El Nino 2023-2024

[bluewave]

4 minutes ago, so_whats_happening said:

Ocean temps probably helping in conjunction with the more frequent 4-6 MJO, top it off with a -PDO period and boy is it going to look rough. Hope we can get tropics to still actively take out the warmth along the east coast through the end of October maybe it gives us a fighting chance at something different.

A 7° warmer Gulf Stream is probably playing  a role in tandem with more frequent and stronger MJO 4-6 activity with the record WPAC warm pool.

 

 

[so_whats_happening]

7 minutes ago, Terpeast said:

Thanks. I was expecting 0.5, so tracking a bit behind

This is probably one of the larger differences we have seen in a warm phase. Definitely gives an idea of just how impactful this El Nino may end up.

[ORH_wxman]

7 minutes ago, bluewave said:

It used to be better especially further to the south of our area when there was more of a PV near the East Coast rather than a SE Ridge. So these days we have to worry more about cutters. Back then, it was a more suppressed storm track favoring the mid-Atlantic. But it was a colder pattern for us back then with more opportunities snow in what would be marginal -PNA patterns for us today. 

Agreed...but Ray's point is that this was pretty extreme. It wasn't solely because of some underlying trend...otherwise it would have been very visible prior to just the last few years. The underlying height trend helps exacerbate strong ridge response when you get a deeply negative PNA trough out west, but it's not the primary cause of the event in the first place. When Pasadena CA is getting snow, it was probably a tough lift even in 1955 to get good snows in New York City in that pattern.

[so_whats_happening]

1 minute ago, bluewave said:

A 7° warmer Gulf Stream is probably playing  a role in tandem with more frequent and stronger MJO 4-6 activity with the record WPAC warm pool.

 

 

True, I mean the whole W Atlantic has just been insanely warm for years now. The Labrador current is non existent right now too. Wonder what it will take to flip the +AMO pattern?

[bluewave]

6 minutes ago, ORH_wxman said:

Agreed...but Ray's point is that this was pretty extreme. It wasn't solely because of some underlying trend...otherwise it would have been very visible prior to just the last few years. The underlying height trend helps exacerbate strong ridge response when you get a deeply negative PNA trough out west, but it's not the primary cause of the event in the first place. When Pasadena CA is getting snow, it was probably a tough lift even in 1955 to get good snows in New York City in that pattern.

The other way of looking at the situation is that it becomes more visible when some threshold get crossed more often. So there could have been numerous years when we were close but the threshold wasn’t crossed. The recent years may just look more extreme when the steady march higher wasn’t as noticeable. A bit in a way like the last little push necessary to top a scale in one direction or another. This point isn’t always very obvious until after it has been crossed.

[40/70 Benchmark]

26 minutes ago, ORH_wxman said:

Agreed...but Ray's point is that this was pretty extreme. It wasn't solely because of some underlying trend...otherwise it would have been very visible prior to just the last few years. The underlying height trend helps exacerbate strong ridge response when you get a deeply negative PNA trough out west, but it's not the primary cause of the event in the first place. When Pasadena CA is getting snow, it was probably a tough lift even in 1955 to get good snows in New York City in that pattern.

Exactly. GW is a very polarizing issue....many folks just can't distinguish between someone how feels as though there is rampant overattributing, like myself, from someone who is denying that it exists. It is possible to acknowledge the reality of GW while feeling that it becomes a convenient excuse for everything and anything...whether it be consciously, or unconsciously.

[40/70 Benchmark]

24 minutes ago, bluewave said:

The other way of looking at the situation is that it becomes more visible when some threshold get crossed more often. So there could have been numerous years when we were close but the threshold wasn’t crossed. The recent years may just look more extreme when the steady march higher wasn’t as noticeable. A bit in a way like the last little push necessary to top a scale in one direction or another. This point isn’t always very obvious until after it has been crossed.

Last year was extreme. It would have been extreme in 256BC and it will be extreme in 2136. That said, are marginal situations becoming more perilous due to GW?

Yes, of course.

[40/70 Benchmark]

The temperature of the Gulf stream is the least of my concerns when a PV lobe phases over Saskatchewan, as the Sierra is building a 50 foot snowpack.

[ORH_wxman]

19 minutes ago, bluewave said:

The other way of looking at the situation is that it becomes more visible when some threshold get crossed more often. So there could have been numerous years when we were close but the threshold wasn’t crossed. The recent years may just look more extreme when the steady march higher wasn’t as noticeable. A bit in a way like the last little push necessary to top a scale in one direction or another. This point isn’t always very obvious until after it has been crossed.

When I look at the most recent 8 winters and compared them directly to the previous 8, I see a larger scale regime shift in the polar domain and the PNA region....that's by far the primary cause of warmth to me in the northeast and not underlying CC change. The underlying CC trend makes our patterns warmer than they used to be all else equal, but it is not the primary driver of this type of shift we see where heights are lower in the NAO region and PNA region and higher over the east coast.

 

Now, maybe you are arguing that CC caused the PNA trough to dip so far south that Pasadena and many other areas that hardly ever get cold enough were getting snow? Maybe....that's a bold claim.... but I haven't seen compelling evidence on that front. I buy that the downstream ridging is warmer in a warmer world, but that still doesn't explain the larger regime shift which we have seen historically. Are you arguing that this new paradigm in the last 8 years is a permanent feature? I'd bet against that for sure. It doesn't mean we will go back to averaging 2008-2015 temps, but that same pattern would still be significantly colder than the 2016-2023 pattern even with underlying CC warming.

 

[40/70 Benchmark]

4 minutes ago, 40/70 Benchmark said:

The temperature of the Gulf stream is the least of my concerns when a PV lobe phases over Saskatchewan, as the Sierra is building a 50 foot snowpack.

There are also some instances when the huge positive anomaly over the gulf stream benefits us...for instance, perhaps it augments cyclogensis a bit more than it would have in 1955 and accordingly, heights crash just a bit more. There will eventually be a tipping point, but we aren't there yet. as evidenced by the past 20 years of snowfall along the east coast.

Like volcanic eruptions and SSW, the impact of GW is too simplified because we don't fully comprehend it and are still learning as we go.

[so_whats_happening]

20 hours ago, so_whats_happening said:

Yea coming from an area that is highly variable in general this is the snow graph from Millersville just SW of me from 1926 to what looks like 2021 (unfortunately 2022 and 2023 not on their but 15.0" and 0.9" respectively).

Average is about 27.4" according to the month to month break down, feel this has gone up a bit from about 24-25" but would have to double check. We are not immune to really bad winters around here but the frequency of not having snow or having alot of snow has definitely changed a bit seems to be a one or the other situation around here.

So going off this we had a deeply negative PDO in the 50's

1950/51: around -2 to -3 over the summer (Neutral ENSO) ~7" of snow

1951/52: was a bit more relaxed but still averaged around -1 and dipped to -2 in winter. (El Nino) ~27" of snow

1955/56: deeply negative again (-2 to -3) at the levels experienced in 1950/51 (moderate to strong La Nina) ~28" of snow

1956/57: again around -1 to -2 (Neutral ENSO)  ~18" of snow

1958/59: neutral to +PDO (strong El Nino) ~8" of snow

1960's were full of snow except for 1967/68 that had ~18"  which was a neutral year (cool PDO didn't average much below -1, with a spike in july august to around -1.5 area)

Early 60's had a -PDO regime that relaxed through much of the mid to late 60's and we had some high snowfall years. Early 70s came back with a -PDO period as well then relaxed.

So strong Nino and +PDO don't go well around here, neutral ENSO and -PDO do not go well around here, La Nina and -PDO are ehh around here. So with the enhancement of the warmer Atlantic it probably nudged us over to lower snow totals during a -PDO/ La Nina pattern there was already a ridge pattern in the east due to the -PNA but it is now enhanced due to warmer waters off the coast creating a stronger ridge profile not necessarily a deeper -PDO profile.

PDO data: https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_OC_PDO.htmlTable?time,PDO

I only state this as being a Mid Atlantic resident.

[bluewave]

11 minutes ago, 40/70 Benchmark said:

Exactly. GW is a very polarizing issue....many folks just can't distinguish between someone how feels as though there is rampant overattributing, like myself, from someone who is denying that it exists. It is possible to acknowledge the reality of GW while feeling that it becomes a convenient excuse for everything and anything...whether it be consciously, or unconsciously.

Unfortunately, GW often gets framed as a political issue since there are some that recommend specific policy prescriptions whether they will be effective or not. I look at this as a way to understand how we can better predict and adapt weather patterns that become more frequent as a result. I don’t care much for politics so I completely get how even talking about GW turns some off and makes them less interested. I even saw an interview with Anthony Watts on PBS when he stated that one of his main issues with GW is some are going to use it to force a political ideology on someone else. He hinted that if he didn’t see his political or economic beliefs getting threatened, then he may not have pushed back so hard against GW. So the inability to separate science from politics can be quite a downfall for society. Even more so sometimes than the original challenge like a warming climate.

[40/70 Benchmark]

2 minutes ago, so_whats_happening said:

So going off this we had a deeply negative PDO in the 50's

1950/51: around -2 to -3 over the summer (Neutral ENSO) ~7" of snow

1951/52: was a bit more relaxed but still averaged around -1 and dipped to -2 in winter. (El Nino) ~27" of snow

1955/56: deeply negative again (-2 to -3) at the levels experienced in 1950/51 (moderate to strong La Nina) ~28" of snow

1956/57: again around -1 to -2 (Neutral ENSO)  ~18" of snow

1958/59: neutral to +PDO (strong El Nino) ~8" of snow

1960's were full of snow except for 1967/68 that had ~18"  which was a neutral year (cool PDO didn't average much below -1, with a spike in july august to around -1.5 area)

Early 60's had a -PDO regime that relaxed through much of the mid to late 60's and we had some high snowfall years. Early 70s came back with a -PDO period as well then relaxed.

So strong Nino and +PDO don't go well around here, neutral ENSO and -PDO do not go well around here, La Nina and -PDO are ehh around here. So with the enhancement of the warmer Atlantic it probably nudged us over to lower snow totals during a -PDO/ La Nina pattern there was already a ridge pattern in the east due to the -PNA but it is now enhanced due to warmer waters off the coast creating a stronger ridge profile not necessarily a deeper -PDO profile.

PDO data: https://oceanview.pfeg.noaa.gov/erddap/tabledap/cciea_OC_PDO.htmlTable?time,PDO

I only state this as being a Mid Atlantic resident.

Well, you will definitely reach that threshold the lower in latitude and elevation a given locale is.

[40/70 Benchmark]

8 minutes ago, ORH_wxman said:

When I look at the most recent 8 winters and compared them directly to the previous 8, I see a larger scale regime shift in the polar domain and the PNA region....that's by far the primary cause of warmth to me in the northeast and not underlying CC change. The underlying CC trend makes our patterns warmer than they used to be all else equal, but it is not the primary driver of this type of shift we see where heights are lower in the NAO region and PNA region and higher over the east coast.

 

Now, maybe you are arguing that CC caused the PNA trough to dip so far south that Pasadena and many other areas that hardly ever get cold enough were getting snow? Maybe....that's a bold claim.... but I haven't seen compelling evidence on that front. I buy that the downstream ridging is warmer in a warmer world, but that still doesn't explain the larger regime shift which we have seen historically. Are you arguing that this new paradigm in the last 8 years is a permanent feature? I'd bet against that for sure. It doesn't mean we will go back to averaging 2008-2015 temps, but that same pattern would still be significantly colder than the 2016-2023 pattern even with underlying CC warming.

 

Precisely.

[so_whats_happening]

1 minute ago, 40/70 Benchmark said:

Well, you will definitely reach that threshold the lower in latitude and elevation a given locale is.

Going solely off the idea of 1955/56 being a moderate/strong La Nina and having a -PDO of near -3 to last year having a moderate La Nina and a -PDO of about -2.5

 

[ORH_wxman]

1 minute ago, so_whats_happening said:

Going solely off the idea of 1955/56 being a moderate/strong La Nina and having a -PDO of near -3 to last year having a moderate La Nina and a -PDO of about -2.5

 

Actually not a terrible match over North America, though the PNA trough is deeper in 2022-23 and the NAO block is in a much better spot in '55-56 for northeast snow (west based near Hudson Bay and Baffin).

[so_whats_happening]

3 minutes ago, ORH_wxman said:

Actually not a terrible match over North America, though the PNA trough is deeper in 2022-23 and the NAO block is in a much better spot in '55-56 for northeast snow (west based near Hudson Bay and Baffin).

55/56 gave us in the mid atlantic around 28" of snow that winter 22-23 gave us 0.9" both solidly negative PDO signals and both in a moderate La Nina pattern. I unfortunately don't have SST reanalysis for 55/56.

By far the biggest difference was the Pacific 55/56 could have a similar ish look had we not had a +WPO pattern this past year. 

[40/70 Benchmark]

4 minutes ago, ORH_wxman said:

Actually not a terrible match over North America, though the PNA trough is deeper in 2022-23 and the NAO block is in a much better spot in '55-56 for northeast snow (west based near Hudson Bay and Baffin).

I was about to analyze the polar domain, but you saved me the trouble. Again, not arguing identical patterns would be warmer now, nor that those would have some impact on the H5 pattern, but that was not the primary issue last year. Did it cost us a few to perhaps several inches in a season with a real dearth of well-timed polar airmasses in the source region of se Canada? Probably.

[bluewave]

19 minutes ago, ORH_wxman said:

When I look at the most recent 8 winters and compared them directly to the previous 8, I see a larger scale regime shift in the polar domain and the PNA region....that's by far the primary cause of warmth to me in the northeast and not underlying CC change. The underlying CC trend makes our patterns warmer than they used to be all else equal, but it is not the primary driver of this type of shift we see where heights are lower in the NAO region and PNA region and higher over the east coast.

 

Now, maybe you are arguing that CC caused the PNA trough to dip so far south that Pasadena and many other areas that hardly ever get cold enough were getting snow? Maybe....that's a bold claim.... but I haven't seen compelling evidence on that front. I buy that the downstream ridging is warmer in a warmer world, but that still doesn't explain the larger regime shift which we have seen historically. Are you arguing that this new paradigm in the last 8 years is a permanent feature? I'd bet against that for sure. It doesn't mean we will go back to averaging 2008-2015 temps, but that same pattern would still be significantly colder than the 2016-2023 pattern even with underlying CC warming.

 

I would probably take a route closer to these studies in explaining the last 8 winters. As to why this became so much more pronounced now could be related to the interactions with other weather patterns along with changes in the AMOC. Plus some potential background patterns in the climate system that may respond in a tipping fashion. But as to whether these elements permanently tip or switch back or another state in the future with further warming remains to be seen.

 

 

 

Posted Wednesday at 12:41 PM

 

https://repository.library.noaa.gov/view/noaa/32935

Twofold expansion of the Indo-Pacific warm pool warps the MJO life cycle
 

https://iopscience.iop.org/article/10.1088/1748-9326/ac5edf/meta

Abstract

The Indo-Pacific warm pool (IPWP) has warmed and expanded substantially over the past decades, which has significantly affected the hydrological cycle and global climate system. It is unclear how the IPWP will change in the future under anthropogenic (ANT) forcing. Here, we quantify the human contribution to the observed IPWP warming/expansion and adjust the projected IPWP changes using an optimal fingerprinting method based on Coupled Model Intercomparison Project phase 6 (CMIP6) simulations. We find that more than 95% rapid warming and 85% expansion of the observed IPWP are detected and attributable to human influence. Furthermore, human activities affect IPWP warming through both greenhouse gases and ANT aerosols. The multiple model ensemble mean can capture the ANT warming trend and tends to underestimate the ANT warming trend. After using the observation constraint, the IPWP warming is projected to increase faster than that of the ensemble mean in the 21st Century, and the Indian Ocean warm pool is projected to expand more than previously expected. The rapid warming and expansion of IPWP over the rest of the 21st century will impact the climate system and the life of human beings.

[40/70 Benchmark]

7 minutes ago, bluewave said:

I would probably take a route closer to these studies in explaining the last 8 winters. As to why this became so much more pronounced now could be related to the interactions with other weather patterns along with changes in the AMOC. Plus some potential background patterns in the climate system that may respond in a tipping fashion. But as to whether these elements permanently tip or switch back or another state in the future with further warming remains to be seen.

 

 

 

Posted Wednesday at 12:41 PM

 

https://repository.library.noaa.gov/view/noaa/32935

Twofold expansion of the Indo-Pacific warm pool warps the MJO life cycle
 

https://iopscience.iop.org/article/10.1088/1748-9326/ac5edf/meta

Abstract

The Indo-Pacific warm pool (IPWP) has warmed and expanded substantially over the past decades, which has significantly affected the hydrological cycle and global climate system. It is unclear how the IPWP will change in the future under anthropogenic (ANT) forcing. Here, we quantify the human contribution to the observed IPWP warming/expansion and adjust the projected IPWP changes using an optimal fingerprinting method based on Coupled Model Intercomparison Project phase 6 (CMIP6) simulations. We find that more than 95% rapid warming and 85% expansion of the observed IPWP are detected and attributable to human influence. Furthermore, human activities affect IPWP warming through both greenhouse gases and ANT aerosols. The multiple model ensemble mean can capture the ANT warming trend and tends to underestimate the ANT warming trend. After using the observation constraint, the IPWP warming is projected to increase faster than that of the ensemble mean in the 21st Century, and the Indian Ocean warm pool is projected to expand more than previously expected. The rapid warming and expansion of IPWP over the rest of the 21st century will impact the climate system and the life of human beings.

Well, that is a big leap that will certainly warrant much more time to confidently discern. We have yet to see one of those theories persevere, whether it be the warm blob in the north Pacific, or changes in the arctic....time will tell.

[ORH_wxman]

18 minutes ago, 40/70 Benchmark said:

Exactly. GW is a very polarizing issue....many folks just can't distinguish between someone how feels as though there is rampant overattributing, like myself, from someone who is denying that it exists. It is possible to acknowledge the reality of GW while feeling that it becomes a convenient excuse for everything and anything...whether it be consciously, or unconsciously.

I think it's good to try and discuss the impacts....so I don't mind these discussions. I've seen a lot of over-attribution in the last 15 years to specific patterns that then change and we stop hearing about them for a while and we move onto the next attribution study. CC is related to all this in some form, but untangling it from natural variation is hard when it comes to specific pattern regimes....and this is doubly true when we are discussing 8 year chunks. That's a terribly small sample to make a lot of longer term conclusions from.

We know what the longer term trend is, but trying to "Adjust" our projections of temperature changes or pattern changes based on very short timescales has it's major drawbacks.

 

I know the longterm trend for ORH temperatures in DJFM is 0.4F per decade....but if we use only the trend since 2008, then it's at 2F (!!) per decade. So that's the end of the debate, right? We can assume it's going to be 2F per decade over the next 20 years or so? Nope, if we did the exact same exercise from 1985-2000, the trend was also 2F per decade....but then the next 15 years was actually a negative trend of -1.1F per decade. In the mean, the positive trends will outweigh the negative trends, but from an empirical standpoint, there is no evidence that they just continue unabated. I'm certainly open to some "tipping point" that has permanently given us a Philadelphia winter climate, but I would obviously treat such claims with extreme skepticism and they should be until evidence is way stronger.

[so_whats_happening]

21 minutes ago, 40/70 Benchmark said:

I was about to analyze the polar domain, but you saved me the trouble. Again, not arguing identical patterns would be warmer now, nor that those would have some impact on the H5 pattern, but that was not the primary issue last year. Did it cost us a few to perhaps several inches in a season with a real dearth of well-timed polar airmasses in the source region of se Canada? Probably.

The polar domain having higher heights means less cold is able to stay up north and be produced versus 1955/56 so in that sense cold air would have spilled through much of the lower latitudes you can see the difference in the amount of cold air. Think this really could have played a major role as there was no issue with precip across the area and many times down this way we were right on the edge of getting snow just ended up too warm. So it is very possible we could have had similar results had the overall atmosphere and polar domain not been warmer.

Again wish I had an SST reanalysis for 55/56. +WPO versus -WPO winter also played a significant role long sustained jet versus a wavier jet.

There also seems to be some counter balance situation between northern hemisphere and southern hemisphere that is interesting to note, probably on a decadal scale of sorts.

[so_whats_happening]

4 minutes ago, ORH_wxman said:

I think it's good to try and discuss the impacts....so I don't mind these discussions. I've seen a lot of over-attribution in the last 15 years to specific patterns that then change and we stop hearing about them for a while and we move onto the next attribution study. CC is related to all this in some form, but untangling it from natural variation is hard when it comes to specific pattern regimes....and this is doubly true when we are discussing 8 year chunks. That's a terribly small sample to make a lot of longer term conclusions from.

We know what the longer term trend is, but trying to "Adjust" our projections of temperature changes or pattern changes based on very short timescales has it's major drawbacks.

 

I know the longterm trend for ORH temperatures in DJFM is 0.4F per decade....but if we use only the trend since 2008, then it's at 2F (!!) per decade. So that's the end of the debate, right? We can assume it's going to be 2F per decade over the next 20 years or so? Nope, if we did the exact same exercise from 1985-2000, the trend was also 2F per decade....but then the next 15 years was actually a negative trend of -1.1F per decade. In the mean, the positive trends will outweigh the negative trends, but from an empirical standpoint, there is no evidence that they just continue unabated. I'm certainly open to some "tipping point" that has permanently given us a Philadelphia winter climate, but I would obviously treat such claims with extreme skepticism and they should be until evidence is way stronger.

Fair points all around

[40/70 Benchmark]

33 minutes ago, so_whats_happening said:

Going solely off the idea of 1955/56 being a moderate/strong La Nina and having a -PDO of near -3 to last year having a moderate La Nina and a -PDO of about -2.5

 

To me, its clear 2023 had a slightly deeper RNA trough. Also, some of the snowfall is just simple variance due to the chaos of the atmosphere. We def. had some bad synoptic breaks last season independent of global warming.

[so_whats_happening]

1 minute ago, 40/70 Benchmark said:

To me, its clear 2023 had a slightly deeper RNA trough. Also, some of the snowfall is just simple variance due to the chaos of the atmosphere. We def. had some bad synoptic breaks last season independent of global warming.

I think we can both agree the west Pacific played a significant role in how the winter went down in both scenarios given a fairly similar stance in large scale patterns such as ENSO/PDO. The only thing I have ever found with higher heights over the poles is less cold to work with. 

[40/70 Benchmark]

6 minutes ago, so_whats_happening said:

I think we can both agree the west Pacific played a significant role in how the winter went down in both scenarios given a fairly similar stance in large scale patterns such as ENSO/PDO. The only thing I have ever found with higher heights over the poles is less cold to work with. 

Well, higher heights over the poles means a weaker PV.....but the catch is that what cold there is will be more readily available to the mid latitudes. However, given the depth of the trough in the west, the vast majority funneled out there.

 

[George001]

4 hours ago, bluewave said:

That 2nd lowest on record -2.1 last summer told us everything we needed to know about last winter well ahead of time.

https://psl.noaa.gov/enso/mei/

I don’t know about that, strong la Nina patterns aren’t necessarily bad in New England. 2007-2008 was pretty good in Boston, and 2010-2011 had the lowest MEI on record and a raging -PDO. The summer of 2010 had an MEI of -2.5 (super).

[griteater]

45 minutes ago, so_whats_happening said:

The polar domain having higher heights means less cold is able to stay up north and be produced versus 1955/56 so in that sense cold air would have spilled through much of the lower latitudes you can see the difference in the amount of cold air. Think this really could have played a major role as there was no issue with precip across the area and many times down this way we were right on the edge of getting snow just ended up too warm. So it is very possible we could have had similar results had the overall atmosphere and polar domain not been warmer.

Again wish I had an SST reanalysis for 55/56. +WPO versus -WPO winter also played a significant role long sustained jet versus a wavier jet.

There also seems to be some counter balance situation between northern hemisphere and southern hemisphere that is interesting to note, probably on a decadal scale of sorts.

Good link here for SST re-analysis - psl.noaa.gov/cgi-bin/gcos_wgsp/printpage.pl

You can compare older years against its climate period.  Image below is Oct-Dec 1955 compared against 1930-1960...hardcore -PDO & La Nina

[40/70 Benchmark]

10 minutes ago, griteater said:

Good link here for SST re-analysis - psl.noaa.gov/cgi-bin/gcos_wgsp/printpage.pl

You can compare older years against its climate period.  Image below is Oct-Dec 1955 compared against 1930-1960...hardcore -PDO & La Nina

That season was actually my top analog last year, so I was obviously expecting more snow haha

[so_whats_happening]

55 minutes ago, 40/70 Benchmark said:

Well, higher heights over the poles means a weaker PV.....but the catch is that what cold there is will be more readily available to the mid latitudes. However, given the depth of the trough in the west, the vast majority funneled out there.

 

Bolded: absolutely that should be a well known idea at this point no differentiation in opinion on that subject. Higher heights unfortunately all year round in conjunction warming oceans leaves with less severe cold outbreaks.

What dictates trough orientation is other things involved and most certainly the pacific pattern influenced it this past year in comparison to a year of similar status. You can see the difference in temp profiles across the US between the two years although scale is different, on the colder end as already discussed, but here nor there you get the idea. Here are the pressure anomalies in comparison you can see weaker pacific high pressure potential and more prominent troughing pattern across the north pacific from Sea of Okhotsk to much of the Bering sea driving it right down the west coast. Where as in 55/56 you had a much stronger high pressure region having cold spill into West Pacific/ Japan and another coming from the north Canada/Alaska region to the Pac NW.