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Stratosphere Temperature Watch 2015/2016


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ALL_emean_phase_full.gif

 

The wildcard MJO event looks odds on to take place now. Is this the atmosphere giving the El Nino the middle finger? Checking the GWO outlook from GEFS to see whether this MJO event might bring about an east-Asian MT event, I see little sign - which if I'm right is a reflection of the model not projecting the MJO to progress beyond the western Indian Ocean. ECMF on the other hand... makes me think about how entertaining it would be to see wave breaking into the strat. from an EAMT followed by wave breaking via the Rockies in line with a typical El Nino configuration. What would you say the odds are off that... or am I straying wide of the mark?

 

I can see where ECMF might be coming from, given that the Indian Ocean continues to feature impressively strong and widespread positive SST anomalies. Not that co-operation from the atmosphere is even close to a given, of course.

 

sst.daily.anom.gif

 

On top of this, I find myself wondering how that huge tongue of highly anomalous warmth extending west from the U.S. toward Hawaii might impact Rossby wave formation in that region? Given that El Nino events encourage their formation with the component trough across the Aleutians and ridge over NW N. America and W. Canada (extending well east at times), and then serves to boost their amplification considerably, could this extra band of warmth serve to further enhance the amplification? If so, would that then have the potential to lead to one of the most intense wave-breaking type strat. warming events ever observed, or would the wavelength be altered such that wave breaking would be jeopardized?

 

 

An awful lot of questions I know, but I am (perhaps insatiably) intrigued by all this. I look forward to seeing what the well informed bunch you are have to say about this... regardless of how much I have right or wrong  :D

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ALL_emean_phase_full.gif

 

The wildcard MJO event looks odds on to take place now. Is this the atmosphere giving the El Nino the middle finger? Checking the GWO outlook from GEFS to see whether this MJO event might bring about an east-Asian MT event, I see little sign - which if I'm right is a reflection of the model not projecting the MJO to progress beyond the western Indian Ocean. ECMF on the other hand... makes me think about how entertaining it would be to see wave breaking into the strat. from an EAMT followed by wave breaking via the Rockies in line with a typical El Nino configuration. What would you say the odds are off that... or am I straying wide of the mark?

 

I can see where ECMF might be coming from, given that the Indian Ocean continues to feature impressively strong and widespread positive SST anomalies. Not that co-operation from the atmosphere is even close to a given, of course.

 

%7Boption%7Dhttp://www.esrl.noaa.gov/psd/map/images/sst/sst.daily.anom.gif[/

El Niño remains the big show. Aleutian Low moving in to place correlating with MJO's forecasted high phase 2. Position of low in NW Pacific still unknown.

Down stream is highlighting ++ NAO.

post-21685-0-51341000-1445591705_thumb.j

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In Conclusion:

 

We are essentially in uncharted territory since at least 1950 in terms of a basin wide El Nino event of this strength, when combined with a warm Indian Ocean, very warm waters compared to Hawaii to California and a very warm N. Pacific. However, there is evidence that the warm Indian Ocean may act to cause somewhat more MJO activity that what is common during stronger El Nino winters, and in general, the warmer waters elsewhere in the East Pacific tended to pull the Aleutian low farther west when compared with other moderate to strong basin wide El Nino events. This suggests that a +PNA may become more likely as the winter goes on, after Pacific air likely floods a good portion of the CONUS in December.

 

In general, basin wide El Nino winters favor a negative NAO as you head farther into winter, although not as strongly as modoki events. The three moderate to strong basin wide El Nino events since 1950 that had a +QBO as we’ll have this winter featured decent AO/NAO blocking by February, after a warm December and up and down January. Research done on October snow advance in Eurasia by Dr. Judah Cohen and on October N. Pacific sea level pressure by Al Marinaro both suggest that trends this month also support a –AO/NAO this winter.

 

In general, a rising +PNA could limit California/west coast rainfall by later in winter. Hopefully they’re very active before then, as they desperately need the rain. The eastern US looks cold/active for the second half of winter, after a potentially very slow start.

 

The potential bust factor here revolves around how the Nino behaves. Other basin wide El Nino events with such a warm Indian Ocean (1987-88, 2002-03) saw more MJO activity than normal for stronger EL Nino winters, which likely contributed to a favorable pattern for eastern US snow. If this event becomes more strongly east based, this may not be able to occur. Another overall question mark is if all of the correlations discussed, small sample size for some of them notwithstanding, hold up with such a strong El Nino. We may learn quite a bit this winter…hopefully not at the expense of this forecast.

 

Analogs, based on good SST matches globally and QBO:

 

1957-58, 1987-88 (2), 2002-03, 2006-07

http://www.americanwx.com/bb/index.php/topic/47089-my-2015-2016-winter-outlook/

 

A winter forecast from the States. When you sign in, you got the possibility to see the charts.

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Time to continue the theme of what was said on the post made shortly before the previous stratosphere thread closed.
 

Aside from the numerical model weightings we can use to try to assess weather pattern evolvement over medium and longer terms, we can use the structure of diagnostic tool Global seasonal synoptic models as well - which organises multiple subseasonal phenomena into a repeatable sequence.

 

These can prove very useful as a starting intra seasonal benchmark to try and extrapolate patterns - and whether they repeat cyclically, or whether they signpost a new stage and changing dynamic to the atmospheric circulation.

 

Its my judgement that we are *somewhere* in the middle of the strong Nino dynamic which began in earnest in the first half of this summer.

 

Returning to the theme of sub seasonal and intra seasonal timescales we know already that eastward propagating waves from equatorial regions to high polar regions that occurs during MJO orbit life span impact on the intraseasonal phenomena of the base ENSO state.

 

This is where our history lesson, as documented in my previous post in the old strat thread is so relevant. Using the Global seasonal template we also know that the true ocean/atmosphere coupling that occurred in the first part of the summer and verified the birth of the strong/super Nino was the product of an extratropical EAMT and a major MJO convective wave. Two sub-seasonal  phenomena acting to set the scene for the much longer time scale of an intraseasonal phenemona. The ocean/atmosphere coupling of the Pacific Nino

 

This provides a strong focus of interest, fascination and anticipation how this particular 'life story' will unfold into the winter and how it will impact onto the atmospheric state in terms of Atmospheric Angular Momentum.

 

AAM is an ideal index of ENSO, MJO and other subseasonal variability. Frictional and Mountain torque have medium and fast time scales. Mountain Torque forces AAM anomalies and are positive when GLAAM is increasing. Extreme global AAM events such as the MT of end June/July this year provide a very useful benchmark for extrapolating medium longer term time scale evolutions of weather patterns and potential cyclical patterns on a seasonal basis

 

We use the Global Wind Oscillation orbit to determine this index representation of the state of flux of the atmosphere, and how it is is likely to impact on both the tropospheric patterns and in turn potential trop>strat interplay.

 

High AAM orbit state Phases 5/6/7/8 through the summer and first half of Autumn continues to build more and more poleward amplification into the hemispheric atmosphere system.

 

Change, when it comes will be indicated by the GWO dropping from Phase 8 into Phase 1. This will tell us that the Nino life span has gone full circle and that the SST profile in the western hemisphere and Indian Ocean is set to start the process of overwriting the atmospheric circulation. The MJO provides one clue to this, but changes in AAM as determined by movement and changes in direction of the GWO orbit will give the full confirmational story - when it comes

 

I think that change in atmosphere/ocean coupling is highly unlikely to happen this side of 2015 - and, as part of the life cycle of this Nino, the start of the westward 'pull' of the ENSO pattern focusses on the intruiguing possibility of a Modoki signature before the Nino collapses and forcing moves away from the Pacific. This poses the possibility of attaining the ideal wave feedback process to achieve blocking in out part of the NH - that is, if we are to remove the external stratospheric pathway forcings from the equation of course. Namely, solar activity in conjunction with the west QBO

 

Super El Nino's such as this one show an important role for the Mountain torque in forcing the enhancement of westerly flow across, typically 35N, into the atmosphere during the mature stages of El Nino.

 

Right where we are now.

 

And it is precisely here that it gets even more interesting as enter the next Global Seasonal diagnostic stage of this ocean/atmosphere pattern. Each kelvin wave push of this Nino likely imprinting further and further west in the Pacific - allowing the eastern basin extent to cool

 

 We now have a tropical convection wave response emanating from the Tropical Indian Ocean with the MJO in a decent 1/2 amplitude, set to head eastwards. With additional recent kelvin wave activity boosting further anomalous westerly winds across the Pacific, and sustaining a +AAM state, the signposting here at face value is that if this next wave of activity progresses to the Pacific it implies further imprint of the ENSO ocean/atmosphere signal with another another large EAMT which has considerable implications for early winter time stratospheric feedback.

The other implication, taking into the account the balance of the opposite effects between the SST anomalies in the tropical Pacific and that over the tropical Indian Ocean basin is that the warm ENSO feedback corresponding to a Nino teleconnective +PNA pattern and associated known warm trop/strat feedback would override the stronger vortex signal emanating from the SST arrangement in the Indian Ocean.

 

The Global Wind Oscillation as ever will provide the clue. The GEFS suite has a known bias for over egging tropical forcing in the Indian Ocean. Remember, Phase 1 GWO signifies a major change of circulation and associated negative MT (Phase 8/1)

 

A Phase 5/6/7/8 persisting, with another considerable boost to AAM builds yet more amplification into the system and such enhanced meridionality is some antidote to a vortex - even one consolidated by a west QBO

We can use the sub-seasonal 30 to 60 day oscillatory benchmark to make some calculations as to when such activity might impact the surface synoptic patterns. A current MJO wave orbiting through November towards the Pacific coming towards start of the winter has significant feedback implications for the start of winter.

 

The AAM budget is obviously not wholly accounted for through the mechanisms for global torque mechanisms described so far. The phasing of the QBO and El Nino are forced primarily through frictional torque. The QBO is driven by wave activity propagating upwards from the troposphere and obviously a clear feature of the stratospheric circulation, represented in the angular momentum distribution of the stratosphere outside the equatorial belt.

 

The external forcing budget of AAM into the stratosphere cannot yet be determined till we see how much effect the west QBO/solar combo has on the vortex. But we can gain clues already about the trop pathway Nino feedback.

 

Best not get hung up about the Indian Ocean SST forcing. There is some race to run yet in terms of the Pacific wave forcing.

 

Keep watching the Global Wind Oscillation :) 
 

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Thank you - as always - for your thoughts Tamara.

 

It's a shame solar activity has been so feeble over the past 6 months or so as high activity would have in theory mitigated the possible impact of the westerly QBO

 

I'll put the Indian Ocean SST forcing to one side for the time being (though I'm still going to check out those warm IO + El Nino analogues out of interest).

 

I'm fascinated by the nature of this basin-wide El Nino and it's potential implications. The U.S. to Hawaii band of +ve SST anomalies is also setting my mind whirring. A basin-wide super El Nino with benefits?  :shok:  :D

 

 

Alas, there's a particularly terrible side-effect of this event due to slam into the western coast of Mexico today; Category 5 hurricane Patricia with top sustained winds of 200 mph gusting to 245 mph. Yes, you read that right! Thoughts go out to those in the firing line - the NHC are making good use of the word 'catastrophic' this morning.

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ALL_emean_phase_full.gif

 

The wildcard MJO event looks odds on to take place now. Is this the atmosphere giving the El Nino the middle finger? Checking the GWO outlook from GEFS to see whether this MJO event might bring about an east-Asian MT event, I see little sign - which if I'm right is a reflection of the model not projecting the MJO to progress beyond the western Indian Ocean. ECMF on the other hand... makes me think about how entertaining it would be to see wave breaking into the strat. from an EAMT followed by wave breaking via the Rockies in line with a typical El Nino configuration. What would you say the odds are off that... or am I straying wide of the mark?

 

I can see where ECMF might be coming from, given that the Indian Ocean continues to feature impressively strong and widespread positive SST anomalies. Not that co-operation from the atmosphere is even close to a given, of course.

 

sst.daily.anom.gif

 

On top of this, I find myself wondering how that huge tongue of highly anomalous warmth extending west from the U.S. toward Hawaii might impact Rossby wave formation in that region? Given that El Nino events encourage their formation with the component trough across the Aleutians and ridge over NW N. America and W. Canada (extending well east at times), and then serves to boost their amplification considerably, could this extra band of warmth serve to further enhance the amplification? If so, would that then have the potential to lead to one of the most intense wave-breaking type strat. warming events ever observed, or would the wavelength be altered such that wave breaking would be jeopardized?

 

 

An awful lot of questions I know, but I am (perhaps insatiably) intrigued by all this. I look forward to seeing what the well informed bunch you are have to say about this... regardless of how much I have right or wrong  :D

I think that judgement on the current IO MJO wave amplification and how far east this travels need to be watched carefully. We may see some over enthusiastic forecasts regarding stage 3, but the risk is that these may get dampened down as we get closer in timeframe - much like FI strat forecasts.

 

If, and this is a big if, we see the MJO reach phase 3 in some kind of amplified state during November, then there is the possibility that this decoupling with the El Nino may have some ramifications regarding early December - an increase in wave 2 activity could occur leading to a greater meridional flow affecting the Atlantic sector. If the MJO wave gets overwhelmed by the strong EN, then a more traditional EN winter pattern may ensue. Certainly, an interesting few weeks watching the MJO coming up.

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Thanks Chiono  :good:

 

ECMF has stuck to its guns today and now CANM has joined the party although only just as the MJO is decaying steadily by the time it gets so far east.

 

I'm currently compiling some thoughts for the winter and this phase 3 potential remains in the 'wildcard' folder for the time being, following input from both you and Tamara.

 

Interesting GFS 12z det. run today as in some ways it was like a souped-up version of a classic El Nino November. The U.S.-Hawaii band combining with the more or less record breaking C-E Pac tropical SST anomalies?

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I don't think you could have anything more going on in the Pacific right now, this Nino winter is less than boring. Nor is it without many sub-plots.

 

Re GWO now on downward tendency as MJO initiates. 

post-7292-0-59505100-1445642831_thumb.gipost-7292-0-71170700-1445643362_thumb.pn

 

Studies show MJO waves to travel more quickly in ENSO years,, not without there impacts. Decent amplitude visible on the VP anomalies however, the speed of travel / degrade is of interest.

 

Bonfire night sees progression move to circle of doom time will tell for it's depart and then re-appearance time frame, also the impacts much further up in the atmosphere provide intrigue.

post-7292-0-47031600-1445643125_thumb.jp

 

2 tests of academia now - the MJO coupling and effects on Vortex Formation / Intensificaton , further to that the impact of the Strat Trop pathway vs the qQBO, lots to look out for this season...

 

 

 

 

 

post-7292-0-28651700-1445642952_thumb.pn

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Caution with MJO assessment currently however... as UKMO note: "...MJO not having much predictive value at present. Models had been suggesting that it should be emerging into Phase 1 by now (and into Phase 2 subsequently), however confidence in this was always low due to contamination from tropical storms messing up the OLR assimilation."

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Caution with MJO assessment currently however... as UKMO note: "...MJO not having much predictive value at present. Models had been suggesting that it should be emerging into Phase 1 by now (and into Phase 2 subsequently), however confidence in this was always low due to contamination from tropical storms messing up the OLR assimilation."

Yes, that is what I meant with over enthusiastic forecasts- they never quite reach their target. November 1987 had a large MJO/ El Nino decoupling and was followed by an early December SSW as discussed here

 https://twitter.com/chionomaniac/status/656213780448354304

Could it happen again is the question over the next couple of weeks - not the favourite but an outsider one needs to keep an eye on!

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I thought the MJO forecasts were being over progressive as it was taking its time to depart the COD - large strides taken in the last two days.

 

ECM monthly still pushing into phase 3 ....   RSWncFi.gif

 

There are IOBW composites for temps and precip on the JMA website - those looking for signals of a frigid winter, best leave the link unopened.

 

http://ds.data.jma.go.jp/gmd/tcc/tcc/products/climate/ENSO/composite/index_iobw.html

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Caution with MJO assessment currently however... as UKMO note: "...MJO not having much predictive value at present. Models had been suggesting that it should be emerging into Phase 1 by now (and into Phase 2 subsequently), however confidence in this was always low due to contamination from tropical storms messing up the OLR assimilation."

As you say Fergie, regarding OLR. The 4th Kelvin wave has begun down welling in region ENSO 1.2.

Hence the opening for a westerly wind burst pushing MJO into phase 2.

MJO will most likely return to COD and emerge back into phases 5 or 6.

El Niño is king driver until it's demise. The levels of thermal energy stored in the Pacific sink just shows how much it dictates global weather patterns.

post-21685-0-74368000-1445763469_thumb.j

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Very striking difference this year generally in the stratosphere compared to the same period last year,which shows up nicely at 30mb.

 

2014..post-2839-0-88904100-1445887985_thumb.gi  2015..post-2839-0-36907000-1445887996_thumb.gi

 

 

PV looks to be late to the party this year.

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According to Judah Cohen in his blog SAI and SCE are above average, altough not that high as in the last two winters.

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

It is our experience that above normal polar cap geopotential height anomalies tend to persist this time of year, with embedded variability, until vertical wave activity flux becomes active.  Therefore assuming near normal vertical wave activity flux, we feel that the prediction of above normal polar cap geopotential height anomalies over the next two weeks favors above normal polar cap geopotential height anomalies and a negative bias in the AO longer term.  However for wave activity flux to become more active, the atmospheric pattern will need to project onto the tripole pattern that we have shown is favorable for increasing the energy transfer or wave activity flux between the troposphere and the stratosphere (Cohen and Jones 2012).  The models do not predict this solution for at least the next two weeks but it is still early and is something that needs to monitored.

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Very striking difference this year generally in the stratosphere compared to the same period last year,which shows up nicely at 30mb.

 

2014..attachicon.gif30mb14.gif  2015..attachicon.gif30mb15.gif

 

 

PV looks to be late to the party this year.

Indeed,

 

The height anomalies suggest that the PV is neither weaker nor stronger than normal at present...

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/hgt.shtml

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I'm surprised nobody refers to Fergie's post

The latest Contingency Planning summary is N-D-J. That GloSea5 output is J-F-M. Note cautionary comment by seasonal team re increased SSW potential late season in today's update. In other words, the message remains consistent: coherent, cross-model support for notion of milder/wetter/poss stormier start to winter, but potential for colder flip later (this clearly v uncertain of course). But the notion of broadly +ve NAO conditions into winter at least initially has been strongly signalled by the key output (GloSea5, EC Seasonal, EuroSip) for a while now.  https://forum.netweather.tv/topic/84126-winter-201516/page-34#entry3275001         

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I'm surprised nobody refers to Fergie's post

The latest Contingency Planning summary is N-D-J. That GloSea5 output is J-F-M. Note cautionary comment by seasonal team re increased SSW potential late season in today's update. In other words, the message remains consistent: coherent, cross-model support for notion of milder/wetter/poss stormier start to winter, but potential for colder flip later (this clearly v uncertain of course). But the notion of broadly +ve NAO conditions into winter at least initially has been strongly signalled by the key output (GloSea5, EC Seasonal, EuroSip) for a while now.  https://forum.netweather.tv/topic/84126-winter-201516/page-34#entry3275001

What's uncertain? The mold start or cold flip? Both uncertain in my book.

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Lock down mode in place from surface through to trophisphere.

Stratosphere included and it comes as no surprise due to strength of El Niño.

Will do for next 8 weeks minimum.

What it does mean is the cold air is tightly contained. The break out I feel will be impressive when it's released.

post-21685-0-37845500-1446461809_thumb.j

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