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

[aspen]

As the saying goes, it isn't over until the fat lady sings (and this season could certainly pop off a nasty one again before the calendar flips to December) ~ but I'm close to writing this year off.

If none of these orange-tagged storms become cyclones, it's the strongest signal possible for a complete season shutdown on par with 2013. It's peak season and there's.. nothing and hasn't been for days. That is weird in El Nino years, but in neutral-ENSO/La Nina years it's especially unusual.

Wild that Beryl could be our most significant storm of the year, and that was in June/July.

There’s a real chance this season could fall below 2013 in NS total, making it the biggest bust relative to seasonal forecasts. I wouldn’t exclude the possibility of zero storms in September.

[ElectricStorm]

Well I said I'd give it until Labor Day before I would become skeptical of this season and here we are with exactly zero active TCs and just 2 AOIs, both of which currently have a less than 50% chance to develop. I think it's becoming pretty obvious this season will not live up to the lofty expectations most people expected.

That being said however we still have a long way to go and while I don't think we'll hit 20 NS and 6 majors like some of the forecasts had, I do think we'll see an uptick in activity over the next few weeks. Revising my numbers to 16/8/3 ACE 155. I guess all we can do is wait and see.

[LarryWx]

The Euro Weeklies are persisting with a well below avg mean ACE prog for the next 3 weeks followed by an increase to near to a little above normal ACE the last week of the month. Should this 4 week period happen to verify well, we would end Sept with ~83 ACE vs 94 1991-2020 averaged ACE through 9/30. Then, if the remainder of the season were to be at the 30 yr avg, the season would end up with 111 ACE. The Weeklies have been doing well this season overall with the prior weeks ACE-wise.

[Iceresistance]

I am wondering if June/July acted like August/September and now it's acting like June/July before it will flip back to the more reasonable September-like pattern

[Steve]

I am wondering if June/July acted like August/September and now it's acting like June/July before it will flip back to the more reasonable September-like pattern

Maybe mid to late month or October? You could see some named storms develop but I don’t think anything crazy unless something comes out the Caribbean. Not gonna be MJO based systems until after the 20th unless they have crazy amplification in a random phase.

[Teban54]

But wait, I thought the Atlantic was supposed to be so dry that every wave entering the basin would just poof and stop firing convection for good?

(Just in case: Not a serious comment.)

[dexterlabio]

It's interesting many people pointed out how dead the Pacific was, only able to pump very few short-lived TCs, and how it was a strong indicator of an active hurricane season in the Atlantic...but things have been shaken up a bit since August 20.

[WiscoWx02]

As the saying goes, it isn't over until the fat lady sings (and this season could certainly pop off a nasty one again before the calendar flips to December) ~ but I'm close to writing this year off.

If none of these orange-tagged storms become cyclones, it's the strongest signal possible for a complete season shutdown on par with 2013. It's peak season and there's.. nothing and hasn't been for days. That is weird in El Nino years, but in neutral-ENSO/La Nina years it's especially unusual.

Wild that Beryl could be our most significant storm of the year, and that was in June/July.

There’s a real chance this season could fall below 2013 in NS total, making it the biggest bust relative to seasonal forecasts. I wouldn’t exclude the possibility of zero storms in September.

I actually wouldn't be surprised if that happened at this point.

[WiscoWx02]

 https://x.com/webberweather/status/1830231025026203680




This post is very insightful. 2013 is an analogue if you want to look at it from a strictly SSTA stance...starting to make sense now...not only that though, but record low instability is another nod toward a 2013 level bust.

The main reason I pointed this tweet out though, is the nod toward our changing climate and hurricane seasons. Idk, maybe this is a meant for another thread or deserves and entire thread of its own, but there seems to be a lot of confliction on how our changing will impact the hurricane season. Eric Webb does bring a valid argument to the table though...the ITCZ being so far north is something we have seen more often than not since 2017 if memory serves. With the ITCZ being anomalously far north, eventually one would figure it would cause the vegetation line in Africa to expand northward...which creates a positive feedback loop that only leads to a further and further north ITCZ as time goes on. Perhaps this further north ITCZ has something to do with the adiabatic lapse rates not being favorable for tropical development, but I am not going to pretend I know the answer here. It would make sense that instability is near record low though if the lapse rates are being altered...which I can only assume is not due to SSTA's so much as to the ITCZ being displaced to the north. If the Hadley Cell is expanding this would also translate to a northward displaced ITCZ compared to normal...Andy Hazelton has really gone into the Hadley Cell expansion theory over the last few years.

I guess the point I'm trying to make is I am beginning to think that 2024 is a blueprint for future hurricane seasons. I think the expanding Hadley Cell is going to only continue to limit the instability that can be found in the deep tropics as had been seen since 2013. The whole idea that hurricane seasons are going to be worse thanks to climate change no longer makes sense if we apply this Hadley Cell theory...instead we may well be looking at seasons like 2013, 2022 and how 2024 is likely to turn out at this point. I also have to wonder if El Nino years are soon to become years that are actually more favorable for the Atlantic because the heat from a developing El Nino would help keep the Hadley Cell more anchored in the tropics where more warmth is thanks to El Nino, thus helping the Atlantic if and only if SSTA's are warmer than normal as they were in 2023. Would be a great thing to study!!!

[Teban54]

This post is very insightful. 2013 is an analogue if you want to look at it from a strictly SSTA stance...starting to make sense now...not only that though, but record low instability is another nod toward a 2013 level bust.

I'll just mention that I have to disagree with Webb's use of 2013 as an SSTA analog for 2024, regardless of his overall thesis of "-SSTAs offshore Africa hurts the Atlantic".

In the tweet, he used the JAS average of 2013's SSTAs. But as I mentioned here, if you single out August 2013, it's the polar opposite of 2024 in the Eastern Atlantic. Aug 2013 had anomalously warm waters off Western Sahara through Guinea, and cold waters near Portugal; both are flipped for 2024.

(In my comment that I linked above, I also highlighted other differences between August 2023 and this year, including much dryer 850 mb atmosphere.)

[chaser1]

There's still so much uncertainty in these model forecasts I'm not really sure why people on social media are already calling for a 2005/2020 level season. Still so many other variables at play. Looks like it could shape up to be an active season, but I wouldn't go that far this early.

I think it’s possible this season could be like 2020, in that everyone expects a monster CV season based on the SST/precip anomaly forecasts, but it ends up being west-based with a little lower-than-expected ACE for its NS total. Or maybe an unforeseen limiting factor pops up, like 2022’s North Atlantic marine heatwave. It’s way too early to say anything other than the potential is there for quite an active season.

Well tbf both 2020 and 2005 were west based season with majority of the storm intensity peaking west of MDR. 2020 had lower ACE because many of the storms reached their peak intensity from last minute RI 24-48 hours before landfall while 2005 saw storms ramp up quickly and stay near peak intensity for at least 24-48 hours, which still kept the ACE count very high despite the fact there were no classic CV storms.

Even before the season started, I believed that this was going to be that type of year where a greater number of tropical cyclones would not develop until much further west within the basin and that this alone would suggest a much more enhanced risk to Central America, Greater Antilles, and U.S. Well, I was way off regarding the numbers but still hold the belief that the Eastern MDR will not be where significant risk to the Western basin will originate. At this stage, I'm beginning to question whether any tropical storm that forms in the MDR east of 50W will make CONUS landfall for the remainder of the 2024 Atlantic season. That would be a risky bet to make on September 3rd but i'm beginning to consider it a real possibility.

[kevin]

Meanwhile SSTs in the WCar and Gulf are near-record levels with MPIs well below even 880 mb in the western portions of the Gulf and very favorable shear across the entire WCar and Gulf. Shear in the southern portion of the MDR is also quite good. If I saw images like this without context together with the date September 3 I'd expect multiple TCs and potentially even multiple (major) hurricanes active at the same time.

[cycloneye]

Posted this message from Phil Klotzbach and he is asking the question all have.

 https://x.com/philklotzbach/status/1830922249093763522

@philklotzbach
So what the heck is happening with the Atlantic #hurricane season, and is this going to be an enormous forecast bust? CSU will post an updated extensive discussion on its website by the end of today.

[NDG]

Meanwhile SSTs in the WCar and Gulf are near-record levels with MPIs well below even 880 mb in the western portions of the Gulf and very favorable shear across the entire WCar and Gulf. Shear in the southern portion of the MDR is also quite good. If I saw images like this without context together with the date September 3 I'd expect multiple TCs and potentially even multiple (major) hurricanes active at the same time.

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

https://i.imgur.com/eg50IuP.gif

If anything I would say that shear is unusually strong across the northern gulf for this time of the year, and forecasted to stay strong for through the peak of the season thanks to an early deep trough across the eastern US, if anything forms in the southern gulf over the next few days it will be shredded to pieces if it heads towards the northern gulf coast.

[Weathertracker96]

I know it’s September but does anyone realistically see anything else forming for the rest of the season or are we done?
With the models barely showing anything & these months are flying by, could the season be done already?

[tolakram]

I know it’s September but does anyone realistically see anything else forming for the rest of the season or are we done?
With the models barely showing anything & these months are flying by, could the season be done already?

How can anyone answer that question? The models have show development and backed off, the euro which was so right about high ACE now must be correct about low ACE, and we really do not know why conditions are so hostile right now. So I do not know.

[caneman]

Pretty good post from our local forecaster Denis Phillips. Specifically #4:
"Yellow is the new Orange"

1. Area we've been watching down from 40% to 30%. Orange to yellow.

2. In spite of a trio of yellow blobs, this has been the quietest stretch of tropical weather from mid August to early September since 1968.

3. Regardless of whether or not we see any hurricanes threaten the Gulf coast again this season, it's clearly been a complete disaster for those forecasting a hyperactive or record breaking season. I, for one, am thankful they were wrong. But remember, it only takes 1 to make it a bad season if it strikes where you live.

4. While most of the stories focused on La Nina and record warm water temperatures, we've said since the beginning there are so many other factors that come in to play. It's just not so simple trying to boil it down to 1 or 2 specifics. Saharan Dust, Atlantic Nina, unusually active African rainy season and even the Tonga volcano could all be partially responsible. Truth is, we might not ever know. Just another reason, in my opinion, long range hurricane forecasts are often pretty useless.

5. Lots more season to go. We'll be here for you 24/7.

[WeatherBoy2000]

I know it’s September but does anyone realistically see anything else forming for the rest of the season or are we done?
With the models barely showing anything & these months are flying by, could the season be done already?

There will very likely be more storms whether they amount to anything is another question. The season could flip back on at any moment to produce some powerful storms during the next couple months, complete suppression like 2013 is very rare.

A season that comes to mind for me is 2016. 2016 started with a strong el nino but transitioned to cool neutral/weak la nina during the peak, similar to this year. 2016 was also another season that struggled during the peak, September saw no hurricanes develop until Matthew at the very end. 2016's most notable, intense, and highest ace producing storms happened during October-November (Matthew, Nicole, and Otto). It isn't over until it's over.

[WiscoWx02]

I know it’s September but does anyone realistically see anything else forming for the rest of the season or are we done?
With the models barely showing anything & these months are flying by, could the season be done already?

There will very likely be more storms whether they amount to anything is another question. The season could flip back on at any moment to produce some powerful storms during the next couple months, complete suppression like 2013 is very rare.

A season that comes to mind for me is 2016. 2016 started with a strong el nino but transitioned to cool neutral/weak la nina during the peak, similar to this year. 2016 was also another season that struggled during the peak, September saw no hurricanes develop until Matthew at the very end. 2016's most notable, intense, and highest ace producing storms happened during October-November (Matthew, Nicole, and Otto). It isn't over until it's over.

I would not be surprised if Ernesto was the last storm of the year. I would expect one or two more storms but that’s about it. Maybe one more hurricane but overall the season is basically over at this point imo, that much is clear. We are in unprecedented times of quiet, no reason to believe that’ll change the rest of the month at this rate. Not to mention October is always a major wildcard and usually November is pretty quiet. With how unfavorable the Atlantic is this year…I wouldn’t expect much through the end

[Ubuntwo]

I know it’s September but does anyone realistically see anything else forming for the rest of the season or are we done?
With the models barely showing anything & these months are flying by, could the season be done already?

There will very likely be more storms whether they amount to anything is another question. The season could flip back on at any moment to produce some powerful storms during the next couple months, complete suppression like 2013 is very rare.

A season that comes to mind for me is 2016. 2016 started with a strong el nino but transitioned to cool neutral/weak la nina during the peak, similar to this year. 2016 was also another season that struggled during the peak, September saw no hurricanes develop until Matthew at the very end. 2016's most notable, intense, and highest ace producing storms happened during October-November (Matthew, Nicole, and Otto). It isn't over until it's over.

I would not be surprised if Ernesto was the last storm of the year. I would expect one or two more storms but that’s about it. Maybe one more hurricane but overall the season is basically over at this point imo, that much is clear. We are in unprecedented times of quiet, no reason to believe that’ll change the rest of the month at this rate. Not to mention October is always a major wildcard and usually November is pretty quiet. With how unfavorable the Atlantic is this year…I wouldn’t expect much through the end

I don’t following this logic as most inhibiting factors look to improve by end of month. I suppose such an anomalous September pattern throws climo on its head. If we see no more hurricanes this year, I will without hesitation donate $50 to S2k. $10 otherwise