2024 Global Model Runs Discussion (Out thru day 16)

[zzzh]

Atlantic is waking up

[IcyTundra]

12Z Euro is forecasting shear to be very light near the Bahamas at day 10 with the flow out of the east or east southeast at all levels. Biggest issue will be dry air imo.

[Kingarabian]

12z Euro develops the wave emerging from Africa now.

https://i.imgur.com/tB8AR4i.png

How are you accessing the 12z models? I can only see up to 6z

12z Euro 24 hour increments comes out before.

[BobHarlem]

Pivotal weather usually is a bit faster than Tidbits on getting out frames on new model runs, especially the Euro.

[SFLcane]

 https://x.com/nbergwx/status/1815846029440475478

[Hypercane_Kyle]

Faint signal, but it's there.

 https://x.com/NStewWX/status/1815940976721981883

[Hurricane2022]

These phantom tracks reminds me of something that happened in Aug 2005...
I really can wait very long to see another Katrina

Faint signal, but it's there.

 https://x.com/NStewWX/status/1815940976721981883

[Teban54]

These phantom tracks reminds me of something that happened in Aug 2005...
I really can wait very long to see another Katrina

Faint signal, but it's there.

 https://x.com/NStewWX/status/1815940976721981883

Thankfully, these are only a few members out of 51, and hopefully it would only result in another Gordon 2018 or Erin 1995 instead of you-know-who. But of course, that's what everyone said when hints of Beryl showed up on the ensembles, and we know how that turned out.

[Keldeo1997]

Sure hope that a strong ridge doesn't build at that timeframe. Last thing we need is that dreaded Western track into the gulf.

[chaser1]

Models bare all! Wait, no. What I'm trying to say is that the models bear watching with two Globals now hinting at potential cyclogenesis on development just east (or northeast) of Puerto Rico and perhaps an extrapolated approach to S. Florida. The new 0Z ICON remains in line with the earlier 12Z ICON model run. Those signals now appear quite in sync with the EURO 850mb at about 186 hr from its 12Z model run earlier today. Let's not wake up the GFS and CMC quite yet, they need their little nap

[kevin]

00z Euro ensemble with surprisingly and sudden strong support for a TC which forms in about 6 - 7 days. Let's see what the upcoming ensembles do and whether the other models also jump on board.

[N2FSU]

0z Euro




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[REDHurricane]

00z Euro ensemble with surprisingly and sudden strong support for a TC which forms in about 6 - 7 days. Let's see what the upcoming ensembles do and whether the other models also jump on board.

https://i.imgur.com/imKSXCB.png

Here's my heuristic for assessing these kinds of situations where one of the Euro/GFS is consistently predicting development 7-10 days out and the other isn't:

1) Does it make sense that something might try to develop in that specific area based on shear/SST/moisture/disturbance/climatology?

----> In this case, yes. Let's go through both models and check all of our boxes:

----------> A. Anomalously favorable wind shear conditions on both ensembles? Check

Euro 7 days out:


GFS 7 days out:


Euro 9 days out:


GFS 9 days out:


----------> B. SSTs conducive for tropical development? Check (obviously)

----------> C. Adequate atmospheric moisture content? Mostly check, dry air will still be present but we'll see if any moisture can consolidate to block it out

Euro 7 days out:


GFS 7 days out:


----------> D. Presence of a pre-existing disturbance as a possible spark for tropical cyclogenesis? Check

According to my totally amateur eye, it looks like maybe what's happening is a disturbance/area of convection emerging off Africa just north of Cabo Verde is going to be enhanced by an inflow of tropical moisture from the monsoon trough/ITCZ enough to the point where it may be able to take advantage of the favorable shear/SST conditions approaching the Caribbean despite the dry air surrounding it?

Euro forecast through 9 days:


Relevant area of convection circled in pink possibly?


----------> E. Climatology? Not quite yet -- but as we all learned with Beryl, typical climatology might not really apply this year, so I'll check it off even though it's only July 24

2) Is the GFS ensemble predicting a sloppy CAG system that seemingly emerges out of thin air?

----> If the answer to this question is yes, then nothing is going to develop

3) Which solution do the Canadian and ICON favor?

----> Both models are showing a similar setup to the Euro/GFS, just no actual development yet except for maybe 2-3 members of the Canadian ensemble, so I'll call this one a tie for now

Taking all of these factors into account, though, I personally believe that the current Euro forecast will likely end up being more accurate and we'll see some sort of development from this disturbance. I won't say the name we're all thinking of because it's way too early for that... but people should be keeping a very close eye on this one for sure.

[Category5Kaiju]

00z Euro ensemble with surprisingly and sudden strong support for a TC which forms in about 6 - 7 days. Let's see what the upcoming ensembles do and whether the other models also jump on board.

https://i.imgur.com/imKSXCB.png

Here's my heuristic for assessing these kinds of situations where one of the Euro/GFS is consistently predicting development 7-10 days out and the other isn't:

1) Does it make sense that something might try to develop in that specific area based on shear/SST/moisture/disturbance/climatology?

----> In this case, yes. Let's go through both models and check all of our boxes:

----------> A. Anomalously favorable wind shear conditions on both ensembles? Check

Euro 7 days out:
https://www.tropicaltidbits.com/analysis/models/eps/2024072400/eps_ashear_atl_29.png

GFS 7 days out:
https://www.tropicaltidbits.com/analysis/models/gfs-ens/2024072400/gfs-ens_ashear_atl_29.png

Euro 9 days out:
https://www.tropicaltidbits.com/analysis/models/eps/2024072400/eps_ashear_atl_37.png

GFS 9 days out:
https://www.tropicaltidbits.com/analysis/models/gfs-ens/2024072400/gfs-ens_ashear_atl_37.png

----------> B. SSTs conducive for tropical development? Check (obviously)

----------> C. Adequate atmospheric moisture content? Mostly check, dry air will still be present but we'll see if any moisture can consolidate to block it out

Euro 7 days out:
https://www.tropicaltidbits.com/analysis/models/eps/2024072400/eps_mslp_pwata_atl_29.png

GFS 7 days out:
https://www.tropicaltidbits.com/analysis/models/gfs-ens/2024072400/gfs-ens_mslp_pwata_atl_29.png

----------> D. Presence of a pre-existing disturbance as a possible spark for tropical cyclogenesis? Check

According to my totally amateur eye, it looks like maybe what's happening is a disturbance/area of convection emerging off Africa just north of Cabo Verde is going to be enhanced by an inflow of tropical moisture from the monsoon trough/ITCZ enough to the point where it may be able to take advantage of the favorable shear/SST conditions approaching the Caribbean despite the dry air surrounding it?

Euro forecast through 9 days:
https://media3.giphy.com/media/v1.Y2lkPTc5MGI3NjExY2ZlbzFxNDZvNnhkaXdjb3FyMjA2ZWl2MWp2NHJtZG1ib3BvaTAzbiZlcD12MV9pbnRlcm5hbF9naWZfYnlfaWQmY3Q9Zw/8ZnkiryIo9ZjMEBVbB/giphy.gif

Relevant area of convection circled in pink possibly?
https://media3.giphy.com/media/v1.Y2lkPTc5MGI3NjExbnZ2MjYxY2FqNHlwMmgzYzltOHdteWl0bWo3ZnBidXh2OGFtY3owciZlcD12MV9pbnRlcm5hbF9naWZfYnlfaWQmY3Q9Zw/t4bChqxpAJwqyobXes/giphy.gif

----------> E. Climatology? Not quite yet -- but as we all learned with Beryl, typical climatology might not really apply this year, so I'll check it off even though it's only July 24

2) Is the GFS ensemble predicting a sloppy CAG system that seemingly emerges out of thin air?

----> If the answer to this question is yes, then nothing is going to develop

3) Which solution do the Canadian and ICON favor?

----> Both models are showing a similar setup to the Euro/GFS, just no actual development yet except for maybe 2-3 members of the Canadian ensemble, so I'll call this one a tie for now

Taking all of these factors into account, though, I personally believe that the current Euro forecast will likely end up being more accurate and we'll see some sort of development from this disturbance. I won't say the name we're all thinking of because it's way too early for that... but people should be keeping a very close eye on this one for sure.

The one red flag with the GFS right now is it seems to be spitting out cyclones after cyclones in the EPAC, thereby shutting down the Atlantic. I personally am very doubtful about this outcome, considering how poorly the EPAC has been performing and how we're not entering a warm ENSO phase. I also remember how the Euro ensembles correctly sniffed out Beryl before it formed and was one of the first models to do so, so I'm willing to hedge my money on the Euro ensembles if I had to.

Also...yeah, the K storm can go mind its own beeswax for the time being.

[Ubuntwo]

A big difference here (and likely why the GFS does not currently show development) is in modeled MJO propagation.

The GFS struggles in showing any propagation. We see movement towards the Eastern Pacific before backtracking back towards the Maritime Continent/WPAC. This is the long-range run going out to late August - notice, amplitude also remains quite low.


On the most recent short-range run out to early August, we can see the same effect:


This is very common GFS bias! We see ‘stickiness’ in its MJO foreacasts, a standing wave tendency. Standing waves do occur from time to time, but one over the Pacific in August of 2024? Hmm… Let’s look at the Euro for contrast.


Wow, a couple differences here. We see swift movement towards the Western Hemisphere until the start of August, with good consensus among ensemble members. We also see amplification to just outside the null circle. That is, the Euro displays a stronger MJO moving towards a favorable position for the Atlantic.

[AnnularCane]

The one red flag with the GFS right now is it seems to be spitting out cyclones after cyclones in the EPAC, thereby shutting down the Atlantic. I personally am very doubtful about this outcome, considering how poorly the EPAC has been performing and how we're not entering a warm ENSO phase. I also remember how the Euro ensembles correctly sniffed out Beryl before it formed and was one of the first models to do so, so I'm willing to hedge my money on the Euro ensembles if I had to.

Also...yeah, the K storm can go mind its own beeswax for the time being.

I am currently wondering if all this EPAC activity that the GFS is showing is actually supposed to be Atlantic activity, just misplaced due to GFS issues. Not that I'm expecting storm after storm in the Atlantic at the moment (not yet, maybe next month ).

[Kingarabian]

The one red flag with the GFS right now is it seems to be spitting out cyclones after cyclones in the EPAC, thereby shutting down the Atlantic. I personally am very doubtful about this outcome, considering how poorly the EPAC has been performing and how we're not entering a warm ENSO phase. I also remember how the Euro ensembles correctly sniffed out Beryl before it formed and was one of the first models to do so, so I'm willing to hedge my money on the Euro ensembles if I had to.

Also...yeah, the K storm can go mind its own beeswax for the time being.

I am currently wondering if all this EPAC activity that the GFS is showing is actually supposed to be Atlantic activity, just misplaced due to GFS issues. Not that I'm expecting storm after storm in the Atlantic at the moment (not yet, maybe next month ).

It's a possibility. It's usually every TW that enters the EPAC or lows within the monsoon trough that it wants to spin up thinking its 2018.

[ScottNAtlanta]

Check out some other MJO models...CFSv2. Goes fully into 1 and 2



GEFS (bc) bias corrected



The trend is your friend, and the models have been trending towards the Atlantic favorable areas.

[Ubuntwo]

Check out some other MJO models...CFSv2. Goes fully into 1 and 2

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/NCFS.png

GEFS (bc) bias corrected

https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/GEFS_BC.png

The trend is your friend, and the models have been trending towards the Atlantic favorable areas.

Absolutely. The delta between the GFS and the GFS w/ bias correction says it all. The GFS will perk up the instant it catches the MJO propagation into the Atlantic.

[Tailgater33]

00z Euro ensemble with surprisingly and sudden strong support for a TC which forms in about 6 - 7 days. Let's see what the upcoming ensembles do and whether the other models also jump on board.

https://i.imgur.com/imKSXCB.png

Here's my heuristic for assessing these kinds of situations where one of the Euro/GFS is consistently predicting development 7-10 days out and the other isn't:

1) Does it make sense that something might try to develop in that specific area based on shear/SST/moisture/disturbance/climatology?

----> In this case, yes. Let's go through both models and check all of our boxes:

----------> A. Anomalously favorable wind shear conditions on both ensembles? Check

Euro 7 days out:
https://www.tropicaltidbits.com/analysis/models/eps/2024072400/eps_ashear_atl_29.png

GFS 7 days out:
https://www.tropicaltidbits.com/analysis/models/gfs-ens/2024072400/gfs-ens_ashear_atl_29.png

Euro 9 days out:
https://www.tropicaltidbits.com/analysis/models/eps/2024072400/eps_ashear_atl_37.png

GFS 9 days out:
https://www.tropicaltidbits.com/analysis/models/gfs-ens/2024072400/gfs-ens_ashear_atl_37.png

----------> B. SSTs conducive for tropical development? Check (obviously)

----------> C. Adequate atmospheric moisture content? Mostly check, dry air will still be present but we'll see if any moisture can consolidate to block it out

Euro 7 days out:
https://www.tropicaltidbits.com/analysis/models/eps/2024072400/eps_mslp_pwata_atl_29.png

GFS 7 days out:
https://www.tropicaltidbits.com/analysis/models/gfs-ens/2024072400/gfs-ens_mslp_pwata_atl_29.png

----------> D. Presence of a pre-existing disturbance as a possible spark for tropical cyclogenesis? Check

According to my totally amateur eye, it looks like maybe what's happening is a disturbance/area of convection emerging off Africa just north of Cabo Verde is going to be enhanced by an inflow of tropical moisture from the monsoon trough/ITCZ enough to the point where it may be able to take advantage of the favorable shear/SST conditions approaching the Caribbean despite the dry air surrounding it?

Euro forecast through 9 days:
https://media3.giphy.com/media/v1.Y2lkPTc5MGI3NjExY2ZlbzFxNDZvNnhkaXdjb3FyMjA2ZWl2MWp2NHJtZG1ib3BvaTAzbiZlcD12MV9pbnRlcm5hbF9naWZfYnlfaWQmY3Q9Zw/8ZnkiryIo9ZjMEBVbB/giphy.gif

Relevant area of convection circled in pink possibly?
https://media3.giphy.com/media/v1.Y2lkPTc5MGI3NjExbnZ2MjYxY2FqNHlwMmgzYzltOHdteWl0bWo3ZnBidXh2OGFtY3owciZlcD12MV9pbnRlcm5hbF9naWZfYnlfaWQmY3Q9Zw/t4bChqxpAJwqyobXes/giphy.gif

----------> E. Climatology? Not quite yet -- but as we all learned with Beryl, typical climatology might not really apply this year, so I'll check it off even though it's only July 24

2) Is the GFS ensemble predicting a sloppy CAG system that seemingly emerges out of thin air?

----> If the answer to this question is yes, then nothing is going to develop

3) Which solution do the Canadian and ICON favor?

----> Both models are showing a similar setup to the Euro/GFS, just no actual development yet except for maybe 2-3 members of the Canadian ensemble, so I'll call this one a tie for now

Taking all of these factors into account, though, I personally believe that the current Euro forecast will likely end up being more accurate and we'll see some sort of development from this disturbance. I won't say the name we're all thinking of because it's way too early for that... but people should be keeping a very close eye on this one for sure.

I have no idea whether either plot plays out but those are some awesome graphics. Well done.