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