2024-2025 La Nina

[MJO812]

2 hours ago, PhiEaglesfan712 said:

Torch January was the easiest thing to predict for this winter.

It's only December 4 for crying out loud. Models can't even get anything right a week out let along a month out.

[MJO812]

20 minutes ago, jm1220 said:

Exactly. Bluewave might not be posting what a lot of us want to read but he’s also been accurate. I’ll take accurate and don’t want to see it vs JB-esque weenie garbage that never verifies. 

He was right last winter while everyone kept bashing him.

[uofmiami]

20 minutes ago, jm1220 said:

Exactly. Bluewave might not be posting what a lot of us want to read but he’s also been accurate. I’ll take accurate and don’t want to see it vs JB-esque weenie garbage that never verifies. 

Didn’t enter Central Park snowfall contest in NYC subforum. Did he post a winter outlook either?  

[bluewave]

11 minutes ago, uofmiami said:

Didn’t enter Central Park snowfall contest in NYC subforum. Did he post a winter outlook either?  

I don’t devote separate threads to my discussions and forecasts. They are included in the NYC Metro and annual ENSO threads here. My sea ice and global temperature discussions are in the CC forum.

[jm1220]

2 hours ago, bluewave said:

It’s no surprise the models have adjusted warmer going forward. The WPAC warm pool along the equator was the warmest for November at just over a +29.05°C. Forcing in these areas leads to a more pronounced Southeast Ridge. 
 

I’m honestly surprised the constant convection there doesn’t cool it down. 

[40/70 Benchmark]

19 minutes ago, uofmiami said:

Didn’t enter Central Park snowfall contest in NYC subforum. Did he post a winter outlook either?  

He doesn't do seasonal outlooks...just like two week increments.

[GaWx]

-Nov QBO (at 30 mb): came in at +13.78 (about as expected) vs Oct’s +11.64.

-Based on historical patterns (back to 1947 on this table), either Nov or more than likely Dec will be the peak. Jan has only a very small shot to be the month of the highest as it will likely already be starting to fall then. Peak almost definitely to be from +13.78 to +15.6 with best guess in the +14s:

https://psl.noaa.gov/data/correlation/qbo.data

 We very likely will have a solid -QBO next winter.

[snowman19]

3 minutes ago, GaWx said:

-Nov QBO (at 30 mb): came in at +13.78 (about as expected) vs Oct’s +11.64.

-Based on historical patterns (back to 1947 on this table), either Nov or more than likely Dec will be the peak. Jan has only a very small shot to be the month of the highest as it will likely already be starting to fall then. Peak almost definitely to be from +13.78 to +15.6.

https://psl.noaa.gov/data/correlation/qbo.data

I think it may have a shot at being the strongest +QBO event on record. We’ll see 

[GaWx]

4 minutes ago, snowman19 said:

I think it may have a shot at being the strongest +QBO event on record. We’ll see 

The record high is +15.62 (June of 1995). I give it about a 10% chance to be exceeded. If so, that would almost definitely be in Dec or Jan.

[snowman19]

2 hours ago, bluewave said:

It’s no surprise the models have adjusted warmer going forward. The WPAC warm pool along the equator was the warmest for November at just over a +29.05°C. Forcing in these areas leads to a more pronounced Southeast Ridge. 
 

It’s thermodynamics 101. The atmosphere is going to fire the strongest and most persistent convection over the warmest SSTs (MJO 4-6). That’s where the global heat budget is centered. And even despite the rise in the PDO last month, it was still record strong at over -3 as @GaWx pointed out yesterday. I honestly fail to see any change from last year in the PAC other than ENSO. This La Niña is finally, at long last starting to really take off (EWBs, +SOI, region 3.4 cooling, AAM slowly falling, -IOD) and it is entirely central-based/Modoki now too

 

 

 

 

[bluewave]

1 minute ago, snowman19 said:

It’s thermodynamics 101. The atmosphere is going to fire the strongest and most persistent convection over the warmest SSTs (MJO 4-6). That’s where the global heat budget is centered. And even despite the rise in the PDO last month, it was still record strong at over -3 as @GaWx pointed out yesterday. I honestly fail to see any change from last year in the PAC other than ENSO. This La Niña is finally, at long last starting to really take off (EWBs, +SOI, 3.4 cooling, AAM slowly falling) and it is entirely central-based/Modoki now too

 

 

 

 

Yeah, the nearly doubling of the Indio-Pacific warm pool has become a major climate driver especially for us in the East.

 

https://www.climate.gov/news-features/featured-images/warm-pool-indo-pacific-ocean-has-almost-doubled-size-changing-global

[jconsor]

19 hours ago, GaWx said:

 

 Nov NOAA PDO just came in about where I expected (based on adjusting WCS’ PDO) at -3.24 (rise of 0.54 from Oct). This compares to the WCS’ Nov of ~-2.10. So, this is only the 2nd time since 1851 with three sub -3 PDO months in a row. The other time was in 1894 (6 months earlier that year than 2024). We actually only barely missed 7 months in a row of sub -3 as the last 7 have all been sub -2.90:
 

-2.99 -3.16 -2.99 -2.91 -3.54 -3.78 -3.24

https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat

 Current daily NOAA PDOs are likely in the low -3 range.

@snowman19

Per Eric Webb, the PDO has limited influence and limited usefulness for subseasonal predictability (especially in a winter like this with a strong Indo-W Pacific warm pool).

https://x.com/webberweather/status/1864088518886322455

https://x.com/webberweather/status/1864091992386605400

https://x.com/webberweather/status/1864095069449699705

https://x.com/webberweather/status/1864150597710369022

Also interesting comments on PDO's limited usefulness as a teleconnection here:
https://x.com/_WxPhil_/status/1864148237403263157

[snowman19]

8 minutes ago, bluewave said:

Yeah, the nearly doubling of the Indio-Pacific warm pool has become a major climate driver especially for us in the East.

 

https://www.climate.gov/news-features/featured-images/warm-pool-indo-pacific-ocean-has-almost-doubled-size-changing-global

The background La Niña state just keeps chiving on unabated. The recent changes in the ENSO genre and constructive interference from the -IOD are just going to reinforce the whole process going forward

[GaWx]

27 minutes ago, snowman19 said:

It’s thermodynamics 101. The atmosphere is going to fire the strongest and most persistent convection over the warmest SSTs (MJO 4-6). That’s where the global heat budget is centered. And even despite the rise in the PDO last month, it was still record strong at over -3 as @GaWx pointed out yesterday. I honestly fail to see any change from last year in the PAC other than ENSO. This La Niña is finally, at long last starting to really take off (EWBs, +SOI, region 3.4 cooling, AAM slowly falling, -IOD) and it is entirely central-based/Modoki now too

 

 

 

 

-RONI for SON just came out at -0.80. So, on a RONI basis this event will end up with at least a solid weak La Niña peak.

-ONI for SON: -0.24

-So, difference between RONI and ONI in SON was -0.56 (difference between -0.80 and -0.24)

- Difference between RONI and ONI:
MJJ: -0.60
JJA: -0.55
JAS: -0.52
ASO: -0.54
SON: -0.56

 So, when I see an OISST and want to very roughly estimate the equivalent daily RONI, I’m currently subtracting ~0.55. The Dec. 1st OISST was -0.35. So, I have the current equivalent Dec 1st RONI near -0.90**(**Corrected for typo).
 

[bluewave]

22 minutes ago, snowman19 said:

The background La Niña state just keeps chiving on unabated. The recent changes in the ENSO genre and constructive interference from the -IOD are just going to reinforce the whole process going forward

Yeah, we were discussing the issues with the much faster Pacific Jet and inability to sustain -EPO patterns. All the guidance has been underestimating this influence beyond a week out. This recent +AAM driven Pacific blocking pattern reverses fairy quickly. The forcing near the Maritime Continent accelerates the Pacific Jet, weakens the -EPO, and leads to a Southeast Ridge.

New run faster Pacific Jet weakening -EPO block and leading to Southeast Ridge several days later

Old run

[GaWx]

14 minutes ago, bluewave said:

This recent +AAM driven Pacific blocking pattern couldn’t sustain it self against the forcing near the Maritime Continent which accelerates the Pacific Jet and leads to a Southeast Ridge.

Chris,  
 At what latitudinal range are you saying the forcing near the MC warm pool is accelerating the Pacific jet? What is the latitude of this warm pool?

[40/70 Benchmark]

2 minutes ago, 40/70 Benchmark said:

Strongly agree with all of this. 

https://youtu.be/OdBnQZCFcQM?si=o9E18FO-SuFdihKq

 

[bluewave]

7 minutes ago, GaWx said:

Chris,  
 At what latitudinal range are you saying the forcing near the MC warm pool is accelerating the Pacific jet?

I posted the Pacific Jet correcting much stronger in the above post. The JMA site has the MJO jet composites. Just select the options for 200mb zonal wind anomaly. The jet increases across large swaths of the North Pacific when forcing is in the 4-7 regions. We are currently near a 4 composite for December with the jet pushing through the -EPO block this weekend.

 

https://ds.data.jma.go.jp/tcc/tcc/products/clisys/mjo/composite.html

 

[GaWx]

3 minutes ago, bluewave said:

I posted the Pacific Jet correcting much stronger in the above post. The JMA site has the MJO jet composites. Just select the options for 200mb zonal wind anomaly. The jet increases across large swaths of the North Pacific when forcing is in the 4-7 regions. We are currently near a 4 composite for December with the jet pushing through the -EPO block this weekend.

 

https://ds.data.jma.go.jp/tcc/tcc/products/clisys/mjo/composite.html

 

Thanks but I need to restate my question.  What is the latitudinal range of this warm pool that is leading to the stronger Pacific jet? I didn’t word my original question well.

[bluewave]

1 minute ago, GaWx said:

Thanks but I need to restate my question.  What is the latitudinal range of this warm pool that is leading to the stronger Pacific jet?

It’s described in this story that I posted above.

https://www.climate.gov/news-features/featured-images/warm-pool-indo-pacific-ocean-has-almost-doubled-size-changing-global

[GaWx]

8 minutes ago, bluewave said:

It’s described in this story that I posted above.

https://www.climate.gov/news-features/featured-images/warm-pool-indo-pacific-ocean-has-almost-doubled-size-changing-global

So, would you agree that the warm pool is between 15N and 15S latitudinal range? I want to make sure I’m properly following along with you on the waters you’re focusing on.

 So, does this mean that the marine heatwave E of Japan is having minimal impact on the atmosphere?

[bluewave]

5 minutes ago, GaWx said:

So, would you agree that the warm pool is between 15N and 15S latitudinal range? I want to make sure I’m properly following along with you on the waters you’re focusing on.

 So, does this mean that the marine heatwave E of Japan is having minimal impact on the atmosphere?

Yeah, close to those areas around the equator. The warm pool east of Japan to north of Hawaii raises some interesting questions. I suppose you can make the argument that the forcing from the WPAC warm pool near the equator leads to stronger 500mb ridging across the North Pacific which warms the SSTs below. So the -PDO signature could be a result of the tropical forcing in the WPAC. When it aligns with the tropical forcing perhaps the subtropical -PDO marine heatwaves can lead to feedbacks which help to strengthen the pattern when in alignment. 

[GaWx]

1 hour ago, jconsor said:

Per Eric Webb, the PDO has limited influence and limited usefulness for subseasonal predictability (especially in a winter like this with a strong Indo-W Pacific warm pool).

https://x.com/webberweather/status/1864088518886322455

https://x.com/webberweather/status/1864091992386605400

https://x.com/webberweather/status/1864095069449699705

https://x.com/webberweather/status/1864150597710369022

Also interesting comments on PDO's limited usefulness as a teleconnection here:
https://x.com/_WxPhil_/status/1864148237403263157

 

56 minutes ago, bluewave said:

Yeah, close to those areas around the equator. The warm pool east of Japan to north of Hawaii raises some interesting questions. I suppose you can make the argument that the forcing from the WPAC warm pool near the equator leads to stronger 500mb ridging across the North Pacific which warms the SSTs below. So the -PDO signature could be a result of the tropical forcing in the WPAC. When it aligns with the tropical forcing perhaps the subtropical -PDO marine heatwaves can lead to feedbacks which help to strengthen the pattern when in alignment. 

 So, I want to make sure that Webb, jconsor and Chris are on the same page. Jconsor said this based on what Webb said:

“Per Eric Webb, the PDO has limited influence and limited usefulness for subseasonal predictability (especially in a winter like this with a strong Indo-W Pacific warm pool).”

This is what Webb said:

“Most people misunderstand the direction of forcing. Extratropical SSTs are mostly forced by atmospheric circulation anomalies, not the other way around. I.e. the -PDO’s contemporary correlation with things like the -PNA is more of a reflection of the -PNA pattern forcing the -PDO on interannual scales, not the other way around”

 
 Chris, do you agree with jconsor and Webb that the PDO actually has limited influence on the atmosphere? So, does this mean that the record -PDO we’ve been having, itself, has been having only minimal impact on the atmosphere?

 There seems to be a lot of disagreement about this among the meteorological community, which has been confusing to me over the last few years. I‘m just trying to learn. For example, I used to think that -PDO, itself, including the W Pacific marine heatwave E of Japan, tended to help force a -PNA/stronger mean Aleutian ridge/stronger than avg mean SE ridge. But in reality it appears that the 15N to 15S warm pool in addition to La Niña is what drives that pattern and not also the marine heatwave to the north/-PDO. Chris and Yaakov, do I have this right?

 So, if so, does following the PDO, itself, have much usefulness for seasonal predictions for, say, the US and the Atlantic tropics? If not, what’s the point with regard to forecasting mean seasonal atmospheric circulation in following the PDO index and the E of Japan marine heatwave?

[michsnowfreak]

15 hours ago, FPizz said:

You can have a wealth of knowledge while also cherry picking and having a bias.  

1000%. There is plenty of knowledge AND bias by the frequent posters in this thread. In nearly every post, as a matter of fact, from some.

[jm1220]

1 hour ago, snowman19 said:

The background La Niña state just keeps chiving on unabated. The recent changes in the ENSO genre and constructive interference from the -IOD are just going to reinforce the whole process going forward

Perma-Nina. It’s so prevalent that it was noticeable even in the strong Nino last year. It just added a lot more moisture to the perma-Nina so the East had a near or record wet winter but zero cold other than short couple day periods where it was cold enough for snow IMBY. 

[40/70 Benchmark]

35 minutes ago, michsnowfreak said:

1000%. There is plenty of knowledge AND bias by the frequent posters in this thread. In nearly every post, as a matter of fact, from some.

I wouldn't include Chris in that....when it looked colder early month, he reported that. Its important to observe the behavior of a contributor during an instance in which the overwhelming perponderance of evidence goes against perceived bias.

[MJO812]

1 hour ago, 40/70 Benchmark said:

 

This is excellent.  He put alot of thought into this forecast .

He thinks a brief break and then winter comes back in early Janaury.

[michsnowfreak]

10 minutes ago, 40/70 Benchmark said:

I wouldn't include Chris in that....when it looked colder early month, he reported that. Its important to observe the behavior of a contributor during an instance in which the overwhelming perponderance of evidence goes against perceived bias.

Oh I dont mean every poster...just some. Sorry if it came across another way. I just think overall there is a huge difference between having a preference and a bias. I usually have general thoughts for my area and keep it vague like that; getting in too deep increases the chance to get burned. Im kind of a mix between BAM and Don Sutherland on my thoughts- a variable winter.

Had snow on the ground when I cut down the Christmas tree Sunday and should have a little bit of snow on the ground at an event Im going to Friday. Those were my 2 "outdoor" holiday events planned, so while Im never a fan of the up and down, Im actually fine if it warms up sooner rather than later, as it increases the chances of another turn colder by Christmas itself. 

[GaWx]

2 hours ago, 40/70 Benchmark said:

 

My opinion on this:

-Michael Clark clearly presents his thoughts in detail with solid reasoning, especially regarding the MJO and TPV. Well done. He’s hinting at a strong possibility of a cold Jan in the Midwest to interior NE though he didn’t know about the coastal NE and said (virtually) nothing about the SE.

-Per his history, I don’t put him in the Bastardi category of being a strongly cold biased hypester by any means (exhibited by him talking about warmth Dec 10-25/30….Bastardi would unlike Michael gloss over the warmth and skip to the cold potential)..so a big positive vs JB

-Per that same history though, my feel is that he’s probably still a bit cold biased though not as much as a few years ago when I first followed him.

-My biggest disappointment is how much emphasis he puts on the typically highly unreliable CFS. He focuses on the 12/4/24 0Z CFS 4 member ensemble run. Although that’s much better than just showing a control run (something JB often does when it is very cold), it’s still highly unreliable.

-Besides it being typically highly unreliable, the CFS (though it has backed away slightly) is still calling for a record rate of Nino 3.4 cooling of -0.8C from Nov to Dec to -1.0C and then -1.25C in Jan! No other model is anywhere close. That potential huge error makes me wonder if it is affecting the CFS in Jan.

-I also don’t like to see his displaying WxBell CFS US 2 meter temperature maps. They’re usually several degrees colder than what the NOAA CFS maps show on avg in the E US and are messed up. He showed the very cold WB 12/4/24 0Z ensemble run for Jan, which is almost definitely colder than what that actual CFS  run has. Also, the maps he showed had the ever-present cold spot in S Lake Michigan and warm spot in N Lake Michigan.

-My overall feeling is to take this with a grain but hope he’s generally right for Jan and hope that the cold includes the SE/Mid-Atlantic/coastal NE with no blocking mean SE ridge.

[GaWx]

16 hours ago, GaWx said:

 I just emailed my Maxar contact to see if he’ll give me an update on the latest ensemble biases based on internal analyses. I hope he responds. He (Brad) really is fantastic with this kind of analysis.

This is from pro-met Brad’s email response:

“Your ideas about model biases are generally true. The CAN EN (GEPS) is often cold biased, and this is especially the case in the West as you have noted. The GEFS is often cold-biased as well, but this has not been the case more recently. I think the maps and graph from DTN make sense from what I remember this fall. With that said, model performance in the fall can vary more than other times of year. This might be a function of tropical activity, which peaks in the fall, but also the changing of seasons itself. So in that respect, I probably wouldn't consider the biases from this past fall to be an indication of how models will perform going forward.”

“While I can’t say for sure what caused models to be too warm this fall season, their handling of soil moisture might be a theory:”

 So, in other words, Brad is suggesting that we not count on the net warm EPS/GEFS E US day 6-15 model biases of this past autumn continuing into this winter.