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

[toad strangler]

This is dangerous thinking, and seems to be partially based in the fact that models have been seemingly struggling to capture genesis properly in the deep tropics this year (GFS having a habit of stringing things out too quick). While it’s true the monsoon trough is further north then normal, it is expected to sink back down to normal levels by the end of the month and the 12z EURO already seems to be picking up on that with several lows in the MDR around the 29th - which over the next week will likely wax and wane in appearance before beginning to trend upwards into stronger systems, just like Debby and Ernesto showed.

Dangerous thinking! I don't think you actually meant that, I hope. Make comments on the season, the indicators, the forecasts, but not the person or the thinking please. Discussion should be fun and interesting here, not combative.

Apologies. I don’t have any ill will at all, but my post was mainly meant to say that just because August is being kinda slow doesn’t mean that the season will underperform statistic wise. The main reason it is a bit slow is because of the northward ITCZ right now that is expected to shift back south at the end of the month (which models are beginning to agree on).

I disagree that August has been kind of slow. Two hurricanes. One US landfall. That ain’t kinda slow. IMO of course.

[MarioProtVI]

Dangerous thinking! I don't think you actually meant that, I hope. Make comments on the season, the indicators, the forecasts, but not the person or the thinking please. Discussion should be fun and interesting here, not combative.

Apologies. I don’t have any ill will at all, but my post was mainly meant to say that just because August is being kinda slow doesn’t mean that the season will underperform statistic wise. The main reason it is a bit slow is because of the northward ITCZ right now that is expected to shift back south at the end of the month (which models are beginning to agree on).

I disagree that August has been kind of slow. Two hurricanes. One US landfall. That ain’t kinda slow. IMO of course.

True, but I meant “slow” as in how some people were expecting August to go into very active mode with 100 ACE before month’s end. That ain’t happening it seems.

[jlauderdal]

The only reason this season feels kind of "slow" is because so far, 2024 has not seen many short-lived, weak storms like most recent seasons have. The number of named storms is actually above average. The NATL has already crossed the 50 ACE mark!

Here's another comparison to consider: 2010 was only at 3-1-0 at this date, and didn't really get going until the last third of August. 2024 is already at 5-3-1. 1998 and 1999 both only had one tropical storm before this date, and both got to the "hyperactive" ACE category. Since it is a first-year -ENSO, I think we'll have to watch the western basin for hurricanes late in the season. Even the most active seasons often have short breaks in activity, 2020 had no hurricanes between August 4-23, 2005 also had no hurricanes early in August. The upcoming short lull is nothing too unusual, and it looks like the MDR should really get going after it ends.

It would really be something if this season manages to attain a NS count in the mid to upper-10s but also 7 major hurricanes

It appears we are heading towards a big ACE number and when the season ends it will feel like a very busy season regardless NS.

[Hammy]

Apologies. I don’t have any ill will at all, but my post was mainly meant to say that just because August is being kinda slow doesn’t mean that the season will underperform statistic wise. The main reason it is a bit slow is because of the northward ITCZ right now that is expected to shift back south at the end of the month (which models are beginning to agree on).

I disagree that August has been kind of slow. Two hurricanes. One US landfall. That ain’t kinda slow. IMO of course.

True, but I meant “slow” as in how some people were expecting August to go into very active mode with 100 ACE before month’s end. That ain’t happening it seems.

The season is actually pacing about average to slightly above as far as the count: we're five days away from when we normally have the fifth storm, August typically has four storms two hurricanes (we've had that, and on average two more storms form after the 20th) and the fourth hurricane isn't until Sep 16 normally so we're at no risk of falling behind unless something unforseen happens, and we don't normally get the second major until late September

At this point we may end up with a roughly average range of total storm count, but with significantly higher ACE--essentially, this year looks like it might end up as the inverse of 2019, where all but 3-4 storms had marginal ACE or barely any, despite a very high storm count

[Category5Kaiju]

I disagree that August has been kind of slow. Two hurricanes. One US landfall. That ain’t kinda slow. IMO of course.

True, but I meant “slow” as in how some people were expecting August to go into very active mode with 100 ACE before month’s end. That ain’t happening it seems.

The season is actually pacing about average to slightly above as far as the count: we're five days away from when we normally have the fifth storm, August typically has four storms two hurricanes (we've had that, and on average two more storms form after the 20th) and the fourth hurricane isn't until Sep 16 normally so we're at no risk of falling behind unless something unforseen happens, and we don't normally get the second major until late September

At this point we may end up with a roughly average range of total storm count, but with significantly higher ACE--essentially, this year looks like it might end up as the inverse of 2019, where all but 3-4 storms had marginal ACE or barely any, despite a very high storm count

A great example of a recent season that really went quality over quantity is 1999. Below average number of named storms, but nearly 67% of those storms became hurricanes, and of those 5 became major hurricanes. All Cat 4 hurricanes too. Even among the non-major hurricanes, all were Cat 2s. No Cat 1s. Ended up as an operationally hyperactive year.

[NotSparta]

The only reason this season feels kind of "slow" is because so far, 2024 has not seen many short-lived, weak storms like most recent seasons have. The number of named storms is actually above average. The NATL has already crossed the 50 ACE mark!

Here's another comparison to consider: 2010 was only at 3-1-0 at this date, and didn't really get going until the last third of August. 2024 is already at 5-3-1. 1998 and 1999 both only had one tropical storm before this date, and both got to the "hyperactive" ACE category. Since it is a first-year -ENSO, I think we'll have to watch the western basin for hurricanes late in the season. Even the most active seasons often have short breaks in activity, 2020 had no hurricanes between August 4-23, 2005 also had no hurricanes early in August. The upcoming short lull is nothing too unusual, and it looks like the MDR should really get going after it ends.

Even the ACE total for this season would be near average if Beryl didn't exist. Not slow in the slightest, that's for sure

[skyline385]

I disagree that August has been kind of slow. Two hurricanes. One US landfall. That ain’t kinda slow. IMO of course.

True, but I meant “slow” as in how some people were expecting August to go into very active mode with 100 ACE before month’s end. That ain’t happening it seems.

The season is actually pacing about average to slightly above as far as the count: we're five days away from when we normally have the fifth storm

Ernesto formed on Aug 12 which is 10 days before the fifth storm forms (Aug 22), Ernesto also became a hurricane on Aug 14 which is 26 days ahead of the formation of the third hurricane (Sep 7) so I would say we are pacing well above average as far as count goes. And with the ITCZ lifted so north and expected to produce AEWs into October as it drops down, combined with an ongoing transition to La Nina and record high temps and OHC in the Caribbean for late season, I find it very hard to imagine that we end the season with average NS count.

[Hammy]

True, but I meant “slow” as in how some people were expecting August to go into very active mode with 100 ACE before month’s end. That ain’t happening it seems.

The season is actually pacing about average to slightly above as far as the count: we're five days away from when we normally have the fifth storm

Ernesto formed on Aug 12 which is 10 days before the fifth storm forms (Aug 22), Ernesto also became a hurricane on Aug 14 which is 26 days ahead of the formation of the third hurricane (Sep 7) so I would say we are pacing well above average as far as count goes. And with the ITCZ lifted so north and expected to produce AEWs into October as it drops down, combined with an ongoing transition to La Nina and record high temps and OHC in the Caribbean for late season, I find it very hard to imagine that we end the season with average NS count.

https://i.imgur.com/CW6WSzu.png

Keep in mind an average season is 14 storms and I'm thinking we're going to have 13-16, which is fairly close to average. But I still think the ACE count is going to be quite a bit above normal, something we would only avert if some unforeseen atmospheric conditions exist and we actually do end up dead through the rest of August as the GFS shows (something I find unlikely)

But it has becoming clear the early numbers forecasts are going to wind up inflated from the actual totals--we've ended up taking longer to reach La Nina than was originally forecast, and there appears to be more dry air than was expected. 2017 is probably the best analog--I think we're going to see steady formation, with one or two forming at a time, and very limited development stemming from non-tropical origins.

[MarioProtVI]

The season is actually pacing about average to slightly above as far as the count: we're five days away from when we normally have the fifth storm

Ernesto formed on Aug 12 which is 10 days before the fifth storm forms (Aug 22), Ernesto also became a hurricane on Aug 14 which is 26 days ahead of the formation of the third hurricane (Sep 7) so I would say we are pacing well above average as far as count goes. And with the ITCZ lifted so north and expected to produce AEWs into October as it drops down, combined with an ongoing transition to La Nina and record high temps and OHC in the Caribbean for late season, I find it very hard to imagine that we end the season with average NS count.

https://i.imgur.com/CW6WSzu.png

Keep in mind an average season is 14 storms and I'm thinking we're going to have 13-16, which is fairly close to average. But I still think the ACE count is going to be quite a bit above normal, something we would only avert if some unforeseen atmospheric conditions exist and we actually do end up dead through the rest of August as the GFS shows (something I find unlikely)

But it has becoming clear the early numbers forecasts are going to wind up inflated from the actual totals--we've ended up taking longer to reach La Nina than was originally forecast, and there appears to be more dry air than was expected. 2017 is probably the best analog--I think we're going to see steady formation, with one or two forming at a time, and very limited development stemming from non-tropical origins.

I still think 20 named storms is very possible, especially when considering the fact ensembles and even some of the oper models are beginning to pick up on MDR activity and some Gulf nonsense too. Additionally the CFS has a lot of storms from late August onward and ends up getting to I think 18-19 storms by season’s end.

I think that while Beryl is certainly an ominous sign of things to come, it made people go exceptionally wild with predictions and predict that August would be bonkers like 2004 and wind up with seasonal totals rivaling that of 2020 with ~250 ACE. obviously not the case (so far it seems), and because of that people are downcasting like usual when it didn’t explode with the activity they were expecting. The only negative it seems right now as to why models are seemingly dead until the end of the month is because of the monsoon trough being a bit too north whereas all indications are that it will be lowering by months end - there’s a reason the ensembles are beginning to sniff out the activity and why the CFS has a strong MDR train going through a good chunk of September, and the fact that the MJO seems to be aligning itself in a favorable position, all leads to the fact that things will pick up very soon and fast, probably like 2017. I think a final tally of around 19-21 / 10-12 / 5-6 with around roughly 200 ACE is still extremely likely. Additionally late season can produce shenanigans that result in short spin ups.

[skyline385]

Ernesto formed on Aug 12 which is 10 days before the fifth storm forms (Aug 22), Ernesto also became a hurricane on Aug 14 which is 26 days ahead of the formation of the third hurricane (Sep 7) so I would say we are pacing well above average as far as count goes. And with the ITCZ lifted so north and expected to produce AEWs into October as it drops down, combined with an ongoing transition to La Nina and record high temps and OHC in the Caribbean for late season, I find it very hard to imagine that we end the season with average NS count.

https://i.imgur.com/CW6WSzu.png

Keep in mind an average season is 14 storms and I'm thinking we're going to have 13-16, which is fairly close to average. But I still think the ACE count is going to be quite a bit above normal, something we would only avert if some unforeseen atmospheric conditions exist and we actually do end up dead through the rest of August as the GFS shows (something I find unlikely)

But it has becoming clear the early numbers forecasts are going to wind up inflated from the actual totals--we've ended up taking longer to reach La Nina than was originally forecast, and there appears to be more dry air than was expected. 2017 is probably the best analog--I think we're going to see steady formation, with one or two forming at a time, and very limited development stemming from non-tropical origins.

I still think 20 named storms is very possible, especially when considering the fact ensembles and even some of the oper models are beginning to pick up on MDR activity and some Gulf nonsense too. Additionally the CFS has a lot of storms from late August onward and ends up getting to I think 18-19 storms by season’s end.

I think that while Beryl is certainly an ominous sign of things to come, it made people go exceptionally wild with predictions and predict that August would be bonkers like 2004 and wind up with seasonal totals rivaling that of 2020 with ~250 ACE. obviously not the case (so far it seems), and because of that people are downcasting like usual when it didn’t explode with the activity they were expecting. The only negative it seems right now as to why models are seemingly dead until the end of the month is because of the monsoon trough being a bit too north whereas all indications are that it will be lowering by months end - there’s a reason the ensembles are beginning to sniff out the activity and why the CFS has a strong MDR train going through a good chunk of September, and the fact that the MJO seems to be aligning itself in a favorable position, all leads to the fact that things will pick up very soon and fast, probably like 2017. I think a final tally of around 19-21 / 10-12 / 5-6 with around roughly 200 ACE is still extremely likely. Additionally late season can produce shenanigans that result in short spin ups.

Think you meant 2005 and not 2020. Regardless though, personally I still think that its too early to say for sure that a record breaking ACE system is off the books, we are 3rd ACE-wise and heading into peak with a transitioning La Nina and a record +AMO.

One of the main reasons August was quiet was because of the ITCZ being raised too far north from a very active WAM and SAL having an active season which is also related to having a strong AEJ this year. Now both the factors which are causing August to remain relatively less active than expected are also extremely favorable once we get into peak seasons. And these factors will become favourable, there is no doubt in that. The ITCZ will drop south again just like SAL will decrease going into peak season. Seasons like 2004, 2010 and 2017 are a reminder that NATL peak season really has no limits even if early August is tame.

And keep in mind that the "tame" early August in discussion here had a C1 and C2 even with unfavourable conditions in the basin. June activity in the MDR is also heavily corelated with an active season and we just had a record breaking C5 in Beryl to send us a message that this season will not be holding back. So to summarize, it is still way too early in my opinion to start downtrending on the season's expectations. If we are into early September and season is struggling to pick up pace then a very serious discussion can be had on how the expectations of this season will not be met. Of course, these are just my personal opinions.

[CyclonicFury]

The discussions right now remind me of this time in 2017. Just like this year, 2017 had two hurricanes in the first half of August as well, a Category 1 over the Gulf (Franklin) and a Category 2 over the open Atlantic (Gert). Both formed from AEWs just like Debby and Ernesto this year. Then Harvey formed over the MDR, struggled for a while, and there was a lot of speculation that the favorable conditions in the MDR had not materialized. After Harvey, no new storms formed in the Atlantic until August 30, when Irma formed and the rest is history.

I don't think the MDR has been any less active than expected for a hyperactive year. If anything, the low NS count is due to a total lack of non-tropical origin developments compared to recent years. All 5 cyclones in the NATL this season have formed south of 20°N and from tropical sources.

I do think we'll see a few day lull after Ernesto goes post-tropical, but I don't think it's anything unusual. Even 2020 had a 10-day lull in late September, hyperactive seasons often have brief lulls during peak season between favorable windows.

[Hammy]

The discussions right now remind me of this time in 2017. Just like this year, 2017 had two hurricanes in the first half of August as well, a Category 1 over the Gulf (Franklin) and a Category 2 over the open Atlantic (Gert). Both formed from AEWs just like Debby and Ernesto this year. Then Harvey formed over the MDR, struggled for a while, and there was a lot of speculation that the favorable conditions in the MDR had not materialized. After Harvey, no new storms formed in the Atlantic until August 30, when Irma formed and the rest is history.

I don't think the MDR has been any less active than expected for a hyperactive year. If anything, the low NS count is due to a total lack of non-tropical origin developments compared to recent years. All 5 cyclones in the NATL this season have formed south of 20°N and from tropical sources.

I do think we'll see a few day lull after Ernesto goes post-tropical, but I don't think it's anything unusual. Even 2020 had a 10-day lull in late September, hyperactive seasons often have brief lulls during peak season between favorable windows.

This is the primary reason I don't think we'll reach 20. If we were getting the 'slop storms' in addition to what we've gotten, similar to 2020 or 21, I would've expected this season to easily exhaust the list.

[gatorcane]

The GFS has lows in the 40s as far as south as western areas of North Carolina for Wed which is below normal and highs for portions of the Northeast US only in the 50s for Wed which is well below normal (some 10-15 degrees). The below normal temps are due to an anomalously strong eastern CONUS trough. Then in the long-range, the GFS shows a massive trough over eastern North America with well below normal temps returning. Meanwhile the Euro has some kind of cut-off low in the long-range that develops over the Western Atlantic next weekend, which looks more like a "Bermuda Low" than a Bermuda High. The Bermuda High is looking weak lately (as Wxman57 noted in the Global Models thread), will it continue into the peak?

[Stratton23]

very unlikely

[LarryWx]

The GFS has lows in the 40s as far as south as western areas of North Carolina for Wed which is below normal and highs for portions of the Northeast US only in the 50s for Wed which is well below normal (some 10-15 degrees). The below normal temps are due to an anomalously strong eastern CONUS trough. Then in the long-range, the GFS shows a massive trough over eastern North America with well below normal temps returning. Meanwhile the Euro has some kind of cut-off low in the long-range that develops over the Western Atlantic next weekend, which looks more like a "Bermuda Low" than a Bermuda High. The Bermuda High is looking weak lately (as Wxman57 noted in the Global Models thread), will it continue into the peak?

Hey Gator,
Of course it’s possible but I say probably not because:
- we’re already in a RONI based La Niña, which favors a somewhat stronger than avg Bermuda high in the means
- as you know the strength of the Bermuda high tends to ebb and flow many times during most seasons as it isn’t static just like many features in the atmosphere. So, with
the center of the peak still nearly a month away, I highly doubt it will stay weak for that long.

[MarioProtVI]

The discussions right now remind me of this time in 2017. Just like this year, 2017 had two hurricanes in the first half of August as well, a Category 1 over the Gulf (Franklin) and a Category 2 over the open Atlantic (Gert). Both formed from AEWs just like Debby and Ernesto this year. Then Harvey formed over the MDR, struggled for a while, and there was a lot of speculation that the favorable conditions in the MDR had not materialized. After Harvey, no new storms formed in the Atlantic until August 30, when Irma formed and the rest is history.

I don't think the MDR has been any less active than expected for a hyperactive year. If anything, the low NS count is due to a total lack of non-tropical origin developments compared to recent years. All 5 cyclones in the NATL this season have formed south of 20°N and from tropical sources.

I do think we'll see a few day lull after Ernesto goes post-tropical, but I don't think it's anything unusual. Even 2020 had a 10-day lull in late September, hyperactive seasons often have brief lulls during peak season between favorable windows.

This is the primary reason I don't think we'll reach 20. If we were getting the 'slop storms' in addition to what we've gotten, similar to 2020 or 21, I would've expected this season to easily exhaust the list.

Let’s wait and see until we get to October and see where we are at. If we’re at like 15-16 by then (meaning only 10-11 more storms until September 30, it’s possible), then 20 is still achievable. If we’re at only like 12-13, then I’d begin questioning it but all indicators point towards a very busy September. Also, the named storm spam in late August last year all came from tropical waves (Franklin, Gert, Harold, Jose, Katia).

[Teban54]

Also, the named storm spam in late August last year all came from tropical waves (Franklin, Gert, Harold, Jose, Katia).

I had always felt there's an inverse relationship between quantity and quality for Atlantic storms, especially MDR storms. The 2023 MDR spam consisted of many short-lived tropical storms, and when we got to the later part with Lee, Margot and Nigel, the pace had slowed down. 2020 was similar, with 5 MDR named storms but only Teddy achieving (major) hurricane intensity within the MDR.

It almost seems like there's limited energy available, which can be used to either produce many storms that all compete with each other, or a few storms that bomb out.

[weatherdude1108]

This is dangerous thinking, and seems to be partially based in the fact that models have been seemingly struggling to capture genesis properly in the deep tropics this year (GFS having a habit of stringing things out too quick). While it’s true the monsoon trough is further north then normal, it is expected to sink back down to normal levels by the end of the month and the 12z EURO already seems to be picking up on that with several lows in the MDR around the 29th - which over the next week will likely wax and wane in appearance before beginning to trend upwards into stronger systems, just like Debby and Ernesto showed.

Dangerous thinking! I don't think you actually meant that, I hope. Make comments on the season, the indicators, the forecasts, but not the person or the thinking please. Discussion should be fun and interesting here, not combative.

Apologies. I don’t have any ill will at all, but my post was mainly meant to say that just because August is being kinda slow doesn’t mean that the season will underperform statistic wise. The main reason it is a bit slow is because of the northward ITCZ right now that is expected to shift back south at the end of the month (which models are beginning to agree on).

One of the TV pro mets here was talking about the northern ITCZ yesterday and how it has not lined up with the moisture coming off Africa, per its usual placement. Didn't say why.

Do they know why it's happening?

Apologies if this was already answered. I'm late to the party.

[skyline385]

Also, the named storm spam in late August last year all came from tropical waves (Franklin, Gert, Harold, Jose, Katia).

I had always felt there's an inverse relationship between quantity and quality for Atlantic storms, especially MDR storms. The 2023 MDR spam consisted of many short-lived tropical storms, and when we got to the later part with Lee, Margot and Nigel, the pace had slowed down. 2020 was similar, with 5 MDR named storms but only Teddy achieving (major) hurricane intensity within the MDR.

It almost seems like there's limited energy available, which can be used to either produce many storms that all compete with each other, or a few storms that bomb out.

well one simple reason for that is that anytime a strong system forms in the MDR, its outflow is more than likely shearing everything behind it so the environment just becomes unfavourable behind strong systems and is likely one of the reasons for a slower pace of NS

[LarryWx]

Dangerous thinking! I don't think you actually meant that, I hope. Make comments on the season, the indicators, the forecasts, but not the person or the thinking please. Discussion should be fun and interesting here, not combative.

Apologies. I don’t have any ill will at all, but my post was mainly meant to say that just because August is being kinda slow doesn’t mean that the season will underperform statistic wise. The main reason it is a bit slow is because of the northward ITCZ right now that is expected to shift back south at the end of the month (which models are beginning to agree on).

One of the TV pro mets here was talking about the northern ITCZ yesterday and how it has not lined up with the moisture coming off Africa, per its usual placement. Didn't say why.

Do they know why it's happening?

Apologies if this was already answered. I'm late to the party.

Just like many other aspects related to tropical climo, it is going to vary between and even within seasons. But I don’t know why it is being treated as a big deal when keeping in mind that there already were two TCGs E of the Caribbean by Aug 9th that attained NS status at some point, not an easy feat. That is tied for the most by Aug 9th in the active era since 1995! So, there’s been no E of Caribbean weakness in TCGs in 2024!

The other years since 1995 with two TCGs E of the Caribbean by Aug 9 that attained NS status at some point were 2023, 2017, 2013, 2012, 2005, 2004, and 1995. That’s only 7 of 29 or 24% of seasons in the active era! There were zero in 2022, 2019, 2016, 2015, 2011, 2009, 2007, 2003, 2002, 2001, 1999, and 1997. There was one in 2021, 2020, 2018, 2014, 2010, 2008, 2006, 2000, 1998, and 1996. So, the avg since 1995 is only 0.8. Thus, 2024’s 2 is 250% of the mean of the active era. So, regardless of where the ITCZ has been so far this season, it certainly hasn’t lead to quiet so far this season as it has been active.

*Edit: It was pointed out 2017 also had TD #4 that formed in July E of the Caribbean. I missed it because the 2017 map I saw didn’t have it. That’s almost certainly because it didn’t ever reach NS status. Thus, I just reworded this to refer only to early TCGs E of the Caribbean that at some point lead to a NS somewhere in the basin.