2024-2025 La Nina

[snowman19]

12 minutes ago, Rtd208 said:

Update on La Niña from DT (WxRisk). 

DT lol The guy who wishes cancer on people and hasn’t gotten a winter forecast right in the last 10 years, then completely jumps ship and bails on his own forecast in the middle of winter and visciously attacks anyone who disagrees with him. He’s a reprehensible person and real lousy at winter forecasts

[GaWx]

2 hours ago, Rtd208 said:

Update on La Niña from DT (WxRisk). 

June OND Euro prog for ONI/actual ONI/RONI

’23 +2.04/+1.92/+1.49

’22 -0.25/-0.92/-1.03

’21 -0.30/-0.98/-1.21

’20 -0.49/-1.27/-1.52

’19 +0.67/+0.51/+0.24

‘18 +1.1/+0.9/+0.8

’17 +0.4/-0.8/-1.1

‘16 -0.4/-0.7/-1.1

’15 +2.4/+2.6/+2.3

’14 +1.3/+0.6/+0.5

’13 +0.6/-0.2/-0.2

‘12 +1.2/+0.1/-0.1

*’11 +0.1/-1.0/-0.9

*’10 -1.0/-1.6/-1.7

*’09 +1.3/+1.0/+0.9

*’08 +0.3/-0.4/-0.4

*’07 -1.1/-1.3/-1.3

AVG +0.5/-0.1/-0.3

Analysis:
- The June Euro avg miss for ONI was 0.6 too warm.

- It missed too warm 16 of 17!

- When there was no El Niño, it missed on avg too warm by 0.7.

- When there was El Niño, it missed on avg only by +0.2.

- Out of 17, biggest misses were +1.2 (‘17) and +1.1 (‘12 and ‘11)

- June Euro is progging SON/OND at -0.3 (vs -0.5 in May).

- Based on avg miss of +0.7 for non-Nino, bias corrected June Euro prog for OND ONI is -1.0. Based on largest miss of +1.2, OND ONI could end up as low as -1.5. Based on smallest miss for non-Nino of +0.2, OND ONI could end up as high as -0.5.

- Based on the assumption that RONI, which in MAM was 0.64 cooler than ONI and has been at least 0.4 cooler than ONI for a year, will be at least 0.4 cooler than ONI in OND, this implies that bc June Euro OND RONI prog is for -1.4 or cooler.

*SON instead of OND (OND N/A)

 

Sources:

Euro progs https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-sst_table

 

Actual ONI: https://www.cpc.ncep.noaa.gov/data/indices/oni.ascii.txt

 

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

[raindancewx]

Nino 3.4 was 28.25C in May. The years coming off an El Nino winter that are with 0.2C of that (28.05-28.45C) are:

1958, 1969 - El Nino

2005, 2016 - La Nina conditions observed briefly

1980, 1983, 1987, 1998, 2019 are all following El Nino (ish) but either a bit too warm/cool or don't go to La Ninas.

1980, 1983, 1998, 2005, 2010, 2016 look ~correct as a blend for estimating the La Nina strength at the moment.

26.32 + 26.01 + 25.08 + 25.80 + 25.22 + 26.3 --> 25.78C in DJF

Keep in mind, none of Dec-Feb periods in 3.4 have finished below 25.5C since 2010-11. The 2020-21 La Nina had an Oct-Dec with all three months colder than 25.5C, but it faded fast.

I expect 25.8 - 26.2 for DJF, with a colder peak in Oct-Dec or Nov-Jan, but we'll see.

[George001]

5 hours ago, snowman19 said:

DT lol The guy who wishes cancer on people and hasn’t gotten a winter forecast right in the last 10 years, then completely jumps ship and bails on his own forecast in the middle of winter and visciously attacks anyone who disagrees with him. He’s a reprehensible person and real lousy at winter forecasts

Yeah I’m not a DT fan. I am of the opinion that he is calling off the Nina way too early, the European model has a warm bias (roughly .6 ONI based on GAwx’s post). So it will overestimate the strength of Nino’s and underestimate the strength of Nina’s.

[George001]

3 hours ago, GaWx said:

June OND Euro prog for ONI/actual ONI/RONI

’23 +2.04/+1.92/+1.49

’22 -0.25/-0.92/-1.03

’21 -0.30/-0.98/-1.21

’20 -0.49/-1.27/-1.52

’19 +0.67/+0.51/+0.24

‘18 +1.1/+0.9/+0.8

’17 +0.4/-0.8/-1.1

‘16 -0.4/-0.7/-1.1

’15 +2.4/+2.6/+2.3

’14 +1.3/+0.6/+0.5

’13 +0.6/-0.2/-0.2

‘12 +1.2/+0.1/-0.1

*’11 +0.1/-1.0/-0.9

*’10 -1.0/-1.6/-1.7

*’09 +1.3/+1.0/+0.9

*’08 +0.3/-0.4/-0.4

*’07 -1.1/-1.3/-1.3

AVG +0.5/-0.1/-0.3

Analysis:
- The June Euro avg miss for ONI was 0.6 too warm.

- It missed too warm 16 of 17!

- When there was no El Niño, it missed on avg too warm by 0.7.

- When there was El Niño, it missed on avg only by +0.2.

- Out of 17, biggest misses were +1.2 (‘17) and +1.1 (‘12 and ‘11)

- June Euro is progging SON/OND at -0.3 (vs -0.5 in May).

- Based on avg miss of +0.7 for non-Nino, bias corrected June Euro prog for OND ONI is -1.0. Based on largest miss of +1.2, OND ONI could end up as low as -1.5. Based on smallest miss for non-Nino of +0.2, OND ONI could end up as high as -0.5.

- Based on the assumption that RONI, which in MAM was 0.64 cooler than ONI and has been at least 0.4 cooler than ONI for a year, will be at least 0.4 cooler than ONI in OND, this implies that bc June Euro OND RONI prog is for -1.4 or cooler.

*SON instead of OND (OND N/A)

 

Sources:

Euro progs https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-sst_table

 

Actual ONI: https://www.cpc.ncep.noaa.gov/data/indices/oni.ascii.txt

 

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

Interesting, so if you adjust for the Euros +0.7 ONI warm bias for non nino winters, that would bump the ONI from roughly -0.3 to -1, so the difference between cold neutral and a moderate Niña. Especially for DTs forecasting area (lower Mid Atlantic), I would assume the difference between a cold neutral and moderate Niña would be somewhat significant

[Terpeast]

4 hours ago, George001 said:

Interesting, so if you adjust for the Euros +0.7 ONI warm bias for non nino winters, that would bump the ONI from roughly -0.3 to -1, so the difference between cold neutral and a moderate Niña. Especially for DTs forecasting area (lower Mid Atlantic), I would assume the difference between a cold neutral and moderate Niña would be somewhat significant

Honestly, out of all the neutral winters since 1999, most were pretty bad except for 2013-14. The worst ones was when we had a -pdo background state. So for the MA, I don’t think it’ll make much difference whether cold neutral or La Nina. It’ll be a warm -pdo winter either way.

[snowman19]

[bluewave]

On 6/7/2024 at 1:00 PM, 40/70 Benchmark said:

I agree we are in a "rut" period akin to the 80's, only adjusted warmer due to CC....it's also a different type of "rut", since that was a +PDO period....often those winters were done in by a lack of high latitude blocking, but this period has been marked by an extra tropical Pacific regime so hostile that it has largely negated any episodes of blocking, which has become easier to do given the warmer climate.

Yeah, the 2022-2023 winter had the lowest snowfall on record by a wide margin in NYC and BOS for such a strong December -AO pattern. 
 

December -AO lower than -2.000 and seasonal snowfall

2022…..-2.719…….NYC…..2.3”…..BOS….12.4”

2010..…-2.631…….NYC…..61.9”….BOS….81.0”

2009….-3.413…….NYC…..51.4”….BOS….35.7”

2005….-2.104……..NYC….40.0”….BOS…..39.9”

2000….-2.354…….NYC…..35.0”….BOS….45.9”

1995….-2.127……..NYC……75.6”….BOS…107.6”

1976…..-2.074……NYC…..24.5”…..BOS….58.0”

[snowman19]

10 hours ago, Terpeast said:

Honestly, out of all the neutral winters since 1999, most were pretty bad except for 2013-14. The worst ones was when we had a -pdo background state. So for the MA, I don’t think it’ll make much difference whether cold neutral or La Nina. It’ll be a warm -pdo winter either way.

Which is exactly why DT saying that a neutral winter with a -PDO along with the other background factors we have this year would be good for winter is truly perplexing

[so_whats_happening]

5 hours ago, snowman19 said:

 

Yea you typically dont have a cooling in the EPAC and the Atlantic. I wonder if this has to do with the ever resilient warmth around the maritime throwing things off a bit. 

From looking at some of the past Nina/Nino episodes typically you have a warming EPAC with a cooling WPAC and Atlantic and vice versa when entering Nina state. Since the WPAC just has not cooled maybe we are starting to see a different setup take place? As always a bit too early to tell what will come about.

[snowman19]

16 minutes ago, so_whats_happening said:

Yea you typically dont have a cooling in the EPAC and the Atlantic. I wonder if this has to do with the ever resilient warmth around the maritime throwing things off a bit. 

From looking at some of the past Nina/Nino episodes typically you have a warming EPAC with a cooling WPAC and Atlantic and vice versa when entering Nina state. Since the WPAC just has not cooled maybe we are starting to see a different setup take place? As always a bit too early to tell what will come about.

That relentless, resilient heat wave in the WPAC around the maritime tells me at this real early stage that we are very likely to see MJO waves favoring phases 4-7 once again this coming winter, especially given the developing Niña. Wash, rinse, repeat

[40/70 Benchmark]

3 hours ago, snowman19 said:

Which is exactly why DT saying that a neutral winter with a -PDO along with the other background factors we have this year would be good for winter is truly perplexing

I like DT as a medium range forecaster, but I think he, like most mets, leaves much to be desired on a seasonal level. One thing I have noticed with him is that he tends to employ a very reductive train of logic....ie "neutral ENSO as opposed to La Niña=better winter".  I am with you on rolling my eyes on that take...not to mention that I think its premature and highly presumptive for anyone to be touting ENSO neutral at this stage..

[snowman19]

34 minutes ago, 40/70 Benchmark said:

I like DT as a medium range forecaster, but I think he, like most mets, leaves much to be desired on a seasonal level. One thing I have noticed with him is that he tends to employ a very reductive train of logic....ie "neutral ENSO as opposed to La Niña=better winter".  I am with you on rolling my eyes on that take...not to mention that I think its premature and highly presumptive for anyone to be touting ENSO neutral at this stage..

Neutral/La Nada is extremely unlikely this year, besides the point though. That aside, when was the last time, in the last 10 years that DT hasn’t put out a cold and snowy in the East forecast going into the season, only to do a complete 180 and retract it mid-winter, say it was wrong, then go on to attack and lambaste anyone who disagrees with with him, calling them idiots, morons, cursing at them like a sailor, wishing diseases on them and going on profanity filled rants? 

[mitchnick]

1 minute ago, snowman19 said:

Neutral/La Nada is extremely unlikely this year, besides the point though. That aside, when was the last time, in the last 10 years that DT hasn’t put out a cold and snowy in the East forecast going into the season, only to do a complete 180 and retract it mid-winter, then go on to attack and lambaste anyone who disagrees with with him, calling them idiots, morons, cursing at them like a sailor, wishing diseases on them and going on profanity filled rants? 

Personally, none of that bothers me about DT. Subtract from it a lot of it intended for the shock humor value, and there's little left imho.

But I  do think he relies on the Euro more than one should in light of the gains in other modeling. It just ain't what it used to be relative to other guidance, at least when it comes to winter forecasting in the MA imho. But it can still score a coup or 2 which forces you to give it more weight than you should, again imho.

 

[Stormchaserchuck1]

I do think we can almost rule Strong La Nina out. 

Subsurface though continues to favor possibly a Moderate La Nina, at the very least Weak. There is major global ocean warming this year, and I was wondering if that would spill over into ENSO.. it looks like it might. MEI/RONI might be a better gauge for effects this year, although it's hard to separate out the PDO.

[Stormchaserchuck1]

7 hours ago, bluewave said:

Yeah, the 2022-2023 winter had the lowest snowfall on record by a wide margin in NYC and BOS for such a strong December -AO pattern. 

March 2023 too, we had a -NAO and -EPO for some time. It amounted to nothing.  I think later in the -PNA decadal phase a SE ridge becomes more constant vs early in the cycle. That's something I think we could batteling again this Winter, even if the NAO goes negative. 

[GaWx]

21 minutes ago, Stormchaserchuck1 said:

I do think we can almost rule Strong La Nina out. 

Subsurface though continues to favor possibly a Moderate La Nina, at the very least Weak. There is major ocean warming this year, and I was wondering if that would spill over into ENSO.. it looks like it might. MEI/RONI might be a better gauge for effects this year, although it's hard to separate out the PDO. 

 If you’re referring to ONI, I’d largely agree as of now at least. I count -1.5- low point as strong. But in terms of RONI, the data I’ve analyzed suggests a -1.5- low point is still a good possibility, especially when considering the bc June Euro implied prog of -1.4 or lower for RONI per my analysis above.

[GaWx]

On 6/7/2024 at 2:44 PM, GaWx said:

Wow, what a two day rise of the WCS PDO! It rose ~0.6, the fastest two day increase on this chart.  But this is likely just a dead-cat bounce reaction to the prior two week very steep drop. Even after this bounce, it is still very low (at -2.26) and the corresponding NOAA PDA is probably still down at ~-3 to -3.5.

 

There have been another two days of steep rises with the latest WCS PDO all the way up to -1.70. It was ~-3.00 just one week ago! But it still looks like merely a big deadcat bounce after the prior plunge. The NOAA PDO is likely still down near -2.5 to -2.75. 

[raindancewx]

Just for future visual reference: We remain very far behind the 2022-23 La Nina so far since we started from a warmer point last winter. The 2020-21 La Nina isn't super far off but we seem a bit ahead of it.

[snowman19]

14 hours ago, GaWx said:

 If you’re referring to ONI, I’d largely agree as of now at least. I count -1.5- low point as strong. But in terms of RONI, the data I’ve analyzed suggests a -1.5- low point is still a good possibility, especially when considering the bc June Euro implied prog of -1.4 or lower for RONI per my analysis above.

Agree. I can absolutely see the RONI going strong while the ONI is only moderate with this event

[snowman19]

14 hours ago, Stormchaserchuck1 said:

March 2023 too, we had a -NAO and -EPO for some time. It amounted to nothing.  I think later in the -PNA decadal phase a SE ridge becomes more constant vs early in the cycle. That's something I think we could batteling again this Winter, even if the NAO goes negative. 

While the strong -PDO and accompanying -PNA cycle is definitely playing a major role, I also think the ridiculously positive AMO is magnifying and feeding back into the SE ridge. The “stuck” MJO 4-7 may also be playing a role too

[PhiEaglesfan712]

15 hours ago, Stormchaserchuck1 said:

March 2023 too, we had a -NAO and -EPO for some time. It amounted to nothing.  I think later in the -PNA decadal phase a SE ridge becomes more constant vs early in the cycle. That's something I think we could batteling again this Winter, even if the NAO goes negative. 

It was just too late in the season. However, we did get a nice blocking pattern in June (who could forget about the smoke out). June 2023 was the coldest June since 1985.

Would have been nice if we had -NAO and -EPO in late December or even early February. 

[GaWx]

June 8th BoM updated run: SON ONI +0.07. The prior run (2 weeks ago) had -0.10. So, it rose slightly. But keep in mind it was the worst last year with the 6/3/23 run having +2.7 for SON and the 6/17/23 run having +3.0 for SON. Actual SON ONI was only +1.8. So, these runs were +0.9 and +1.2 too warm, respectively. Thus, if we cool their +0.07 SON prog by 0.9 to 1.2, we get -0.8 to -1.1 for a bc ONI prog. And then this implied bc RONI prog would be -1.2 to -1.5 or cooler. Thus, the bc implied 6/8/24 BoM RONI prog for SON is for a moderate to strong La Niña.

[roardog]

3 minutes ago, GaWx said:

June 8th BoM updated run: SON ONI +0.07. The prior run (2 weeks ago) had -0.10. So, it rose slightly. But keep in mind it was the worst last year with the 6/3/23 run having +2.7 for SON and the 6/17/23 run having +3.0 for SON. Actual SON ONI was only +1.8. So, these runs were +0.9 and +1.2 too warm, respectively. Thus, if we cool their +0.07 SON prog by 0.9 to 1.2, we get -0.8 to -1.1 for its bc ONI prog. And then implied bc RONI prog would be -1.2 to -1.5  or cooler.

Might as well stop running the model at this point. lol

[GaWx]

15 minutes ago, roardog said:

Might as well stop running the model at this point. lol

Actually though, with a fairly predictable bias correction, it can still be useful for trend purposes. Like if the next run were to be, say, +0.5 or -0.5, that would tell me the true trend of the progged ONI/RONI is probably warmer or cooler.

[GaWx]

The UKMET and JMA did best last year. The updated JMA (June run) for autumn ONI is very similar to the May run with a very slightly warmer prog that is still borderline weak Nino/cold neutral for ONI near -0.5 (implying RONI near borderline weak/moderate La Niña)(no significant bc needed since did well last year and longterm bias fairly small):

 

[GaWx]

18 hours ago, GaWx said:

There have been another two days of steep rises with the latest WCS PDO all the way up to -1.70. It was ~-3.00 just one week ago! But it still looks like merely a big deadcat bounce after the prior plunge. The NOAA PDO is likely still down near -2.5 to -2.75. 

The latest daily WCS PDO update continues the rapid bounce back to -1.47 (implying NOAA PDO has probably bounced back up to ~~-2.5) after being ~-3 (NOAA ~~-4) just eight days earlier:

[PhiEaglesfan712]

2016-17 wasn't enso neutral. It was a weak la nina. We had the 5 trimonthlys of -0.5 on the NOAA ONI, and got down to -0.7 on both the Eric Webb Ensemble and NOAA ONI. We even got down to -1.09 on the RONI. 

2014-15 has a better argument for enso neutral than 2016-17. That one had the same strength as 2016-17 on the ONI, and only 0.58 on the RONI.

So, the only ones that can be considered enso neutral are 2001-02, 2003-04, 2012-13, 2013-14, and maybe 2019-20 (an ENSO neutral on the RONI, but you could argue a continuation of a weak el nino on the ONI that began in 2018).

[Terpeast]

5 minutes ago, PhiEaglesfan712 said:

2016-17 wasn't enso neutral. It was a weak la nina. We had the 5 trimonthlys of -0.5 on the NOAA ONI, and got down to -0.7 on both the Eric Webb Ensemble and NOAA ONI. We even got down to -1.09 on the RONI. 

2014-15 has a better argument for enso neutral than 2016-17. That one had the same strength as 2016-17 on the ONI, and only 0.58 on the RONI.

So, the only ones that can be considered enso neutral are 2001-02, 2003-04, 2012-13, 2013-14, and maybe 2019-20 (an ENSO neutral on the RONI, but you could argue a continuation of a weak el nino on the ONI that began in 2018).

Good points. I would think that if we’re going be on the cool ENSO side of neutral, 2016-17 would be a better analog match than 2014-15 since the latter was in a +pdo regime whereas we’ve been in -pdo since the 2015-16 super nino. 

Despite the +1.5 rise in the PDO, still think we’ll stay negative through this year and next unless it actually breaks through into positive territory, which is remotely possible if that warm blob migrates eastward to the NA west coast. 

[snowman19]

40 minutes ago, PhiEaglesfan712 said:

2016-17 wasn't enso neutral. It was a weak la nina. We had the 5 trimonthlys of -0.5 on the NOAA ONI, and got down to -0.7 on both the Eric Webb Ensemble and NOAA ONI. We even got down to -1.09 on the RONI. 

2014-15 has a better argument for enso neutral than 2016-17. That one had the same strength as 2016-17 on the ONI, and only 0.58 on the RONI.

So, the only ones that can be considered enso neutral are 2001-02, 2003-04, 2012-13, 2013-14, and maybe 2019-20 (an ENSO neutral on the RONI, but you could argue a continuation of a weak el nino on the ONI that began in 2018).

The 14-15 winter was ++PDO driven. It wasn’t just positive, it was record positive, it fed back and lead to the relentless -EPO/+PNA/-WPO that winter. Totally PAC driven winter