2025 Indicators: SST's, MSLP, Shear, SAL, Steering, Instability (Day 16+ Climate Models)

[WeatherBoy2000]

It'll be interesting to see if this season continues the trend of being bimodal in nature, i.e. having a peak in June/July and a significant peak in October with below average activity in-between.

It's possible, but I don't think it'll be to the extent of last year. To have very little occur from late August to mid-September is exceptionally anomalous

Yeah for all we know 2024 was an anomaly and not the start of a trend. Even though late June/early July mdr activity has been a common occurrence for the past several years now, every season except last year had most of its activity occur as climatologically expected (late August/September). More than likely 2025 will revert to that, weak early season mdr activity in late June/early July, a break, and then the meat of the season around August 20th.

[cycloneye]

 https://x.com/BigJoeBastardi/status/1911196684593267131

[Hammy]

It'll be interesting to see if this season continues the trend of being bimodal in nature, i.e. having a peak in June/July and a significant peak in October with below average activity in-between.

It's possible, but I don't think it'll be to the extent of last year. To have very little occur from late August to mid-September is exceptionally anomalous

Yeah for all we know 2024 was an anomaly and not the start of a trend. Even though late June/early July mdr activity has been a common occurrence for the past several years now, every season except last year had most of its activity occur as climatologically expected (late August/September). More than likely 2025 will revert to that, weak early season mdr activity in late June/early July, a break, and then the meat of the season around August 20th.

Worth noting 2022 was storm-free the entirety of August

[cycloneye]

The OISST data shows the MDR cooling on a steady pace in the last few weeks.

[cycloneye]

Hurricane2022, Teban54, WaveBreaking, DorkyMcDorkface, USTropics, on April 15th, this 2025 indicators thread has only 7 pages while the 2024 one already had 31 pages on the same date. This shows a lot about the expectations for the 2025 season that are not too high in terms of activity vs 2024 that already in December 2023, there were already signs that indicated it was going to be a hyperactive season. I started the 2024 thread on December 1 for that reason.

https://www.storm2k.org/phpbb2/viewtopi ... 1&t=123889

[DorkyMcDorkface]

Hurricane2022, Teban54, WaveBreaking, DorkyMcDorkface, USTropics, on April 15th, this 2025 indicators thread has only 7 pages while the 2024 one already had 31 pages on the same date. This shows a lot about the expectations for the 2025 season that are not too high in terms of activity vs 2024 that already in December 2023, there were already signs that indicated it was going to be a hyperactive season. I started the 2024 thread on December 1 for that reason.

https://www.storm2k.org/phpbb2/viewtopi ... 1&t=123889

Could be a combination of tempered expectations + more uncertainty surrounding the general indicators (particularly SSTs and ENSO)

[AnnularCane]

Might be feeling a "wait and see what happens" mode. Well, I know I am at least. Do kind of wish it was more active in here though.

[cycloneye]

Might be feeling a "wait and see what happens" mode. Well, I know I am at least. Do kind of wish it was more active in here though.

Only one month left for the TWO's to begin and here we are with only 7 pages.

[Steve]

It'll be interesting to see if this season continues the trend of being bimodal in nature, i.e. having a peak in June/July and a significant peak in October with below average activity in-between.

It's possible, but I don't think it'll be to the extent of last year. To have very little occur from late August to mid-September is exceptionally anomalous

Yeah for all we know 2024 was an anomaly and not the start of a trend. Even though late June/early July mdr activity has been a common occurrence for the past several years now, every season except last year had most of its activity occur as climatologically expected (late August/September). More than likely 2025 will revert to that, weak early season mdr activity in late June/early July, a break, and then the meat of the season around August 20th.

Agreed. 24’s lack of peak season activity was at least partly a function of the MJO not being in active or hyperactive phases for the Atlantic in a season that MJO was predictive. Since it’s roughly a 45 day cycle, there is always the possibility that it could be in Phases 5-6-7 (and usually less active 4) or the circle near them for stretches of a few weeks. Most seasons we see it swinging around through the Western Hemisphere & Africa Phases (8-1) and the Indian Ocean Phases (2-3) sometime around the peak occasionally taking the shortcut back through 8-1-2 and sometimes 3. There’s no rule that says it has to. Natures gonna do nature.

[Steve]

Might be feeling a "wait and see what happens" mode. Well, I know I am at least. Do kind of wish it was more active in here though.

Only one month left for the TWO's to begin and here we are with only 7 pages.

7 pages and less nonsense than more pages with existential and hypothetical arguments is preferable. Oh and hey Luis!!

[Category5Kaiju]

Hurricane2022, Teban54, WaveBreaking, DorkyMcDorkface, USTropics, on April 15th, this 2025 indicators thread has only 7 pages while the 2024 one already had 31 pages on the same date. This shows a lot about the expectations for the 2025 season that are not too high in terms of activity vs 2024 that already in December 2023, there were already signs that indicated it was going to be a hyperactive season. I started the 2024 thread on December 1 for that reason.

https://www.storm2k.org/phpbb2/viewtopi ... 1&t=123889

Could be a combination of tempered expectations + more uncertainty surrounding the general indicators (particularly SSTs and ENSO)

I'll also add that I think we've reached a point where the default expectation in any given Atlantic season is at least some sort of above average season, with one or several destructive, powerful storms. The Atlantic has been stuck in this kind of pattern since 2016, and with 9 consecutive seasons thus far featuring this kind of wild behavior (with maybe the exception of 2023, though that season still featured Idalia and much above average activity) and counting, I think there's a general expectation that 2025 will follow suit. 2018 had chilly MDR sst anomalies in August, 2020 had giant SAL outbreaks, and 2022 had wavebreaking problems reminiscent of 2013. Yet they still ended up generating titans like Florence, Iota, and Ian. No matter how unfavorable things looked at any point in a given recent Atlantic season, it still managed to claw back.

One important lesson I think we've learned is that mid-season stability issues and -ENSO simply delay activity rather than quashing it entirely season-wide. 2022 and 2024 have demonstrated this pretty clearly, and I think that will be key to watch in future seasons, this year included (whether mid-season struggles due to stability, wavebreaking, or whatever do present an issue this year or if they are absent).

[Teban54]

Hurricane2022, Teban54, WaveBreaking, DorkyMcDorkface, USTropics, on April 15th, this 2025 indicators thread has only 7 pages while the 2024 one already had 31 pages on the same date. This shows a lot about the expectations for the 2025 season that are not too high in terms of activity vs 2024 that already in December 2023, there were already signs that indicated it was going to be a hyperactive season. I started the 2024 thread on December 1 for that reason.

https://www.storm2k.org/phpbb2/viewtopi ... 1&t=123889

Could be a combination of tempered expectations + more uncertainty surrounding the general indicators (particularly SSTs and ENSO)

I'll also add that I think we've reached a point where the default expectation in any given Atlantic season is at least some sort of above average season, with one or several destructive, powerful storms. The Atlantic has been stuck in this kind of pattern since 2016, and with 9 consecutive seasons thus far featuring this kind of wild behavior (with maybe the exception of 2023, though that season still featured Idalia and much above average activity) and counting, I think there's a general expectation that 2025 will follow suit. 2018 had chilly MDR sst anomalies in August, 2020 had giant SAL outbreaks, and 2022 had wavebreaking problems reminiscent of 2013. Yet they still ended up generating titans like Florence, Iota, and Ian. No matter how unfavorable things looked at any point in a given recent Atlantic season, it still managed to claw back.

One important lesson I think we've learned is that mid-season stability issues and -ENSO simply delay activity rather than quashing it entirely season-wide. 2022 and 2024 have demonstrated this pretty clearly, and I think that will be key to watch in future seasons, this year included (whether mid-season struggles due to stability, wavebreaking, or whatever do present an issue this year or if they are absent).

2024 may be the year that taught a lot of people how conventional seasonal indicators doesn't guarantee activity during conventional peak seasons. Which is a good realization in itself, in that we have a more holistic view of seasonal forecasts... Except that when more people have this mindset that indicators aren't everything, there will naturally be less discussions of indicators themselves pre-season if we think "do they really matter anyway".

[chaser1]

Might be feeling a "wait and see what happens" mode. Well, I know I am at least. Do kind of wish it was more active in here though.

Only one month left for the TWO's to begin and here we are with only 7 pages.

Here's one additional perspective that I can sort of relate too. A significant number of members and frequent posters are right here in Florida. I seriously question whether some extent of PTSD might have impacted a significant number of Floridians following the number of Florida threats and landfalls in just the last 4 years, thus reducing much of their own posts & input?

I clearly recall a similar impact to some S2K members following a dramatic hurricane that affected them over the years. In fact, I'd bet a fairly sizeable "where are they now" list would bare that out.

[cycloneye]

 https://x.com/AndyHazelton/status/1912160858903372196

[USTropics]

 https://x.com/AndyHazelton/status/1912160858903372196

That first graphic by Andy is a bit misleading, you can essentially do that for any season and 2024 will be significantly warmer. Instead of just looking at skin temperatures or anomalies, I prefer using OHC (essentially the total amount of heat stored in the ocean's upper layer). Let's give it a few more months and see where we are in June. Isolating the MDR, this year is still trending above the average (and still ranks as one of the highest OHCs for this current time in the last 10 years). 2023 Started at an even lower anomaly value in April and was exceeding 2024 during parts of the Summer.



Including the Caribbean and MDR:


You can find these products here at Brian McNoldy's site - https://bmcnoldy.earth.miami.edu/tropics/ohc/

As for the lack of posts this preseason, I do think there is some layover from all the hype and build up to last season (and the lull after Beryl). I think there might be a little bit of a disinterest in seasonal forecasting given the season didn't mirror something like 2005. As usual, when we get closer to the official start, I expect more action.

I'll try and post more frequently, especially as this semester winds down (I'm working on a seasonal forecast), but currently it has been extremely busy, with not many opportunities to do any coding/writing.

[mixedDanilo.E]

I think everyone is purposefully being more reserved this year since last year didn't really live up to the hurricane season from hell expectations, even though it still was active.

[Kingarabian]

Indicators are pointing towards an inactive hurricane season for the EPAC. Unless we get something like 2013, a slow EPAC season likely means an active hurricane season since there will be less sinking motion over the Caribbean and less shear.

If waters just off of Africa remain cooler than normal than there's a better chance for waves to develop in the GOM and Caribbean. So depending on overall steering, it could be another impactful season even if we don't see hyperactive numbers.

[Hurricane2022]

 https://x.com/AndyHazelton/status/1913259703062126910

[WeatherBoy2000]

Looks like the mdr cooling trend is going to reverse soon:

[Long John]

Looks like the mdr cooling trend is going to reverse soon:

https://cyclonicwx.com/data/models/gfs/hovs/gfs_15N_hov_uanom_2025042106.png

https://cyclonicwx.com/data/models/gefs/hovs/gefs_15N_hov_uanom_2025042106.png

Let us see how this ages