December 2023

[MJO812]

4 minutes ago, Allsnow said:

No cold at all on our side of the globe on the entire eps run last night. The pac improvements around mid month are very brief as we go back to the same -pna look…

Quite a different look than what the models were once showing. Seems like Deja vu like last year ( for now )

 

[EastonSN+]

Our first opportunity window looks to start around the 9th.

[bluewave]

20 minutes ago, Allsnow said:

No cold at all on our side of the globe on the entire eps run last night. The pac improvements around mid month are very brief as we go back to the same -pna look…

My guess is that the models are picking up on the forcing slowing near the MJO 4-7 regions on VP anomaly charts. Notice how the recent runs have the forcing closer to the warmer phases. This seems to be a regular December occurrence in recent years with models initially trying to rush the warm phases. I like the VP anomaly charts better sometimes since models can really rush the RMM charts leaving the warmer phases. Notice how the new runs of the Euro are correcting stronger with the jet extension near Japan. I believe this much stronger jet tries to knock down the ridge over the Western US. Probably related to that big forcing cell near MJO 4. The silver lining for the general public outside this forum is that heating  demand for most of the continent will be below average. So most will be happy to see a break on their heating bills. 
 

New run stronger jet extension near Japan 

Old run much weaker allowed more Western ridging

 

[EastonSN+]

12 hours ago, bluewave said:

The static background state is the expanding record WPAC warm pool leading to stronger and more frequent MJO 4-6 phases and multiyear La Ninas. This can even occur during super El Niños like in December 2015. And we saw how this background state prevented the 18-19 El Niño from coupling.
 

https://www.nature.com/articles/s41558-023-01801-6

Understanding the recent increase in multiyear La Niñas

• Bin Wang, 
• Weiyi Sun, 
• Chunhan Jin, 
• Xiao Luo, 
• Young-Min Yang, 
• Tim Li, 
• Baoqiang Xiang, 
• Michael J. McPhaden, 
• Mark A. Cane, 
• Feifei Jin, 
• Fei Liu & 
• Jian Liu 

Nature Climate Change volume 13, pages 1075–1081 (2023)Cite this article

• 8180 Accesses

• 188 Altmetric

• Metrics details

Abstract

Five out of six La Niña events since 1998 have lasted two to three years. Why so many long-lasting multiyear La Niña events have emerged recently and whether they will become more common remains unknown. Here we show that ten multiyear La Niña events over the past century had an accelerated trend, with eight of these occurring after 1970. The two types of multiyear La Niña events over this time period followed either a super El Niño or a central Pacific El Niño. We find that multiyear La Niña events differ from single-year La Niñas by a prominent onset rate, which is rooted in the western Pacific warming-enhanced zonal advective feedback for the central Pacific multiyear La Niña events type and thermocline feedback for the super El Niño multiyear La Niña events type. The results from large ensemble climate simulations support the observed multiyear La Niña events–western Pacific warming link. More multiyear La Niña events will exacerbate adverse socioeconomic impacts if the western Pacific continues to warm relative to the central Pacific.

 

https://link.springer.com/article/10.1007/s00376-020-0261-x

Distinctive MJO Activity during the Boreal Winter of the 2015/16 Super El Niño in Comparison with Other Super El Niño Events

Abstract

Many previous studies have demonstrated that the boreal winters of super El Niño events are usually accompanied by severely suppressed Madden-Julian oscillation (MJO) activity over the western Pacific due to strong descending motion associated with a weakened Walker Circulation. However, the boreal winter of the 2015/16 super El Niño event is concurrent with enhanced MJO activity over the western Pacific despite its sea surface temperature anomaly (SSTA) magnitude over the Niño 3.4 region being comparable to the SSTA magnitudes of the two former super El Niño events (i.e., 1982/83 and 1997/98). This study suggests that the MJO enhanced over western Pacific during the 2015/16 super El Niño event is mainly related to its distinctive SSTA structure and associated background thermodynamic conditions. In comparison with the previous super El Niño events, the warming SSTA center of the 2015/16 super El Niño is located further westward, and a strong cold SSTA is not detected in the western Pacific. Accordingly, the low-level moisture and air temperature (as well as the moist static energy, MSE) tend to increase in the central-western Pacific. In contrast, the low-level moisture and MSE show negative anomalies over the western Pacific during the previous super El Niño events. As the MJO-related horizontal wind anomalies contribute to the further westward warm SST-induced positive moisture and MSE anomalies over the western tropical Pacific in the boreal winter of 2015/16, stronger moisture convergence and MSE advection are generated over the western Pacific and lead to the enhancement of MJO convection.

 

https://www.climate.gov/news-features/blogs/enso/csi-enso-case-missing-central-pacific-rainfall

I feel better about this year given that we have already spent time in the cooler phases.

It may take a few years for the WPAC waters to cool. 

[qg_omega]

On 11/25/2023 at 2:56 PM, brooklynwx99 said:

all major ensembles are in agreement and they all look great

11 to 16 forecasts, even if all in agreement, are very low skill

[brooklynwx99]

1 minute ago, qg_omega said:

11 to 16 forecasts, even if all in agreement, are very low skill

that is true, but they are really all that we have

[brooklynwx99]

this kind of pattern may cut it in like mid Jan through Feb, but it's too early to compensate for a less than ideal Pacific

luckily, it really doesn't snow much before the 15-20th anywhere near the coast, so it's not like we're really missing out on much

[brooklynwx99]

I would still be encouraged seeing significant -NAO blocking this early, as well as a much weaker than average SPV. these are known to help lead to blocking later in the winter, especially in -QBO/Nino regimes. the Pacific is usually the issue in El Nino Decembers

[EastonSN+]

1 minute ago, brooklynwx99 said:

this kind of pattern may cut it in like mid Jan through Feb, but it's too early to compensate for a less than ideal Pacific

luckily, it really doesn't snow much before the 15-20th anywhere near the coast, so it's not like we're really missing out on much

Correct, by the 9th we should be heading towards phase 7. Anything before the 2nd week of December is a bonus. The MJO cooler phases may line up nicely with climo. No guarantees, however I would rather propagate through the warm phases now than in mid December.

[EastonSN+]

8 minutes ago, bluewave said:

My guess is that the models are picking up on the forcing slowing near the MJO 4-7 regions on VP anomaly charts. Notice how the recent runs have the forcing closer to the warmer phases. This seems to be a regular December occurrence in recent years with models initially trying to rush the warm phases. I like the VP anomaly charts better sometimes since models can really rush the RMM charts leaving the warmer phases. Notice how the new runs of the Euro are correcting stronger with the jet extension near Japan. I believe this much stronger jet tries to knock down the ridge over the Western US. Probably related to that big forcing cell near MJO 4. The silver lining for the general public outside this forum is that heating  demand for most of the continent will be below average. So most will be happy to see a break on their heating bills. 
 

New run stronger jet extension near Japan 

Old run much weaker allowed more Western ridging

 

Given that we are in a Nino now, even if we have strong forcing in 4 through 6, wouldn't that allow the forcing to remain strong through 7-1 rather than a la Nina environment that would kill the wave beforehand.

[wdrag]

7 minutes ago, bluewave said:

My guess is that the models are picking up on the forcing slowing near the MJO 4-7 regions on VP anomaly charts. Notice how the recent runs have the forcing closer to the warmer phases. This seems to be a regular December occurrence in recent years with models initially trying to rush the warm phases. I like the VP anomaly charts better sometimes since models can really rush the RMM charts leaving the warmer phases. Notice how the new runs of the Euro are correcting stronger with the jet extension near Japan. I believe this much stronger jet tries to knock down the ridge over the Western US. Probably related to that big forcing cell near MJO 4. The silver lining for the general public outside this forum is that heating  demand for most of the continent will be below average. So most will be happy to see a break on their heating bills. 
 

New run stronger jet extension near Japan 

Old run much weaker allowed more Western ridging

 

Are not ensemble wind fields 10 days in advance more conservative because of  member spread (la/lo/speed)?  Ditto the same thing eastern USA in the posted graphics. I think the location is more important and in this post... really looks decent for 10 days out.  

[wdrag]

10 minutes ago, qg_omega said:

11 to 16 forecasts, even if all in agreement, are very low skill

Also... patterns beyond 7 days... can verify fairly well... some skill, but imo only,  it's how we get to that pattern.  

 

I've not checked today, so I can't be sure but a few days ago when the post started... low pressure was generally modeled to our north in all 12 hour periods except around 12/5.  

 

I think we need short waves in the southern stream to dominate in tandem with the block across northeast Canada-Davis Strait.  Just my 2c... but that's what I check in ensembles. 

Til tomorrow.

[brooklynwx99]

4 minutes ago, EastonSN+ said:

Given that we are in a Nino now, even if we have strong forcing in 4 through 6, wouldn't that allow the forcing to remain strong through 7-1 rather than a la Nina environment that would kill the wave beforehand.

yes, generally. the EPS shows this progression back into 7-8-1 well

a couple intrusions into 4-5-6 are going to happen early on in the year before the Nino is truly established. this intrusion was actually well forecast... models saw it around a week ago

[Allsnow]

16 minutes ago, bluewave said:

My guess is that the models are picking up on the forcing slowing near the MJO 4-7 regions on VP anomaly charts. Notice how the recent runs have the forcing closer to the warmer phases. This seems to be a regular December occurrence in recent years with models initially trying to rush the warm phases. I like the VP anomaly charts better sometimes since models can really rush the RMM charts leaving the warmer phases. Notice how the new runs of the Euro are correcting stronger with the jet extension near Japan. I believe this much stronger jet tries to knock down the ridge over the Western US. Probably related to that big forcing cell near MJO 4. The silver lining for the general public outside this forum is that heating  demand for most of the continent will be below average. So most will be happy to see a break on their heating bills. 
 

New run stronger jet extension near Japan 

Old run much weaker allowed more Western ridging

 

Yeah, the jet ext is killing whatever brief window of favorable pac we get as the block moves southwest. This is so reminiscent of the past few Decembers it’s scary. 
 

In winters past once the jet retracts the -epo pops to far west to favor cold in the east. This could be the case again for the second half of the month if the mjo slows in the warm phases, which is why I didn’t understand why people expected it to race through 

[brooklynwx99]

Just now, Allsnow said:

Yeah, the jet ext is killing whatever brief window of favorable pac we get as the block moves southwest. This is so reminiscent of the past few Decembers it’s scary. 
 

In winters past once the jet retracts the -epo pops to far west to favor cold in the east. This could be the case again for the second half of the month if the mjo slows in the warm phases, which is why I didn’t understand why people expected it to race through 

the thing is that the passes through warmer phases are weaker and quicker than they are during Ninas. but they are still going to happen sometimes, especially early in the year

[bluewave]

Just now, wdrag said:

Are not ensemble wind fields 10 days in advance more conservative because of  member spread (la/lo/speed)?  Ditto the same thing eastern USA in the posted graphics. I think the location is more important and in this post... really looks decent for 10 days out.  

That’s one of the issues with the smoothed out ensemble means for the day 11-15 forecasts. They miss details like the MJO and jet speed. So we end up with a trough closer to West in the newer runs and mild Pacific air across most of North America in early December.

 

New run is warmer due to faster Pacific Jet pushing trough into West

 

 

Older run cooler for our area with more ridging out West 

 

New run Western trough
 

 

Old run Western ridge

[Allsnow]

1 minute ago, brooklynwx99 said:

the thing is that the passes through warmer phases are weaker and quicker than they are during Ninas. but they are still going to happen sometimes, especially early in the year

I have zero confidence the MJO will move quickly in any phase other than the cold ones. All the warm water is where we don’t want it…

[brooklynwx99]

1 minute ago, Allsnow said:

I have zero confidence the MJO will move quickly in any phase other than the cold ones. All the warm water is where we don’t want it…

that's silly. that's how El Ninos usually go. we've just had 5 Ninas in the last 7 years, so people have forgotten how they usually work. there is no meteorological reason that we would spend most of the winter in 4-5-6

the warmest water is also still over the central Pacific. SSTs also only really help feed back on atmospheric processes, they don't drive them 

[Allsnow]

18 minutes ago, brooklynwx99 said:

I would still be encouraged seeing significant -NAO blocking this early, as well as a much weaker than average SPV. these are known to help lead to blocking later in the winter, especially in -QBO/Nino regimes. the Pacific is usually the issue in El Nino Decembers

Yeah but it regains strength, which needs to be watched if it recovers even stronger like December 2019 

[Allsnow]

4 minutes ago, brooklynwx99 said:

that's silly. that's how El Ninos usually go. we've just had 5 Ninas in the last 7 years, so people have forgotten how they usually work. there is no meteorological reason that we would spend most of the winter in 4-5-6

the warmest water is also still over the central Pacific. SSTs also only really help feed back on atmospheric processes, they don't drive them 

The MJO wave works like a training thunderstorm in the summer. Very hard to predict and feeds off warm water which can keep is lingering in the warm phases 

[EastonSN+]

10 minutes ago, brooklynwx99 said:

that's silly. that's how El Ninos usually go. we've just had 5 Ninas in the last 7 years, so people have forgotten how they usually work. there is no meteorological reason that we would spend most of the winter in 4-5-6

the warmest water is also still over the central Pacific. SSTs also only really help feed back on atmospheric processes, they don't drive them 

They think it was bad the last 4 out of 5 years, they would have absolutely lost their minds and thought winters as we knew them were over during the 70s, 80s and especially the 90s which were extremely warm for the most part.

The epic period from 2000 through 2018, which somewhat mirrored 55 through 69, has skewed a lot of posters views on what is expected I believe.

[bluewave]

33 minutes ago, brooklynwx99 said:

that's silly. that's how El Ninos usually go. we've just had 5 Ninas in the last 7 years, so people have forgotten how they usually work. there is no meteorological reason that we would spend most of the winter in 4-5-6

the warmest water is also still over the central Pacific. SSTs also only really help feed back on atmospheric processes, they don't drive them 

The warmest +30C waters are spread out from MJO 4 to MJO 7 near the Dateline. So that’s  why we suddenly saw the models correct warmer for early December. Some version of this has been happening most Decembers last decade.

 

 

[Brian5671]

The good news is that blocking is showing up-may bode well later in the winter...the bad news is that it will just trap Pac Polar air in the short term which is not going to cut it.     

[EastonSN+]

11 minutes ago, Brian5671 said:

The good news is that blocking is showing up-may bode well later in the winter...the bad news is that it will just trap Pac Polar air in the short term which is not going to cut it.     

Only until the 9th and after where we go through phases 7 through 1. Timing is great it's a bit early now.

[Allsnow]

53 minutes ago, bluewave said:

The warmest +30C waters are spread out from MJO 4 to MJO 7 near the Dateline. So that’s  why we suddenly saw the models correct warmer for early December. Some version of this has been happening most Decembers last decade.

 

 

That why I think the late December window will favor the west. P7 in December favors cold dump into the west.

Those silly RMM plots had it going into cod which isn’t going to happen with that warm water in 4-7 

[forkyfork]

2 hours ago, EastonSN+ said:

It may take a few years for the WPAC waters to cool. 

why should they cool when co2 is only increasing? 

[donsutherland1]

It should be noted that even as there is large variability in the percentage of days during which the MJO is in Phases 4-6 during El Niño events, the percentage has been trending higher during the winter months. The trend is based on the 16 El Niños for which daily MJO data is available.

[Allsnow]

6 minutes ago, donsutherland1 said:

It should be noted that even as there is large variability in the percentage of days during which the MJO is in Phases 4-6 during El Niño events, the percentage has been trending higher during the winter months. The trend is based on the 16 El Niños for which daily MJO data is available.

Nina conditions 

[bluewave]

3 minutes ago, Allsnow said:

Nina conditions 

Yeah, very Niña-like MJO activity during our last 2 El Niño Decembers. 

 

[MJO812]

1 hour ago, EastonSN+ said:

Only until the 9th and after where we go through phases 7 through 1. Timing is great it's a bit early now.

Yep one week at a time.