2024-2025 La Nina

[so_whats_happening]

Here is the 90 day SST bonkers amount of warm anomalies showing up just south of the Aleutians. This will change over time since there is a 12mb file limit on posts.

[so_whats_happening]

Here was the 500mb pattern from 2/28-5/28

Here is the preceding 3 month period when we were in full swing Nino territory (11/28-2/28)

Changes but notably the ridging has indeed pushed further east into the north Pacific so we may start to see a cooling in time of the WPAC? Especially if we do have a decent typhoon season but yet to be seen as of now. Which I would guess we eek out a typical WPAC season given we are transitioning to La Nina status.

[so_whats_happening]

Just for comparison sake 97-98 compared to 23-24. Winter 500mb seemed pretty spot on as far as placement with key features of course intensities varied spring however does have some similarities thus far but not all the same. Should be interesting to see how we continue into summer.

[chubbs]

21 hours ago, bluewave said:

There are a few ways that a warming climate can manifest in our our weather patterns. The first way is linear by which the winters gradually become warmer and snowfall decreases. But there will still be colder and snowier winters in the mix along the way. I think this gradual shift is what most people are more familiar with. But the second way is more non-linear or threshold dependent. The climate models don’t really do well at picking out these temperature thresholds in advance. So they usually don’t become obvious until after a certain period of time has passed. It does appear that we may have crossed a temperature threshold during the 15-16 super El Niño. But we still probably need to see how winter temperatures progress through 2030 in order to know whether it was a shift or just loading the dice for warmer winters with some colder ones still mixed in.

The snowfall experience has been different for us. From 93-94 through 17-18 we saw a steady increase in snowfall. But the off seasons like 97-98, 01-02, 06-07, and 11-12 fell near the bottom of the list. So it was an all or nothing snowfall pattern and lacking the median snowfall seasons which were more common from the 60s to early 90s. While the better seasons were more frequent, we traded the median seasons for near record low seasons. Since the most recent downturn only began in 18-19 for snowfall, more time is need to know if we entered a longer term declining phase or passed a threshold where the much lower seasons replace the higher ones as the norm. In any event, the 2010s record snowfall decade would be a tough act to follow even in a more stable climate absent the warming trend. 

Yes climate change doesn't have to be steady, particularly at the regional level. Our regional snowfall history is uneven so wouldn't expect a linear change. Its possible that the 2015/16 nino kicked us into a new regional winter/snowfall state. If so the current nino may kick us into another. Using global SST as an example the impact on the global climate system is just as large. Of course in the absence of a good scientific study, its also possible that our snowfall wasn't impacted by the 15/16 nino. We'll see.

[snowman19]

2 hours ago, so_whats_happening said:

Here is the 90 day SST bonkers amount of warm anomalies showing up just south of the Aleutians. This will change over time since there is a 12mb file limit on posts.

The furnace south of the Aleutians (if it continues), would strongly support Aleutian ridging/Aleutian high going into the cold season. Which would fit typical Niña climo

[Terpeast]

5 hours ago, so_whats_happening said:

Here is the 90 day SST bonkers amount of warm anomalies showing up just south of the Aleutians. This will change over time since there is a 12mb file limit on posts.

Such a broad area of warm ssta across 90% of the north pacific makes me suspect that the global circulation cells are expanding northward, resulting in a more northward shift in the jet stream. If this keeps up through winter, we’ll likely see the jet stream blast warm pac air across NA, except it won’t be going underneath as in a nino… but rather over the top. Scary to think about potential temp departures come winter.

In case I wasn't black pilled about this coming winter, I am now.

[bluewave]

Yeah, I agree with the authors description of the first and second EOFs of the PDO undergoing a remarkable evolution since 2014. 

 

Remarkable Changes in the Dominant Modes of North Pacific Sea Surface Temperature

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022GL101078

The second PC is mostly positive from 1990 to 2021 and strongly positive from 2014 to 2021 (Figure 6b), reflecting the positive SSTa across much of the North Pacific that EOF 1 alone does not capture. The weak negative lobe in the second EOF lessens the warming near the coast of North America. As EOF 2 describes less of the variance than EOF 1, it might be expected that its shape is more variable when calculated over different time periods, interestingly, the positive lobe in EOF 2 has grown steadily when calculated over successively longer time periods (Figure 6b, x-ticks). The positive lobe of EOF 2 filled up 98% of the North Pacific when calculated over the period 1950–2018 and similarly for HadISST data at 93% (Figure S1.6 in Supporting Information S1). While EOF 2 has not been invoked as often as the PDO as a measure of SST variability, the robust evolution since 2014 is still worthy of note.

 

Figure 6

Open in figure viewerPowerPoint

(a) The second EOF of SST over the PDO region for the entire time series (1950–2021). (b) The principal component for the second EOF is shown on the left y-axis using colored bars. The right y-axis (x symbols) shows the percentage of data points greater than zero in the second EOF from 1970 to 2021.

5 Conclusions

The fundamental result of this study is that the first EOF of SST in the North Pacific has changed starting in 2014. For more than 20 years, the PDO has been used to describe the state of the North Pacific. However, since the marine heatwave of 2014, there have been remarkable changes to the dominant mode of SST in the North Pacific. The spatial pattern of the first EOF of SST from 1950 to 2021 is notably different from the PDO, suggesting that though the PDO served as a useful metric of SST variations until 2014 (Johnstone & Mantua, 2014), it may no longer be as effective a climate index for the North Pacific. From 1950 until the 2014 MHW, the first EOF remained consistent in its proportion of positive and negative regions with both taking up roughly half the area of the North Pacific (and with the positive region taken to be the eastern Pacific). When EOFs are calculated from 1950 to endpoints after 2014, the first EOF has a maximum positive region covering 77% of the North Pacific, with a PC indicating the largest anomalies on record. These changes to the first EOF/PC of North Pacific SST are nothing short of remarkable.

In concert with these changes, the second EOF/PC of SST has also undergone profound evolution since 2014. This second EOF now accounts for approximately 18% of the variability, growing from 13% during the 1950–2013 period. The spatial structure of the second EOF now is positive over almost the entire basin, with a PC that has grown strongly positive in the last several years. Thus, the second EOF/PC describes warming over much of the Pacific not in the positive lobe of the first EOF.

A relevant aspect of our analysis is that we did not remove a trend from the data before calculating the EOFs and PCs. This is consistent with the original calculations of EOFs in the North Pacific (Davis, 1976) and more recent analysis by Johnstone and Mantua (2014), but inconsistent with the definition of the PDO which did have a global mean trend removed (Mantua et al., 1997; Zhang et al., 1997). Whether or not a trend was removed had little effect on the first EOF, and thus the PDO, until 2014. Two of our results lead to this conclusion: first, our first PC calculated between 1950 and 1993 agreed with the PDO with a correlation coefficient of 0.97; and second, our first EOF calculated with successively longer time series did not change in shape until 2014. There are many approaches to removing a trend from time series (Deser & Phillips, 2021; Frankignoul et al., 2017; Solomon & Newman, 2012). We investigated two of these approaches: first we removed a least-squares fit of a line to the global average temperature as in the original definition of the PDO (Figure S2 in Supporting Information S1), and second, we removed a least-squares fit of a line from each grid point in the North Pacific (Figure S3 in Supporing Information S1). In each case the EOF analysis reproduced the PDO spatial pattern and index, suggesting that the PDO remains a good measure for the variability relative to the trend. In general, removal of a trend (as by least-squares fitting of a line, e.g.,) tends to deemphasize the ends of a record. In our analysis, the inclusion of the trend highlights the fact that the warming in the eastern Pacific has increased notably in recent years, a fact that would be obscured if a linear trend had been removed.

The PDO is recognized to be a result of many processes that may cause temperature variability (Newman et al., 2016) rather than any singular phenomenon. The many processes that affect SST have apparently combined to create both this era of frequent marine heatwaves beginning in 2014 and a fundamental change to the first mode of SST. The persistence of the marine heatwaves was studied by Di Lorenzo and Mantua (2016) who also invoked a number of interacting processes, suggesting that the variance described by the PDO would increase in a warmer climate. Di Lorenzo and Mantua (2016) explicitly removed a trend before calculating the EOFs of SST, so that their EOFs described variance relative to the trend. The PDO is based on a constant spatial pattern defined by the EOF that described the most variance of SST through the mid 1990's. However, there is no guarantee that the EOFs of SST will remain constant as climate change continues. This concern about indices based on EOFs applies also to the North Pacific Gyre Oscillation (Di Lorenzo et al., 2008), which describes variance in sea surface height.

The PDO is widely used as a measure of temperature in the eastern boundary upwelling system along the west coast of North America (e.g., Weber et al., 2021). The period of persistent marine heatwaves since 2014 has made the PDO less useful as an index of temperature in this region because it does not reflect the recent increase. In general, using PCs from a basin-wide analysis as indices of temperature for specific regions may be problematic because the influences from distant parts of the basin affect the PCs. Options moving forward may include: (a) updating the definition of the first mode of temperature variability, as we have done here, (b) explicitly accounting for the trend in addition to the PDO for a measure of temperature, or (c) defining a new temperature metric in a specified area in the region as is done for the various measures of El Niño (Trenberth, 1997) or more recently as in the NEP index (Johnstone & Mantua, 2014). Interestingly, the NEP was first published just before the recent period of MHWs, and the value of the approach championed in Johnstone and Mantua (2014) has only increased. The wide-ranging effects of the recent period of MHWs are likely to be seen in continuing studies of the eastern North Pacific.

[Spartman]

https://www.x.com/commoditywx/status/1796588170747969744

[snowman19]

This high solar cycle continues to overperform

[mitchnick]

1 hour ago, snowman19 said:

This high solar cycle continues to overperform
 

Nice site for solar activity. 

https://solen.info/solar/index.html

[snowman19]

This SSTA animation is showing very well defined tropical instability waves (“TIWs”), which are indicative of real healthy La Niña event developing. Enhanced trade winds and easterly wind bursts usually follow. To me, this suggests that at the very least, a moderate event becoming more and more likely. It is forming more rapidly than both ‘98 and ‘10 were at this point in time @GaWx
 

[PhiEaglesfan712]

1 hour ago, snowman19 said:

This SSTA animation is showing very well defined tropical instability waves (“TIWs”), which are indicative of real healthy La Niña event developing. Enhanced trade winds and easterly wind bursts usually follow. To me, this suggests that at the very least, a moderate event becoming more and more likely. It is forming more rapidly than both ‘98 and ‘10 were at this point in time
 

I figured that it would be performing ahead of 1998 at this time, as that was a stronger nino that dissipated later. However, the fact that it is performing ahead of 2010 suggests this is going to be a strong la nina. Remember, the 2009-10 el nino peaked lower than 2023-24 (at least on the ONI).

[snowman19]

9 minutes ago, PhiEaglesfan712 said:

I figured that it would be performing ahead of 1998 at this time, as that was a stronger nino that dissipated later. However, the fact that it is performing ahead of 2010 suggests this is going to be a strong la nina. Remember, the 2009-10 el nino peaked lower than 2023-24 (at least on the ONI).

Agreed. When you see tropical instability waves that well pronounced, you know it means business. I think we see enhanced trades and easterly wind bursts (triggering upwelling and surface/subsurface cooling) shortly, which is typical with this kind of progression

[bluewave]

On 5/30/2024 at 1:42 PM, Typhoon Tip said:

Just anecdotally/observation on my part but agreed ... there does seem to be less occurrences of ridging over the eastern mid latitude continent during summers.  In fact, I've noticed more success in doing that in May's ... yup.

It's hard to say if this just some fractal at larger scales - repeating until it doesn't and it may take 10 years or whatever.  I have a sneaking suspicion though that coupling the geophysical circumstances of canonical western heights, with greater heat absorption spectrum associated with greenhouse gassing, might be triggering the western heights as the summer dominating mode. In other words, coupling/super-imposing those overwhelms...

Man... should a Sonoran heat release take place, however rarefying that may be ..., it would be interesting if one of these synergistic heat wave events would take place over the eastern continental mid latitudes - that might get it done.  And we'd put PHL-PWM into the VIP class with some of these other locations around the globe filling E.R.s and lighting up social media with conspiracy theories.  the latter's been funny actually.

 

Yeah, right in cue the ridge is returning to the Western US as we start June. This has been the dominant summer pattern since the 15-16 super El Niño. But the winter pattern has been the opposite with more of a trough over the Western US and record ridging and warmth over the Northeast. So that record NE PAC block during the 13-14 and 14-15 winters shifted to the summer. And the winters have had trouble maintaining any type of ridging In these areas as a trough has been dominating out West. The recent exception was during January 22. That was the result of the MJO 8 pattern. But most of the winter MJO activity has been in the phase 4-7 range since the 15-16 super El Niño. 

 

[GaWx]

On 5/29/2024 at 2:27 PM, GaWx said:

 The WCS daily PDO as of 5/28/24 has plunged further to -2.66, the lowest since at least late Oct of 2022 (not just since Sep of 2023, which dipped as low as ~-2.63 as this graph shows). That means that the equivalent NOAA daily PDO would likely be in the general vicinity of -3.4 to -3.7! The May 2024 NOAA PDO is likely going to be down to the -2.5 to -2.9 range as the WCS May 2024 PDO drops to ~-1.8 to -1.9.

Now look at the PDO: -3.04

[40/70 Benchmark]

8 hours ago, snowman19 said:

This high solar cycle continues to overperform
 

If the solar peak ends up delayed, then that also delays the hostile period of geomagnetic particle disbursing solar wind that makes episodes of high latitude blocking so elusive.

[snowman19]

16 hours ago, 40/70 Benchmark said:

If the solar peak ends up delayed, then that also delays the hostile period of geomagnetic particle disbursing solar wind that makes episodes of high latitude blocking so elusive.

If you look back at every -NAO/-AO winter over the last 44+ years, since 1979, every single one of them occurred at a solar minimum, with a low number of sunspots and low geomag…..Without any exceptions. 

I don’t think we need to be at the exact peak of this solar max for it to be hostile to AO/NAO blocking. The high solar flux/high sunspots/high geomag alone argue very strongly against any sustained blocking in those domains this winter. That said, some experts are predicting that this solar max cycle peaks this winter/early next year. This should be an interesting one to watch

[snowman19]

If you look back at every -NAO/-AO winter over the last 44+ years, since 1979, every single one of them occurred at a solar minimum, with a low number of sunspots and low geomag…..Without any exceptions. 
I don’t think we need to be at the exact peak of this solar max for it to be hostile to AO/NAO blocking. The high solar flux/high sunspots/high geomag alone argue very strongly against any sustained blocking in those domains this winter. That said, some experts are predicting that this solar max cycle peaks this winter/early next year. This should be an interesting one to watch

“How long does solar maximum last?

Though solar maximum is often referred to in terms of the month where the sunspot number peaks, the associated period of high activity lasts longer than that — from one year to over two years. So, in the current solar maximum, we expect high levels of solar activity throughout 2024 and likely into 2025.”

https://www.space.com/what-is-solar-maximum-and-when-will-it-happen#:~:text=Though%20solar%20maximum%20is%20often,2024%20and%20likely%20into%202025.

[snowman19]

With the epic furnace in the Atlantic (++AMO), if this (dust) continues, it may be the only thing that could help cap the number of cyclones that form this hurricane season, otherwise it’s probably going to be real bad given the other antecedent conditions globally
 

[40/70 Benchmark]

14 hours ago, snowman19 said:

If you look back at every -NAO/-AO winter over the last 44+ years, since 1979, every single one of them occurred at a solar minimum, with a low number of sunspots and low geomag…..Without any exceptions. 

I don’t think we need to be at the exact peak of this solar max for it to be hostile to AO/NAO blocking. The high solar flux/high sunspots/high geomag alone argue very strongly against any sustained blocking in those domains this winter. That said, some experts are predicting that this solar max cycle peaks this winter/early next year. This should be an interesting one to watch

First of all, I'm not necessarily referring to a -NAO/AO season....I wrote "episodes of high latitude blocking". Second, my point is that geomagnetic energy and solar wind peak during the descending phase, not solar max...thus the descending phase is most hostile...more so than max.

[BuffaloWeather]

1 hour ago, 40/70 Benchmark said:

First of all, I'm not necessarily referring to a -NAO/AO season....I wrote "episodes of high latitude blocking". Second, my point is that geomagnetic energy and solar wind peak during the descending phase, not solar max...thus the descending phase is most hostile...more so than max.

Is blocking really tied to solar cycles? That sounds insane to me. How much data is there to prove that true?

[bluewave]

On 6/1/2024 at 2:03 PM, GaWx said:

Now look at the PDO: -3.04

Being driven by that ridiculous marine heat wave to the east of Japan and north of Hawaii. 

 

https://x.com/extremetemps/status/1797596879703908370
 

May 2024 in #Japan had a temperature anomaly of +0.67C above normal and was the 16th consecutive warmer than average month. Tokyo hasn't seen any colder than average month since late 2022. Maps by JMA.

https://x.com/MercatorOcean/status/1795090981810819261

This week's Marine Heatwave Bulletin is online! For more data and forecasts, click here https

 

 

 

 

 

 

[40/70 Benchmark]

10 hours ago, BuffaloWeather said:

Is blocking really tied to solar cycles? That sounds insane to me. How much data is there to prove that true?

Fair question with respect to anything pertaining to seasonal forecasting.

[snowman19]

12 hours ago, 40/70 Benchmark said:

First of all, I'm not necessarily referring to a -NAO/AO season....I wrote "episodes of high latitude blocking". Second, my point is that geomagnetic energy and solar wind peak during the descending phase, not solar max...thus the descending phase is most hostile...more so than max.

Not disagreeing with you. Either way it looks like this solar max is going to peak sometime in early 2025, then we start descending 

[snowman19]

19 hours ago, snowman19 said:

With the epic furnace in the Atlantic (++AMO), if this (dust) continues, it may be the only thing that could help cap the number of cyclones that form this hurricane season, otherwise it’s probably going to be real bad given the other antecedent conditions globally
 

@40/70 Benchmark I wonder if this ends up being more of a factor than people, including myself were thinking with the Atlantic hurricane season? Could it possibly cause all the record tropical season forecasts to bust IF it continues?

 

 

 

 

[40/70 Benchmark]

3 hours ago, snowman19 said:

@40/70 Benchmark I wonder if this ends up being more of a factor than people, including myself were thinking with the Atlantic hurricane season? Could it possibly cause all the record tropical season forecasts to bust IF it continues?

 

 

 

 

SAL is expected this time of year....there are a few reasons that we don't usually see long-tracking CV systems in June. The earliest I recall is Bertha in early July of 1996.

[40/70 Benchmark]

3 hours ago, snowman19 said:

Not disagreeing with you. Either way it looks like this solar max is going to peak sometime in early 2025, then we start descending 

Which means we can probably get away with some bout(s) of blocking this year, theoretically speaking. Not suggesting it will be a favorable season per se, but perhaps not a wall-to-wall death star PV.

Doesn't mean it can't end up like that, either....just something to think about-

[snowman19]

26 minutes ago, 40/70 Benchmark said:

Which means we can probably get away with some bout(s) of blocking this year, theoretically speaking. Not suggesting it will be a favorable season per se, but perhaps not a wall-to-wall death star PV.

Doesn't mean it can't end up like that, either....just something to think about-

Maybe, question is when in “early” 2025 does it peak and start descending? Is it January, February, March? 

[Terpeast]

5 hours ago, bluewave said:

Being driven by that ridiculous marine heat wave to the east of Japan and north of Hawaii. 

 

https://x.com/extremetemps/status/1797596879703908370
 

May 2024 in #Japan had a temperature anomaly of +0.67C above normal and was the 16th consecutive warmer than average month. Tokyo hasn't seen any colder than average month since late 2022. Maps by JMA.

https://x.com/MercatorOcean/status/1795090981810819261

This week's Marine Heatwave Bulletin is online! For more data and forecasts, click here https

 

 

 

 

 

 

I still wonder if the discharge of radioactive water off Japan has played, or is playing a role, in this marine heat wave. Perhaps a small role, and its more likely that changes in atmospheric circulations thanks to the WP warm pool is playing a larger role. But I don’t really know for sure.

Also notice the marine heat wave seems to be spreading eastward with its extent all the way south of the GOA. One way we could see wholesale pacific changes is if that heat wave spreads all the way to the western coast of NA, while it abates off Japan and NW of Hawaii. Then we’d circle back to a 2013-15-like pattern. But that remains to be seen whether it happens, if ever. And if it does, it could take a few years.

 

[GaWx]

9 minutes ago, snowman19 said:

Maybe, question is when in “early” 2025 does it peak and start descending? Is it January, February, March? 

 Does it matter that much exactly what month the peak is determined to have occurred (which I’d think would have to be after the fact, regardless) if the peak is indeed going to end up occuring in early 2025?