Emily looking much better on SAT PICS.

[mike18xx]

I don't know what "descending motion" you're talking about it; hurricane eyes form due to centrifuging; there may be some slight downward motion due to eddying with rapidly-rising convection in the eyewall (much as water near a stream-bank flows in reverse in places) -- but that isn't always so either:

That is incorrect. There is a lot of descending motion inside an eye. That is why the temperatures in an eye are warmer than elsewhere...it's called adiabatic warming. That is why there is no cirrus...and why clouds clear out from the top to the bottom.

In what way is that inconsistant with eddying? And "a lot of descending motion" relative to what? Rising motion in the eyewall? There's no comparison.

The idea that it is "centrifuging" alone...

I have not made a "'centrifuging' alone" assertion.

....It's not the rotation that pulls the clouds out...

Centrifuging clears the eyes of tornados.

if that alone were true...stronger storms would have bigger eyes because of the centrifugal force invovled.

Centrifigual force is opposed by the force of low pressure drawing the storm inward. I could also throw the same argument back at you, btw, e.g., "If stronger storms have more divergence aloft, then air should sinking more strongly in their eyes, clearing them out and making their eyes bigger!" Obviously, such relentless deductive logic off questionable premises in an actual evidence-free vacuum is imprudent.

The rotation actually works to help pull the air down as it centriguges out.

I'm watching Emily's eye form right now; cirrus veiling over the eye is....just sitting there, stubbornly refusing to sink and erode (it is, however, eventually leaking past eyewall cells and escaping outward). If there's downdrafting in the eye at 10,000 feet, it's not coming from the altitude of that cirrus, but rather represents a componant of internal eddying.

What causes the clearness in the eye is primarily due to decending air...centrifuging is one of the mechanisms that help in creating that decending air...

Via eddying, and I'm glad you're not discounting centrifuging now.

along with the convergence at the top of the storm.

A bunch of buoyant air being shoved by more buoyant air from underneath and thereby creating high-pressure aloft should not be automatically assumed to be converging. -- A helium ballon doesn't sink until it's popped, and latent heat-of-condensation warmed air parcels don't sink either until they expanded and cooled (which is why the stuff over Emily is just sitting there, queued up to flow outward and away).

OVer the eye itself...even in the upper levels...there is cyclonic flow.

I know that (it's quite obvious on the Isabel loop, btw).

My note: Warming air...because it is sinking...clears out the eye. The same is true concerning clear areas under ridges of high pressure.

If you're trying to make an analogy here, then you must account for the fact that hurricane eyes aren't high-pressure zones, but instead contain the lowest pressure of the storm (rather than lowest pressures being found in a doughnut under the eyewall with a high-pressure spike in the center). The fact that the eye has the lowest pressure is prima-facia evidence of a centrifuging partial-vacuum.

The sky is clear because the air is sinking and warms. There is much downward motion in the center of a hurricane...and the stronger the hurricane...the more downward motion there is.

Perfectly explainable by eddying internal to the eye.

Air comes upward through the eyewall and spreads. Some goes out in the form of outflow, some goes inward. That part that goes inward eventually collides with the other air that is going inward and has no place to go but down.

That's a theory, one of which I cannot see observable evidence. Just the opposite, in fact: In Isabel, there is no "convergience" of eyewall convection at all -- it ramps up and outward, with clear air (gravity?) waves rippling across the top of the CDO canopy; meanwhile, the eye is a zone of internalized eddying: http://cimss.ssec.wisc.edu/tropic/archive/2003/storms/isabel/movies/isabel-eye.html

[Pebbles]

This has to be one of the most facinating debates I've ever seen on this board..

[mike18xx]

Dude...read the AOML site...the guys who actually research WHY storms do things.

*Ahem*, *cough*, *cough*. I research storms too....and have been for quite awhile too, thank you.

... (Willoughby 1990, 1998)....[etc] "

I was in a Warner Robbins AFB WX office getting fresh facsimili prints of Hurricane Alicia in 1983, and I've personally ran my skinned eyeballs over virtually every storm since then. -- Don't let the low post-count here on this site throw you off.

[banshee]

This is one of the best threads I've seen. I love when the experts explain whats happening, to me a weather dummy, instead of just talking back and forth to each other.

Thanks, great info.

[mike18xx]

(Anyway.....)

Boy, is she ever a churning cauldron this morning....

I'm standing fast on my 135mph cat-4 prediction from last night

[Air Force Met]

OK...you know what...I've posted data and research from the HRD. Cyclonic flow in the upper levels converges and descends. I have posted numerous illustrations and links proving that the clearing of the clouds is caused by sinking air.

Tornados? You are compairing a microscale event to a synoptic event. Not even a comparison on structure...and it shouldn't be compaired. Also...nobody compaired the descending motion to rising motion of the eyewall. However, it is descending air that dries air out. Ever heard of a lee-side trough...Chinook winds? Its the same principle and it doesn't take a lot of descending air to warm it to a point...well above the dewpoint...where there can be no condensation.

As I have posted...the eye is clear because of sinking air. If you want to argue with that theory...argue with the HRD and the NHC...including those who do the research.

Here more proof for you on why the eye is clear:

"Why is the eye clear? <b> An eye becomes visible when some of the rising air in the eye wall is forced towards the center of the storm instead of outward -- where most of it goes. This air is coming inward towards the center from all directions. This convergence causes the air to actually sink in the eye. This sinking creates a warmer environment and the clouds evaporate leaving a clear area in the center (see warm core formation below). </b> Although subsidence in the eye is sometimes sufficiently strong to produce clear skies, there are often shallow cumulus clouds near the surface. The eye is easily recognized in radar photographs and satellite pictures unless a cirrus canopy covers the top of the storm."

http://www.newmediastudio.org/DataDisco ... truct.html

As far as Emily goes...she is not classically structured yet. Again...post some resources to back up your claim. Right now all you are offering is your opion...with nothing to back it up. Opinions without facts are worthless. Please post something by a hurricane researcher that disputes what teh HRD and AMS have said about sinking air.

And finally...from the Air Force training program...

4.3.1.6. Eye
The eye is the center of the cyclone. Here, the wind weakens rapidly towards the eye center. The diameter of the eye can be as small as 10 km and as large as 75 km. Within the eye, the winds are weak and there is downward motion causing adiabatic warming. <b> This usually results in fair weather until the eye passes. </b>

In all the posts and resources I have cited...you will see that I have said...backed up by data...that descending air inside the eye due to convergence at the top and centrifuging of the air outward...create the atmosphere of descending air in the eye.

Please explain the meteorological reason the eye is warmer...and much drier. AS far as centrfuging...I NEVER discounted it...I said it was one of the mechanisms that led to descending air. Please quote me correctly. I also did not say there was convergence of the "eyewall convection". You don't understand what I am saying...and of course what teh HRD researchers are saying. Air ASCENDS in the eyewall...and hits the tropopause. It can't keep going UP so it has to go out. It goes out in all direction...but most of it goes out in the form of outflow. Some of it...albeit small...goes INWARD and once it collides with other air going INWARD...it has to sink...because it can't go up. Sinking air warms and dries. As far as that being THEORY...no it is not. Again...I reference the HRD...and the fact that with the invention of doppler analysis on the NOAA WP-3D aircraft ...we can now SEE the motions and the air flow. We KNOW that is what is happening...it is not theory.

Here...argue with Willoughby...

http://www.aoml.noaa.gov/hrd/project96/hw_proj1.html

[swimaster20]

I love threads like this!!! (wonders where the popcorn is)

[shawn67]

OK...you know what...I've posted data and research from the HRD. Cyclonic flow in the upper levels converges and descends. I have posted numerous illustrations and links proving that the clearing of the clouds is caused by sinking air.

Tornados? You are compairing a microscale event to a synoptic event. Not even a comparison on structure...and it shouldn't be compaired. Also...nobody compaired the descending motion to rising motion of the eyewall. However, it is descending air that dries air out. Ever heard of a lee-side trough...Chinook winds? Its the same principle and it doesn't take a lot of descending air to warm it to a point...well above the dewpoint...where there can be no condensation.

As I have posted...the eye is clear because of sinking air. If you want to argue with that theory...argue with the HRD and the NHC...including those who do the research.

Here more proof for you on why the eye is clear:

"Why is the eye clear? <b> An eye becomes visible when some of the rising air in the eye wall is forced towards the center of the storm instead of outward -- where most of it goes. This air is coming inward towards the center from all directions. This convergence causes the air to actually sink in the eye. This sinking creates a warmer environment and the clouds evaporate leaving a clear area in the center (see warm core formation below). </b> Although subsidence in the eye is sometimes sufficiently strong to produce clear skies, there are often shallow cumulus clouds near the surface. The eye is easily recognized in radar photographs and satellite pictures unless a cirrus canopy covers the top of the storm."

http://www.newmediastudio.org/DataDisco ... truct.html

As far as Emily goes...she is not classically structured yet. Again...post some resources to back up your claim. Right now all you are offering is your opion...with nothing to back it up. Opinions without facts are worthless. Please post something by a hurricane researcher that disputes what teh HRD and AMS have said about sinking air.

And finally...from the Air Force training program...

4.3.1.6. Eye
The eye is the center of the cyclone. Here, the wind weakens rapidly towards the eye center. The diameter of the eye can be as small as 10 km and as large as 75 km. Within the eye, the winds are weak and there is downward motion causing adiabatic warming. <b> This usually results in fair weather until the eye passes. </b>

In all the posts and resources I have cited...you will see that I have said...backed up by data...that descending air inside the eye due to convergence at the top and centrifuging of the air outward...create the atmosphere of descending air in the eye.

Please explain the meteorological reason the eye is warmer...and much drier. AS far as centrfuging...I NEVER discounted it...I said it was one of the mechanisms that led to descending air. Please quote me correctly. I also did not say there was convergence of the "eyewall convection". You don't understand what I am saying...and of course what teh HRD researchers are saying. Air ASCENDS in the eyewall...and hits the tropopause. It can't keep going UP so it has to go out. It goes out in all direction...but most of it goes out in the form of outflow. Some of it...albeit small...goes INWARD and once it collides with other air going INWARD...it has to sink...because it can't go up. Sinking air warms and dries. As far as that being THEORY...no it is not. Again...I reference the HRD...and the fact that with the invention of doppler analysis on the NOAA WP-3D aircraft ...we can now SEE the motions and the air flow. We KNOW that is what is happening...it is not theory.

Here...argue with Willoughby...

http://www.aoml.noaa.gov/hrd/project96/hw_proj1.html

Seems like Mike wanted to quit arguing and have the discussion refocus on the orginal topic.

Shawn

[Air Force Met]

Dude...read the AOML site...the guys who actually research WHY storms do things.

*Ahem*, *cough*, *cough*. I research storms too....and have been for quite awhile too, thank you.

... (Willoughby 1990, 1998)....[etc] "

I was in a Warner Robbins AFB WX office getting fresh facsimili prints of Hurricane Alicia in 1983, and I've personally ran my skinned eyeballs over virtually every storm since then. -- Don't let the low post-count here on this site throw you off.

Great...post some resources instead of your opinions. Otherwise...this conversation is pointless and over. Also...I never said anything about a post count. Post the data to back up your research. Because right now all you are offering is your opinion and that opnion is not supported by other's research.

[Brent]

I love threads like this!!! (wonders where the popcorn is)

***puts feet on desk***

[Air Force Met]

I love threads like this!!! (wonders where the popcorn is)

***puts feet on desk***

You can take 'em off...because I am done. I'm not going to discuss something that is pointless. The research and links are there for all to see. Please do not take my opinion on it. Everybody should do their own reading and come to their own conclusions. Descending air warms adiabatically. Adiabatically warmed air dries. Dry air inhibits cloud formation. It's basic meteorology.

Again...let every read...not mine or Derek's posts...but the resources and researchers we've cited. They are the experts in the field. I am just piggy-backing what I have learned from them and combining it with thermodynamic rules.

[deltadog03]

great match folks...but, i just got back and she jumped NNE...what the heck??

[JTD]

great match folks...but, i just got back and she jumped NNE...what the heck??

me doest think that it is time to view a satelite loop based on that. I try to put it off since I'm on dial-up but ah well, I guess I'll bite the bullet.

[deltadog03]

lol....you need high speed...jk...yeah she did or is wobbling N....it won't matter much in the end..just and obs...

[Wthrman13]

Sorry to jump in on this, but I feel I should back up Air Force Met on this.

Centrifigual force is opposed by the force of low pressure drawing the storm inward. I could also throw the same argument back at you, btw, e.g., "If stronger storms have more divergence aloft, then air should sinking more strongly in their eyes, clearing them out and making their eyes bigger!" Obviously, such relentless deductive logic off questionable premises in an actual evidence-free vacuum is imprudent.

Just because there is more or less subsidence in a hurricane eye because it is more or less stronger doesn't necessarily have anything to do with the size of the eye. The subsidence could simply be concentrated in a smaller area. Think about this for a minute. From mass continuity, you have to have stronger divergence aloft in stronger storms, and thus you would have stronger downdrafts in the eye, but this doesn't mean the eye has to bigger.

I'm watching Emily's eye form right now; cirrus veiling over the eye is....just sitting there, stubbornly refusing to sink and erode (it is, however, eventually leaking past eyewall cells and escaping outward). If there's downdrafting in the eye at 10,000 feet, it's not coming from the altitude of that cirrus, but rather represents a componant of internal eddying.

Emily's eye is a developing eye. As such, the aforementioned mechanism likely hasn't kicked into full gear yet (that is, the downward directed PGF in the eye either hasn't become strong enough yet, or hasn't extended all the way to the altitude of the cirrus, as you say. As the eye becomes better defined, this downward PGF in the eye will also become stronger, and the cirrus will clear out. I don't see what the issue is here.

A bunch of buoyant air being shoved by more buoyant air from underneath and thereby creating high-pressure aloft should not be automatically assumed to be converging. -- A helium ballon doesn't sink until it's popped, and latent heat-of-condensation warmed air parcels don't sink either until they expanded and cooled (which is why the stuff over Emily is just sitting there, queued up to flow outward and away).

You are forgetting mass continuity. The rising air coming out of the top of the eyewall convection has to diverge. It does so both inward toward the center of the eye, and outward. This means that aloft over the center of the eye you have converging air. There is no escaping it. This converging air, then, by mass continuity, must also sink. Keep in mind that this is assuming a nice, well-formed symmetrical eye. Since Emily's is still organizing, it is none of these. Thus, you can have an imbalance on one side causing cirrus to spread ov
er the eye, which is likely what is happening with Emily.

Buoyant air parcels can sink, IF a downward pressure gradient force overwhelms their buoyancy force (think of a kid in a pool forcing a beach ball underwater: the buoyancy of the beach ball wants to make it rise, but the force of the kid's arms pushes it under. In this way, even air that is still buoyant can be forced down by downward directed PGF). By the time the rising air reaches the top of the eyewall, however, it has virtually no buoyancy left anyway.

If you're trying to make an analogy here, then you must account for the fact that hurricane eyes aren't high-pressure zones, but instead contain the lowest pressure of the storm (rather than lowest pressures being found in a doughnut under the eyewall with a high-pressure spike in the center). The fact that the eye has the lowest pressure is prima-facia evidence of a centrifuging partial-vacuum.

You are correct, the center of the eye does indeed have the lowest pressures of the storm, but this doesn't mean there isn't sinking motion. In fact, it is these low pressures near the center that causes the sinking motion. This is because the low pressure anomaly (i.e. the difference between the pressure at the center of the storm versus outside of it at the same level) decreases with height, and in fact, aloft there is high pressure perturbations over the eye. This creates a downward directed pressure gradient force in the center of the eye. The downward flowing air has to warm adiabatically, and this creates the large warm temperature anomaly in the eye.[/b]

[mike18xx]

OK...you know what...I've posted data and research from the HRD.

*Shrug* OK...you know what...I've posted links to directly observable phenomena (e.g., http://cimss.ssec.wisc.edu/tropic/archive/2003/storms/isabel/movies/isabel-eye.html, and today's visibles loops showing cirrus veiling over Emily's eye not sinking and evaporating, but instead slowly circling until it departs laterally) where what you claim to be occurring is manifestly not occurring.

you provide the links that support YOUR point of view...

(Done...for the fourth time.)

that there is no downdraft in the eye (because if there IS a downdraft...adiabatic warming MUST take place according to the laws of physics and that creates a clearing). I'll be waiting for your resources.

You have completely ignored every mention of internal eddying I submitted. Obviously such eddying will account for such.

"The intense convection in the eyewall region induces sinking motion and adiabatic warming inside the eye (Willoughby 1990, 1998).

"...induces..."? Internal eddying is, indeed, "induced". For example, Isabel's eye's internal vortices doubtless have vertical as well as lateral components.

As I have posted...the eye is clear because of sinking air. If you want to argue with that theory...

Please attend to what I actually wrote; I disagreed with the theory that any descending motion in hurricane eyes is part of a system-loop including eyewall convection; and forwarded an alternate theory involving eddying, and forwarded observational phenomena to support it.

argue with the HRD and the NHC...including those who do the research.

I'll argue with anyone whose theory doesn't jibe with the observational phenomena -- What else would you suggest I do when a theory and observations don't mesh? E.g.,

"Why is the eye clear? <b> An eye becomes visible when some of the rising air in the eye wall is forced towards the center of the storm instead of outward -- where most of it goes.

Show me the slightest hint of troposhere-downward vectoring in Isabel.

This air is coming inward (aloft) towards the center from all directions. This convergence causes the air to actually sink in the eye.

Not happening in Isabel.

As far as Emily goes...she is not classically structured yet.

Classically structured like Isabel?

Again...post some resources to back up your claim. Right now all you are offering is your opion...with nothing to back it up.

Fifth time: http://cimss.ssec.wisc.edu/tropic/archive/2003/storms/isabel/movies/isabel-eye.html.

Opinions without facts are worthless.

You're absolutely correct -- let's still to the facts. Data we both can observe with our own eyes should suffice: http://cimss.ssec.wisc.edu/tropic/archive/2003/storms/isabel/movies/isabel-eye.html.

Please post something by a hurricane researcher....

I submit....me.

... that disputes what teh HRD and MS have said about sinking air.

...and I dispute anyone's assertion (whether or not it's been made in this discussion yet) that sinking air causes eyes rather than is merely a manifestation within them. I dispute the theory that any sinking air in eyes is doing so as a result of convergence aloft rather than internal eddying. I cheerfully re-submit observational phenomena in the form of the Isabel loop.

And finally...from the Air Force training program... 4.3.1.6. Eye
The eye is the center of the cyclone. Here, the wind weakens rapidly towards the eye center. The diameter of the eye can be as small as 10 km and as large as 75 km. Within the eye, the winds are weak and there is downward motion causing adiabatic warming.

Easily explainable by internal eddying not involving a greater-scale loop involving eyewall convection.

In all the posts and resources I have cited...you will see that I have said...backed up by data...that descending air inside the eye due to convergence at the top and

You will observe that I have backed up my statements by linking to loops of Isabel's eye vortices.

centrifuging of the air outward...create the atmosphere of descending air in the eye. ...AS far as centrfuging...I NEVER discounted it...I said it was one of the mechanisms that led to descending air.

Didn't you pounce all over me earlier to describe centrifuging as a "myth"?

.... Please quote me correctly. I also did not say there was convergence of the "eyewall convection". You don't understand what I am saying...and of course what teh HRD researchers are saying. Air ASCENDS in the eyewall...and hits the tropopause. It can't keep going UP so it has to go out. It goes out in all direction...but most of it goes out in the form of outflow. Some of it...albeit small...goes INWARD and once it collides with other air going INWARD...it has to sink...because it can't go up.

That doesn't mean it MUST go down. It can, for instance, just sit there like that encircled cirrus in Emily's eye this morning, or a helium balloon stuck on the ceiling, milling about until it can escape between eyewall cells (and thereby expand fully and thus cool); this air is still far too buoyant to sink in any appreciable quantity (if any); consequently, some other factor must be at work to explain the date of sinking air in eyes. I have forwarded such an explanation: internal eddying within the eye.

[huricanwatcher]

nothing like hitting all the nails on the head........... but that just drives me crazy... sorry imo

[Astro_man92]

Alright, is it just me, or is she REALLY starting to look a lot better than just a few hours ago...!?!

holy crap she is

[mike18xx]

Sorry to jump in on this, but I feel I should back up Air Force Met on this.

A bunch of buoyant air being shoved by more buoyant air from underneath and thereby creating high-pressure aloft should not be automatically assumed to be converging. -- A helium ballon doesn't sink until it's popped, and latent heat-of-condensation warmed air parcels don't sink either until they expanded and cooled (which is why the stuff over Emily is just sitting there, queued up to flow outward and away).

You are forgetting mass continuity. The rising air coming out of the top of the eyewall convection has to diverge. It does so both inward toward the center of the eye, and outward. This means that aloft over the center of the eye you have converging air. There is no escaping it. This converging air, then, by mass continuity, must also sink.

Nonsense; it can stay right where it is, remaining buoyant. For instance, we could all stand on chairs and repeatedly punch a helium balloon bouncing along the ceiling -- and it's not going to go down. The high-pressures at the top of a hurricane are the result of upward buoyant pressure to expand; and unexpanded (and thereby cooled) parcels of such buoyant air aren't going to sink under the influence of not-more-greatly-bouyant air surrounding it. Consequently, there must be some other phenomena explaining downdrafting in eyes, and I have submitted internal eddying to account for it.

And, as I opinioned back a few posts, if hurricane eyes were analogy to ordinary high-pressure ridges (which are closed loop systems involving convection in lows at their peripheries involving exhaust from the lows being fully expanded, cooled, and descending in the centers of the highs), then the lowest pressure readings in a hurricane would be in a ring under the eyewall, not in the center of the eye (which would, instead, exhibit high pressure).

[Air Force Met]

All I can say is...it should be pretty easy for the average reader to make up their mind...since your sources are "Me" and all the pro-mets are citing the best in the business.

Thanks for making it so easy.