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Snowy Hibbo

Teleconnections: Advanced Meteorological Discussion

Snowy Hibbo

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22 minutes ago, MattHugo said:

Just a quick request for a link to a journal/paper or another resource if possible;

 

 

...but does any member know of any literature on where the upper wQBO and lower eQBO combination, like this winter, doesn't actually limit SSW formation or any information on this link between this type of QBO evolution and SSW development?

 

Also, looking for more info on how EL Nino links to AAM and mountain torque events if possible too.

 

I know, up above, there's an array of links to 33andrain, but just thought I'd ask directly if anyone knows of any journals/papers etc.

 

Many thanks in advance for any links,

 

Matt.

You should be able to find that info within this thread...

 

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2 hours ago, MattHugo said:

Just a quick request for a link to a journal/paper or another resource if possible;

 

 

...but does any member know of any literature on where the upper wQBO and lower eQBO combination, like this winter, doesn't actually limit SSW formation or any information on this link between this type of QBO evolution and SSW development?

 

Also, looking for more info on how EL Nino links to AAM and mountain torque events if possible too.

 

I know, up above, there's an array of links to 33andrain, but just thought I'd ask directly if anyone knows of any journals/papers etc.

 

Many thanks in advance for any links,

 

Matt.

I don't have specific papers, however there is this map.

IMG_5810.JPG

It shows that there is a correlation between Easterly QBO- Westerly QBO transitions and more SSWs. That was fine by Sam Lillo, and has been posted by @Webberweather on Twitter in the past, so those two may have additional papers/evidence to go with the conclusions that can be made from the above chart.

 

I personally think that pretty much everything you need to do with the AAM and ENSO relationship is in this thread, but if you are looking for specific papers, here is a few that intrigue me:

 

https://www.earth-syst-dynam.net/8/1009/2017/esd-8-1009-2017.pdf

 

This is a case study through Michigan storms in relation to the GWO:

https://www.weather.gov/media/grr/GLOM2015/Presentations/Marino_GWOSevereStorms.pdf

 

The GSDM paper by Weickmann and Berry also demonstrates it in the specific GSDM stages 1 & 3:

https://www.33andrain.com/topic/921-a-synoptic–dynamic-model-of-subseasonal-atmospheric-variability/

 

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May I ask could be at 12th december mjo 5 phase with MT effects set up first days of January SSW?

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This 12z run difference between the EC and the GFS is raising a few eyebrows. For those expecting a more amplified pattern after opening week of Dec, me included!...

 

 

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1 minute ago, burgwx said:

Thanks! Still lurking right now haha. Lots of good threads to read through like this one...

Welcome to 33andrain! Thank you for joining 

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33 minutes ago, burgwx said:

Thanks! Still lurking right now haha. Lots of good threads to read through like this one...

Great to have you on board, Tomer!! 

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great post

7 hours ago, Bring Back 1962-63 said:

ENSO UPDATE - IS A BASIN WIDE EVENT NOW MORE LIKELY?

 

During the last 3 months or so we have seen repeated attempts for El Nino conditions to assert themselves. As often happens, we have seen a number of setbacks and perhaps some of these have been slightly more substantial compared to some previous events. Certainly the model consensus for the Nino episode "was" delayed by a couple of months. There has been some problems with ocean-atmosphere coupling and the surface conditions have not always been playing ball. We have seen repeated WWBs (westerly wind bursts) initiate warming in the WPAC and this has sometimes pushed through further east only for some temporary easterly trades to scrub out the progress with more Nina-like conditions.  A sort of feedback loop developed but with each surge taking SST anomalies somewhat higher. Kelvin waves have passed through with temporary warming and cooling of the upper sea surface layers.  The EPAC has been particularly variable as it often is with the battle of colder waters being pushed up from the south along the Chilean and Peruvian coasts on the Humbolt current and often enhanced by the -ve SPO (South Pacific Oscillation) favouring stronger winds blowing from the south and south east.  These cold waters kept mixing in and sometimes pushed further westwards towards the east CPAC.  This led many commentators to believe (at least initially) that we would likely see a CPAC Nino, perhaps a Modoki, rather than a basin wide event and certainly not an EPAC event.

 

Now I appreciate that others have stronger knowledge than me of the impacts of some of the key Teleconnections and how they influence ENSO changes. The AAM state, FT, the MJO, the IOD, WWBs, Kelvin Waves, ocean-atmosphere coupling, the Walker Circulation, the thermocline and the deeper sub surface currents all interplay and have a lesser of greater role in dictating the ENSO state, the timing of changes, the strength of Nino and Nina episodes and position of them (type and flavour).  I feel that we may have seen some rather more decisive changes during the last couple of weeks.  I'll go through the current conditions and look at yesterday's NOAA weekly ENSO update, their monthly ENSO report and the model consensus.  I'll leave it to the specialists to comment on those Teleconnections while I'll just update the current SST anomalies and comment on them.

27a.PNG

We have finally reached a point with more consistent SSTs along the Equator with a strong temp gradient just to the south in the CPAC and the EPAC.

27b.PNG

The anomalies are +ve at the Pacific Equator except in the extreme west.

27c.PNG

Weekly anomalies show that there has been further cooling around 100W to 120W but note that strong warming along the Chilean and Peruvian coasts.  I drew attention to this in my last update on here on November 14th (link: https://www.33andrain.com/topic/868-teleconnections-a-more-technical-discussion/?do=findComment&comment=102372). I stated that these were the highest +ve anomalies there for nearly 3 years (prior to the last La Nina event) and suggested that the -ve SPO appeared to be weakening and that the EPAC would see a strong rise in SSTs (see 4th chart below).  The Nino region map is shown further below (within the NOAA report).

27d.PNG

The main ENSO yardstick region, Nino 3.4 in the CPAC, fell back strongly in the first half of this month but has levelled off since then around or just above the +0.5c anomaly.

27e.PNG

Nino 3 in the ECAP has seen a similar pattern

27f.PNG

Nino 4 in the WCPAC has seen a similar trend but has held at a higher level.

27g.PNG

Now Nino 1+2 in the EPAC.  The anomalies have been rising pretty steadily for the last 2 weeks and are now much higher than in the other regions (more later on this).

 

The latest NOAA weekly report was published this morning. Although this is dated November 26th, the comments and the charts are from some 3 to 4 days ago. Here's a link to the full report:     http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

 

I'll show a few of the charts and comment on each one below:

27h.PNG

While the chances of an imminent El Nino episode have now increased  to 80% (was 70% until recently) the longer term has decreased from 70% to 55-60%. So NOAA are suggesting a fairly brief Nino event.

27i.PNG

Remember, there readings are from around 4 days ago and there might be a small error as they do not quite match the graphs on the right.  There is usually a small discrepancy between the NOAA and CDAS readings but not within NOAA's own figures. 

27j.PNG

You can clearly see that warm anomaly working its way up from off the Chilean coast.

27k.PNG

The sub surface temp anomalies usually give us a good indication of what to expect going forward with a 3 - 4+ month time lag and depending on the other factors that I referred to at the start of this update. They are still well above +1c but have been declining steadily for the last 6 weeks.  Conditions might change but this "may" be another indication of a fairly short El Nino episode.

27l.PNG

Now, this where I'm still learning. Another reason for those higher EPAC anomalies seems to be due to the last kelvin wave pushing those warmest waters further east. Perhaps in combination with what I referred to (the recent lack of colder waters mixing in from the south) we may see the Nino 1+2 anomalies rise even higher during the next week or so (over +2c?) but how long will that last?  

27m.PNG

The latest "monthly" model consensus was updated last week. I have repeated the October chart below for a good comparison.  Some models go higher in the short term but most fall back steadily but there is increasing uncertainty through Spring and into Summer 2019.  It is, of course possible that we see a temporary weakening before another stronger period later on. Far too early to call that one at all. The statistical average (the bold green line - purely as a guide for the consensus) ends up with a weak Nino lasting beyond next Summer.  The CPC control run (bold blue line) returns to neutral conditions by early Summer 2019. 

27o.PNG

 

 

The last NOAA monthly report was produced over 2 weeks ago. Here's the link:     http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.pdf

Things have changed somewhat since the report but I copy the written part of it below:

27n.PNG

 

 

Finally, the WMO produce regular reports too.  Her'e a link to the one that they released this morning:   http://www.wmo.int/pages/prog/wcp/wcasp/enso_update_latest.html

I copy their summary below:

27p.PNG

The full report is a worth a read and there are numerous links to other sites.

 

Overall, I would say that El Nino conditions are just about here. Perhaps this will be more basin wide rather than a CPAC event (comments please on this). It looks like it'll be a fairly weak (perhaps near moderate at best) event and may only last for 6 to 9 months.  SST anomalies can change very quickly in the short term. Further kelvin wave activity may impact on the flavour of the El Nino (more CPAC or basin wide) and will the ocean-atmosphere, once fully coupled, continue to be coupled for an extended period?  Total AAM has been rising but we have another setback in relative GLAAM.  The outlook for the next couple of weeks is for AAM to trend downwards but this is expected to be temporary with another strong rise after that.  This has strong implifications for the northern hemisphere winter patterns quite apart from Nino conditions.  So, there is loads of interest and a lot to monitor.  David :) 

 

Great post, the most important aspect of this is the differential of the actual SSTs, and not the anomalies. As this year has evolved, it's clear to me that the Walker circulation will not connect this El Nino because the 5 degree difference between the WPAC and the EPAC. And this may explain why every time it looks like we might get some increase, the trades pick up and cool Nino 3.4 again. Which is why with every move of the CHI 200 to the Atlantic either doesn't come off in the forecasts, or if it does, it splinters and still leaves upward motion near the Maritime continent. And what it also reinforces to me is how important a role the atmosphere plays, it is front running this event as it did in 2009. Here in Australia, in 2009 we had the El Nino weather in the first 9 or 10 months of the year, and then we saw huge rains and lower pressures from then on, despite a very nice warm Pacific Basin, and moderate El Nino. This year is almost playing out similar, which is why I wasn't surprised when I saw JB say 09/10 was a similar analog, along with others on twitter as well.

 

And then now we are seeing the AAM sinking fast into the negatives, so if it stays that way for a fortnight it might produce a stronger forcing that pushes the South Pacific Convergence Zone onto the Maritime Continent, which is a bit of a stretch but an early season cyclone getting close to Australia is nothing like an El Nino here locally. And that should keep the pressures down enough to keep trades going to stop this connection happening. Which is why the models now see the CHI 200 heavily over the Maritime Continent again later next weekend. So IMO the atmosphere is actually the most important part of this whole set up, and if we look at other failed Nino years, I suspect it might be the same. Would be fascinating to see archived AAM and GWO charts, which are hard to find, and see what role they played, in the 2012 and 2014 events.

 

 

 

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On 11/26/2018 at 3:32 PM, Tamara said:

 

 

An east based La Nina, as seen last winter for example, often produces an a-typical El Nino response due to the West and Central Pacific seeing anomalously warmer water than under a traditional La Nina, and so therefore also significantly warmer than the colder than average eastern most ENSO zone .

 

This spatial SST regime accentuates the chances of a tropospheric/stratospheric pathway being enabled due to MJO patterns converging further east than under a typical La Nina - and so therefore greater poleward propagation of +AAM anomalies which alter the typically dominant amplified Pacific and Atlantic patterns to one that more closely resembles an El Nino (+ve EAMT jet extension and potential stratospheric disruption). This also therefore increases the chances that such a La Nina pattern may, a-typically, produce a high latitude Nino type pattern as identified by the paper, should such substantive stratospheric disruption occur.

 

This, equating to the Phase 7 type MJO evolution as discussed by the paper.

 

The converse holds true with an especially west based El Nino, where tropical convection patterns are accordingly also found further west of the dateline than under a typical El Nino, and this may produce a more disconnected extra tropical (GWO) pattern characteristic of relatively lower angular momentum regimes and hence both Pacific and Atlantic regimes more amplified, overall, than found under a traditional regime. This in turn affects the tropospheric/stratospheric relationship and potential for higher latitude blocking - where the strongest forcing is further away from the Eastern Hemisphere and so rossby wave propagation is also less likely to have influence on amplifying higher latitudes in these regions of the NH.

 

 

 

 

A really good post I think Tamara - and this bit in particular highlights well how we need to think carefully about the actual profile of the Nino/Nina in operation. I think last winter taught us much about this.

 

I'm musing now - but Total AAM is high - in fact it is very high.

1568458568_gltotaam_sig.90day(1).gif.02c604e3a3e09bc987f6925fa92c2dfb.gif

 

If we look at the long range picture going back many years we are looking at an event that smacks of top 5.

totaam_sig.58-curr.reanal.gif.f16e7a35023c5743ae742a700ab1d6f4.gif

 

There would seem to be a link in the graph above to previously strong Nino years for spikes at +3SD - but this year we are in low Nino territory at the moment but experiencing a significant uptick in Glaam. Taking the year as a whole the best fit gradient since the summer is clear:gltotaam_sig.gif.330c29c2c550b4480a82ff6856407827.gif

 

Our current MJO forecast is strong too - and I'm sure I've read somewhere that in a Nino event the strength of the MJO tends to fall in winter. No sign of that yet. Anyone got any theories as to why we are seeing such a strong development in Glaam over many months? Given that we appear to be looking at a more west based than east based Nino at the moment, the analysis you put forward here would suggest a pattern more conducive to blocking in the atlantic with an almost Nina-esque feel to the wave pattern....but where in all this does the Glaam total fit? From a position of +3SD one would assume there has to be a response that will force it down....but this seems to run counter to the MJO setup at present, which in itself seems higher than we would expect? (or am I off beam here....?)

 

I guess in simple terms I'm just wondering what has created such a dynamic upwards trend in glaam, and just what this is likely to mean given the ENSO profile this winter season. I had not expected to see it climb so high.

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@Catacol -- keep in mind those two AAM charts you posted have disparate periods for calculation. The 1958-present GLAAM graph depicts monthly averages, whereas, the 90-day chart is obviously intra-monthly, so a transient spike to +3 standard deviations is substantially less than a +3 standard deviation monthly anomaly. We're not even close to the AAM of strong Nino years.

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2 minutes ago, Isotherm said:

@Catacol -- keep in mind those two AAM charts you posted have disparate periods for calculation. The 1958-present GLAAM graph depicts monthly averages, whereas, the 90-day chart is obviously intra-monthly, so a transient spike to +3 standard deviations is substantially less than a +3 standard deviation monthly anomaly. We're not even close to the AAM of strong Nino years.

Yep - accepted and agreed. Monthly average not the same as a short term peak. However the climb up to +3SD is still a surprise given ENSO context, at least to me.

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