ATL: FOUR - Remnants - Discussion

[GCANE]

Pretty decent anti-cyclone building over this.

Shear ahead has been consistently dropping for some time.

200mb vort looks clear ahead.

Convection much better today than yesterday with overshooting tops firing all morning.

Very true, however, dry air is all around this system and choking it. According to the models, which could be wrong, once it exits the dry air it will then have to contend with shear. If the GFS is right, and it heads into the Bahamas it seems shear will die down some. Which makes me wonder why it does not redevelop there, and strengthen some. Hmmm.

Edit: Also, the center is becoming naked right now. Very easy to see center is east of convection.

I think this goes back to the pouch paradigm which protects the wave from SAL.

http://www.met.nps.edu/~mtmontgo/marsupial.html

A key in this is the vort column up to about 600mb.
94L does have a decent vort signature up to 500mb albeit displaced.
A good indication that TC genesis may occur is when the column starts to become more vertically aligned.

[tarheelprogrammer]

Oh what a difference 3 days makes on the GFS. This is why you cannot trust GFS long range from run to run.

12z today:


18z July 2nd:


Also, shorter range.

12z today:


06z yesterday:


Crap model is going to be crap most of the time. This is why you should never trust the GFS unless the ECMWF is on board as well.

[GCANE]

Strongest convection firing directly under the anti-cyclone.
Estimated surface low just to the east

[Aric Dunn]

with the shear its going to be hard to keep out that SAL and dry air.. but by all definitions it should be a depression once convection persists for 24hrs. so if by later this evening it should be upgraded if convection maintains sheared or not. .

[NDG]

At least the circulation is much better defined that 24 hrs ago but it looks like the easterly shear is inducing some dry air into the weak LLC, which is just about naked now.

[Hurricaneman]

Might have to start watching this carefully once this gets to 65to 70w as the conditions I'm seeing modeled seem to be favorable around there and I do believe this will be a trackable entity the entire time like the GFS suggests

[AutoPenalti]

Naked swirl alert!

[RL3AO]

Crap model is going to be crap most of the time. This is why you should never trust the GFS unless the ECMWF is on board as well.

The GFS is a world-class model that drives changes in the global economy every morning as it runs. It is only slightly worse than the Euro in the long run. You can call out the busts, but don't call it crap. A lot of very smart people have put in hundreds of thousands of hours of hard work to make that model what it is today.

[GCANE]

Crap model is going to be crap most of the time. This is why you should never trust the GFS unless the ECMWF is on board as well.

The GFS is a world-class model that drives changes in the global economy every morning as it runs. It is only slightly worse than the Euro in the long run. You can call out the busts, but don't call it crap. A lot of very smart people have put in hundreds of thousands of hard work to make that model what it is today.

As everyone knows, reliability improves once recon data is put in.
I wonder if CYGNSS data is getting into it now or if there is a plan in the future to do so.

[Aric Dunn]

The last few frames are showing the center slightly elongating and possibly building or reforming near that new convective burst. only time will tell.

[AutoPenalti]

Oh what a difference 3 days makes on the GFS. This is why you cannot trust GFS long range from run to run.

Crap model is going to be crap most of the time. This is why you should never trust the GFS unless the ECMWF is on board as well.

Not to be THAT guy but as far as I can tell, this is a slow moving system. There's about 10-12 days left before it starts to become a slight concern considering it's movement. Models change from run to run, so we won't be sure if it's right until we get closer to that timeframe.

[cycloneye]

No more red.


Tropical Weather Outlook
NWS National Hurricane Center Miami FL
Issued by the NWS Weather Prediction Center College Park MD
200 PM EDT Wed Jul 5 2017

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

1. A low pressure system located about 850 miles west-southwest of
the Cabo Verde Islands continues to produce a small area of showers
and thunderstorms to the west of the center. This system still has
the potential to become a tropical depression before it moves
west-northwestward into a drier and more stable air mass during the
next day or two.
* Formation chance through 48 hours...medium...60 percent
* Formation chance through 5 days...medium...60 percent

$$
Forecaster Bann/Cangialosi

[GCANE]

85GHz just came in. Data about 1 hr old.
Refiring cell looks strong.

[abajan]

Latest TWO lowers development chances to 60% for both 2-day and 5-day periods.

A low pressure system located about 850 miles west-southwest of
the Cabo Verde Islands continues to produce a small area of showers
and thunderstorms to the west of the center. This system still has
the potential to become a tropical depression before it moves
west-northwestward into a drier and more stable air mass during the
next day or two.
* Formation chance through 48 hours...medium...60 percent
* Formation chance through 5 days...medium...60 percent

Forecaster Bann/Cangialosi

[Aric Dunn]

No more red.


Tropical Weather Outlook
NWS National Hurricane Center Miami FL
Issued by the NWS Weather Prediction Center College Park MD
200 PM EDT Wed Jul 5 2017

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

1. A low pressure system located about 850 miles west-southwest of
the Cabo Verde Islands continues to produce a small area of showers
and thunderstorms to the west of the center. This system still has
the potential to become a tropical depression before it moves
west-northwestward into a drier and more stable air mass during the
next day or two.
* Formation chance through 48 hours...medium...60 percent
* Formation chance through 5 days...medium...60 percent

$$
Forecaster Bann/Cangialosi

Its ok we all know if this was closer to land we would already have Don ... lol

[Hammy]

This is about as organized as it's going to get--the dry dusty air and shear are steadily on the increase. If they aren't going to upgrade now, it's essentially over.

[Ntxw]

Crap model is going to be crap most of the time. This is why you should never trust the GFS unless the ECMWF is on board as well.

The GFS is a world-class model that drives changes in the global economy every morning as it runs. It is only slightly worse than the Euro in the long run. You can call out the busts, but don't call it crap. A lot of very smart people have put in hundreds of thousands of hours of hard work to make that model what it is today.

I think short to medium range has done an decent job even by GFS. Only when you start believing 7+ days out runs is when blame is put on the guidance, not a good way to go about it. Good forecasting is still valuable vs pure modelology.

[Aric Dunn]

newest image. the llc has nearly completely been pulled/reformed near or under the recent convection. that will help it.

[Nimbus]

Starting to stack up now, the naked eddy fell apart really fast from the west inflow, almost doesn't look like a primary center. Regardless of that, I doubt we will have two centers rotating around if the convection continues to bloom.

[Aric Dunn]

Starting to stack up now, the naked eddy fell apart really fast from the west inflow, almost doesn't look like a primary center. Regardless of that, I doubt we will have two centers rotating around if the convection continues to bloom.

latest image. it has completely reformed/tucked under the building and sustaining convection .. if it keep up with it should stay ahead of the sal plume to its east..