very closely at the eye.

Okay, explain what those are. Please.

[Anonymous]

If ever a hurricane has challenged Gilbert as far as intimidation (looks wise), Isabel was it.

[WXBUFFJIM]

I remember she also got the spoked wheeled look in her eye....Some stunning shots from her as well.

those were actually mesovorticies rotating around within the eye it's self.

This is the best Image i have, but you should be able to see what im talking about by looking very closely at the eye.

That looks like Isabel to me. Isabel was a classic example of these small mesovorticies circulating inside the eye itself. Folks have been doing research on how these relate to the intensity of tropical cyclones. It's definitely awesome to look into for the future.

[Air Force Met]

The TMI pass shows the 2 eyewalls. The inner one is dissipating. The outer one looks to be about 80 miles across...with about 60 miles in the middle. Frances is peaked at the time being and will fill from here. The new eyewall show continue to move in and by tomorrow night...I suspect we will see a storm with a 20 or 30 miles wide eye.

http://www.nrlmry.navy.mil/tc_pages/04_ ... _full.html

[WXBUFFJIM]

It's quite obvious the inner wall is collapsing and the outer wall will replace that. A larger diameter eye wouldn't surprise me by this time tomorrow. It's also possible this may not be the only eyewall replacement cycle either throughout Frances life.

Jim

[Hyperstorm]

It's definitely going through one of those eyewall replacement cycles. It's definitely obvious the inner wall will collapse and the outer wall will likely replace that. A larger diameter eye wouldn't surprise me by this time tomorrow. It's possible this may not be the only eyewall replacement cycle either.

Jim

I would not say it's possible this may not...It's LIKELY this WILL not be the only eyewall replacement cycle.

BTW...the outflow on the western side of the system is not expanding much now, which could mean...some shear in the horizon. However, we'll just have to wait and see if those winds retreat soon as forecast by the models...or...strengthening may be limited later on.

[Pebbles]

YEp that's Isabel...those pics still give me shivers. Thanks for resharing USAwx1. And if you know any links about mesovorticies in hurricanes I would love to look at them.