2024-2025 La Nina

[40/70 Benchmark]

2 hours ago, Stormchaserchuck1 said:

Hey @40/70 Benchmark (Ray?), 

I just looked at this yesterday. The reading for May - Aug 5 right now (63% of the way through) is about +0.50, making it a 50% chance of having the DJFM NAO -0.04 to +1.04. Meaning, we have just as good of a chance of seeing a strong Winter NAO of +1 over 4-months, as Neutral. 

The August 5th reading is +1.00, so it's looking like the index will continue to increase at least through this month, and possibly going into the final month, September. I would guess right now it finishes May-Sept around +0.70, making it a 50% chance that the DJFM NAO is +0.16 to +1.24! (Since inception, that 0.54 SD, is 9 wins, 9 loses, right at the original assessment in 2005.) Also remember, that means there are equal chances of the NAO going >+1.24 as < +0.16. 

Yes-Ray.

Thanks alot. If it's too cumbersome- don't worry about it, but if you have the time to run a hindsight of that formula for 1970, please let me know. 

[40/70 Benchmark]

2 hours ago, George001 said:

The non Euro modeling was too cold, but things have been developing more quickly over the past couple of weeks. The weeklies are already in cold neutral territory for the enso 3.4 region (vs warm neutral about 3-4 weeks ago), and the negative subsurface anomalies have been strengthening again. I am extremely skeptical that the Euro will be right based on what has happened the past few weeks, as for it to be right the cooling in the ENSO 3.4 region needs to stall out for the next 4 months. Climatology doesn’t support that, historically after strong and super ninos you get la Nina’s, and they usually peak in late fall/early winter. Something I learned from tracking these past few years is climatology usually wins out.

So obvious guidance had backed off too much on La Nina, just like it had at this point last year with respect to el Nino. I still feel good about my ENSO peak expectations.

[snowman19]

34 minutes ago, mitchnick said:

Well, let's not forget that Enso 3.4 only goes from 120W to 170W. If you look at that prog, most of the strongest anomalies are west of that. In fact, the strongest are west of 160E, which is the limit of Enso 4. So even assuming this prog verifies, I  doubt it has a huge impact in Enso 3 and 3.4. Just mho.

Nino 3.4 is going to cool a lot if these model runs are correct. Looking more and more certain by the day that there’s going to be an official La Niña this winter. Cold-neutral is already a given

[Stormchaserchuck1]

41 minutes ago, 40/70 Benchmark said:

Yes-Ray.

Thanks alot. If it's too cumbersome- don't worry about it, but if you have the time to run a hindsight of that formula for 1970, please let me know. 

I did it before and published my work on easternuswx, but I don't have those filed saved anymore. Here is what you are looking at though, if you want to do an analysis yourself (it would take a few hours). 

The +SSTA area I give 1.00 weight to, and the -SSTA area I give 0.65 weight to. It looks something like this:

Because the northern area has more volatility. 

I made the total dataset, SSTs and NAO even, by multiplying the total historical absolute number of both, and dividing it by each other. 

Here is what 8-5-2024 looks like:

[Stormchaserchuck1]

October has a slight opposite correlation to the Winter's NAO (and it's the only month of the year where this is true), so it may be a backwards way of doing things, but if we are looking at a +NAO Winter, I'd watch for a -NAO October, or maybe before.. -NAO in October could connect up with a -PNA, or even if it's not a strong NAO signal, I think the -PNA would be amplified by the tendency.. 

These -wind bursts may strengthen the central-ENSO-subsurface which is already in Moderate La Nina range, just further amplifying the -PNA signal in the coming months.. 

[PhiEaglesfan712]

3 hours ago, George001 said:

https://www.cpc.ncep.noaa.gov/products/CFSv2/imagesInd3/nino34Mon.gif

latest CFS, mean of roughly -1.4C in the ENSO 3.4 region with a late Nov/early Dec peak.

This would almost be a perfect ENSO/RONI/subsurface match to 1998-99.

[Stormchaserchuck1]

2 minutes ago, PhiEaglesfan712 said:

This would almost be a perfect ENSO/RONI/subsurface match to 1998-99.

98-99 was also very warm across the CONUS Dec-July [97-98], which matches that this year is #1 in that regard.. 

[so_whats_happening]

Hot linked so this will change from day to day. It does look like the Atlantic cool anomalies are taming a bit as the trade wind increase in this area finally goes away. Concentration of trades are finally happening around 120E to about 150W and may slowly move eastward to about 120W by mid to late month. Hoping this really knocks a dent in the warm pool east of New Guinea. Forcing right now looks to set up around 70-100E over the eastern Indian Ocean so fairly 1998 like in that manner.

The models are trying to push a potentially decent MJO wave as we move into mid month so look for activity to ramp up in the tropical Atlantic before maybe close to the end of the month getting some activity into the western PAC. I do think the models are moving the MJO a bit too fast but we will see. If we can get cooling into the 150E to 150W equatorial region there will be no hurry for the MJO to want to go to 5/6/7. Have a busy weekend coming up so hopefully we see some good changes by the start of next week.

[snowman19]

The new Euro is clearly showing classic La Niña/-PDO/-PMM/-IOD looking atmosphere, along with a very muted STJ this winter. Also very suggestive of Niña MJO (4-6) forcing, which is no surprise at all:
 

[40/70 Benchmark]

8 hours ago, Stormchaserchuck1 said:

I did it before and published my work on easternuswx, but I don't have those filed saved anymore. Here is what you are looking at though, if you want to do an analysis yourself (it would take a few hours). 

The +SSTA area I give 1.00 weight to, and the -SSTA area I give 0.65 weight to. It looks something like this:

Because the northern area has more volatility. 

I made the total dataset, SSTs and NAO even, by multiplying the total historical absolute number of both, and dividing it by each other. 

Here is what 8-5-2024 looks like:

Thank you. I am still bitter about how things ended at Eastern and how the forum and everything on it is not in accessible. 

[40/70 Benchmark]

1 hour ago, snowman19 said:

The new Euro is clearly showing classic La Niña/-PDO/-PMM/-IOD looking atmosphere, along with a very muted STJ this winter. Also very suggestive of Niña MJO (4-6) forcing, which is no surprise at all:
 

I will take an active N branch over a strong STJ any day of the week in my neck of the woods. I undersrand that its different not too far to my south and that temps are still likely to be an issue this year.

[bluewave]

11 hours ago, roardog said:

The 30 day SOI is at -9.22. I think that’s more negative than last year at this time with a strong Nino developing. 

We have seen this disconnect in recent years between the SOI and trade winds. The stronger EWB recently matches up more with the EQSOI which was +0.4 in July +0.6 in June. The disconnect this month may also be related to the -AAO rising pressures further south and still leaving lower pressures right along the equator near the WPAC warm pool driving the stronger trades. 
 

EQSOI positive

https://www.cpc.ncep.noaa.gov/data/indices/reqsoi.for

stronger trades with the EWB

https://www.cpc.ncep.noaa.gov/data/indices/cpac850

[40/70 Benchmark]

5 minutes ago, bluewave said:

We have seen this disconnect in recent years between the SOI and trade winds. The stronger EWB recently matches up more with the EQSOI which was +0.4 in July +0.6 in June. The disconnect this month may also be related to the -AAO rising pressures further south and still leaving lower pressures right along the equator near the WPAC warm pool driving the stronger trades. 
 

EQSOI positive

https://www.cpc.ncep.noaa.gov/data/indices/reqsoi.for

stronger trades with the EWB

https://www.cpc.ncep.noaa.gov/data/indices/cpac850

I think the ONI lagging maybe at least partially attributable to the SOI disconnect (residual from strong El Nino), which causes that particular metric to underestimate the intensity of the cool ENSO Walker cell.....much like what was observed last season when the west PAC warm pool maked the intensity of the El Nino.

[40/70 Benchmark]

3 minutes ago, 40/70 Benchmark said:

I think the ONI lagging maybe at least partially attributable to the SOI disconnect (residual from strong El Nino), which causes that particular metric to underestimate the intensity of the cool ENSO Walker cell.....much like what was observed last season when the west PAC warm pool maked the intensity of the El Nino.

I misunderstood the implications of this last year, but I won't make that same mistake again this season.....my forecast will be off because I'll make some other assortment of mistakes.

[bluewave]

20 minutes ago, 40/70 Benchmark said:

I think the ONI lagging maybe at least partially attributable to the SOI disconnect (residual from strong El Nino), which causes that particular metric to underestimate the intensity of the cool ENSO Walker cell.....much like what was observed last season when the west PAC warm pool maked the intensity of the El Nino.

It’s interesting how weak the -SOI and -EQSOI were for such a strong El Niño. This also lead to the weaker WWBs. Notice how much lower both SOIs were during the 15-16 and 97-98 events. My guess this is a result of the much stronger WPAC warm pool. 

[40/70 Benchmark]

18 minutes ago, bluewave said:

It’s interesting how weak the -SOI and -EQSOI were for such a strong El Niño. This also lead to the weaker WWBs. Notice how much lower both SOIs were during the 15-16 and 97-98 events. My guess this is a result of the much stronger WPAC warm pool. 

Yes, I correctly pointed out all of that in last season's outlook, complete with schematics, but again....totally screwed the pooch on what impact it would have.

Frustratingly educational.

[PhiEaglesfan712]

10 minutes ago, 40/70 Benchmark said:

Yes, I correctly pointed out all of that in last season's outlook, complete with schematics, but again....totally screwed the pooch on what impact it would have.

Frustratingly educational.

Knowing what I know now, I probably would have used 1957-58 and 2009-10 as the best analogs for 2023-24. 1957-58 had the best ENSO match to 2023-24 (I mean the 5 year lead up matches perfectly: 1952-54 disjointed el nino = 2018-20 disjointed el nino and 1954-57 triple la nina = 2020-23 triple la nina). 2009-10 had the best RONI match to 2023-24. Both 1957-58 and 2009-10 were very snowy winters in the PHL area, so I probably would have predicted 2023-24 to be a very snowy winter, which didn't pan out.

[40/70 Benchmark]

1 hour ago, PhiEaglesfan712 said:

Knowing what I know now, I probably would have used 1957-58 and 2009-10 as the best analogs for 2023-24. 1957-58 had the best ENSO match to 2023-24 (I mean the 5 year lead up matches perfectly: 1952-54 disjointed el nino = 2018-20 disjointed el nino and 1954-57 triple la nina = 2020-23 triple la nina). 2009-10 had the best RONI match to 2023-24. Both 1957-58 and 2009-10 were very snowy winters in the PHL area, so I probably would have predicted 2023-24 to be a very snowy winter, which didn't pan out.

What I didn't understand was that last year, the weaker coupling of El Nino with the atmosphere was merely a reflection of the very prevalent cool ENSO background, which was/is evident by the west PAC being ablaze. This made the positioning of the el Nino (Modoki scale) largely irrelevent because the forcing was pinned to the MC, regardless. However, in years like 1965 and 1957 and 2009, since we didn't have the west PAC inferno, the weaker coupling of el Nino to the atmosphere was indeed indicative of a weaker warm ENSO walker cell, which truely was more redolent of a modoki and thus favorable for NE cold and snow.

What it comes down to is we must not only determine the intensity of El Nino, but if it is weaker, WHY is it weaker.....figure out which other players in the atmosphere are competing with it, how much proxy they will have and how the assertion of said factors will manifest in the configuration of the overall pattern around the hemisphere. The other major players on the field in 2009 and 1957 were an exceptionably favorable extra tropical Pacific and arctic/atlantic. 1965 featured a very favorable arctic/atlantic, which was more helpful to NE cold/snow interests in the face of a hostile extra tropicl Pacific without the immense degree of west PAC warmth. 

We have been far too reductive in our analysis of ENSO and the changing climate is exposing that more than ever before. Bluewave has been ahead of his time amongst mainstream meteorological circles.

[Terpeast]

52 minutes ago, PhiEaglesfan712 said:

Knowing what I know now, I probably would have used 1957-58 and 2009-10 as the best analogs for 2023-24. 1957-58 had the best ENSO match to 2023-24 (I mean the 5 year lead up matches perfectly: 1952-54 disjointed el nino = 2018-20 disjointed el nino and 1954-57 triple la nina = 2020-23 triple la nina). 2009-10 had the best RONI match to 2023-24. Both 1957-58 and 2009-10 were very snowy winters in the PHL area, so I probably would have predicted 2023-24 to be a very snowy winter, which didn't pan out.

It would probably have turned out to be a snowy winter too had the Japan marine heat wave abated enough and the PDO more neutral or on the positive side.

While it was our best chance for a snowy winter in years, there was indeed a 1972-73 flavor given how negative the PDO was and the ENSO-induced SE trough was more tilted to the west giving California all these atmospheric rivers and historic mountain snows.

I noticed 72-73 and mentioned it in my winter outlook, but didn’t want to emphasize it too much because well… that would’ve been a disaster. At least we avoided a total shutout thanks to that January -EPO block. 

[40/70 Benchmark]

21 minutes ago, Terpeast said:

It would probably have turned out to be a snowy winter too had the Japan marine heat wave abated enough and the PDO more neutral or on the positive side.

While it was our best chance for a snowy winter in years, there was indeed a 1972-73 flavor given how negative the PDO was and the ENSO-induced SE trough was more tilted to the west giving California all these atmospheric rivers and historic mountain snows.

I noticed 72-73 and mentioned it in my winter outlook, but didn’t want to emphasize it too much because well… that would’ve been a disaster. At least we avoided a total shutout thanks to that January -EPO block. 

Absolutely. This is why the lower MEI and RONI relative to the ONI were actually symbolic of a fatal hemispheric issue for NE winter enthusiasts last season. 

[GaWx]

3 hours ago, bluewave said:

It’s interesting how weak the -SOI and -EQSOI were for such a strong El Niño. This also lead to the weaker WWBs. Notice how much lower both SOIs were during the 15-16 and 97-98 events. My guess this is a result of the much stronger WPAC warm pool. 

Based on RONI peak, 2023-4 wasn’t even close to 15-6 and 97-8 and thus wasn’t that strong of an El Niño:

23-4: +1.49 moderate/strong border

15-6: +2.39 well into super

97-8: +2.36 well into super

 

 Based on RONI, 23-4 was close to 2009-10, 2002-3, and 1986-7:

https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

[snowman19]

[snowman19]

[michsnowfreak]

5 hours ago, 40/70 Benchmark said:

I will take an active N branch over a strong STJ any day of the week in my neck of the woods. I undersrand that its different not too far to my south and that temps are still likely to be an issue this year.

Me too. Great Lakes repeatedly are showing up in the AN precip category and not as warm as further east, which is usually a recipe for good snows.

[40/70 Benchmark]

7 hours ago, GaWx said:

Based on RONI peak, 2023-4 wasn’t even close to 15-6 and 97-8 and thus wasn’t that strong of an El Niño:

23-4: +1.49 moderate/strong border

15-6: +2.39 well into super

97-8: +2.36 well into super

 

 Based on RONI, 23-4 was close to 2009-10, 2002-3, and 1986-7:

https://www.cpc.ncep.noaa.gov/data/indices/RONI.ascii.txt

Those years arrive at those RONI values in a far different manner, though. 

 

[GaWx]

48 minutes ago, 40/70 Benchmark said:

Those years arrive at those RONI values in a far different manner, though. 

 

 I’m saying that regarding peak strength 2023-4 and despite similar ONI, I don’t think of 2023-4 as comparable to 2015-6 and 1997-8 due to a much cooler RONI. Therefore, I wouldn’t expect the 2023-4 SOIs to be anywhere near as negative as those for the other two. The other two dipped to as low as -20s for monthly SOI vs 2023-4 dipping to only the -10s. Thus I’m not surprised.

 When comparing to other Ninos of similar strength, I prefer to look at RONI. So, I looked back to 1950 to see what other El Niños had a RONI peak similar to 2023-4’s +1.49 peak. That’s when I found these with similar peak:

2009-10: +1.57

2002-3: +1.46

1994-5: +1.44 (I inadvertently left this out)

1986-7: +1.54

  That’s all I meant by them being “close”. Close in RONI strength. I’m not saying they were necessarily close in any other way except for lowest SOI months as these 4 had lowest months in the -10s just like 2023-4, which makes sense from a RONI based strength point of view.

 

[Terpeast]

2 hours ago, GaWx said:

 I’m saying that regarding peak strength 2023-4 and despite similar ONI, I don’t think of 2023-4 as comparable to 2015-6 and 1997-8 due to a much cooler RONI. Therefore, I wouldn’t expect the 2023-4 SOIs to be anywhere near as negative as those for the other two. The other two dipped to as low as -20s for monthly SOI vs 2023-4 dipping to only the -10s. Thus I’m not surprised.

 When comparing to other Ninos of similar strength, I prefer to look at RONI. So, I looked back to 1950 to see what other El Niños had a RONI peak similar to 2023-4’s +1.49 peak. That’s when I found these with similar peak:

2009-10: +1.57

2002-3: +1.46

1994-5: +1.44 (I inadvertently left this out)

1986-7: +1.54

  That’s all I meant by them being “close”. Close in RONI strength. I’m not saying they were necessarily close in any other way except for lowest SOI months as these 4 had lowest months in the -10s just like 2023-4, which makes sense from a RONI based strength point of view.

 

I am starting to think that the difference between ONI and RONI should be a factor in and of itself when thinking about seasonal outlooks. I don’t think that we had a 0.6 difference in ONI vs RONI for 86-87 and 09-10…

[snowman19]

Just out of curiosity for comparison to this year, (obviously current anomalies like the ++AMO, record low arctic sea ice, AGW and extreme WPAC/Atlantic warm pools are not going to be able to be found). But if someone can lookup any years that were the following: La Niña (non east-based events), strong -PDO, -PMM, +QBO, -IOD, +AMO, MJO 4-6 dominant, high solar/high geomag. Also, if any years had all those factors and were also volcanic. Thank you

[PhiEaglesfan712]

31 minutes ago, Terpeast said:

I am starting to think that the difference between ONI and RONI should be a factor in and of itself when thinking about seasonal outlooks. I don’t think that we had a 0.6 difference in ONI vs RONI for 86-87 and 09-10…

If I remember correctly, the RONI and ONI were almost in line in 2009-10. The 86-87 one was weird. The RONI had a double peak, while the ONI peaked in the summer.

 JJA 1986   RONI: 0.25 ONI: 0.3
 JAS 1986   RONI: 0.55 ONI: 0.6
 ASO 1986   RONI: 0.87 ONI: 0.9
 SON 1986   RONI: 1.12 ONI: 1.1
 OND 1986   RONI: 1.35 ONI: 1.2
 NDJ 1986   RONI: 1.49 ONI: 1.2
 DJF 1987   RONI: 1.54 ONI: 1.2 - First RONI (winter) peak
 JFM 1987   RONI: 1.43 ONI: 1.2
 FMA 1987   RONI: 1.17 ONI: 1.1
 MAM 1987   RONI: 0.87 ONI: 1.0
 AMJ 1987   RONI: 0.77 ONI: 1.1
 MJJ 1987   RONI: 0.94 ONI: 1.3
 JJA 1987   RONI: 1.23 ONI: 1.6
 JAS 1987   RONI: 1.46 ONI: 1.7 - Second RONI (summer) peak
 ASO 1987   RONI: 1.43 ONI: 1.8 - ONI peak
 SON 1987   RONI: 1.24 ONI: 1.7 
 OND 1987   RONI: 1.02 ONI: 1.4
 NDJ 1987   RONI: 0.93 ONI: 1.1
 DJF 1988   RONI: 0.65 ONI: 0.7
 JFM 1988   RONI: 0.30 ONI: 0.3

So, the RONI began and ended the el nino at roughly the same. In between, the RONI was ahead by as much as .34 over the ONI in the winter. This would flip flop during the year, as the ONI ended up ahead as much as .46 over the RONI by the fall.

Of course, when this el nino dissipated, it transitioned into a strong la nina in 1988-89 (just as the 2009-10 strong el nino transitioned into the 2010-11 strong la nina).

[Stormchaserchuck1]

4 hours ago, snowman19 said:

Just out of curiosity for comparison to this year, (obviously current anomalies like the ++AMO, record low arctic sea ice, AGW and extreme WPAC/Atlantic warm pools are not going to be able to be found). But if someone can lookup any years that were the following: La Niña (non east-based events), strong -PDO, -PMM, +QBO, -IOD, +AMO, MJO 4-6 dominant, high solar/high geomag. Also, if any years had all those factors and were also volcanic. Thank you

99-00 is probably your best match, but you aren't going to find anything that fits all of that. A lot of recent analogs are closer to your guidelines than older ones..