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

[aspen]

We had a Cat 4 in the MDR in June and a Cat 5 in the Caribbean in the first days of July. We've already had an insane season no matter how you look at it

And adding to this, while Beryl is indeed a freak anomaly of a storm, I also see it as a consequence of the unusually favorable Atlantic conditions that many other years, with the exceptions of sinister years like 1933 and 2005, lacked. Under normal circumstances, we shouldn't have seen this kind of system. If this is not an indication of a year that may bring many powerful systems and be extremely active, then I don't really know what is.

It's a great example of why SSTs matter. Even if given the same atmospheric conditions, a regular SST configuration would have delayed the initial formation significantly. The peak intensity of Beryl would've been much lower, maybe up to Cat 2 or so. Finally, without the ample fuel and a very strong vortex to resist shear, Beryl quickly falls apart mid Carribean and glides into Central America as a wave.

You’re right, but I think this is also a great example of why other atmospheric factors matter alongside SSTs. Event with near-record warm waters for this time of year, Beryl wouldn’t have reached the heights it did without a favorable shear/UL environment. The fact that it managed to find such an ideal environment in terms of SSTs and shear in late June/early July, when usually everything else struggles with strong trade-induced shear, is one heck of a sign that the basin is abnormally favorable this year. I was expecting a repeat of Elsa where the typical early season trades in The Graveyard would’ve decapitated the system.

[Deshaunrob17]

The case for an insane 2024 is starting to crack. La Nina coming later than originally thought, extreme SAL, temperatures not quite as off the charts as they were at the start of the season.

Most of the March and April seasonal forecasts predicted MDR SSTAs to be around where they are currently during peak season (i.e. cooling down from the spring anomalies), instead of jaw-dropping +2C that people may have been used to during the past year. Also, even some models like the Euro that have a warm ENSO bias still forecasted a hyperactive season.

And it’s not easy to get 2C + in the tropics during the summer. Nature has an away balancing this heat. Hence the actual warming since spring has been very slow but if we were to warm at the normal pace , we probably would have been seeing widespread 32C +- which would have been insane. Nature would naturally balance this off.
Regardless, SST in the Atlantic are still mind-blowing and this quiet period should be taken seriously to get things in place. I have a feeling when the hurricanes start coming late July or August it will be non stop activity till late October .

[JRD]

Let's keep in mind 2023 was an active season despite El Niño and fairly high SAL.

[Hurricane2022]

Let's keep in mind 2023 was an active season despite El Niño and fairly high SAL.

2023 had a below-average SAL season overall.

[JRD]

Let's keep in mind 2023 was an active season despite El Niño and fairly high SAL.

2023 had a below-average SAL season overall.

My bad, should have paid more attention.

[weeniepatrol]

Let's keep in mind 2023 was an active season despite El Niño and fairly high SAL.

2023 had a below-average SAL season overall.

My bad, should have paid more attention.

August-October ONI of +1.6 with an Atlantic ACE of 146 units is still crazy

[weeniepatrol]

Also, keep in mind Beryl. I would understand hesitation beginning regarding the ACE forecasts had Beryl not occurred. However, due to Beryl we stand at 36.1 units, meaning in order to reach 200 this season we only need 164 more. This is the bottom range of hyperactive status. Think about that for a second - all we need at this point to reach 200 ACE is the lowest tier of hyperactivity. It's 14 July... this is easily doable.

[al78]

I had a small exchange with Phil Klotzbach shortly after he released his seasonal Atlantic forecast. I got in touch after I saw his probability of exceedance chart which suggested a 30% chance of breaking the 1933 record ACE and I asked whether he really believed the probability was that high. This led to a discussion of past extreme seasons like 1933 and 2005, the former he believes could, in reality, have had close to 300 ACE if current observational technology was available back then, and when I looked at the ACE from just the MDR forming storms in 2005, it was around average. 2005 was as active as it was because of the supercharged Caribbean and Gulf. Storms forming in the MDR didn't do much at all until they got close to the Caribbean/Bahamas/U.S. and we ended up with a high westerly bias in tropical cyclone activity, with destructive consequences for the U.S.. If you look at the previous year, 2004, that was different and dominated by very high MDR activity in which the steering winds were favourable for keeping storm tracks over the deep tropics and into the Caribbean and Gulf. I don't know if it is dynamically possible but if you had a season with the MDR as favourable as 2004 combined with a Caribbean and Gulf as favourable as 2005, you might be able to break 300 ACE in a season combined with record breaking seasonal insured losses. I am in no way saying 2024 could be that year, more I was thinking about what the upper limit on activity in the Atlantic could be.

[Hurricane2022]

I had a small exchange with Phil Klotzbach shortly after he released his seasonal Atlantic forecast. I got in touch after I saw his probability of exceedance chart which suggested a 30% chance of breaking the 1933 record ACE and I asked whether he really believed the probability was that high. This led to a discussion of past extreme seasons like 1933 and 2005, the former he believes could, in reality, have had close to 300 ACE if current observational technology was available back then, and when I looked at the ACE from just the MDR forming storms in 2005, it was around average. 2005 was as active as it was because of the supercharged Caribbean and Gulf. Storms forming in the MDR didn't do much at all until they got close to the Caribbean/Bahamas/U.S. and we ended up with a high westerly bias in tropical cyclone activity, with destructive consequences for the U.S.. If you look at the previous year, 2004, that was different and dominated by very high MDR activity in which the steering winds were favourable for keeping storm tracks over the deep tropics and into the Caribbean and Gulf. I don't know if it is dynamically possible but if you had a season with the MDR as favourable as 2004 combined with a Caribbean and Gulf as favourable as 2005, you might be able to break 300 ACE in a season combined with record breaking seasonal insured losses. I am in no way saying 2024 could be that year, more I was thinking about what the upper limit on activity in the Atlantic could be.

Well, so I think the discussion of the Atlantic "not being insane" this year can be closed, finally. Cycloneye, please close this topic!

[Iceresistance]

I have never seen anything like this in Mid-July, even the Vertical Shear is extremely low


https://s12.gifyu.com/images/StixL.gif


https://s10.gifyu.com/images/Stixw.gif


https://s12.gifyu.com/images/Stixh.gif

[underthwx]

the itcz looks more tranquil this morning....time for a breather...good morning yall....

[LarryWx]

Gotta love Season Cancel Season.

Season Cancel’s Greetings!

[WaveBreaking]

Looks like the Newfoundland warm blob might actually reduce the chances of wave breaking this year.

 https://x.com/wxtca/status/1812584195748696494

[Hammy]

And adding to this, while Beryl is indeed a freak anomaly of a storm, I also see it as a consequence of the unusually favorable Atlantic conditions that many other years, with the exceptions of sinister years like 1933 and 2005, lacked. Under normal circumstances, we shouldn't have seen this kind of system. If this is not an indication of a year that may bring many powerful systems and be extremely active, then I don't really know what is.

It's a great example of why SSTs matter. Even if given the same atmospheric conditions, a regular SST configuration would have delayed the initial formation significantly. The peak intensity of Beryl would've been much lower, maybe up to Cat 2 or so. Finally, without the ample fuel and a very strong vortex to resist shear, Beryl quickly falls apart mid Carribean and glides into Central America as a wave.

Elsa 2021 is a good analog of this scenario. Cat 1 peak right around where Beryl peaked as a Cat 5, followed by weakening in the Caribbean to the point where people were doubting if it still had a circulation. And Elsa was already very anomalous for its time, with the only comparison being 1933:

 https://x.com/philklotzbach/status/1410538986548781057


 https://x.com/philklotzbach/status/1410931814877835266

Something that's kind of interesting when you look at Elsa as an example: 2021 was active numerically, but a lot of storms also underperformed (on top of having nothing, and a lot of storms formed in the subtropics (something we have not seen yet this season)

Prior to Elsa, we had only Claudette in the Gulf, which just barely formed as it was moving inland, and even then there's still debate whether it was organized enough to be classified in the first place. Likewise, Elsa was forecast to become stronger, but (thanks in part to the forward speed) really fell apart as it entered the Caribbean, only briefly reattaining hurricane in the eastern Gulf before decoupling again.

This year, obviously we had Beryl which consistently overperformed, and began rapidly intensifying as it neared landfall, along with two tropical storms in the Gulf, both of which overperformed (Chris was only shows by a handful of isolated runs consolidating enough before landfall) so this year could end up being a supercharged version of 2021, essentially, what if whatever those unfavorable conditions were, were removed

[WaveBreaking]

It's a great example of why SSTs matter. Even if given the same atmospheric conditions, a regular SST configuration would have delayed the initial formation significantly. The peak intensity of Beryl would've been much lower, maybe up to Cat 2 or so. Finally, without the ample fuel and a very strong vortex to resist shear, Beryl quickly falls apart mid Carribean and glides into Central America as a wave.

Elsa 2021 is a good analog of this scenario. Cat 1 peak right around where Beryl peaked as a Cat 5, followed by weakening in the Caribbean to the point where people were doubting if it still had a circulation. And Elsa was already very anomalous for its time, with the only comparison being 1933:

 https://x.com/philklotzbach/status/1410538986548781057


 https://x.com/philklotzbach/status/1410931814877835266

Something that's kind of interesting when you look at Elsa as an example: 2021 was active numerically, but a lot of storms also underperformed (on top of having nothing, and a lot of storms formed in the subtropics (something we have not seen yet this season)

Prior to Elsa, we had only Claudette in the Gulf, which just barely formed as it was moving inland, and even then there's still debate whether it was organized enough to be classified in the first place. Likewise, Elsa was forecast to become stronger, but (thanks in part to the forward speed) really fell apart as it entered the Caribbean, only briefly reattaining hurricane in the eastern Gulf before decoupling again.

This year, obviously we had Beryl which consistently overperformed, and began rapidly intensifying as it neared landfall, along with two tropical storms in the Gulf, both of which overperformed (Chris was only shows by a handful of isolated runs consolidating enough before landfall) so this year could end up being a supercharged version of 2021, essentially, what if whatever those unfavorable conditions were, were removed

And seeing how the Caribbean shut down that year in October due to constant troughing, I don’t even want to think about what could happen this year if waves are able to take advantage of the late-season warm waters and more favorable upper-level conditions.

[skyline385]

Gotta love Season Cancel Season.

Season Cancel’s Greetings!

I have been away from the forums after losing power during Beryl. Are there folks seriously cancelling the season after we just had a C5 in June/July? Cause I went back a few pages and couldn't find much at all about it.

On another note, I can now say I was in the eye of the incredible record breaking system for the history books that was Beryl

[Cpv17]

Gotta love Season Cancel Season.

Season Cancel’s Greetings!

I have been away from the forums after losing power during Beryl. Are there folks seriously cancelling the season after we just had a C5 in June/July? Cause I went back a few pages and couldn't find much at all about it.

On another note, I can now say I was in the eye of the incredible record breaking system for the history books that was Beryl

I was in the eye as well!

[al78]

I can understand some of the skepticism regarding the extreme seasonal forecasts given activity has been non-existant since Beryl. We have to remember that July is normally very quiet and maybe we should not try to predict the whole season based on the lack of activity in the last two weeks. Phil said he expects the Atlantic to be quiet for now then a pickup in the last week of July based on extremely conducive lower and upper-level wind anomalies combined with the MJO moving into phase 1 and 2 which is favourable for TC genesis in the Atlantic.

A forecast bust is unlikely but not impossible. Seasonal forecasts do not predict hurricanes, they forecast how conducive the conditions in the tropics are for TC genesis and intensification, and relate that to how active hurricane seasons have been in the past under similar conditions using data going back several decades. This works the majority of the time but there are always random unpredictable factors that can throw a spanner in the works. ACE per storm can depend heavily on where that storm tracks and how much land it encounters, or whether it passes over the cold wake of another storm. An unusually active SAL can heavily suppress TC activity despite favourable SSTs and atmospheric winds. The intra-seasonal variability is very difficult or impossible to predict weeks or months in advance, e.g. August 2022.

[zzzh]

Looks like the Newfoundland warm blob might actually reduce the chances of wave breaking this year.

 https://x.com/wxtca/status/1812584195748696494

Does it? I don't have a PVS frequency anomaly map but the 200mb vorticity should work as well: You can clearly see the enhanced anticyclonic wavebreaking near 30N, which is the opposite of what the 'bottom PVS' figure shows. I wonder if anyone has the link to the paper? I would like to read it.

[WeatherBoy2000]

Looks like the Newfoundland warm blob might actually reduce the chances of wave breaking this year.

 https://x.com/wxtca/status/1812584195748696494

https://i.imgur.com/V5gGUzG.png
Does it? I don't have a PVS frequency anomaly map but the 200mb vorticity should work as well: You can clearly see the enhanced anticyclonic wavebreaking near 30N, which is the opposite of what the 'bottom PVS' figure shows. I wonder if anyone has the link to the paper? I would like to read it.

It could just be early season climo at this point, gotta see what happens in the coming weeks.