ATL: Ex INVEST 92L - Discussion

[xironman]

I never thought model support was a requirement for tropical development. I've seen it happen before without it. Just saying.

So is this the genesis of the spin off the north coast of Cuba? At the low levels it does not look that bad, but with no models on board I guess it is going nowhere.

Well the models can take a lot into account, like the influx of dry air or lack of instability that might not be apparent from normal observation. Generally when they don't call for development it does not happen, at times it does though. Hence my interest in the spin off Cuba.

[northjaxpro]

The ULL is pulling away west- w/sw at a good clip, about to enter into the Central GOM currently and that should allow the system to not encounter any crippling wind shear , plus the anticyclone moving in tandum with ex-92L also will help. Convection still is trying to build along and just off the northeast coast of Cuba.

[AJC3]

The ULL is pulling away west- w/sw at a good clip, about to enter into the Central GOM currently and that should allow the system to not encounter any crippling wind shear , plus the anticyclone moving in tandum with ex-92L also will help. Convection still is trying to build along and just off the northeast coast of Cuba.

If the 250 MB progs from the globals are to be believed (and I don't see why they shouldn't be), shear will become less hostile over the central-western Caribbean over the next 2-3 days. However, the area north of Cuba will see the very strong and divergent SW shear currently in place become NW to W, while remaining strong, but not nearly as divergent. This is courtesy of yet another strong mid/upper level trough retrograding SW from offshore the Carolinas through late week.

[northjaxpro]

The ULL is pulling away west- w/sw at a good clip, about to enter into the Central GOM currently and that should allow the system to not encounter any crippling wind shear , plus the anticyclone moving in tandum with ex-92L also will help. Convection still is trying to build along and just off the northeast coast of Cuba.

If the 250 MB progs from the globals are to be believed (and I don't see why they shouldn't be), shear will become less hostile over the central-western Caribbean over the next 2-3 days. However, the area north of Cuba will see the very strong and divergent SW shear currently in place become NW to W, while remaining strong, but not nearly as divergent. This is courtesy of yet another strong mid/upper level trough retrograding SW from offshore the Carolinas through late week.

I was thinking that mid-ULL trough off the Mid Atantic coast was more of a cutoff Low not moving very much, but it may be moving southwest as you indicated AJC3 We saw a trough axis which helped spawn TD 8 last week off the North Carolina coast.

[AJC3]

I was thinking that mid-ULL trough off the Mid Atantic coast was more of a cutoff Low not moving very much, but it may be moving southwest as you indicated AJC3 We saw a trough axis which helped spawn TD 8 last week off the North Carolina coast.

The 250 progs from the ECM/GFS/UKM/CMC are quite similar in showing the ULL retrograding SW underneath the building SE-E CONUS deep layer ridge. By late Friday-early Saturday, it becomes a sharp neutral to slightly negatively tilted trough with its along 77-78W, running from offshore the Carolinas to the central Bahamas. Any remnant piece of the wave that will be sliding WNW north of Cuba will be in really bad place for TC development (or even diurnal convection, for that matter) - the high shear area with dry/confluent/subsident N-NW flow on the upper trough's back side.

[northjaxpro]

I was thinking that mid-ULL trough off the Mid Atantic coast was more of a cutoff Low not moving very much, but it may be moving southwest as you indicated AJC3 We saw a trough axis which helped spawn TD 8 last week off the North Carolina coast.

The 250 progs from the ECM/GFS/UKM/CMC are quite similar in showing the ULL retrograding SW underneath the building SE-E CONUS deep layer ridge. By late Friday-early Saturday, it becomes a sharp neutral to slightly negatively tilted trough with its along 77-78W, running from offshore the Carolinas to the central Bahamas. Any remnant piece of the wave that will be sliding WNW north of Cuba will be in really bad place for TC development (or even diurnal convection, for that matter) - the high shear area with dry/confluent/subsident N-NW flow on the upper trough's back side.

Yes, that trough likely would be the nail in the coffin as 92L would get sheared relentlessly if indeed it shakes down the way you analyzed, especially if the trough becomes negatively tilted by this weekend.

[tpr1967]

Looking at last visible last night and close up Ir tonight and Radar looks like a weak low pressure area has formed on the North end of tropical wave(ex 92L). What are your thoughts?

[northjaxpro]

I thought this was the remnant of ex-92L which has flared up, is that the case?

[Dave C]

Water vapor shows some bad conditions pressing down from the north. Maybe better chance if the gulf moistens up when it tracks into that area.

[tpr1967]

I thought this was the remnant of ex-92L which has flared up, is that the case?

Yes this is the northern end of it.

[tailgater]

Decent low level structure this morning on this ex-92 wave but big time shear right now and conditions don't get much better in the near future from what I see. Nam carries a weak low along the northern coast of Cuba.

[cycloneye]

A small area of disturbed weather associated with a weak low
has formed between Cuba and the western Bahamas. This activity is
expected to spread westward across southern Florida and the Florida
Keys later today and Saturday. Upper-level winds are not favorable
for additional development.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...low...10 percent

[StormTracker]

A small area of disturbed weather associated with a weak low
has formed between Cuba and the western Bahamas. This activity is
expected to spread westward across southern Florida and the Florida
Keys later today and Saturday. Upper-level winds are not favorable
for additional development.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...low...10 percent

[northjaxpro]

Trough which dropped down south down the Mid Atlantic to about the Central Bahamas has caused unfavorable shear environment for now. However, if it survives the next few days, it may find a bit better conditions once it gets into the SE Gulf of Mexico. We will monitor it.

[srainhoutx]

The ECMWF suggests the wave axis will move West across the Gulf and near Texas later next week. Probably nothing more that a rain maker along the Gulf Coast, but anytime there is an Easterly Wave moving across the Gulf in mid September, it is worth monitoring.

[Frank P]

Looking at the few loops available on the vis sat it does appear ATM to have a decent LLC, all the convection that is trying to build is just southeast of the center of rotation... not sure if it will survive the shear, probably not, nor how long this LLC can exist, but it is an interesting little feature to watch... appears to be heading off to the WNW or just due north of west... somewhere in-between perhaps.. additionally, rotation showing up on the long range radar loop out of Miami..

[ronjon]

Only model support I could find is the NAM - forms a weak 1011 mb low in the SE GOM. Yes I know its the NAM.

http://www.tropicaltidbits.com/analysis/models/?model=namconus&region=us&pkg=ref_frzn&runtime=2016090906&fh=84&xpos=0&ypos=221&xpos=0&ypos=221

[stormlover2013]

the nam babyyy lol man that model

[tpr1967]

On latest visible seems that maybe llc is trying to get closer to the convection. But still upper level winds are strong out of nw.

[lrak]

Is this little system 92L leftovers?