Low pressure trough in the Central Atlantic/Tropical Wave Near the Cabo Verde Islands (Is Invest 93L)

[cycloneye]

Complicated scenario here with the monsoon trough and wave that will emerge next week.

Eastern and Central Tropical Atlantic:
Disorganized showers and thunderstorms associated with a trough of
low pressure are located several hundred miles east-southeast of
the Cabo Verde Islands. Some slow development of this system is
possible as it interacts with a tropical wave expected to move off
the African continent early next week and moves west-northwestward
at 5 to 10 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...low...20 percent.

[Teban54]

This is the wave that GFS was hyping up to be the long-tracking MH from a few days ago. More recent runs often favor the 10/40 AOI (making it the recurving MH instead), and have this wave either badly sheared or not develop at all. However, 12z GFS has a solution where the eastern half of the trough becomes dominant and absorbs the wave.

Euro was showing this wave developing immediately off Africa a while ago, but has since dropped it. (Note that GFS almost never showed it developing that far east.) 12z CMC was trying to spin this up, but it became less organized upon reaching central Atlantic.

Both this wave and the 10/40 still have decent support from both GEFS and EPS.

[Ubuntwo]

12z Euro ends with a strong hurricane northeast of the Leewards. This is from the eastern end of the monsoon trough, the same area the 12z GFS developed.

[cycloneye]

12z Euro develops this area as the wave emerges from Africa and then merges with the monsoon trough.

[cycloneye]

8 PM:

Eastern and Central Tropical Atlantic:
Disorganized showers and thunderstorms associated with a trough of
low pressure are located several hundred miles southwest of
the Cabo Verde Islands. The disturbance is expected to move very
little during the next few days until it potentially interacts with
a tropical wave that is forecast to move off the west coast of
Africa by early Monday. Environmental conditions are expected to be
favorable for gradual development of this system, and a tropical
depression could form by the middle or late portions of next week.
The system is expected to begin moving slowly westward by the end
of the week.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...40 percent.

[Teban54]

Three concurrent oranges? That can't be 2024, right?

[Teban54]

Up to 0/50.

3. Eastern and Central Tropical Atlantic:
A trough of low pressure located several hundred miles southwest of
the Cabo Verde Islands is producing some disorganized showers and
thunderstorms. The disturbance is expected to move very little
during the next couple of days until it potentially interacts with
a tropical wave that is forecast to move off the west coast of
Africa by early Monday. Environmental conditions are expected to be
favorable for gradual development of this system, and a tropical
depression could form by the middle or latter part of the week while
the system moves slowly westward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...50 percent.

[Teban54]

0z Euro continues to be aggressive with this system. At the end of this run, it intensifies from 976 mb to 953 mb within 24 hours. Operational Euro is usually very conservative with intensity, so seeing pressure in the 950s is huge.

0z GFS also peaks this at 952 mb, as this run has the system free of interference from 92L.

Regardless of how many systems come out of MDR (I still think 1 is the most likely), one system will have great potential.

[cycloneye]

8 AM:

Eastern and Central Tropical Atlantic:
A trough of low pressure located several hundred miles southwest of
the Cabo Verde Islands is producing a broad area of disorganized
showers and thunderstorms. This system is expected to move very
little during the next couple of days until it potentially interacts
with a tropical wave that is forecast to move off the west coast of
Africa on Monday. Environmental conditions thereafter are expected
to be favorable for gradual development of this system, and a
tropical depression could form by the middle or latter part of the
week while the system begins moving slowly west-northwestward.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...50 percent.

[gatorcane]

I would have thought the NHC would have this one with the higher development chances than 92L to the west, given model support seems more bullish with this one. Also the models, including the ensembles, are unanimously recurving this system into the Central Atlantic.

[underthwx]

This is the wave that GFS was hyping up to be the long-tracking MH from a few days ago. More recent runs often favor the 10/40 AOI (making it the recurving MH instead), and have this wave either badly sheared or not develop at all. However, 12z GFS has a solution where the eastern half of the trough becomes dominant and absorbs the wave.

Euro was showing this wave developing immediately off Africa a while ago, but has since dropped it. (Note that GFS almost never showed it developing that far east.) 12z CMC was trying to spin this up, but it became less organized upon reaching central Atlantic.

Both this wave and the 10/40 still have decent support from both GEFS and EPS.

Which of these do you favor the most?...

[Teban54]

This is the wave that GFS was hyping up to be the long-tracking MH from a few days ago. More recent runs often favor the 10/40 AOI (making it the recurving MH instead), and have this wave either badly sheared or not develop at all. However, 12z GFS has a solution where the eastern half of the trough becomes dominant and absorbs the wave.

Euro was showing this wave developing immediately off Africa a while ago, but has since dropped it. (Note that GFS almost never showed it developing that far east.) 12z CMC was trying to spin this up, but it became less organized upon reaching central Atlantic.

Both this wave and the 10/40 still have decent support from both GEFS and EPS.

Which of these do you favor the most?...

Looks like both Euro and CMC (which just showed bonafide development this run for the first time in a while) favor this system over 92L. GFS was the main support for a significant 92L, but it and its ensembles have since backed off on the 3 most recent runs.

Yet, despite all this, NHC raised 92L's chances to 40/60 today. I don't understand this decision, but they obviously have more expertise than I do. My current impression is that this eastern system has better chance at both formation and intensification than 92L, but my confidence is low.

[underthwx]

This is the wave that GFS was hyping up to be the long-tracking MH from a few days ago. More recent runs often favor the 10/40 AOI (making it the recurving MH instead), and have this wave either badly sheared or not develop at all. However, 12z GFS has a solution where the eastern half of the trough becomes dominant and absorbs the wave.

Euro was showing this wave developing immediately off Africa a while ago, but has since dropped it. (Note that GFS almost never showed it developing that far east.) 12z CMC was trying to spin this up, but it became less organized upon reaching central Atlantic.

Both this wave and the 10/40 still have decent support from both GEFS and EPS.

Which of these do you favor the most?...

Looks like both Euro and CMC (which just showed bonafide development this run for the first time in a while) favor this system over 92L. GFS was the main support for a significant 92L, but it and its ensembles have since backed off on the 3 most recent runs.

Yet, despite all this, NHC raised 92L's chances to 40/60 today. I don't understand this decision, but they obviously have more expertise than I do. My current impression is that this eastern system has better chance at both formation and intensification than 92L, but my confidence is low.

Complicated business....forecasting these systems...thanks for your reply bro...

[Teban54]

Haven't checked 12z GEFS beyond what Weathernerds shows (I know TT loads them faster), but one interesting thing is that more members are showing the subsequent wave (leaving Africa around 9/10) having 30+ kt winds by itself before interacting with the eastern half of the trough.

At 6 days out, you can see two clusters of blue lines: one moving NNW from Eastern Atlantic (the trough), and one moving WNW from Africa (the wave). Signal for the latter was a lot fainter on earlier runs.

[Teban54]

0z Euro continues to be aggressive with this system. At the end of this run, it intensifies from 976 mb to 953 mb within 24 hours. Operational Euro is usually very conservative with intensity, so seeing pressure in the 950s is huge.

0z GFS also peaks this at 952 mb, as this run has the system free of interference from 92L.

Regardless of how many systems come out of MDR (I still think 1 is the most likely), one system will have great potential.

12z Euro is the third full-length run in a row with a hurricane in the 960s, and the second in a row in the 950s. Unlike 0z, it misses the trough and seems to be heading west or WNW at 240 hrs.

12z GFS has a complicated tug-of-war between the eastern trough and the wave that takes days to sort out, and never merges them together. Despite this, the run still makes a recurving hurricane out of the eastern trough, just not as strong.

[Category5Kaiju]

Umm...

[MetroMike]

I thought this was 92L that the Euro is aggressive with developing?

[Hammy]

I thought this was 92L that the Euro is aggressive with developing?

I think the models are all struggling to figure out how this is going to play out, given the monsoon and it seems 3-4 low centers that are going to develop. Seems like the same business we often see with the CAG where they keep alternating between Caribbean, Gulf, and Pacific or simply not at all from run to run

[MarioProtVI]

Euro broadens this out to hell and basically drops it because it’s too weak to reorganize.

[Teban54]

Up to 0/60.

2. Eastern and Central Tropical Atlantic:
A trough of low pressure located several hundred miles
west-southwest of the Cabo Verde Islands is producing a broad area
of disorganized showers and thunderstorms. In a couple of days, this
trough is expected to interact with an approaching tropical wave.
Thereafter, Environmental conditions appear favorable for gradual
development of this system, and a tropical depression could form
during the middle to latter part of this week while the system moves
west-northwestward at 10 to 15 mph.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 7 days...medium...60 percent.