2025-2026 ENSO

[Typhoon Tip]

17 hours ago, bluewave said:

The tendency has been more +PNA in July since 2013 with a strong 500 mb ridge in the East. Prior to this recent decade we usually had more of a -PNA when there was a strong ridge in the East. Have also been seeing more ridging in the East during the winters in the 2020s with + PNAs than we used to in the past. 
 

 

It's because the mean latitude of the westerlies/gradient is shifting N associated with CC.   A shift that's doing so on the scale of life time, not mere seasons...  So we don't really observe it year to year, but 15 or 20 years goes by and the jet axis are N of where they were... And idiosyncratic aspects emerge like like that where positive height anomalies cushion under the nadirs of the planetary wave spacings.   I've noticed this more and more so over the years... where the bottom of the L/W axis appear to be 'compressing a balloon' at time.

[bluewave]

23 minutes ago, Typhoon Tip said:

It's because the mean latitude of the westerlies/gradient is shifting N associated with CC.   A shift that's doing so on the scale of life time, not mere seasons...  So we don't really observe it year to year, but 15 or 20 years goes by and the jet axis are N of where they were... and idiosyncratic aspects emerge like positive heights under the nadirs of the planetary wave spacings.   I've noticed this more and more so over the years... where the bottom of the L/W axis appear to be 'compressing a balloon' 

Yeah, I was just discussing this shift across the seasons a few days ago. The mid-latitude ridge from Japan across the U.S. to Europe has been a new dominant player since the 18-19.

This has lessened the influence of the usual higher latitude teleconnections like the WPO, EPO,PNA,AO, and NAO. So we have been getting strong Southeast ridge  patterns even with -EPO,+PNA, -WPO,-AO, and -NAO. 

It essentially forces the winter storm track further north through the Great Lakes. So in February we had our first -5 -AO result in a strong cutter leading to the record snows in Toronto and Montreal instead of the typical KU storm track. 

We also saw the -EPO +PNA merger back in December with the mid-latitude ridge leading to the 4th warmest December on record in the CONUS with what used to be colder teleconnections when this mid-latitude ridge was absent in the past. 

During January the 850 mb cold pool was at the smallest on record. So what used to be very cold telconnections in the past were much milder than past instances with similar higher latitude teleconnections.

I also posted the other day on how we just set a new all-time July record 500 mb height record from Japan to Europe along 40N to 50N. This is why the Southeast ridge was the strongest on record for July even with a strong -EPO and +PNA block on the Pacific side.

Past instances of such a strong ridge in the East had more of a -PNA and weaker blocking near Alaska than we have been seeing over the last decade.

So this new mid-latitude ridge is becoming its own teleconnection leading to new combinations of 500mb patterns that we used to get before 18-19. 

 

 

[40/70 Benchmark]

It will be interesting to see how strong the SE ridge is when we manage to get a robust -AO/NAO/EPO/WPO, +PNA combo. My guess is there won't be one.

[Stormchaserchuck1]

January on the Euro seasonal looks like -EPO/-AO

[40/70 Benchmark]

1 hour ago, Stormchaserchuck1 said:

January on the Euro seasonal looks like -EPO/-AO

I understand the limitations of these data at this range, but I don't disagree.

[snowman19]

Yeah, I was just discussing this shift across the seasons a few days ago. The mid-latitude ridge from Japan across the U.S. to Europe has been a new dominant player since the 18-19.
This has lessened the influence of the usual higher latitude teleconnections like the WPO, EPO,PNA,AO, and NAO. So we have been getting strong Southeast ridge  patterns even with -EPO,+PNA, -WPO,-AO, and -NAO. 
It essentially forces the winter storm track further north through the Great Lakes. So in February we had our first -5 -AO result in a strong cutter leading to the record snows in Toronto and Montreal instead of the typical KU storm track. 
We also saw the -EPO +PNA merger back in December with the mid-latitude ridge leading to the 4th warmest December on record in the CONUS with what used to be colder teleconnections when this mid-latitude ridge was absent in the past. 
During January the 850 mb cold pool was at the smallest on record. So what used to be very cold telconnections in the past were much milder than past instances with similar higher latitude teleconnections.
I also posted the other day on how we just set a new all-time July record 500 mb height record from Japan to Europe along 40N to 50N. This is why the Southeast ridge was the strongest on record for July even with a strong -EPO and +PNA block on the Pacific side.
Past instances of such a strong ridge in the East had more of a -PNA and weaker blocking near Alaska than we have been seeing over the last decade.
So this new mid-latitude ridge is becoming its own teleconnection leading to new combinations of 500mb patterns that we used to get before 18-19. 
 

 

Low frequency forcing/MJO 5-6-7 still in the same familiar area (around Maritime Continent) as we go further into this month. The Niña background state remains

[CAPE]

2 hours ago, Stormchaserchuck1 said:

January on the Euro seasonal looks like -EPO/-AO

Also hinting at a ridge over GL, but it would need to be a bit further south. With a -EPO and TPV in that position, there would be plenty of NS energy dropping southward. How far south and how it interacts with any potential southern stream waves might be interesting. Overall that depiction looks quite Nina-ish, but with the NE Pac ridge in a more favorable position/orientation for cold in the central and perhaps eastern US, especially NE.

[Typhoon Tip]

4 hours ago, 40/70 Benchmark said:

It will be interesting to see how strong the SE ridge is when we manage to get a robust -AO/NAO/EPO/WPO, +PNA combo. My guess is there won't be one.

It'd still be there; the eye isn't drawn to it because the trough may appear foreboding.  But, it's presence is betrayed by the very fast flow around the trough.  Speed anomalies is what you'd look for.

It takes some "physics intuition" if you will, but can be shown mathematically ... The HC doesn't really "deflate" or go away in the winter.  What happens is that the geometry of it gets converted to mechanical power in the form of wind - the balanced geostrophic wind velocity in the means.  As the hgt field compresses south, the winds increase in direct proportion. The more the increase, the more compression took place ( steeper gradient).  

 

 

[Typhoon Tip]

5 hours ago, bluewave said:

Yeah, I was just discussing this shift across the seasons a few days ago. The mid-latitude ridge from Japan across the U.S. to Europe has been a new dominant player since the 18-19.

This has lessened the influence of the usual higher latitude teleconnections like the WPO, EPO,PNA,AO, and NAO. So we have been getting strong Southeast ridge  patterns even with -EPO,+PNA, -WPO,-AO, and -NAO. 

It essentially forces the winter storm track further north through the Great Lakes. So in February we had our first -5 -AO result in a strong cutter leading to the record snows in Toronto and Montreal instead of the typical KU storm track. 

We also saw the -EPO +PNA merger back in December with the mid-latitude ridge leading to the 4th warmest December on record in the CONUS with what used to be colder teleconnections when this mid-latitude ridge was absent in the past. 

During January the 850 mb cold pool was at the smallest on record. So what used to be very cold telconnections in the past were much milder than past instances with similar higher latitude teleconnections.

I also posted the other day on how we just set a new all-time July record 500 mb height record from Japan to Europe along 40N to 50N. This is why the Southeast ridge was the strongest on record for July even with a strong -EPO and +PNA block on the Pacific side.

Past instances of such a strong ridge in the East had more of a -PNA and weaker blocking near Alaska than we have been seeing over the last decade.

So this new mid-latitude ridge is becoming its own teleconnection leading to new combinations of 500mb patterns that we used to get before 18-19. 

 

 

Ray and I began noticing the atmospheric teleconnector correlation stressing over the last 10 years actually.  It's an interesting aspect. 

I haven't dug into the matter at the granularity of that, but have noticed it and what you're saying isn't far off from what Ray and I have discussed in the past.   From what I'm anecdotally observing ...  it's not so much that a -EPOs or +PNAs ...-NAOs don't correlate.  It's more about the lack of resonance feed-backs locking in patterns long enough to give the correlations a time to manifest. The ephemeral atmosphere syndrome ... they abandon the storms ... cold and hot looks.

That heat wave near the end of June was clipped for length by higher frequency for example.  

[bluewave]

1 hour ago, Typhoon Tip said:

Ray and I began noticing the atmospheric teleconnector correlation stressing over the last 10 years actually.  It's an interesting aspect. 

I haven't dug into the matter at the granularity of that, but have noticed it and what you're saying isn't far off from what Ray and I have discussed in the past.   From what I'm anecdotally observing ...  it's not so much that a -EPOs or +PNAs ...-NAOs don't correlate.  It's more about the lack of resonance feed-backs locking in patterns long enough to give the correlations a time to manifest. The ephemeral atmosphere syndrome ... they abandon the storms ... cold and hot looks.

That heat wave near the end of June was clipped for length by higher frequency for example.  

There were some early signs that the ridge in the East was becoming much stronger back in December 2015. It was the first 50° December around NYC Metro which was a +13.3° even against the warmer climate normals. It backed off and we had the great January into early February.

The 2016-2017 winter continued the strong ridging but the storm track was still in colder mode since 09-10.

February 2018 had what Ryan called that bananas record 500 mb height with the first 80° warmth in February around NYC Metro.

18-19 continued the ridge in the Northeast but the storm track shifted warmer through the Great Lakes. So we began the current 7 year stretch of record low snowfall.

20-21 briefly had more of a benchmark track especially near the start of February. But the record Binghampton 40” snowstorm in December featured the -AO linking up with the ridge east of New England forcing the storm track too far west for NYC to Boston to get the heaviest totals. Then the serious flash flood and landslide at the ski resorts on Christmas as the ridge flexed pushing the storm track north with 50s into the mountains.

December 2021 had the record ridging from the Southern Plains to the East with the record +13 at DFW. Brief January return to Benchmark storm tracks followed by a milder February. January 2022 was the last time many areas around NYC Metro had a cold and snowy winter month.

2022-2023 and 2023-2024 continued the very strong ridge near the Northeast.

January was the only month last winter that the ridge in the East was suppressed. But since we were in a La Niña pattern, the Northern Stream of the Pacific Jet remained too strong. So the much weaker STJ was easily suppressed and the Gulf Coast got the historic snows. My guess is if it was a strong enough El Niño instead, perhaps the STJ could have been juiced enough to force the storm track further north into the Mid-Atlantic and Southern New England. 

But yeah like in the post below, we continue to set new 500mb records throughout most seasons of the year. 
 

 

 

 

[TheClimateChanger]

 

[Stormchaserchuck1]

^Phoenix broke their all-time August monthly high at 118F yesterday. 

[FPizz]

6 hours ago, TheClimateChanger said:

 

How does this relate to enso?  Oh yeah, it doesnt

[40/70 Benchmark]

14 hours ago, Typhoon Tip said:

It'd still be there; the eye isn't drawn to it because the trough may appear foreboding.  But, it's presence is betrayed by the very fast flow around the trough.  Speed anomalies is what you'd look for.

It takes some "physics intuition" if you will, but can be shown mathematically ... The HC doesn't really "deflate" or go away in the winter.  What happens is that the geometry of it gets converted to mechanical power in the form of wind - the balanced geostrophic wind velocity in the means.  As the hgt field compresses south, the winds increase in direct proportion. The more the increase, the more compression took place ( steeper gradient).  

 

 

True. It will be interesting to analyze how we "thread the needle", so to speak the next time the east coast scores on a grander scale.

[40/70 Benchmark]

18 hours ago, Stormchaserchuck1 said:

January on the Euro seasonal looks like -EPO/-AO

Heh....case en point, John.....even this image of an ostensibly favorable pattern breaks your "Miami rule" of greater than 580dm heights.

14 hours ago, Typhoon Tip said:

It'd still be there; the eye isn't drawn to it because the trough may appear foreboding.  But, it's presence is betrayed by the very fast flow around the trough.  Speed anomalies is what you'd look for.

It takes some "physics intuition" if you will, but can be shown mathematically ... The HC doesn't really "deflate" or go away in the winter.  What happens is that the geometry of it gets converted to mechanical power in the form of wind - the balanced geostrophic wind velocity in the means.  As the hgt field compresses south, the winds increase in direct proportion. The more the increase, the more compression took place ( steeper gradient).  

 

 

 

[snowman19]

Persistent easterlies being modeled over the tropical Pacific this month….I think next month’s long range model updates are going to move further towards a La Niña event for this coming fall/winter…..

[PhiEaglesfan712]

18 hours ago, bluewave said:

The 2016-2017 winter continued the strong ridging but the storm track was still in colder mode since 09-10.

That was the year when we started to see a shift to the warmer storm tracks. We weren't getting snow in southern places, like Baltimore or DC. 16-17 felt more like 07-08, 11-12, and 12-13 rather than the great 09-10/10-11/13-14/14-15. 

[40/70 Benchmark]

3 hours ago, snowman19 said:

Persistent easterlies being modeled over the tropical Pacific this month….I think next month’s long range model updates are going to move further towards a La Niña event for this coming fall/winter…..

Absolutely....they have been too warm all summer.

[michsnowfreak]

22 hours ago, bluewave said:

There were some early signs that the ridge in the East was becoming much stronger back in December 2015. It was the first 50° December around NYC Metro which was a +13.3° even against the warmer climate normals. It backed off and we had the great January into early February.

The 2016-2017 winter continued the strong ridging but the storm track was still in colder mode since 09-10.

February 2018 had what Ryan called that bananas record 500 mb height with the first 80° warmth in February around NYC Metro.

18-19 continued the ridge in the Northeast but the storm track shifted warmer through the Great Lakes. So we began the current 7 year stretch of record low snowfall.

20-21 briefly had more of a benchmark track especially near the start of February. But the record Binghampton 40” snowstorm in December featured the -AO linking up with the ridge east of New England forcing the storm track too far west for NYC to Boston to get the heaviest totals. Then the serious flash flood and landslide at the ski resorts on Christmas as the ridge flexed pushing the storm track north with 50s into the mountains.

December 2021 had the record ridging from the Southern Plains to the East with the record +13 at DFW. Brief January return to Benchmark storm tracks followed by a milder February. January 2022 was the last time many areas around NYC Metro had a cold and snowy winter month.

2022-2023 and 2023-2024 continued the very strong ridge near the Northeast.

January was the only month last winter that the ridge in the East was suppressed. But since we were in a La Niña pattern, the Northern Stream of the Pacific Jet remained too strong. So the much weaker STJ was easily suppressed and the Gulf Coast got the historic snows. My guess is if it was a strong enough El Niño instead, perhaps the STJ could have been juiced enough to force the storm track further north into the Mid-Atlantic and Southern New England. 

But yeah like in the post below, we continue to set new 500mb records throughout most seasons of the year. 
 

 

 

 

The Feb 2018 warm spell that allowed 80° weather in NY was extra crazy because it occurred in an otherwise wall to wall good winter in many places.

We did hit 65° here, leading to a rapid melting of a deep snowpack, but outside of the last third of Feb, the period of Nov 2017 to Apr 2018 was pretty much wall to wall cold.

[raindancewx]

May-July has high-level similarities to a 2013/2022 blend. Would be a fairly severe winter, and probably not a La Nina technically, more cold-neutral. It's the pseudo cold AMO/Atlantic May-July look with strong highs by NE Asia. It is dislocated further south on the Pacific side though. CFS has essentially La Nina conditions until Dec, then neutral. For Albuquerque I've always found a strong direct correlation in La Nina in Nov-Feb cold days/cold waves (5F or more below daily mean) and ACE. But it doesn't work in Neutrals. 

ACE ahead of 2024-25 was 161.6. Cold day projection (ACE correlation image is from my 2022 winter forecast)

Cold Days = (-0.1177 x 161.6) + (42.063) = 23 cold days Nov-Feb (daily average 5F or more below avg). So the 2024-25 La Nina strengthened the long-term trend. Observed cold days in 2024-2025 - 

Nov: 6

Dec: 1

Jan: 17

Feb: 0

Total: 24

Love it or hate it, the math is the math. Right now there is no sign of an imminent huge burst in the Atlantic and we should have borderline La Nina conditions in the Fall. I don't expect the actual winter to be cold here, but I could see Oct 15-Jan 15 running cold, or Feb 15-Apr 15 running cold. Most likely outcome? Three of five months in those two periods cold here from what I can see. In 2022, we had already had a major hurricane by now and finished below 100 ACE for what its worth while 2013 had no hurricanes until September. I can see the late Fall turning pretty cold nationally after a warm start. But it should be centered on the Plains and only bleed out to the West and East.

[snowman19]

May-July has high-level similarities to a 2013/2022 blend. Would be a fairly severe winter, and probably not a La Nina technically, more cold-neutral. It's the pseudo cold AMO/Atlantic May-July look with strong highs by NE Asia. It is dislocated further south on the Pacific side though. CFS has essentially La Nina conditions until Dec, then neutral. For Albuquerque I've always found a strong direct correlation in La Nina in Nov-Feb cold days/cold waves (5F or more below daily mean) and ACE. But it doesn't work in Neutrals. 


ACE ahead of 2024-25 was 161.6. Cold day projection (ACE correlation image is from my 2022 winter forecast)

Cold Days = (-0.1177 x 161.6) + (42.063) = 23 cold days Nov-Feb (daily average 5F or more below avg). So the 2024-25 La Nina strengthened the long-term trend. Observed cold days in 2024-2025 - 
Nov: 6
Dec: 1
Jan: 17
Feb: 0
Total: 24
Love it or hate it, the math is the math. Right now there is no sign of an imminent huge burst in the Atlantic and we should have borderline La Nina conditions in the Fall. I don't expect the actual winter to be cold here, but I could see Oct 15-Jan 15 running cold, or Feb 15-Apr 15 running cold. Most likely outcome? Three of five months in those two periods cold here from what I can see. In 2022, we had already had a major hurricane by now and finished below 100 ACE for what its worth while 2013 had no hurricanes until September. I can see the late Fall turning pretty cold nationally after a warm start. But it should be centered on the Plains and only bleed out to the West and East.

Interesting that a cold-neutral/borderline weak La Niña would produce a completely different result than an actual weak La Niña, the classification between the two is basically negligible in the SST sense. 2013 was a “Victoria mode” PDO, which looked exactly like a +PDO but was *technically* a very weak -PDO. Certainly possible, but it has a lot of work to do to get there before met winter starts….

[PhiEaglesfan712]

38 minutes ago, snowman19 said:

Interesting that a cold-neutral/borderline weak La Niña would produce a completely different result than an actual weak La Niña, the classification between the two is basically negligible in the SST sense. 2013 was a “Victoria mode” PDO, which looked exactly like a +PDO but was *technically* a very weak -PDO. Certainly possible, but it has a lot of work to do to get there before met winter starts….

I disagree about the classification between the two being 'basically negligable'. 2022 started out as a (continued) moderate la nina from 2020-21/2021-22, but dissipated as the season went on (by the end of the winter, we were at an ENSO neutral). We didn't really have a dissipating la nina in 2013-14 (the la nina event dissipated in spring 2012), just a textbook cool ENSO neutral.

[bluewave]

2 hours ago, michsnowfreak said:

The Feb 2018 warm spell that allowed 80° weather in NY was extra crazy because it occurred in an otherwise wall to wall good winter in many places.

We did hit 65° here, leading to a rapid melting of a deep snowpack, but outside of the last third of Feb, the period of Nov 2017 to Apr 2018 was pretty much wall to wall cold.

Don’t mind the warmth during the winters as long as there are great snowfall outcomes.

The NYC Metro first began to get these warmer and snowy winter combos back in the mid-2000s. The first half of January 2005 began at record warm levels but reversed mid-month to record cold and very snowy.

Then the 2005-2006 winter started cold and snowy in December. This was followed by record warmth in January with some spots in the Midwest around +15°. Then the cold and snow returned in February with the 2nd heaviest snowstorm on record in NYC. 

We had a mild start to winter in 2012-2013 followed by one of the greatest February snowstorms on record from LI into SNE in February. 

The 2015-2016 winter stated with the +13.3 December followed by the heaviest snowstorm on record in January.

The 2016-2017 winter featured 60s record warmth the day before the February blizzard and a very mild January and February.

2017-2018 winter had record cold and snow from from December into January before the record 80° warmth in February. Then the record breaking March monthly snowfall on Long Island.

2020-2021 was a milder than  average winter which also turned out very snowy.

We had the record warmth in December 2021 followed by the cold and snowy January especially Eastern sections of NYC Metro. January 2022 was our last cold and snowy month.

So the warmth began to emerge periodically around NYC Metro while it was still very snowy. But unfortunately the warming continued while the snowfall declined over the last 7 seasons. Since the storm tracks shifted further north warming the storm tracks. 

Our last semblance of a colder storm track was back in January 2022. Maybe with some luck we can see at least a few months the rest of the 2020s with colder storm tracks somewhat reflecting January 2022 . Wouldn’t mind even a weaker reflection of that month with just a single KU instead of the multiple events that month. 

But the record Northern Stream of the Pacific Jet has been very persistent since 2018-2019 leading to the dominant storm tracks through the Great Lakes. 

 

[snowman19]

I disagree about the classification between the two being 'basically negligable'. 2022 started out as a (continued) moderate la nina from 2020-21/2021-22, but dissipated as the season went on (by the end of the winter, we were at an ENSO neutral). We didn't really have a dissipating la nina in 2013-14 (the la nina event dissipated in spring 2012), just a textbook cool ENSO neutral.

If you read my post, I wasn’t referring specifically to 22-23 and 13-14. I was referring in general to the classification between cold-neutral/borderline weak La Niña and a weak La Niña