ATL: Ex INVEST 92L - Discussion

[Gustywind]

We have a small lull even if isolated ligthings are maybe coming in my way while thunder is rumbling too.

[northjaxpro]

92L has bounced back nicely as of early this afternoon after the convection the previous night had died literally. literally. The system looks rather spry as a matter of fact as the convection has expanded even moreso than it appeared yesterday. 92L looks like it continues to move on a w-nw heading to me and If it continues on a 270 degree heading, the system may be able to miss Hispaniola in a couple of days.

[LarryWx]

This looks better to me than 99L did in this general vicinity over a week ago. I think it is a worthy invest. No models show it developing that I can find. But, I am not impressed with the models track record on genesis lately. Direction of movement seems much more WNW today vs west movement we observed previously.

I do not understand why when a wave struggles for a few hours people just write if off.

Just to clarify since I'm one of those posting about it today, I, personally, didn't write it off. What I said is that it clearly looked less organized this morning than yesterday per satellite loops (others said the same thing) though yesterday's supposed organization may have actually been an illusion. Also, with today's CMC runs no longer forming a TC from it, it now has zero model support though model support from just the often crazy CMC, alone, isn't real model support imo.

I also earlier said there still looked to be some kind of weak circulation, which seems to be sparking renewed convection for now. Regardless, it is battling strong shear. Something to keep watching for now.

[northjaxpro]

Hey Larry. Well, I was not among those who wrote this system off. I posted from yesterday how the vort was vigorous and organizing yesterday. I personally never write off a system until a vort completely dissipates. 92L looks good this afternoon for sure.

[blp]

Looks better this afternoon. More symmetry in the convection. Still has the mid level circulation over to the NW of the low level.

[LarryWx]

Hey Larry. Well, I was not among those who wrote this system off. I posted from yesterday how the LLC was vigorous and organizing yesterday. I personally never write off a system until a vort completely dissipates. 92L looks good this afternoon for sure.

I think we're pretty much thinking the same way about this. It does look better than it did this morning. But with zero model support to form into a TC, I'm not going to bet on it even though I have by no means written it off and am certainly still following it, especially considering how vigorous a wave it has been in the Lesser Antilles as per Gustywind and others

[Gustywind]

Showers, tstorms , lightnings are back ...

[jlauderdal]

This looks better to me than 99L did in this general vicinity over a week ago. I think it is a worthy invest. No models show it developing that I can find. But, I am not impressed with the models track record on genesis lately. Direction of movement seems much more WNW today vs west movement we observed previously.

I do not understand why when a wave struggles for a few hours people just write if off.

instant gratification world...tropics don't work that way..10 days ago there were people calling for bones on 99l...look at what it has doen since then and its still with us causing damage

[Emmett_Brown]

Yep, we do live in a world with a short attention span. IR is looking pretty good, nice comma shape: http://www.ssd.noaa.gov/PS/TROP/floater ... 0-lalo.gif

[northjaxpro]

Also, it looks as if shear is even a bit less of a problem now than it appeared yesterday as well. Outflow looks much improved on satellite imagery. 92L is ventilating better.

[GeneratorPower]

I think a lot of posters are using the term "organized" or "less organized" incorrectly. Maybe we could settle on a meteorological definition of the terms? Having a lot of nice looking thunderstorms does not necessarily mean it's well organized.

[Gustywind]

DATE/TIME LAT LON CLASSIFICATION STORM
05/1745 UTC 15.5N 66.8W T1.0/1.0 92L
05/1145 UTC 15.2N 65.3W T1.0/1.0 92L
05/0545 UTC 17.1N 62.2W T1.0/1.0 92L
04/2345 UTC 15.5N 60.2W T1.0/1.0 92L

[Emmett_Brown]

92 L appears to have slowed a little. ULL to the NW of 92L is retrograding westward. Shear not that bad. Land will be a bigger limiting factor than shear IMO. Will most of the energy go N or S of PR and HS? My guess is clipping PR, and going right over HS.

[Gustywind]

000
AXNT20 KNHC 051810 CCA
TWDAT

Tropical Weather Discussion...CORRECTED
NWS National Hurricane Center Miami FL
205 PM EDT MON SEP 05 2016

A Caribbean Sea tropical wave is along 65W/66W, from 19N
southward, moving westward 15 to 20 knots. A 1009 mb low
pressure center is along the wave near 14.5N. Convective
precipitation: Scattered strong covers the islands from
Guadeloupe to Anguilla, from 13N to 17N between 62W and 67W, and
from 13N to 15N between 67W and 71W. Rainshowers are possible
elsewhere from 12N to 19N between 60W and 73W.

[GeneratorPower]

I think this time of year, if you have thunderstorms over water, you have a risk of development. TC genesis is not well understood and I think persistent convection is worth watching.

[northjaxpro]

92 L appears to have slowed a little. ULL to the NW of 92L is retrograding westward. Shear not that bad. Land will be a bigger limiting factor than shear IMO. Will most of the energy go N or S of PR and HS? My guess is clipping PR, and going right over HS.

Yeah, the Hispanolia factor always is always huge of course. But, since yesterday 92L has gradually gained a bit of latitude. It is going to be a close call on its approach to Hispanolia. a close call. But, if shear continues to lessen and 92L can miss Hispanolia either way 92L may be around to track for awhile. My.bet it woll miss it north if it does.

[Steve]

I think a lot of posters are using the term "organized" or "less organized" incorrectly. Maybe we could settle on a meteorological definition of the terms? Having a lot of nice looking thunderstorms does not necessarily mean it's well organized.

I don't think you can. It's too subjective of a term. I think NHC overuses "disorganized area of..." even when there is clear rotation. They seem to refer to it as an adjective for tropical classification. But someone could argue something can be "organized" if not classified. Something going from a straight wave axis into a mid or lower level broad or localized cyclonic turning would be organizing. A few disparate showers getting more concentrated could be argued as organizing regardless of what happens. So I don't think you can really settle on a specific clarification. Jmo

Larry,

I don't think anyone was referring to you there. You had your opinion and stated it well. It's more of the "Bones Now!" posts and general lack of activity. May end up nothing, which is probably good odds.

[Emmett_Brown]

Yep. 92L has always been a fairly strong disturbance since leaving Africa. Last week, models almost unanimously developed it, then lost it a couple of days ago. In my amateur experience, models do better at forecasting genesis early and late in the season, when formation is aided by baroclinic setups. For example, models always seem to honk development in the NW Caribbean in late October. One thing I think the models have been pretty good at is forecasting systems to go quiet for a while. They just don't seem good at knowing when they will wake up. 99L was a great example. GFS got the quiet trip through the Bahamas correct, but was wrong in that it didn't show the hurricane developing a few days later.

[alienstorm]

It looks good but I trust the NHC forecasters that they have tools that we dont have and that is why the probs are low 0

[northjaxpro]

It looks good but I trust the NHC forecasters that they have tools that we dont have and that is why the probs are low 0

The probabilities are not exactly 0. They were at 20 percent going out 120 hours by the NHC earlier today and a few models are trying to develop 92L as well. The way 92L looks now, they may have to increase percentages if the trend I am seeing continues in the short term.