Why is the 2024 Atlantic hurricane season underperforming expectations?

[Hammy]

I remember after 2013 it was thought that such an underperforming season would be once-in-a-lifetime anomalies. Now we have a second, potentially even more historic underperformance (counting the chickens before they're hatched, I know) it's clear there's a mechanism that is impacting hurricane seasons we simply do not understand and models aren't able to capture correctly.

I wouldn't exactly call this year "even more historic" given 2013 had 36 ACE and only two hurricanes the entire season, both Cat 1.

[Hypercane_Kyle]

I remember after 2013 it was thought that such an underperforming season would be once-in-a-lifetime anomalies. Now we have a second, potentially even more historic underperformance (counting the chickens before they're hatched, I know) it's clear there's a mechanism that is impacting hurricane seasons we simply do not understand and models aren't able to capture correctly.

I wouldn't exactly call this year "even more historic" given 2013 had 36 ACE and only two hurricanes the entire season, both Cat 1.

2024 had way higher expectations than arguably any other hurricane season in history, so I think it's a more surprising bust if we end up only 60-70 ACE and only 10 named storms, for example.

[Teban54]

I remember after 2013 it was thought that such an underperforming season would be once-in-a-lifetime anomalies. Now we have a second, potentially even more historic underperformance (counting the chickens before they're hatched, I know) it's clear there's a mechanism that is impacting hurricane seasons we simply do not understand and models aren't able to capture correctly.

I wouldn't exactly call this year "even more historic" given 2013 had 36 ACE and only two hurricanes the entire season, both Cat 1.

2024 had way higher expectations than arguably any other hurricane season in history, so I think it's a more surprising bust if we end up only 60-70 ACE and only 10 named storms, for example.

We're already at 61.0 ACE today. To stay below 70 ACE would require that (1) the CAG storm doesn't form or only end up being a TS/Cat 1, (2) the MDR wave that multiple models have shown doesn't form, and (3) virtually nothing forms for the rest of the season.

I find each individual one of them to be highly unlikely, especially with the incoming MJO... Not to mention all three.

[Hypercane_Kyle]

I wouldn't exactly call this year "even more historic" given 2013 had 36 ACE and only two hurricanes the entire season, both Cat 1.

2024 had way higher expectations than arguably any other hurricane season in history, so I think it's a more surprising bust if we end up only 60-70 ACE and only 10 named storms, for example.

We're already at 61.0 ACE today. To stay below 70 ACE would require that (1) the CAG storm doesn't form or only end up being a TS/Cat 1, (2) the MDR wave that multiple models have shown doesn't form, and (3) virtually nothing forms for the rest of the season.

I find each individual one of them to be highly unlikely, especially with the incoming MJO... Not to mention all three.

I disagree, I think there's a distinct possibility the CAG storm doesn't become more than a moderate TS (think Karen in 2013). Not much support for the MDR systems. Not going much beyond 70 ACE is a possibility, especially if there's a 2013 like shutdown in October.

[Hammy]

2024 had way higher expectations than arguably any other hurricane season in history, so I think it's a more surprising bust if we end up only 60-70 ACE and only 10 named storms, for example.

We're already at 61.0 ACE today. To stay below 70 ACE would require that (1) the CAG storm doesn't form or only end up being a TS/Cat 1, (2) the MDR wave that multiple models have shown doesn't form, and (3) virtually nothing forms for the rest of the season.

I find each individual one of them to be highly unlikely, especially with the incoming MJO... Not to mention all three.

I disagree, I think there's a distinct possibility the CAG storm doesn't become more than a moderate TS (think Karen in 2013). Not much support for the MDR systems. Not going much beyond 70 ACE is a possibility, especially if there's a 2013 like shutdown in October.

2013 still had four storms and 7 ACE after this point, half of which occurred in October. There wasn't an October shutdown--that was 2021, and part of that was the ITCZ being too far south.

[Hypercane_Kyle]

We're already at 61.0 ACE today. To stay below 70 ACE would require that (1) the CAG storm doesn't form or only end up being a TS/Cat 1, (2) the MDR wave that multiple models have shown doesn't form, and (3) virtually nothing forms for the rest of the season.

I find each individual one of them to be highly unlikely, especially with the incoming MJO... Not to mention all three.

I disagree, I think there's a distinct possibility the CAG storm doesn't become more than a moderate TS (think Karen in 2013). Not much support for the MDR systems. Not going much beyond 70 ACE is a possibility, especially if there's a 2013 like shutdown in October.

2013 still had four storms and 7 ACE after this point, half of which occurred in October. There wasn't an October shutdown--that was 2021, and part of that was the ITCZ being too far south.

I'll be honest, those four storms were so forgettable I forgot they even formed, lol.

[Hammy]

I disagree, I think there's a distinct possibility the CAG storm doesn't become more than a moderate TS (think Karen in 2013). Not much support for the MDR systems. Not going much beyond 70 ACE is a possibility, especially if there's a 2013 like shutdown in October.

2013 still had four storms and 7 ACE after this point, half of which occurred in October. There wasn't an October shutdown--that was 2021, and part of that was the ITCZ being too far south.

I'll be honest, those four storms were so forgettable I forgot they even formed, lol.

One of them was Karen in early October

Worth noting one of them was not operational so only three of those were named (the unnamed STS in December)

[al78]

I remember after 2013 it was thought that such an underperforming season would be once-in-a-lifetime anomalies. Now we have a second, potentially even more historic underperformance (counting the chickens before they're hatched, I know) it's clear there's a mechanism that is impacting hurricane seasons we simply do not understand and models aren't able to capture correctly.

I wouldn't exactly call this year "even more historic" given 2013 had 36 ACE and only two hurricanes the entire season, both Cat 1.

2013 didn't have nearly as favourable pre-season teleconnections as this year so in terms of absolute forecast vs actual, 2024 is likely to be at least as large an error as 2013 and likely more so.

[MarioProtVI]

It’s increasingly looking likely 2024 is attempting a 2022-style level of comeback. Perhaps this season could be salvaged after all.

[Category5Kaiju]

It’s increasingly looking likely 2024 is attempting a 2022-style level of comeback. Perhaps this season could be salvaged after all.

If some of the long range ensembles verify (as in, one or perhaps more long-tracking Cape Verde systems that reach the W. Atlantic, even during the first part of October), then I'd argue that it may be a more extreme version of the 2022-like comeback as that year didn't really feature any significant systems after Ian.

[KWT]

I personally think we may get a bit of a hyperactive burst in the next 20-30 days, la nina style and oceans are basically still beyond normal peak season levels.

I see no world where we end up having a below average ACE season, and I think we have a better chance of 170 than 70 ACE come the season end.

Of course I'm not saying we get quite to that level from here, bit above average is still in reach imo.

[aspen]

It’s increasingly looking likely 2024 is attempting a 2022-style level of comeback. Perhaps this season could be salvaged after all.

If 97L becomes something substantial and the GFS’s MDR hurricane verifies, 2024 might actually have a shot at 100 ACE.

[Category5Kaiju]

If there's one thing we could learn from 2022 and this year (at least assuming some of the more recent long-range models were to verify), it's that during a -ENSO year that is still fairly warm in the deep tropics but also experiences stability issues during the traditional peak season, you can bet that activity will come with a vengeance after mid-September.

In other words, it seems like stability naturally improves or is overridden as we enter autumn.

[tolakram]

Had we not had the odd wave destruction in August we might have been looking at that record season.

I guess the question is this: did the forecasters only miss one odd event, waves coming off Africa too far north, destroying the normal seeds for hurricane formation? Keep in mind 2005 had a hostile eastern MDR as well, but lots of seeds for storm formation made it west and a record number developed.

[HurricaneRyan]

So, as a Southern California resident, I've noticed something.

Two years ago, we had a REALLY bad heat wave in September. In the early portion of the month. This was during the period Hurricane Kay occurred btw. We cooled down near the latter half of the month, and of course, in the Atlantic - we saw Fiona and Ian do their things.

We had another crazy heat wave at the beginning of the month again that died down in the middle of the month. Now we have Helene doing its thing.

I've been born and raised in California and I do not remember it being this hot in September before these last two years. Not sure if there is a correlation to the Atlantic being inactive at the beginning of September and ramping up at the end, but this is my observation.

[Cyclenall]

Each TC starting with Debby was more underwhelming compared to expectations. I think this may be the most bizarre hurricane season on record.

That just ended with Helene, over-performing so far. The bell has been rung.

[Category5Kaiju]

Beginning of September: "Wow, this season looks like it's going to be a dud, aside from Beryl. I mean, there's a chance we may not see any hurricanes for the rest of the season."

End of September: "AAHHHH please, make it stop!"

[xtyphooncyclonex]

Each TC starting with Debby was more underwhelming compared to expectations. I think this may be the most bizarre hurricane season on record.

That just ended with Helene, over-performing so far. The bell has been rung.

Isaac (not supposed to be a hurricane): Hold my beer!

I think my 15 storms and >140-150 ACE may not be too far off at all.

[Cyclenall]

My guess of 21/10/5 ACE: 196 is too high it appears for NS and ACE, I still think hurricanes and majors values are solid. Oct-Dec would have to be out of this world for the former values to be realized.

[EasyTiger]

This season has almost an almost 1989 feel to it. Predictions for this year were for an extremely active season. However if you look at 1989, the bulk of the storms were mid-September on with Hurricane Hugo in mid to late September being quite the beast. Early fall fronts, followed by tranquil weather for a few weeks until activity fired back up. The MJO also kicks up mid-September which will positively influence convection the remainder of the Fall.

1989 was quite backloaded. Texas got hit by Hurricane Chantal and Jerry in 1989. Jerry is one of the latest hurricane to make landfall on Texas. A hurricane hit Galveston in November of 1839.

https://www.wpc.ncep.noaa.gov/research/txhur.pdf

Unfortunately, this was the exact setup I was fearing which came to fruition. I don't mean that in a Joe Batardi type way, but the conditions in late August and early September just weren't all that favorable for development. The same thing we saw in 1989. While this storm didn't hit Charleston, the impacts to the southeastern US were eerily similar. Once the early fronts passed, conditions became much more tranquil leading to reduced shear in the Gulf and Atlantic basin. It wasn't until the MJO came back around in mid-September to add fuel to the fire. Was always skeptical of the MJO effect but have seen these phases too many times to disregard the impacts. Fortunately, the Atlantic Basin migrates out of this pattern in about a week which should hopefully quiet things down. Still wouldn't be surprised to see a late season Central American storm given the continued setup. Every season is a learning experience for sure and this has been an extremely fascinating one to observe.