Trough dropping down

[corpusbreeze]

from the mid west. It is plain as day on water vapor. We will see if this is the mighty trough the NHC says will move this beast north.It may pull on Ivan a little, but it wont pull him up like the NHC says. After that the treck west will begin again. Of course this is my opinion, and others will have theirs.

[lilbump3000]

For one this is not an all mighty trough like they making it out to be. Second if it was it should atleast start to have an affect on him right now as its leaving him behind as each hour is passing.

[Jevo]

For one this is not an all mighty trough like they making it out to be. Second if it was it should atleast start to have an affect on him right now as its leaving him behind as each hour is passing.

Not quite... troughs and ridges do not start to have a general effect on storms until 300nm from the boundry or said trough or ridge

[cajungal]

I don't think that trough will have an effect on Ivan. He is too big and powerful.

[lilbump3000]

Well anyway i will be waiting for this NW turn. If it doesnt happen by tonight, just say that trough has missed the system.

[bobbisboy]

You saved me a post because I was about to post this WV loop. While the first trough is stalled note the second punch coming on down to reinforce the first trough. I guess I will learn something here because I cannot see IVAN moving into the teeth of this trough to follow the projected path. The way I see this is that either IVAN will be driven MUCH further west (I'm talking YUCATAN and MEXICO) if the trough rides over him OR a track MUCH further east than is now shown by NHC. The good part is we will all know shortly but when I look at this WV loop I have a difficult time understanding the present NHC thinking. Maybe it's my eyes.

http://www.ssd.noaa.gov/PS/TROP/DATA/RT ... -loop.html

[CYCLONE MIKE]

What does the "second punch" have to do with the trough. Is it a reinforcing shot to drive it further south? I still feel that Ivan is just too strong and too far south to just be picked up by this and sent north. With him being as strong as he is doesn't he have the capability to pretty much shape the environmet arouind him and go where he pleases

[BensonTCwatcher]

I think thay we looked at ALL of the past histories of cat 4 and larger stroms we would see that it does not take much of a trough to make a hurricane turn. Currently the steering currents ahead of Ivan are weak. While hurricanes ride around ridges to varying degrees, troughs always affect hurricanes in the axis of thier orientation. This is true no matter how large the hurricane is.

[washington]

If you look at the water wv loop you can see that the trough is still dropping down. If you look you can see the red around TX, LA and Ok that is the vorticity which makes trough dig deeper.

[BensonTCwatcher]

I know that I am not a forecaster and not a Met. BUT look at this:

http://orca.rsmas.miami.edu/wximages/jet/1_05/anis.html

This explains Stewart's discussion and also them keeping the track where it is until the trough actually changes the overall motion.

I have said all along this is going to the big bend, but I reserve the right to be wrong.

[washington]

I agree with you i think the trough is going to turn it soon or later if you look at wv you can see that the trough is still digging. The reds and orange over TX, LA and OK shows this.

[AL Chili Pepper]

From the way I understand it, it's not the trough that's going to drive Ivan. The trough will act to break the ridging down. That will give Ivan an area of weakness to follow through. Now, when he gets above 25 degrees, that's when the trough could actually steer him. The ETA ejects the trough through Tuesday, so Ivan may not even make contact.

[washington]

I am sorry i meant the trough is going to break the ridge down even more so it can take that north then ne track.

[Guest]

I know that I am not a forecaster and not a Met. BUT look at this:

http://orca.rsmas.miami.edu/wximages/jet/1_05/anis.html

This explains Stewart's discussion and also them keeping the track where it is until the trough actually changes the overall motion.

I have said all along this is going to the big bend, but I reserve the right to be wrong.

If you will observe on the link you provided... there is a lifting of this trough rapidly from behind, happening fast over Colorado lifting NE, this will only allow the trough to stay in our area for about 24 to 36 hours.

[BensonTCwatcher]

Al,

I understand it that way too, the trough makes the "ditch" that Ivan can move though. My point is that trough is the driver, since it either pumps up a ridge, or in this case weakens it.

[washington]

Yes you have it right it will weaken the rigde. A lot of people on this site don't seem to see the trough digging down south. All you have to do is look at SKEW T log P diagrams or upper air soundings it will show you the wind shifts in the upper air in the mid-west and south.

[BensonTCwatcher]

Yes, I saw that, hence my reservation. The timing is key. It is very possible for Ivan to wait it out. I can only state what I think I see happening in say 36 hours out maybe a litla more. after that the steering features may have a different pattern.

[Guest]

Everyone sees the trough, its just not going to be in a position to pick Ivan completely up, and the trough lifts within 36 hours, and high pressure on the southeast coast of Florida builds back in to the gulf.

[BensonTCwatcher]

Like these?

http://cimss.ssec.wisc.edu/tropic/real- ... 8dlm5.html

try toggling between the 3 hr plots

[Rainband]

Maybe thats why the west coast of florida is still on alert. Until the cone is 200 miles offshore all bets are off for our area IMHO. Hopefully it continues into mexico.