ATL: GABRIELLE - Models

[Blown Away]

12z...


12z...Recurve models go strong...Westward models stay weak...

[gatorcane]

That is quite a sharp recurve for early September. Looks like a track you would see in October or November. The trough is unseasonably strong for this time of year and the Bermuda High is just not there at all it seems as we approach the peak of the season.

Looks more likely that it won't be a United States issue given the Euro has shifted east as well, which is some good news. Lots of potentially flooding rains for Puerto Rico, Haiti, and the Leeward islands which is unfortunate.

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[tolakram]

My take is that if the euro shifts east then it is trying to develop the storm. I don't think west was ever in the cards unless it stays a wave and continues with the low level flow. Anything can happen, of course, including the models making mistakes with the speed and environment 97L will be in if/when it reaches the Bahamas.

[ROCK]

6Z NAVGEM is an odd run....develops the East low and sends it off to the NE while the west low is left behind barely noticable heading towards the FL straits....hmmmmmm

https://www.fnmoc.navy.mil/wxmap_cgi/cg ... t=Tropical

[alienstorm]

If you look at the water vapor loop - I see the trough digging but you can see the big high coming in after it, not sure that this trough will pick up what ever is down with 97L

http://www.ssec.wisc.edu/data/geo/index.php?satellite=east&channel=wv&coverage=conus&file=gif&imgoranim=8&anim_method=flash

[ROCK]

If you look at the water vapor loop - I see the trough digging but you can see the big high coming in after it, not sure that this trough will pick up what ever is down with 97L

http://www.ssec.wisc.edu/data/geo/index.php?satellite=east&channel=wv&coverage=conus&file=gif&imgoranim=8&anim_method=flash

good point...I will back it up with the 12Z NAM....not that the NAM is good with tropical systems but that 1022MB high dropping down is fixing to trap this at 84hr...going to be close...

http://www.tropicaltidbits.com/analysis/models/nam/2013090412/nam_reflectivity_watl.html

[tolakram]

Please use URL tags.

You can push the URL button above the post box and paste your link between the tags.

Thanks.

[tropicwatch]

If you look at the water vapor loop - I see the trough digging but you can see the big high coming in after it, not sure that this trough will pick up what ever is down with 97L

http://www.ssec.wisc.edu/data/geo/index.php?satellite=east&channel=wv&coverage=conus&file=gif&imgoranim=8&anim_method=flash

I have been looking at that the past couple of days. I think the high could build in cutting off the re-curve.

[CalmBeforeStorm]

If you look at the water vapor loop - I see the trough digging but you can see the big high coming in after it, not sure that this trough will pick up what ever is down with 97L

http://www.ssec.wisc.edu/data/geo/index.php?satellite=east&channel=wv&coverage=conus&file=gif&imgoranim=8&anim_method=flash

good point...I will back it up with the 12Z NAM....not that the NAM is good with tropical systems but that 1022MB high dropping down is fixing to trap this at 84hr...going to be close...

http://www.tropicaltidbits.com/analysis/models/nam/2013090412/nam_reflectivity_watl.html

Did you notice that the NAM, like the 0z CMC, develops the eastern most feature?
http://mag.ncep.noaa.gov/Imageanis.php

[ROCK]

yes it seems some of these are keying off the east low....really hard call for them it seems.

[CalmBeforeStorm]

yes it seems some of these are keying off the east low....really hard call for them it seems.

You have to wonder if the western feature engulfs the eastern feature and develops how that will change the model output.

[Alyono]

yes it seems some of these are keying off the east low....really hard call for them it seems.

You have to wonder if the western feature engulfs the eastern feature and develops how that will change the model output.

it should not. If it were, I'd expect GFDL/HWRF which are focusing on the developing EC system to have a farther west track. They also have solid recurvature

[CalmBeforeStorm]

http://mag.ncep.noaa.gov/model-guidance-model-parameter.php?group=Model%20Guidance&model=gfs&area=atlantic&cycle=20130904%2012%20UTC&param=850_vort_ht&fourpan=no&imageSize=The 12z GFS now makes the eastern most vort the dominant one at 84 hrs. Seems to be a model trend.

[Alyono]

the models trends are likely wrong. Satellite shows that the trailing wave is starting to become entrained into the Caribbean low

[CalmBeforeStorm]

http://mag.ncep.noaa.gov/Image.php?fhr=120&image=data%2Fgfs%2F12%2Fgfs_atlantic_120_10m_wnd_precip.gif&model=gfs&area=atlantic&param=10m_wnd_precip&group=Model+Guidance&imageSize=~~~~~~~~~
At 120 hrs the 12z GFS leaves 97L behind(although very weak) as the more dominant eastern low gets pulled NE out to sea.

[tolakram]

the models trends are likely wrong. Satellite shows that the trailing wave is starting to become entrained into the Caribbean low

Woops, I did not read this before posting in the discussion thread. That's what I thought I was seeing, so it's good to get some confirmation. Will be interesting to see what the models do once this data is ingested.

[tolakram]

The 12Z GFS vorticity is interesting. Still wants to develop the northern feature, but a bit more removed from 97L now, which gets stuck in the Bahamas and dissipates.

http://www.tropicaltidbits.com/analysis/models/gfs/2013090412/gfs_vort850_uv200_atltropics.html



It still moves mostly east of Hispaniola.

[ROCK]

http://www.tropicaltidbits.com/analysis/models/gem/2013090412/gem_mslp_wind_watl.html

well the CMC is wrong then because it to thinks the east low becomes dominant leaving the west low to meander in the carib...

[Aric Dunn]

Models are clearly having an issue resolving the dynamics at play. given the area to the east now appears to have a weak low developing they are likely to start fujiwhara around each other to some extent and given the the low south of PR is nearly stationary and the area/ low to the NE is very quickly swing wnw is an indication that there is bit more interaction between the two and is causing the models to vary widely.

notice the affect the system karen had on Iris it caused iris to stall briefly.

[youtube]http://www.youtube.com/watch?v=Qaj8l6IJpWU[/youtube]

[Alyono]

One issue... there is no low with the eastern system. That is simply a wave. The models may be overdeveloping a low with it due to the very large area of convection