ATL: DORIAN - Post-Tropical - Discussion

[Blown Away]

ATLANTIC SHIPS INTENSITY FORECAST *
* GOES AVAILABLE, OHC AVAILABLE *
* DORIAN AL912013 07/29/13 12 UTC *

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120
SHEAR (KT) 18 12 13 16 20 14 24 18 21 15 17 12 16


Up and down with the shear forecast

[SFLcane]

Ah!! Wake me up when we have a real developed cyclone.

Is that even possible in our basin anymore?

[MiamiensisWx]

The 12Z Euro initialized a closed low then rips it apart in the next frame. In my opinion this will look good for the next few hours, then get blown apart.

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Would not the outflow from the convection tend to neutralize the TUTT? I have seen that argument before and it may still be valid...or is it only valid if ex-Dorian had continuous convection over the past 24 hours?

[Blown Away]

Ah!! Wake me up when we have a real developed cyclone.

Is that even possible in our basin anymore?

North Atlantic and BOC you will get development...MDR nada...

[tolakram]

Would not the outflow from the convection tend to neutralize the TUTT? I have seen that argument before and it may still be valid...or is it only valid if ex-Dorian had continuous convection over the past 24 hours?

You're more qualified than I am to answer that.

I'm liking the GFS simulated IR sat loop. Notice the blowup in convection, then dissipation. Let's see if this plays out.

http://www.tropicaltidbits.com/analysis ... opics.html

[thetruesms]

I'm not aware of any GFS change. I know that the computer it is being run on changed last week, but I thought that was all that changed.

Oh good, I'm not the only one confused by this new GFS talk.

Now, depending on hardware, setups, compilers, etc., we may get some minute differences in truncation/rounding that might eventually make some difference in forecast parameters, it's certainly not going to be on timescales that we're looking at for Dorian. Or, maybe, even noticeable at all. I know they were having some issues at long ranges earlier while the new computer was still in parallel, but I'm pretty sure it was overcome enough to not be worth mentioning.

[SapphireSea]

Well it makes sense that the GFS may not be "new" when it comes to code. I don't know what the architecture was for the old Supercomputer's CPUs were, and what they are for the new one. I only know they quadrupled the MIPS to be on par with the European system. Went from 25k to 100k. I can imagine that the only improvement for now is amplifying the resolution that the GFS runs at. I am, also going to assume that the real 'new' code is not in production, and again probably consists of higher resolution forecast options in the meantime.

[NDG]

It seems like every morning Dorian's remnants seem to start getting better organized at the surface but as the day goes by it falls apart and get left with nothing but a MLC and a dying LLC or surface vorticity. Today could be the case again.
One thing that I noticed this morning is that San Juan's sounding at 12z showed a little more moist mid level and UL winds were much lighter than yesterday, so perhaps that is why is not that bad looking on satellite presentation.

[Blown Away]

It appears 91L is pushing hard against the ULL and winning now, but that may not be the case as the day goes on...Interesting...
http://www.ssd.noaa.gov/goes/east/carb/flash-wv.html

[southerngale]

The new GFS has been left bias all along, just keep that in mind.

Isn't it a bit early for people to be making judgments on the "new" GFS? For starters, is it even that big of an upgrade? And if it is, It's been in use for less than a week and only with one, not very strong Atlantic storm. I'm just saying, if were going to make judgments on the "new" GFS, lets give it some time.

I'm not aware of any GFS change. I know that the computer it is being run on changed last week, but I thought that was all that changed.

I believe this is where we were made aware of the new GFS. That's when I first heard about it, anyway.

http://www.storm2k.org/phpbb2/viewtopic.php?f=59&t=115277&p=2322863&hilit=#p2322863

[RL3AO]

I don't think anything has changed yet with the resolution of the GFS, although it is planned.

Plus remember that these computers run much more than the GFS. Most of the improvements in speed is with the longer term climatic models from my understanding.

[CalmBeforeStorm]

http://www.ssd.noaa.gov/PS/TROP/floater ... short.html
~~~~~~~~~~
If you look at this loop you can see what appears to be an LLC trying to spin up out ahead of the system at around 67.0 There is also some mid level turning further east. This is the same as what the plane found yesterday and consistent with a system that is sheared at the mid levels.

[artist]

here is a pretty good article regarding the upgrade -
http://www.computerworld.com/s/article/ ... rcomputers

[Stephanie]

Dorian's the little train that could. It'll be interesting to see how this all plays out. We've seen so many things happen to different storms over the years.

[weatherwindow]

It appears 91L is pushing hard against the ULL and winning now, but that may not be the case as the day goes on...Interesting...
http://www.ssd.noaa.gov/goes/east/carb/flash-wv.html

The 00z GFS continues to insist that that entire ULL and trof literally go poof by this evening (03Z)...developing an anticyclone over 91L persisting over the next 48-72hrs...the question is will it verify?...Grtz from KW, Rich
http://www.tropicaltidbits.com/analysis ... opics.html

[Alyono]

any center is still located WELL west of the convection... close to 66.5W based upon visible imagery. This indicates that like yesterday, strong shear continues to plague the system

[Blown Away]

12z...Well, here we go again...Most aggressive I've seen in days

06z...

Posted in discussion b/c I thought it was worth discussing...

[Blown Away]

12z...Well, here we go again...Most aggressive I've seen in days

06z...

[Bocadude85]

I see some inflow and outflow appears to be improving.

http://www.ssd.noaa.gov/PS/TROP/floaters/91L/imagery/vis_lalo-animated.gif


But convection is also waning

http://www.ssd.noaa.gov/PS/TROP/floaters/91L/imagery/avn_lalo-animated.gif

I wonder if the convection is being enhanced by the ULL?

[Blown Away]

12z...Look at the slowdown after 48 hours for some models, crawls for a couple of days from SE Bahamas towards SFL/EGOM...