Question about my forecast and analysis.

[SouthFloridawx]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

Any promet or anyone here I have a couple of questions. Please comments are very welcome... I want to see if my thinking is sound.

If you look at the windshear analysis...
http://cimss.ssec.wisc.edu/tropic/real- ... g8shr.html
There is windshear but...

There is no Mid Level windshear.
http://cimss.ssec.wisc.edu/tropic/real- ... idshr.html

Upper Level winds currently look to be aiding in the outflow of the system which is looking good even on satelite imagry.
http://www.nhc.noaa.gov/tafb/QHQA17.jpg


The system seems to be slowing down a bit this evening which will probably noted at the 11pm.

The current Upper Level Trough that is also having an influence on Tropical Storm Debby, pulling her out to sea appears that a ULL is trying to Cut off on the Southern End.
http://cimss.ssec.wisc.edu/tropic/real- ... 8vor1.html

The GFS and the NOGAPS cuts this low off and retrogrades it west across the GOM.
http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... =Animation
http://moe.met.fsu.edu/cgi-bin/nogapstc ... =Animation

The Upper to mid level low that is cutting off fromt he ULT may cause a weakness in the ridge allowing the system to move towards the extreme Southern Gulf of Mexico in 4-5 days.

Given that position another ULT is positioned basically where the one is now.

If i were to say a general track it would be the following. Not giving intesity forecast with this one.

[SouthFloridawx]

bump?

[skysummit]

Nathan, you know I'm no pro met, but I do agree with your track tonight.

[boca]

Nathan I agree and on another thread I guessed a Beamont TX hit. No offense Southerngale but just a guess and I hope I'm wrong.

[Recurve]

Haven't followed all the links, but like the analysis. Also not a pro.
If there's low southwesterly shear, I could see this bouncing away from south America on that pure weird cyclone intuition that tells them to crawl away from land.

Anything else you can say about the ridge position/strength and its impact?

[SouthFloridawx]

Haven't followed all the links, but like the analysis. Also not a pro.
If there's low southwesterly shear, I could see this bouncing away from south America on that pure weird cyclone intuition that tells them to crawl away from land.

Anything else you can say about the ridge position/strength and its impact?

Well I have read a little here at storm2k that some of the models are moving the ridge farther and farther eastward.

I would not be suprised if a Upper Level trough dips down and takes that Upper Level low northward with it.

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... =Animation

At the end of the run you can see a shortwave dipping down a bit and the ULL begins to elongate. Maybe that may indicate an trough possibly weakening the ridge. It would be possible to pull the system north.

This is all of course where and how intense "Ernesto" is.

[btangy]

I agree with your analysis. Again, I must caution using 350K potential vorticity or any upper level analyses to determine steering flows. But, in this case, the upper level low (high potential vorticity) has a signature at 500mb, which is evident by an inverted trough over E Cuba and Jamaica which you can see in both the wind field and the vorticity, e.g. the 18Z init of the UKMET:

http://moe.met.fsu.edu/tcgengifs//ukm/2 ... 0vort0.png

Now, the key to the future track of TD5 is how deep/strong is this feature and how quickly does it retrogrades westward. A deeper and/or slower tracking feature will steer TD5 more northward and will also increase the shear and lead to a weaker system (too weak of a system and it will just continue westward with the low level flow). A weaker and/or faster tracking feature will allow TD5 to remain more on a southerly course and with weaker shear. Global models are notorious in handling the timing of upper level features in the tropics (hence, why we can't really forecast shear that well). Add beta for even more fun.