2024 Indicators: SST's, MSLP, Shear, SAL, Steering, Instability (Day 16+ Climate Models)

[al78]

It's September 17 now and the Northern Hemisphere is almost completely quiet. Nothing in the Atlantic, nothing in the East Pacific, and only a tropical storm in the West Pacific. There's been a lot of theories on why the Atlantic has been so quiet the last six weeks but this also appears to be a global issue as well. There just doesn't seem to be enough moisture for tropical systems to form.

What’s interesting is despite the Northern Hemisphere struggles, it still managed to generate some powerful, destructive storms along the way (namely Beryl in the Atlantic and Yagi in the WPAC). Just really shows how even a slow year doesn’t mean the absence of impacts.

I guess we should be grateful something(s) has put the lid on Atlantic tropical cyclone activity this year, given most of the storms have made landfall, it suggests steering winds have been favourable for moving storms onto land, so if activity had matched the seasonal predictions, we may have been looking at a 2004-like season.

[tolakram]

I think it would be interesting to see chances of another 2013 like bust vs chances of predicting a record breaking season.

IF we get hit by just a few big storms I think the bust will be less recognized, but I sincerely hope the numbers way of predicting a season is revisited.

[wxman57]

Looks like the previous instability graphic I posted was from 2022, not 2024. Here is the 2024 comparison. Relatively stable tropics this year.

http://wxman57.com/images/InstabilityComparison.JPG

[MarioProtVI]

It's September 17 now and the Northern Hemisphere is almost completely quiet. Nothing in the Atlantic, nothing in the East Pacific, and only a tropical storm in the West Pacific. There's been a lot of theories on why the Atlantic has been so quiet the last six weeks but this also appears to be a global issue as well. There just doesn't seem to be enough moisture for tropical systems to form.

This was an issue and also the case in 2013 as well (at least until late September when WPac began popping off). Have to wonder why this is happening again 11 years later. Something caused the atmosphere to seem to get stuck in the late July/early August state globally and hasn’t budged since, and the +NAO and hyperactive AEJ may be a result of this.

[Emmett_Brown]

It's September 17 now and the Northern Hemisphere is almost completely quiet. Nothing in the Atlantic, nothing in the East Pacific, and only a tropical storm in the West Pacific. There's been a lot of theories on why the Atlantic has been so quiet the last six weeks but this also appears to be a global issue as well. There just doesn't seem to be enough moisture for tropical systems to form.

This was an issue and also the case in 2013 as well (at least until late September when WPac began popping off). Have to wonder why this is happening again 11 years later. Something caused the atmosphere to seem to get stuck in the late July/early August state globally and hasn’t budged since, and the +NAO and hyperactive AEJ may be a result of this.

Interesting that we were in a similar part of the 11 year solar cycle back in 2013... nearing peak. Just throwing it out there as a similarity, nothing more

[Hammy]

It's September 17 now and the Northern Hemisphere is almost completely quiet. Nothing in the Atlantic, nothing in the East Pacific, and only a tropical storm in the West Pacific. There's been a lot of theories on why the Atlantic has been so quiet the last six weeks but this also appears to be a global issue as well. There just doesn't seem to be enough moisture for tropical systems to form.

This was an issue and also the case in 2013 as well (at least until late September when WPac began popping off). Have to wonder why this is happening again 11 years later. Something caused the atmosphere to seem to get stuck in the late July/early August state globally and hasn’t budged since, and the +NAO and hyperactive AEJ may be a result of this.

The Atlantic looks more like mid to late fall than it does late July. I really am starting to wonder if another issue with the thermohaline circulation happened (albeit later than 2013)--it seems like once we started getting formative tropical waves, the subtropics did a complete 180 and how it's nothing but wave breaking and troughs and shear

[al78]

It's September 17 now and the Northern Hemisphere is almost completely quiet. Nothing in the Atlantic, nothing in the East Pacific, and only a tropical storm in the West Pacific. There's been a lot of theories on why the Atlantic has been so quiet the last six weeks but this also appears to be a global issue as well. There just doesn't seem to be enough moisture for tropical systems to form.

This was an issue and also the case in 2013 as well (at least until late September when WPac began popping off). Have to wonder why this is happening again 11 years later. Something caused the atmosphere to seem to get stuck in the late July/early August state globally and hasn’t budged since, and the +NAO and hyperactive AEJ may be a result of this.

In 2013 this happened: https://en.wikipedia.org/wiki/Typhoon_Haiyan illustrating it only takes one storm to cause major destruction.

[kevin]

Okay I know long-range CFS runs have a value of ~0, but today's 00z run is so crazy that I have to discuss it.

Now that the Atlantic finally seems to notice that it's peak season (at least in about 5 days according to the models), let's take a look at the most recent CFS run combined with our current knowledge of the GEFS & Euro ensembles for fun to see what it thinks of a backloaded season. Once again, the timeframe is so far out that the practical value of one run is ~0, but it's also just a bit for fun. Since it's for fun anyways I also added potential names and rough ACE estimates. Intensity estimates are more based on track and general pressure since CFS basically never gets something below 990 mb.

September
*Sep 20 - Sep 22: Gordon might briefly re-intensify into a TD but nothing more [ACE ~0, season 7/4/1].
*Sep 21 - Sep 23: A weak TS could form west of Gordon, becoming Helene [ACE 0 - 2, season 8/4/1].
*Sep 24 - Oct 2: The WCar disturbance forms, Isaac. CFS is notoriously bad with Yucatan-related stuff so it becomes a strung out mess. Let's for now use the GEFS and Euro ensembles, assuming a MH making landfall somewhere along the US coast [ACE 15 - 25, season 9/5/2].
*Sep 24 - Sep 29: Around the same time the eastern MDR disturbance forms, potentially stealing the WCar's I-name. For now I put it as Joyce. Recurves quite early on the CFS run. Based on current ensembles probably a recurving hurricane. Let's for now assume a middle-of-the-road case and not the massive MH GFS shows [ACE 10 - 20, season 10/6/2].
*Sep 25 - Sep 28: A STS forms east of the US, Kirk. This one is also showing up in the GEFS ensembles. CFS even seems to make it a low-end hurricane (pressure in the high 980s, which is very low for CFS) before becoming extra-tropical. No threat to land [ACE 5 - 10, season 11/7/2].
*Sep 26 - Oct 6: Another TD/TS forms below Joyce in the lower portion of the MDR, becoming Leslie. This is in-line with some GEFS members which show more MDR action near the end of the ensemble run. Makes landfall in the Lesser Antilles and the Bahamas and then recurves away. Based on track probably a hurricane [ACE 10 - 20, season 12/8/2].
*Sep 27 - Oct 6: Ehm... there's another MDR storm coming from Africa, becoming Milton. Recurves before the Lesser Antilles and dissipates while recurving. Based on track probably a hurricane. For statistics sake, let's assume that either Joyce, Leslie or Milton becomes a MH [ACE 10 - 20, season 13/9/3].

October
*Oct 8 - Oct 15: The Atlantic needs a day or two to recover, but then we get another eastern MDR storm, Nadine. Recurves OTS early, but probably a hurricane based on track [ACE 5 - 15, season 14/10/3].
*Oct 16 - Oct 24: For the first time this year a CFS run which shows long-range TC genesis in the WCar, Oscar. Stays around for quite some days in the boiling WCar and then goes to Cuba/Florida and also impacts the NY region afterwards while turning extra-tropical. Late-season WCar storm makes me go with a MH [ACE 15 - 25, season 15/11/4].
*Oct 17 - 24: A TS forms in the central Atlantic, Patty. Recurves far east, but the low pressure in the 990s for the MDR makes me go with a recurving hurricane. Eventually dissipates west of Spain [ACE 5 - 15, season 16/12/4].
*Oct 20 - 26. A STS forms off the coast of the US, Rafael. Stays around for a few days and moves east, intensifying into probably a high-end TS or low-end hurricane before dissipating. Let's assume a TS for now just to compensate for some of the craziness of this run [ACE 5 - 10, season 17/12/4].
*Oct 31 - Nov 2: Short-lived STS OTS, Sara [ACE 0 - 2, season 18/12/4].

November
*Nov 4 - 8: A STS forms east of the US and intensifies into a strong hurricane, Tony, potentially a MH before impacting NY and Newfoundland. Almost Sandy-like [ACE 10 - 15, season 19/13/5].
*Nov 19 - 24. A huge STS forms in the central Atlantic, Valerie. Intensifies into the 960s mbar, which is unheard of for a large-scale model like CFS. Eventually becomes extra-tropical, but no clue what to make of this. Put it as a hurricane for now [ACE 10 - 15, season 20/14/5].

Conclusion

This has to be the craziest CFS run I've ever seen and would put 2020's late season to shame. Combining this with the season so far would result in season totals of 20/14/5 and an ACE in the range of 160 - 250. Also, somehow the model churns out 6 more TCs in the last 11 days of this month. Does this mean this will become reality? No, of course not. Let's first see whether the relatively short-term prediction of a crazy end of September comes to fruition. But, if CFS is correctly sniffing out late-season favorability, we could be in for quite a ride.

[WeatherBoy2000]

Okay I know long-range CFS runs have a value of ~0, but today's 00z run is so crazy that I have to discuss it.

Now that the Atlantic finally seems to notice that it's peak season (at least in about 5 days according to the models), let's take a look at the most recent CFS run combined with our current knowledge of the GEFS & Euro ensembles for fun to see what it thinks of a backloaded season. Once again, the timeframe is so far out that the practical value of one run is ~0, but it's also just a bit for fun. Since it's for fun anyways I also added potential names and rough ACE estimates. Intensity estimates are more based on track and general pressure since CFS basically never gets something below 990 mb.

September
*Sep 20 - Sep 22: Gordon might briefly re-intensify into a TD but nothing more [ACE ~0, season 7/4/1].
*Sep 21 - Sep 23: A weak TS could form west of Gordon, becoming Helene [ACE 0 - 2, season 8/4/1].
*Sep 24 - Oct 2: The WCar disturbance forms, Isaac. CFS is notoriously bad with Yucatan-related stuff so it becomes a strung out mess. Let's for now use the GEFS and Euro ensembles, assuming a MH making landfall somewhere along the US coast [ACE 15 - 25, season 9/5/2].
*Sep 24 - Sep 29: Around the same time the eastern MDR disturbance forms, potentially stealing the WCar's I-name. For now I put it as Joyce. Recurves quite early on the CFS run. Based on current ensembles probably a recurving hurricane. Let's for now assume a middle-of-the-road case and not the massive MH GFS shows [ACE 10 - 20, season 10/6/2].
*Sep 25 - Sep 28: A STS forms east of the US, Kirk. This one is also showing up in the GEFS ensembles. CFS even seems to make it a low-end hurricane (pressure in the high 980s, which is very low for CFS) before becoming extra-tropical. No threat to land [ACE 5 - 10, season 11/7/2].
*Sep 26 - Oct 6: Another TD/TS forms below Joyce in the lower portion of the MDR, becoming Leslie. This is in-line with some GEFS members which show more MDR action near the end of the ensemble run. Makes landfall in the Lesser Antilles and the Bahamas and then recurves away. Based on track probably a hurricane [ACE 10 - 20, season 12/8/2].
*Sep 27 - Oct 6: Ehm... there's another MDR storm coming from Africa, becoming Milton. Recurves before the Lesser Antilles and dissipates while recurving. Based on track probably a hurricane. For statistics sake, let's assume that either Joyce, Leslie or Milton becomes a MH [ACE 10 - 20, season 13/9/3].

October
*Oct 8 - Oct 15: The Atlantic needs a day or two to recover, but then we get another eastern MDR storm, Nadine. Recurves OTS early, but probably a hurricane based on track [ACE 5 - 15, season 14/10/3].
*Oct 16 - Oct 24: For the first time this year a CFS run which shows long-range TC genesis in the WCar, Oscar. Stays around for quite some days in the boiling WCar and then goes to Cuba/Florida and also impacts the NY region afterwards while turning extra-tropical. Late-season WCar storm makes me go with a MH [ACE 15 - 25, season 15/11/4].
*Oct 17 - 24: A TS forms in the central Atlantic, Patty. Recurves far east, but the low pressure in the 990s for the MDR makes me go with a recurving hurricane. Eventually dissipates west of Spain [ACE 5 - 15, season 16/12/4].
*Oct 20 - 26. A STS forms off the coast of the US, Rafael. Stays around for a few days and moves east, intensifying into probably a high-end TS or low-end hurricane before dissipating. Let's assume a TS for now just to compensate for some of the craziness of this run [ACE 5 - 10, season 17/12/4].
*Oct 31 - Nov 2: Short-lived STS OTS, Sara [ACE 0 - 2, season 18/12/4].

November
*Nov 4 - 8: A STS forms east of the US and intensifies into a strong hurricane, Tony, potentially a MH before impacting NY and Newfoundland. Almost Sandy-like [ACE 10 - 15, season 19/13/5].
*Nov 19 - 24. A huge STS forms in the central Atlantic, Valerie. Intensifies into the 960s mbar, which is unheard of for a large-scale model like CFS. Eventually becomes extra-tropical, but no clue what to make of this. Put it as a hurricane for now [ACE 10 - 15, season 20/14/5].

Conclusion

This has to be the craziest CFS run I've ever seen and would put 2020's late season to shame. Combining this with the season so far would result in season totals of 20/14/5 and an ACE in the range of 160 - 250. Also, somehow the model churns out 6 more TCs in the last 11 days of this month. Does this mean this will become reality? No, of course not. Let's first see whether the relatively short-term prediction of a crazy end of September comes to fruition. But, if CFS is correctly sniffing out late-season favorability, we could be in for quite a ride.

It's not only the CFS that is showing things becoming more favorable to even very favorable for the Atlantic during the last leg of September into October:

 https://x.com/jr_kurt34994/status/1836585835367424123




These predictions could all fail obviously, but it isn't over until it's over.

[Category5Kaiju]

Okay I know long-range CFS runs have a value of ~0, but today's 00z run is so crazy that I have to discuss it.

Now that the Atlantic finally seems to notice that it's peak season (at least in about 5 days according to the models), let's take a look at the most recent CFS run combined with our current knowledge of the GEFS & Euro ensembles for fun to see what it thinks of a backloaded season. Once again, the timeframe is so far out that the practical value of one run is ~0, but it's also just a bit for fun. Since it's for fun anyways I also added potential names and rough ACE estimates. Intensity estimates are more based on track and general pressure since CFS basically never gets something below 990 mb.

September
*Sep 20 - Sep 22: Gordon might briefly re-intensify into a TD but nothing more [ACE ~0, season 7/4/1].
*Sep 21 - Sep 23: A weak TS could form west of Gordon, becoming Helene [ACE 0 - 2, season 8/4/1].
*Sep 24 - Oct 2: The WCar disturbance forms, Isaac. CFS is notoriously bad with Yucatan-related stuff so it becomes a strung out mess. Let's for now use the GEFS and Euro ensembles, assuming a MH making landfall somewhere along the US coast [ACE 15 - 25, season 9/5/2].
*Sep 24 - Sep 29: Around the same time the eastern MDR disturbance forms, potentially stealing the WCar's I-name. For now I put it as Joyce. Recurves quite early on the CFS run. Based on current ensembles probably a recurving hurricane. Let's for now assume a middle-of-the-road case and not the massive MH GFS shows [ACE 10 - 20, season 10/6/2].
*Sep 25 - Sep 28: A STS forms east of the US, Kirk. This one is also showing up in the GEFS ensembles. CFS even seems to make it a low-end hurricane (pressure in the high 980s, which is very low for CFS) before becoming extra-tropical. No threat to land [ACE 5 - 10, season 11/7/2].
*Sep 26 - Oct 6: Another TD/TS forms below Joyce in the lower portion of the MDR, becoming Leslie. This is in-line with some GEFS members which show more MDR action near the end of the ensemble run. Makes landfall in the Lesser Antilles and the Bahamas and then recurves away. Based on track probably a hurricane [ACE 10 - 20, season 12/8/2].
*Sep 27 - Oct 6: Ehm... there's another MDR storm coming from Africa, becoming Milton. Recurves before the Lesser Antilles and dissipates while recurving. Based on track probably a hurricane. For statistics sake, let's assume that either Joyce, Leslie or Milton becomes a MH [ACE 10 - 20, season 13/9/3].

October
*Oct 8 - Oct 15: The Atlantic needs a day or two to recover, but then we get another eastern MDR storm, Nadine. Recurves OTS early, but probably a hurricane based on track [ACE 5 - 15, season 14/10/3].
*Oct 16 - Oct 24: For the first time this year a CFS run which shows long-range TC genesis in the WCar, Oscar. Stays around for quite some days in the boiling WCar and then goes to Cuba/Florida and also impacts the NY region afterwards while turning extra-tropical. Late-season WCar storm makes me go with a MH [ACE 15 - 25, season 15/11/4].
*Oct 17 - 24: A TS forms in the central Atlantic, Patty. Recurves far east, but the low pressure in the 990s for the MDR makes me go with a recurving hurricane. Eventually dissipates west of Spain [ACE 5 - 15, season 16/12/4].
*Oct 20 - 26. A STS forms off the coast of the US, Rafael. Stays around for a few days and moves east, intensifying into probably a high-end TS or low-end hurricane before dissipating. Let's assume a TS for now just to compensate for some of the craziness of this run [ACE 5 - 10, season 17/12/4].
*Oct 31 - Nov 2: Short-lived STS OTS, Sara [ACE 0 - 2, season 18/12/4].

November
*Nov 4 - 8: A STS forms east of the US and intensifies into a strong hurricane, Tony, potentially a MH before impacting NY and Newfoundland. Almost Sandy-like [ACE 10 - 15, season 19/13/5].
*Nov 19 - 24. A huge STS forms in the central Atlantic, Valerie. Intensifies into the 960s mbar, which is unheard of for a large-scale model like CFS. Eventually becomes extra-tropical, but no clue what to make of this. Put it as a hurricane for now [ACE 10 - 15, season 20/14/5].

Conclusion

This has to be the craziest CFS run I've ever seen and would put 2020's late season to shame. Combining this with the season so far would result in season totals of 20/14/5 and an ACE in the range of 160 - 250. Also, somehow the model churns out 6 more TCs in the last 11 days of this month. Does this mean this will become reality? No, of course not. Let's first see whether the relatively short-term prediction of a crazy end of September comes to fruition. But, if CFS is correctly sniffing out late-season favorability, we could be in for quite a ride.

I mean, while something remotely like this would indeed be very shocking, it would also go in line with the somewhat common pattern that first year La Niña seasons after big El Niños can be backloaded (see 1998, 2010, and 2016), with activity also extending into November.

Now at this point I’m going to refrain from saying we’re going to see a Mitch-like storm or an Iota-like storm this year (as there is no way to know for sure now), but at the same time, I think it’s important to acknowledge the idea that perhaps, those very warm deep tropical waters may unfortunately not just slither away calmly.

[chaser1]

NHC is taking note of new areas of suspected development. Experts point toward the impending MJO flip. The media throwing Caribbean and GOM graphics pointing toward "the next one". Models are all beginning to hum.
Meanwhile, nothing but blue sky's across the basin tropics. Maybe we're secretly being trolled by Mother Nature and nothing else forms

[ThomasW]

I think it's worth saying that if the CAG storm and the MDR system both fail to become hurricanes (as is fast becoming likely), that we shouldn't expect many more storms, or any more MH. With October comes the subtropical jet shutdown of the MDR, and the West CARIB will only do so much with the ridging the GEFS depicts. Not sure if we even reach average ACE. A great thing for folks down on the Gulf Coast.

[KWT]

I think it's worth saying that if the CAG storm and the MDR system both fail to become hurricanes (as is fast becoming likely), that we shouldn't expect many more storms, or any more MH. With October comes the subtropical jet shutdown of the MDR, and the West CARIB will only do so much with the ridging the GEFS depicts. Not sure if we even reach average ACE. A great thing for folks down on the Gulf Coast.

All true but we do have still record warm SST and a troposphere that should now be cooling.

With a la nina I really wouldn't be surprised if we get a bombastic Oct/Nov as instability increases. SST are basically still at peak normal season ssts.

I think we are near 100% chance of a normal season ace wise. I still wouldn't rule out above normal either given.how I think the next 45 days pan out (I think 8/4/3...)

[chaser1]

Just a random thought that I had (likely a result of idle time due to the absent hurricane activity for most of August & September). I wonder whether the insurance industry has ever conducted research to determine property damage, health, and life insurance pay-out and cost, as a result of annual ACE totals?

[MarioProtVI]

I think it's worth saying that if the CAG storm and the MDR system both fail to become hurricanes (as is fast becoming likely), that we shouldn't expect many more storms, or any more MH. With October comes the subtropical jet shutdown of the MDR, and the West CARIB will only do so much with the ridging the GEFS depicts. Not sure if we even reach average ACE. A great thing for folks down on the Gulf Coast.

All true but we do have still record warm SST and a troposphere that should now be cooling.

With a la nina I really wouldn't be surprised if we get a bombastic Oct/Nov as instability increases. SST are basically still at peak normal season ssts.

I think we are near 100% chance of a normal season ace wise. I still wouldn't rule out above normal either given.how I think the next 45 days pan out (I think 8/4/3...)

There’s always the possibility 2024 keeps 2024ing and it keeps falling flat on its face. Whether or not 2024 is about to make a 2022-style comeback hinges on the CAG and MDR being strong and if the most we get out of both are sloppy weak TSs or minimal Cat 1s - or even don’t form at all as we’ve seen with prior systems (pre-Francine and Gordon) when guidance suddenly vanishes, then 2024 is most likely done as it will have failed to produce something efficient as the MJO becomes favorable again which in a hyperactive season would’ve had stuff going off like 2020.

[Hammy]

I think it's worth saying that if the CAG storm and the MDR system both fail to become hurricanes (as is fast becoming likely), that we shouldn't expect many more storms, or any more MH. With October comes the subtropical jet shutdown of the MDR, and the West CARIB will only do so much with the ridging the GEFS depicts. Not sure if we even reach average ACE. A great thing for folks down on the Gulf Coast.

All true but we do have still record warm SST and a troposphere that should now be cooling.

With a la nina I really wouldn't be surprised if we get a bombastic Oct/Nov as instability increases. SST are basically still at peak normal season ssts.

I think we are near 100% chance of a normal season ace wise. I still wouldn't rule out above normal either given.how I think the next 45 days pan out (I think 8/4/3...)

There’s always the possibility 2024 keeps 2024ing and it keeps falling flat on its face. Whether or not 2024 is about to make a 2022-style comeback hinges on the CAG and MDR being strong and if the most we get out of both are sloppy weak TSs or minimal Cat 1s - or even don’t form at all as we’ve seen with prior systems (pre-Francine and Gordon) when guidance suddenly vanishes, then 2024 is most likely done as it will have failed to produce something efficient as the MJO becomes favorable again which in a hyperactive season would’ve had stuff going off like 2020.

The Gulf and Caribbean are where the Atlantic has had it's successes so far--Beryl was a Cat 5 in the Caribbean, Debby and Francene both peaked in the Gulf, and the monsoon trough has been successful at spawning multiple storms when it becomes active, so I wouldn't put anything past the western basin

The MDR on the other hand is probably just going to be nothing but slop no matter how the rest of teh season goes.

[kevin]

The average of the North Atlantic SSTs is increasing again over the last week and is now again equal to the 2023 record value for this time of the year.

[weeniepatrol]

My sincere and honest reaction to the 2024 hurricane season:

[MetroMike]

My sincere and honest reaction to the 2024 hurricane season:

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

[MHC Tracking]

Okay I know long-range CFS runs have a value of ~0, but today's 00z run is so crazy that I have to discuss it.

Now that the Atlantic finally seems to notice that it's peak season (at least in about 5 days according to the models), let's take a look at the most recent CFS run combined with our current knowledge of the GEFS & Euro ensembles for fun to see what it thinks of a backloaded season. Once again, the timeframe is so far out that the practical value of one run is ~0, but it's also just a bit for fun. Since it's for fun anyways I also added potential names and rough ACE estimates. Intensity estimates are more based on track and general pressure since CFS basically never gets something below 990 mb.

September
*Sep 20 - Sep 22: Gordon might briefly re-intensify into a TD but nothing more [ACE ~0, season 7/4/1].
*Sep 21 - Sep 23: A weak TS could form west of Gordon, becoming Helene [ACE 0 - 2, season 8/4/1].
*Sep 24 - Oct 2: The WCar disturbance forms, Isaac. CFS is notoriously bad with Yucatan-related stuff so it becomes a strung out mess. Let's for now use the GEFS and Euro ensembles, assuming a MH making landfall somewhere along the US coast [ACE 15 - 25, season 9/5/2].
*Sep 24 - Sep 29: Around the same time the eastern MDR disturbance forms, potentially stealing the WCar's I-name. For now I put it as Joyce. Recurves quite early on the CFS run. Based on current ensembles probably a recurving hurricane. Let's for now assume a middle-of-the-road case and not the massive MH GFS shows [ACE 10 - 20, season 10/6/2].
*Sep 25 - Sep 28: A STS forms east of the US, Kirk. This one is also showing up in the GEFS ensembles. CFS even seems to make it a low-end hurricane (pressure in the high 980s, which is very low for CFS) before becoming extra-tropical. No threat to land [ACE 5 - 10, season 11/7/2].
*Sep 26 - Oct 6: Another TD/TS forms below Joyce in the lower portion of the MDR, becoming Leslie. This is in-line with some GEFS members which show more MDR action near the end of the ensemble run. Makes landfall in the Lesser Antilles and the Bahamas and then recurves away. Based on track probably a hurricane [ACE 10 - 20, season 12/8/2].
*Sep 27 - Oct 6: Ehm... there's another MDR storm coming from Africa, becoming Milton. Recurves before the Lesser Antilles and dissipates while recurving. Based on track probably a hurricane. For statistics sake, let's assume that either Joyce, Leslie or Milton becomes a MH [ACE 10 - 20, season 13/9/3].

October
*Oct 8 - Oct 15: The Atlantic needs a day or two to recover, but then we get another eastern MDR storm, Nadine. Recurves OTS early, but probably a hurricane based on track [ACE 5 - 15, season 14/10/3].
*Oct 16 - Oct 24: For the first time this year a CFS run which shows long-range TC genesis in the WCar, Oscar. Stays around for quite some days in the boiling WCar and then goes to Cuba/Florida and also impacts the NY region afterwards while turning extra-tropical. Late-season WCar storm makes me go with a MH [ACE 15 - 25, season 15/11/4].
*Oct 17 - 24: A TS forms in the central Atlantic, Patty. Recurves far east, but the low pressure in the 990s for the MDR makes me go with a recurving hurricane. Eventually dissipates west of Spain [ACE 5 - 15, season 16/12/4].
*Oct 20 - 26. A STS forms off the coast of the US, Rafael. Stays around for a few days and moves east, intensifying into probably a high-end TS or low-end hurricane before dissipating. Let's assume a TS for now just to compensate for some of the craziness of this run [ACE 5 - 10, season 17/12/4].
*Oct 31 - Nov 2: Short-lived STS OTS, Sara [ACE 0 - 2, season 18/12/4].

November
*Nov 4 - 8: A STS forms east of the US and intensifies into a strong hurricane, Tony, potentially a MH before impacting NY and Newfoundland. Almost Sandy-like [ACE 10 - 15, season 19/13/5].
*Nov 19 - 24. A huge STS forms in the central Atlantic, Valerie. Intensifies into the 960s mbar, which is unheard of for a large-scale model like CFS. Eventually becomes extra-tropical, but no clue what to make of this. Put it as a hurricane for now [ACE 10 - 15, season 20/14/5].

Conclusion

This has to be the craziest CFS run I've ever seen and would put 2020's late season to shame. Combining this with the season so far would result in season totals of 20/14/5 and an ACE in the range of 160 - 250. Also, somehow the model churns out 6 more TCs in the last 11 days of this month. Does this mean this will become reality? No, of course not. Let's first see whether the relatively short-term prediction of a crazy end of September comes to fruition. But, if CFS is correctly sniffing out late-season favorability, we could be in for quite a ride.

This technically isn't the right thread for my post but I thought it was relevant in light of this CFS run. Today's 00z GFS, which runs through only October 8th features all of this:
(1): MH from the Carib 0/70 into the Big Bend. Pressure at 948, so likely HE C3-LE C4

(2):Peak 1 of the current MHC 0/40, pressure at 984 so probably a mid-range C1

(3):Peak 2 of the current NHC 0/40, pressure at 971 so we can assume a mid-upper end C2

(4):2nd CAG system hitting SWFL, pressure in the mid-960s so probably HE C2-LE C3

(5): "3rd Wave" develops into a MH, pressure of 957, probably mid-range C3

(6): "2nd wave" resmains dry until the ECAR, then develops into a HE TS offshore of Hispaniola


I don't think I've seen such an active run since late 2020 and the days of the old PARA model. Doesn't mean anything verbatim past about hour 168, but if this isn't a sign of activity, I don't know what is.