ATL GUSTAV: Tropical Depression - Discussion

[cycloneye]

[HURAKAN]

[KWT]

The thign to note is that the deep convection near 10-11N is where the center is and now the ITCZ burst is gone thats where the focus of convecton is forming, thats a good thing for development.

[wxman57]

The thign to note is that the deep convection near 10-11N is where the center is and now the ITCZ burst is gone thats where the focus of convecton is forming, thats a good thing for development.

Note that the convection is southwest of the MLC. You can see it on the enhanced IR image above as the faint darker blue ring near 11.5N/52.8W. Convection is centered over 10.5N/54.4W. Here's a better show clearly showing the exposed center this evening (the "X").

[KWT]

Actually yeah your right wxman57 I for some reason thought the convection was further east than what it was!
still that convection isn't far from the circulation really and given its current stage of develoment its not terrible but it does suggest development won't be happening yet, as I said I don't think development will occur till past the Leeward slands.

[Clipper96]

Note that the convection is southwest of the MLC. You can see it on the enhanced IR image above as the faint darker blue ring near 11.5N/52.8W. Convection is centered over 10.5N/54.4W. Here's a better show clearly showing the exposed center this evening (the "X").

I was watching it as the sun went down on vis-sat, and those cells exploded right in the middle of a left-over morning mid-level twist. There remains a mid-level trough extending northeast out of the big cell, but I know it's right in the middle of the real action (which would account for why it's developing so fast).

- I think this system should get its own Invest, and not be considered 94L, as it wasn't part of the package-deal which is now dying off to the northwest around 14N near the islands. It formed right off the ITCZ, from a blob to the west of the "old" 95 blob. Or, at least not retain the 14N/94's wave-track, which implies the 11N/94 is a Cape Verde system rather than an ITCZ bird.

(When's the last time we've had an off-Brazil ITCZ system make hurricane?)

[KWT]

Yep Wxman57 even without your image its quite clear where that circulation is, seems like the convection is developing a little ahead of the circulation but then again that does tend to hppen to systems that are in the early stages of development I suppose.
Still I'd rather see deep convection a little SW of the MLC than nothing there at all in terms of development chances.

[HurricaneQueen]

Thanks, wxman57, for the great graphic and explanation. After so many years on this board and others pre S2K, I still have trouble distinguishing an MLC from an LLC from a ULC and a ULL. Explanations like this are so helpful to many of us and I, for one, appreciate your taking the time to teach us. Thanks to you and a few others, I really believe I've learned more already this season, than I have in over 30 years of tropical weather watching. (Or maybe I'm just getting too old to remember from season to season!!! LOL).

I have some serious concerns about this system and its future track as I do believe this will develop and may be in the Gulf by next weekend assuming he moves faster than his older sister.

Lynn

[StormTracker]

So is it safe to say it has detached itself from the ITCZ???

[Sanibel]

I'm pretty sure the 94L spot dissipated - but - it could just be a d-min, but I doubt it.

The middle one looks to have taken the spot and has spin - but that isn't too sure either. Track off this low-riding one has to be Caribbean.

[ConvergenceZone]

Yep, a depression will be in the making......Once the convection can relocate or spread out from its current position, we'll be in business....I'd say we have a depression by sometime late on Monday or Tuesday.

[KWT]

Convection looks decently in front of the MLC, until that changes then we aren't going to see the MLC work down and thus no depression. Still the fact its firing up convection even if its a little ahead of the circulation is a good sign for development.

[dolebot_Broward_NW]

Can anyone identify this weather feature in the pic below? I noticed pretty much the same thing with Fay when she was 92L in about the same longitude. Its like theres a shield on her western side. This layer of clouds/convection, whatever it is seems to be racing off the the north while the rest of 94L sits and kind of turns the other way.

The blue indicates motion, not what I'm pointing at. It seems to extend further up to about 25N too.

Is this even a part of 94L or some sort of convergence or a trough?

[Brent]

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT FRI AUG 22 2008

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
STORM FAY...CENTERED OVER THE EXTREME NORTHEASTERN GULF OF MEXICO
ABOUT 45 MILES SOUTHEAST OF TALLAHASSEE FLORIDA.

A BROAD AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE IS
LOCATED A COUPLE HUNDRED MILES EAST OF THE WINDWARD ISLANDS...AND
IS PRODUCING A SMALL AREA OF SHOWERS AND THUNDERSTORMS. GRADUAL
DEVELOPMENT OF THIS SYSTEM IS POSSIBLE DURING THE NEXT COUPLE OF
DAYS AS IT MOVES GENERALLY WESTWARD AT 10 TO 15 MPH. REGARDLESS OF
DEVELOPMENT...LOCALLY HEAVY RAINS AND GUSTY WINDS ARE EXPECTED TO
SPREAD OVER PORTIONS OF THE WINDWARD AND LEEWARD ISLANDS ON
SATURDAY.

A TROPICAL WAVE LOCATED ABOUT 1200 MILES EAST OF THE LEEWARD ISLANDS
IS PRODUCING A MINIMAL AMOUNT OF SHOWER ACTIVITY. SIGNIFICANT
DEVELOPMENT OF THIS SYSTEM IS UNLIKELY DURING THE NEXT COUPLE OF
DAYS AS THE WAVE MOVES WESTWARD AT ABOUT 20 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER KNABB

[gatorcane]

Yes, this one is a go. I expect the NHC to up their code to red over the next 24-48 hours....movement is just north of west, probably around 280 or so. There is also plenty of moisture available and the shear is progged to be light over the next several days.

[cycloneye]

[cycloneye]

From 8 PM Discussion:

A SMALL 1009 MB LOW IS ANALYZED IN THE W TROPICAL ATLC NEAR
11N56W MOVING W NEAR 15-20 KT. THE LOW IS EMBEDDED WITHIN THE
ITCZ. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS E OF
THE LOW CENTER FROM 9N-12N BETWEEN 53W-56W.

http://www.storm2k.org/weather/hw3.php? ... hwvmetric=

[cycloneye]

SSD Dvorak T numbers increase for 94L:

22/2345 UTC 11.6N 53.5W T1.5/1.5 94L -- Atlantic Ocean

http://www.ssd.noaa.gov/PS/TROP/positions.html

[Aric Dunn]

well ... fay was fun .. so whats next:)
i see the models are having fun again too,

The vortex that was 94L is dissipated and has combined with this much larger system Called 94L still.

which by the is showing some signs of organizing, it has a large envelope and has a good chance to get going. even in the eastern Caribbean do to the fact that the trade winds in the eastern carrib are light. Also upper level winds are becoming much more favorable.

[cycloneye]

The Latest Best Track position at 00:00 UTC:

AL, 94, 2008082300, , BEST, 0, 109N, 545W, 25, 1008, LO, 34, NEQ