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

[caneman]

Given that a few days ago people were saying you couldn't even buy a thunderstorm in the Atlantic, the basin today is quite convectively active, honestly.

https://i.postimg.cc/brW2snGy/goes16-ir-atl.gif

It sure is, but it forming a tropical cyclone is still likely a different matter. Model guidance has really backed off the last day or so, especially the EURO and honestly that’s the only model I trust given the GFS has missed every storm up to this point if memory serves, so can’t start trusting it now just because it shows something. Most likely the Atlantic continues to struggle because of the background state which is supposedly favorable but very clearly is not at this point. Something should give over the next few weeks and we see a couple storms, probably similar to 2014 style but that’s the ceiling imo.

Every year is different and unique. I see many people refer to climatology as the be all end all. While it can give you guidance and maybe even a a tic over 50/50 likelihood of occurring like the past, each year is different and unique. Every year we see new records being set , new trends being created and indeed another different type of year to mix into climatology trends. This year could just as easily be one of the highest performing back loaded seasons. We just have to wait and see.

[CyclonicFury]

Given that a few days ago people were saying you couldn't even buy a thunderstorm in the Atlantic, the basin today is quite convectively active, honestly.

https://i.postimg.cc/brW2snGy/goes16-ir-atl.gif

It sure is, but it forming a tropical cyclone is still likely a different matter. Model guidance has really backed off the last day or so, especially the EURO and honestly that’s the only model I trust given the GFS has missed every storm up to this point if memory serves, so can’t start trusting it now just because it shows something. Most likely the Atlantic continues to struggle because of the background state which is supposedly favorable but very clearly is not at this point. Something should give over the next few weeks and we see a couple storms, probably similar to 2014 style but that’s the ceiling imo.

2014 as the ceiling? I disagree, 2014 had 67 ACE *total* and 2024 is already at around 55. 2014 was also nothing like 2024, with a strong +PDO and El Niño-like atmospheric state. 2014 had a very hostile deep tropics with only one hurricane south of 20°N. The EPAC was also extremely active in 2014, which hasn't been the case this year. 2014 also did not have near record warm MDR SSTs. It's easy to season cancel in a lull like this, but 2014 is just an excessive comparison imo. I don't think 2024 is going to meet the most bullish forecasts but we're not even at the halfway point yet.

2022 was FAR more quiet than this year early on and still ended up with 14 named storms, 8 hurricanes, 2 very significant major hurricanes and ~95 ACE. 2018 also had only a couple weak storms in August before finishing above average in the end.

[caneman]

Given that a few days ago people were saying you couldn't even buy a thunderstorm in the Atlantic, the basin today is quite convectively active, honestly.

https://i.postimg.cc/brW2snGy/goes16-ir-atl.gif

It sure is, but it forming a tropical cyclone is still likely a different matter. Model guidance has really backed off the last day or so, especially the EURO and honestly that’s the only model I trust given the GFS has missed every storm up to this point if memory serves, so can’t start trusting it now just because it shows something. Most likely the Atlantic continues to struggle because of the background state which is supposedly favorable but very clearly is not at this point. Something should give over the next few weeks and we see a couple storms, probably similar to 2014 style but that’s the ceiling imo.

2014 as the ceiling? I disagree, 2014 had 67 ACE *total* and 2024 is already at around 55. 2014 was also nothing like 2024, with a strong +PDO and El Niño-like atmospheric state. 2014 had a very hostile deep tropics with only one hurricane south of 20°N. The EPAC was also extremely active in 2014, which hasn't been the case this year. 2014 also did not have near record warm MDR SSTs. It's easy to season cancel in a lull like this, but 2014 is just an excessive comparison imo. I don't think 2024 is going to meet the most bullish forecasts but we're not even at the halfway point yet.

Agree, people don't seem to understand that in the next week it could just as easily light up like the 4th of July.

[Hypercane_Kyle]

It sure is, but it forming a tropical cyclone is still likely a different matter. Model guidance has really backed off the last day or so, especially the EURO and honestly that’s the only model I trust given the GFS has missed every storm up to this point if memory serves, so can’t start trusting it now just because it shows something. Most likely the Atlantic continues to struggle because of the background state which is supposedly favorable but very clearly is not at this point. Something should give over the next few weeks and we see a couple storms, probably similar to 2014 style but that’s the ceiling imo.

2014 as the ceiling? I disagree, 2014 had 67 ACE *total* and 2024 is already at around 55. 2014 was also nothing like 2024, with a strong +PDO and El Niño-like atmospheric state. 2014 had a very hostile deep tropics with only one hurricane south of 20°N. The EPAC was also extremely active in 2014, which hasn't been the case this year. 2014 also did not have near record warm MDR SSTs. It's easy to season cancel in a lull like this, but 2014 is just an excessive comparison imo. I don't think 2024 is going to meet the most bullish forecasts but we're not even at the halfway point yet.

Agree, people don't seem to understand that in the next week it could just as easily light up like the 4th of July.

Of course we all understand that. But I think the sky high expectations for this season created by Beryl (expectations for which I also contributed to) need to be greatly tampered. It's August 27th and there any support for a named storm anytime soon, heading well into September. Even respected forecasters are pointing this out. It's bone dry out there. To me, I think we're heading into a slightly above-average season that will see its peak in late-September/early-October, very reminiscent of 2022.

[caneman]

2014 as the ceiling? I disagree, 2014 had 67 ACE *total* and 2024 is already at around 55. 2014 was also nothing like 2024, with a strong +PDO and El Niño-like atmospheric state. 2014 had a very hostile deep tropics with only one hurricane south of 20°N. The EPAC was also extremely active in 2014, which hasn't been the case this year. 2014 also did not have near record warm MDR SSTs. It's easy to season cancel in a lull like this, but 2014 is just an excessive comparison imo. I don't think 2024 is going to meet the most bullish forecasts but we're not even at the halfway point yet.

Agree, people don't seem to understand that in the next week it could just as easily light up like the 4th of July.

Of course we all understand that. But I think the sky high expectations for this season created by Beryl (expectations for which I also contributed to) need to be greatly tampered. It's August 27th and there any support for a named storm anytime soon, heading well into September. Even respected forecasters are pointing this out. It's bone dry out there. To me, I think we're heading into a slightly above-average season that will see its peak in late-September/early-October, very reminiscent of 2022.

It may not be as forecasted but could easily be above normal and damaging.

[LarryWx]

2014 as the ceiling? I disagree, 2014 had 67 ACE *total* and 2024 is already at around 55. 2014 was also nothing like 2024, with a strong +PDO and El Niño-like atmospheric state. 2014 had a very hostile deep tropics with only one hurricane south of 20°N. The EPAC was also extremely active in 2014, which hasn't been the case this year. 2014 also did not have near record warm MDR SSTs. It's easy to season cancel in a lull like this, but 2014 is just an excessive comparison imo. I don't think 2024 is going to meet the most bullish forecasts but we're not even at the halfway point yet.

Agree, people don't seem to understand that in the next week it could just as easily light up like the 4th of July.

Of course we all understand that. But I think the sky high expectations for this season created by Beryl (expectations for which I also contributed to) need to be greatly tampered. It's August 27th and there any support for a named storm anytime soon, heading well into September. Even respected forecasters are pointing this out. It's bone dry out there. To me, I think we're heading into a slightly above-average season that will see its peak in late-September/early-October, very reminiscent of 2022.

Is it really bone dry out there? There are two convectively active areas in the MDR now.

[chaser1]

Here is fwiw a copy of some excerpts from a post I made on 4/7/24 regarding the extremely bullish April CSU forecast:

“I see a pretty clear pattern when they’ve gone very active in April:

2. NS days: They’re predicting 115. Prior to this the highest they predicted in April was 85-95 (four times). All four of those progs ended up too high. The highest actual of those four was only 58 and they averaged a whopping 40.5 too high!

3. # H: They’re predicting 11. The prior highest predicted in April was 9 (six times). All of those 6 progs ended up too high by an average of 3.

7. ACE: They’re predicting 210. The prior highest predicted in April were 160-183 (five times). Of these five, all progs ended up too high with even the closest still being 34 too high! The five averaged a whopping 85.8 too high!

Conclusion: If I were a betting man, I’d short CSU’s April ‘24’s forecast overall, especially NS Days, # H, and ACE.”

https://www.storm2k.org/phpbb2/viewtopi ... 0#p3063020

EXCELLENT points made at that juncture (though in spite of that sentiment, "something" did sway you to ultimately predict a fairly high number of NS & Hurricanes as well - 21/10/5 ACE: 176 on that same day )

Thank you. I was talking to “betting” men, which I’m not.
Seriously, when I made my S2K prediction, I still went very active as you said though not hyperactive with 21/10/5 176. My ACE was exactly 34 below their 210 ACE based on this analysis, showing they were 34+ too high all 5 of those times. I didn’t feel comfy going lower because at the time the vast majority of the ~50 earlier S2K ACE picks were higher than 176. So, for contest purposes, I thought it was wise to hedge on the higher side of my range. Same with the NS. Most were above my 21. And my 21 was 2 lower than CSU’s 33. My 10H was also lower than most others. My 5MH was near the median.

I think last years' warm SST's in spite of occurring during an El Nino really primed us all for the year that we expected to have. Anyway, I'm pretty sure that my prediction for # of hurricanes was 50% higher then yours was. I find crow to be rather gamey but will opt to request mine well-done

[Hypercane_Kyle]

Agree, people don't seem to understand that in the next week it could just as easily light up like the 4th of July.

Of course we all understand that. But I think the sky high expectations for this season created by Beryl (expectations for which I also contributed to) need to be greatly tampered. It's August 27th and there any support for a named storm anytime soon, heading well into September. Even respected forecasters are pointing this out. It's bone dry out there. To me, I think we're heading into a slightly above-average season that will see its peak in late-September/early-October, very reminiscent of 2022.

It may not be as forecasted but could easily be above normal and damaging.

What did I say, lol?

[caneman]

Of course we all understand that. But I think the sky high expectations for this season created by Beryl (expectations for which I also contributed to) need to be greatly tampered. It's August 27th and there any support for a named storm anytime soon, heading well into September. Even respected forecasters are pointing this out. It's bone dry out there. To me, I think we're heading into a slightly above-average season that will see its peak in late-September/early-October, very reminiscent of 2022.

It may not be as forecasted but could easily be above normal and damaging.

What did I say, lol?

What did I say? Lol. They don't need to be greatly tampered because we just don't know yet. It could be 2 majors left destroying local communities. It could be a backloaded season. That's all that will be remembered and not if we finish with 18 in a predicted year of 23. Further, I'm not seeing bone dry, I'm seeing things starting to really moisten up. Yearly predictions need to go away. They're foolish, misleading and near impossible to predict.

[Teban54]

Agree, people don't seem to understand that in the next week it could just as easily light up like the 4th of July.

Of course we all understand that. But I think the sky high expectations for this season created by Beryl (expectations for which I also contributed to) need to be greatly tampered. It's August 27th and there any support for a named storm anytime soon, heading well into September. Even respected forecasters are pointing this out. It's bone dry out there. To me, I think we're heading into a slightly above-average season that will see its peak in late-September/early-October, very reminiscent of 2022.

Is it really bone dry out there? There are two convectively active areas in the MDR now.

To reiterate the point I made on Sunday, over the past 8-day period of August 18-25 (to remove the influence of Ernesto), the low levels (850 mb) has actually been slightly wetter than average in most of the Atlantic. As we move up to 700 and 500 mb, the main areas that are anomalously dry seem to be somewhat limited to near South America, including the Caribbean. Eastern Atlantic -- whether it's the tropics or subtropics -- has actually been well above average in relative humidity.







Even if you want to limit to a single day, here's what it looked like on August 23, the day when Hypercane_Kyle said "dry air is absolutely choking out this season from going full-on insanity". While most of the western Atlantic was dry on that day, eastern Atlantic was well wetter than avarege.

(This is not to single out Hypercane_Kyle: the linked comment just happened to be the first I found about someone discussing dry air when scrolling back in the indicators thread.)



I know, all this is counter-intuitive compared to what experts are saying now... But the data doesn't lie.

There can be many reasons explaining the discrepancy (both the data vs. perceptions, and humidity vs. activity levels). In addition to other limiting factors that are possibly placing a lid on activity, such as strong AEJ-induced shear, northward-displaced ITCZ and warm tropopause, I'd suggest two of my own thoughts about humidity itself: (Keep in mind they may not be correct, as I'm far from a pro met.)

• The wet anomalies, especially just north of the eastern MDR, may be due to waves exiting more N than usual trying to mix out the dry air (whether SAL or from higher latitudes). This makes the region wet without necessarily helping development.
• Eastern Atlantic, especially the subtropics, is typically dry as per climo. Yet, that takes the center spot of what people see when looking at a map.

[MarioProtVI]

 https://twitter.com/AndyHazelton/status/1828569629720989776

[Teban54]

Posting it here for the sole reason that week 3 is beyond 16 days for the global models thread:



----------------------------------------

Good thread:
 https://x.com/OSUWXGUY/status/1828503909872345197




And a follow-up comment:
 https://x.com/OSUWXGUY/status/1828532093376176216

[tolakram]

So what's the red letter date for identifying something is actually odd with this season? Sept 10th? 30th? 1st? I'm not talking storm numbers, I think numbers are silly, but identifying an overall unexpected seasonal issue that is preventing development?

Mine is the Sept 10th. If we're still waiting for the models to show something on the 10th with no activity then there's clearly an unidentified issue that we should be able to learn from. If it picks up and we end up having normal to above normal then while we might bemoan a busted forecast I don't know if there's much to learn, other than seasonal variability can screw with any forecast.

[Category5Kaiju]

One thing I've seen raised in terms of a key factor that may be contributing to the inactivity now is abnormally warm extratropics (the marine heatwaves as they call it). We saw this in 2022, and it looks like it's somewhat present again this year. We even had it last year. So....it's still a bit early to determine exactly if this warrants enough attention, but I wonder if it indeed becomes apparent that this is a non-deep tropical sst anomaly, non-ENSO phase related issue that can profoundly impact tropical cyclone activity, if it can be incorporated in future seasonal forecasts.

Two big questions remain. One, why is this happening in the first place? As far as I'm aware, I don't think this has a clearcut answer, but it seems like it's, for some reason, a phenomenon recent hurricane seasons have faced. Two, how can we incorporate this into seasonal forecasts? As far as I remember, I don't think early modeling showed this feature in 2022, last year, and this year. It really seemed to rear its head in August, so perhaps the final seasonal forecasts that are normally released during August could include this?

Whatever the case, we're still light years ahead of 2022. We've already had multiple hurricanes form in August, while that year had zilch in August. 2024's story has yet to be finalized, but I do think we're going to see some appreciable activity in September, even if that means the peak is sort of delayed to the mid to end of the month. Hyperactivity, let alone those 200+ ACE predictions, is another topic of discussion.

[Teban54]

I'm confused, and I would like to be educated.

I was reading up on the Scandinavian block pattern that some professionals are discussing on Twitter, as they seem to think it plays a role in dumping dry air into the Atlantic. Yet, some other pros seem to think it's primarily due to a persistent +NAO.

From this quick guide below, it looks like +NAO and Scandinavian block are two different patterns that don't look alike. And the 500mb height pattern this August resembles more of a +NAO to me (using the past week nets similar results). What am I missing?

[Woofde]

So what's the red letter date for identifying something is actually odd with this season? Sept 10th? 30th? 1st? I'm not talking storm numbers, I think numbers are silly, but identifying an overall unexpected seasonal issue that is preventing development?

Mine is the Sept 10th. If we're still waiting for the models to show something on the 10th with no activity then there's clearly an unidentified issue that we should be able to learn from. If it picks up and we end up having normal to above normal then while we might bemoan a busted forecast I don't know if there's much to learn, other than seasonal variability can screw with any forecast.

I think we're already at a point where things are off of where we expected them. We've gone a week without activity and now we're likely looking at another. The seasons this was supposed to compare to (2020 and 2005) only took 1 week off at max during peak season. We are probably already locked in for a minor bust (NS count and ACE missing by a small to medium amount). Forecasts were so high that I would consider an only above average season a bust.

If we do make it to September 10th without any significant activity (I'm talking hurricanes not tropical storms), it will be time to start considering a 2013 level forecast failure. I don't think that is likely, but I also would've thought 2 weeks of nothing in late August would be extremely unlikely so we shall see.

[toad strangler]

So what's the red letter date for identifying something is actually odd with this season? Sept 10th? 30th? 1st? I'm not talking storm numbers, I think numbers are silly, but identifying an overall unexpected seasonal issue that is preventing development?

Mine is the Sept 10th. If we're still waiting for the models to show something on the 10th with no activity then there's clearly an unidentified issue that we should be able to learn from. If it picks up and we end up having normal to above normal then while we might bemoan a busted forecast I don't know if there's much to learn, other than seasonal variability can screw with any forecast.

I think we're already at a point where things are off of where we expected them. We've gone a week without activity and now we're likely looking at another. The seasons this was supposed to compare to (2020 and 2005) only took 1 week off at max during peak season. We are probably already locked in for a minor bust (NS count and ACE missing by a small to medium amount). Forecasts were so high that I would consider an only above average season a bust.

If we do make it to September 10th without any significant activity (I'm talking hurricanes not tropical storms), it will be time to start considering a 2013 level forecast failure. I don't think that is likely, but I also would've thought 2 weeks of nothing in late August would be extremely unlikely so we shall see.

Tropical activity doesn’t reference a calendar hanging on a wall. Just too much hand wringing far too early. IMO of course.

[weeniepatrol]

So what's the red letter date for identifying something is actually odd with this season? Sept 10th? 30th? 1st? I'm not talking storm numbers, I think numbers are silly, but identifying an overall unexpected seasonal issue that is preventing development?

Mine is the Sept 10th. If we're still waiting for the models to show something on the 10th with no activity then there's clearly an unidentified issue that we should be able to learn from. If it picks up and we end up having normal to above normal then while we might bemoan a busted forecast I don't know if there's much to learn, other than seasonal variability can screw with any forecast.

5-10 Sep is a great choice for this.

[Hurricane2022]

It's quite a bit boring to look at the threads, TropTidbits, CyclonicWx, WxTwitter, etc. and see people a somewhat lost and confused about the near future of this season. Luckily, my new job is making me much busier and I don't have enough time to see if anything has changed on the models forecast and indicators during the day, with those interval minutes reserved for chatting with co-workers or looking at Instagram. It is better to wait for nothing to see everything than to wait for everything to see nothing.

[Teban54]

So what's the red letter date for identifying something is actually odd with this season? Sept 10th? 30th? 1st? I'm not talking storm numbers, I think numbers are silly, but identifying an overall unexpected seasonal issue that is preventing development?

Mine is the Sept 10th. If we're still waiting for the models to show something on the 10th with no activity then there's clearly an unidentified issue that we should be able to learn from. If it picks up and we end up having normal to above normal then while we might bemoan a busted forecast I don't know if there's much to learn, other than seasonal variability can screw with any forecast.

My personal vote would be September 14th. That's when Fiona formed, and its genesis was poorly forecast. On the other hand, some other back-loaded seasons had their first MH form even after the date (9/21 in 2000, 9/18 in 2002), so you can arguably go lower.

We're in a dilemma now where, on one hand, models have been accurate up to this point in their depiction of large-scale conditions; but on the other hand, we also know from experience that models are often too slow in picking up a transition to more favorable conditions. I don't think their outputs can really say much, or anything, about the rest of the season yet, especially not past September 10 or so.

-------------------------------------------------------

In other news, a reduction in trade winds over the MDR is currently forecast:

 https://x.com/weatherman_aaa/status/1828591444027949547