ATL: Ex-Tropical Storm GASTON - Discussion

[Sanibel]

Admittedly Puerto Rican radar looks weak but this one entered the Caribbean with a head start. I look at this more like untapped vapor just needing a spark. We're obviously seeing a developing cyclone here as predicted.


Perhaps ULL shear-enhanced convection? (Either way it might stimulate development)

[tolakram]

20 frame LOOP: http://wwwghcc.msfc.nasa.gov/cgi-bin/ge ... mframes=20

I don't know, looks awfully wave-like.

You can speed up the loop to see the circulation, or what's left, but also notice convection near the 'center' is failing.

[Bailey1777]

question, why is there a discrepancy between the outlook and the forecast discussion? outlook says 20 percent which is an improvement while discussion talks of expected dissipation.

[Steve]

>>If it stays south of Haiti/DR, and develops, you're probably getting a cat-4 in the west-carr. Remember how quickly Gustov intensified?

Cat 4? Eh, I don't know about that. My money would be on a cyclonically turning wave that some think will intensify and others think will dissipate. But that's just me...

[Ivanhater]

I don't think there is a LLC anymore.

However, there still is a sharp wave signature, confirmed by ASCAT. Also, ex-Gaston, is moving out of the dry air region and into the moist Caribbean environment. Being September and a sharp wave with very cold cloud tops moving into the Western Caribbean, there is a lot of potential.

[Frank2]

I don't know, looks awfully wave-like.

You can speed up the loop to see the circulation, or what's left, but also notice convection near the 'center' is failing.

Right - that's probably why the NHC is just keeping it at 20%, since it does have the appearance on radar of a wave that's just rolling along...

Well, back to Perry Mason for me (lol)...

[Brent]

I don't think there is a LLC anymore.

Definitely not. Recon was out 3 hours yesterday and never found one.

This system has a long way to go since it's lacking that. At least a couple of days of sustained convection(and this storm has had a major problem keeping convection).

[Ivanhater]

A little off topic, but the new Euro is really active. The wave behind ex Gaston develops into a cyclone in the Caribbean at 192 hours. This wave being discussed in Talking tropics

[Vortex]

Ivan, I dont have access to the euro at work but what is that approaching the islands...I know off topic but it appears to be the wave the gfs recurves aroud 50w...

[Ivanhater]

Ivan, I dont have access to the euro at work but what is that approaching the islands...I know off topic but it appears to be the wave the gfs recurves aroud 50w...

That is the wave coming off Africa mentioned in the NHC tropical outlook.

[Stormcenter]

More bark then bite here.

[ROCK]

there is a weak LLC here....low level turning is evident....not as vigorous as it once was but its still there...it needs to sustain convection into the evening and night....if it does that then it might be a go...

[ColinDelia]

7 hour change

1045z


1745z

[Macrocane]

It seems that the LLC is gone, so if it redevelops (and that's a big IF) then it will have another name won't it?

[fci]

there is a weak LLC here....low level turning is evident....not as vigorous as it once was but its still there...it needs to sustain convection into the evening and night....if it does that then it might be a go...

Agree!
I'd say it is a "go" too.
20% chance of it.
80% chance it is a wave with no future over the next 48 hours or so.
100% chance that some posters will say that it will still regenerate

[bvigal]

Little "nothing" Gaston has caused my power to be out almost continuously since 1am, 3 outages but the "on" times were brief! First it was lightning, then wind. Sure glad the bulk of it went south of VI/PR, and misses DR/Haiti! He may look disorganized but there is still some energy there.

[lonelymike]

Steve made some good posts about vertical instability. Does anyone have a link to good explanation of what vertical instability is or a link to any graphs or charts detailing it?

[Aric Dunn]

its is a open circ at the moment but there is still a lot of curvature and the convection will help close it off again if it can maintain for long enough. but its clearly in a better environment now which was expected to happen eventually. the eastern carrib is terrible for development do to the easterly flow close to south America being typically faster the westerly flow of developing LLC or weak LLC. thats why it will likely if at all re develop farther west into the central and western caribb.

[Ivanhater]

there is a weak LLC here....low level turning is evident....not as vigorous as it once was but its still there...it needs to sustain convection into the evening and night....if it does that then it might be a go...

[quote="fci"]
Agree!
I'd say it is a "go" too.
20% chance of it.
80% chance it is a wave with no future over the next 48 hours or so.
100% chance that some posters will say that it will still regenerate[/quote]


You still seem to have a problem (sense you continually point it out) when a poster thinks regeneration will occur. We are here to throw out potential and possibilities. If you or any other poster feels the opposite, feel free to post it but stop posting your issue with other posters who point out the potential. This goes for anyone.

We will not go down this road again and derail this thread. If anyone has an issue please revert to PM.

[bvigal]

Steve made some good posts about vertical instability. Does anyone have a link to good explanation of what vertical instability is or a link to any graphs or charts detailing it?

Not exactly the same, but close, the vorticity. http://cimss.ssec.wisc.edu/tropic2/real-time/windmain.php?&basin=atlantic&sat=wg8&prod=vor That's the 850mb, also have 700,500,200. The last time I checked it, I think Sunday or Saturday, Gaston had vorticity on 850,700,500. Look at him now, low-level only.