Stratosphere Temperature Watch 2014/2015

[Interitus]

Out of interest can anyone tell me when was the last time 3 years did pass without a SSW?

 

 

From MERRA data 1995/6, 1996/7, 1997/8

However strictly speaking there was a late SSW in 2014 - 10mb winds reversed on 27/3 and returned westerly for 3 days on 6/4 - but it was effectively a final warming.

[chionomaniac]

Just my final two pennies worth, firstly how quickly has the last 3 to 4 months gone?...Doesn't seem two minutes since this thread was bustling back in October and November with such potential and interest given the initial drivers. Starting by quoting the above;

 

"So, even though it was wrong and I don't yet know why it went wrong, it's still right?" - Before I even saw that post the same thought came to me as well. Clearly the guy is a respected scientist for many reasons, but these winter updates this year, in my opinion, have done him no good at all. They have often been rather specific and calculated to what he believes will happen using specific words and phrases. He has certainly had a 'bashing' at times over on Twitter this year, especially regarding this on-going Barents-Kara sea 'get out clause'. Anyway, that's a different conversation and of which no doubt some will agree and disagree regarding his thoughts and forecasts this winter.

 

What has been the most disappointing thing about this winter, regarding the stratosphere, is how the overall 'potential' at the beginning of the winter has not be realised in anyway, again in my opinion. Clearly we saw what happens when we are in a +QBO state in 13/14 and how relentless and damaging that winter pattern can be once it sets up shop. Clearly with such a significant -QBO pattern this winter, amongst all the other variables, there was clearly a lot of expectations and scientific expectations too for a SSW this year. Clearly the period of interest was early January and whilst one could say we were close, it was a case of 'close but no cigar' in my opinion. It is another learning curve and no doubt if this had been 'another winter' then a full blown SSW would have occurred. Clearly this is the second year running now without an official one and with the QBO likely to be in a +QBO phase next year then, in very brief summary, I would imagine the odds of one next winter will be quite low as well, but clearly that's just a broad suggestion. Out of interest can anyone tell me when was the last time 3 years did pass without a SSW?

 

In terms of local and regional weather this winter the strat hasn't influenced things at all really. You could argue that the highly displaced vortex through the second half of January into Siberia has aided, amongst other features, the Atlantic ridging and far more meridional pattern of late, but clearly the main drivers this winter have been troposphere based like the AAM and MJO for example, which have been discussed at times through the winter on the Model Thread I believe. Here in Lancashire this winter has been far, far better than last year in terms of cold weather. With a decent 'festive' cold spell between Christmas and New Year and certainly a decent amount of snow within the last two weeks along with cold days and persistent frosts. Essentially a very 'typical' and 'average' UK winter really and no doubt by the end of February the stats will confirm just that with temperatures and rainfall totals generally not too far away from the norm.

 

Clearly whilst not the be-all and end-all, *IF* we had achieved a SSW this winter then who knows what would have resulted. The years continue to tick by without a 'proper' Scandinavian block and an easterly flow with 850mb temps below -10C to -15C, the last time is now many years ago and clearly we have not had one prolonged spell of HLB over Greenland this winter with that text-book pattern on the wetterzentrale charts in which the 500mb charts suddenly go all 'yellow' over Greenland rather than deep blue and purple.

 

So, in summary not a complete loss that we didn't get a SSW, but there's a lot more that needs discussing as to the reasons why in my opinion. Why hasn't the HLB developed as per forecasts given such a strong SAI, I think the OPI can be thrown out of the window too, or at least taken with far more caution this coming October. The weather will always do what it wants, no matter what the signs and signals may well indicate and we got a first-hand example of that this winter really as despite the seasonal models from the UKMO, for example, I think most were expecting a SSW this winter and at least some prolonged spells of HLB, but of which clearly neither has materialised.

 

Anyway here's to more 'learning curves' next winter and I wish everyone the very best for the rest of the year and look forward to re-appearing on the strat thread come October and November, as from the strat point of view it's all over bar the 'shouting' now really given latest guidance through the rest of February.

 

Regards, Matt.

Hi Matt.

 

I feel the same and I think that you have summed things up very well. It is another frustrating winter where endless potential is not realised (though I don't think that winter is over yet!) 

 

Stratospherically, we came as close as we can get to a reversal SSW - the perfect 10 pin bowling ball was released to attack the polar vortex in the form of a wave 1 attack, only to find that,  all of a sudden, it had a duplicate set of 10 pins to knock down because a wave 2 had split the pins in half. From that point on, I realised that a technical SSW was not going to occur - though the tropospheric pattern did change as a result of this 'half SSW'.

 

I don't consider that those who forecast an early January SSW were wrong in this respect - just unlucky with the timings of the waves that deflected into the strat. 

 

It has been a completely different year stratospherically compared to last year and so any comparisons just because the tropospheric pattern hasn't provided HLB's are wrong imo. Last year we had a very strong strat vortex that was never going to split, no matter what wave activity was thrown at it. This year the vortex has split multiple times and at every wave episode -so much so that the deflected waves have almost got in the way of each other. The splits have not been in the best position for the UK as well, otherwise we could well be looking at a completely different winter - those who recognise that fact will realise how close we have been to something a lot better, but c'est la vie. I am happy with my strat forecast this winter, just disappointed that it didn't materialise into something more substantial tropospherically.

[phil nw.]

My view is that we have seen plenty of minor warmings this year but as Chio says the big one never quite made it and so we had to be content with transient ridging in the Atlantic which gave us those colder and often marginal north westerly snow setups.
A look at the mean zonal winds time series over the last 2 years show the evidence that the pv was definitely weaker this Winter and primed to fall.



We can see at the beginning of January how close we got to wind reversal at 10hPa and the big rise in temperatures of around 45C at 60N on the graph below.
u

however it wasn't to be.

I am no expert on the background drivers but the MJO hasn't helped this Winter with often weak convection staying west of the dateline weakening further as it moved east which kept the index out of the phases 7/8 which may have led to higher latitude blocking.



Maybe the weak +ve Nino has had an effect on this but i leave others more learned to comment.

I guess other factors have gone against us so far in spite of frequent wave action on the vortex which in another other season could have given cold seekers more of what was wanted.

Edited February 7, 2015 by phil nw.

[polar vortex]

Despite what some say the reason for another poor winter (so far) has been the strength and orientation of the 

vortex which again has been underestimated. last year the vortex was stretched from Siberia to Hudsons bay 

area and actually allowed a negative AO anomaly of almost 1 SD compared to +1 this january.

I am wondering what with the Jan QBO coming in at -26.70 by far the lowest reading for January since 1979

whether this would have the effect of strengthening the easterly winds around the equator but by being so 

strong not allowing them to expand further north as seen below from the 30 hpa mean zonal wind.

Apart from 1 or 2 very brief easterly transitions you can clearly see the dominance of strong westerly 

zonal winds. 

 

[Jonan92]

FI but well

 

 

[Cheshire Freeze]

Am I the only one thinking that last winter was THE potential winter? Just look at the historic charts from Jan 2014 and look how close we were to a major freeze up. +QBO/ cold strat/ etc etc yet we stood on the brink there for a time. Plus, given the compressed cold at high latitudes, it would have been spectacular.

This year, I can't even remember a time when I thought we were going into an extended deep freeze....but I definitely got that feeling at the end of December last year.

Edited February 8, 2015 by CreweCold

[feb1991blizzard]

Split starting to occur on the ECM in the mid strat although without much of a warming.

 

[mountain shadow]

Split starting to occur on the ECM in the mid strat although without much of a warming.

 

The problem with this possible split is no doubt the same as its been for the whole Winter. The numerous splits and displacements have always retained a segment of the vortex in the Greenland locale resultinging in no HLB and consequently no deep cold to these islands.

[feb1991blizzard]

The problem with this possible split is no doubt the same as its been for the whole Winter. The numerous splits and displacements have always retained a segment of the vortex in the Greenland locale resultinging in no HLB and consequently no deep cold to these islands.

 

Not sure there have been NUMEROUS splits to be honest and whatever has happened has had the expected influence on the troposphere In my opinion, the brief split did bring a brief split of the trop vortex and the displacement has brought the most recent arctic outbreak (if you can call it that), If I had just come back from MARS and you had shown me the stratospheric output for the winter, I don't thing It would have screamed serious HLB to me.

 

 

This is an example of a proper split.

 

Edited February 11, 2015 by feb1991blizzard

[Weather-history]

Latest Cohen analysis

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

There is no question in my mind that these forecasts on AO have gone wrong. The line of recent analyses kept saying -AO is favoured. Now the latest analysis has wrote off any -AO chances for the rest of February and ergo this meteorological winter.

Whatever went wrong, will hopefully be looked and learnt from.

[Nouska]

IMO, both the Cohen and OPI theories have fallen foul of looking at too limited a time span and (probably) too limited driving mechanisms. The recent changes in mid latitude weather patterns and extreme blocking events have been well researched and variously attributed to changing solar conditions and/or rapid decline in Arctic ice/snow cover. These factors are not constant - continuously reconfiguring - depending on a multitude of factors.

 

Europe's recent cold winters coincided with very low ice in Kara/Barents seas but they also coincided with low and extended solar minimum - one or the other? - bit of both would be my guess.

 

Kevin, I know you are not a fan of solar theory for cold winters but, again IMO, it is of no help if the two geomagnetic spikes in this cycle have occurred just before or during NH winter.

[Weather-history]

 

Kevin, I know you are not a fan of solar theory for cold winters but, again IMO, it is of no help if the two geomagnetic spikes in this cycle have occurred just before or during NH winter.

I think there is some kind of connection between colder winters and low solar activity, what I'm not a fan of is people riding on every nuance of activity on the sun to explain the weather here. Also to solely use solar activity as an excuse for this winter not quite delivering, I don't buy it.

[feb1991blizzard]

The final rights are about to be written, these are the dictionary definition of a dartboard, just about as bad as it gets.

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2015021506&var=HGT&lev=1mb&hour=384

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2015021506&var=HGT&lev=10mb&hour=384

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2015021506&var=HGT&lev=30mb&hour=384

 

 

[feb1991blizzard]

I think there is some kind of connection between colder winters and low solar activity, what I'm not a fan of is people riding on every nuance of activity on the sun to explain the weather here. Also to solely use solar activity as an excuse for this winter not quite delivering, I don't buy it.

 

I actually think if we had been right in a solar minimum this winter would have delivered big style, -QBO, EL NINO (albeit weak with nina like atmospheric conditions), the acid test will be around or just before the turn of the decade, the next minimum is likely to be even weaker than the last and we all know what happened at the end of the last decade.

[Weather-history]

I actually think if we had been right in a solar minimum this winter would have delivered big style, -QBO, EL NINO (albeit weak with nina like atmospheric conditions), the acid test will be around or just before the turn of the decade, the next minimum is likely to be even weaker than the last and we all know what happened at the end of the last decade.

You say big style but as I pointed out, 5 of the last 7 great winters occured at or close to a solar maximum. Even 1962-63 wasn't at a solar minimum.

Why was this?

Some will say well there was a dip in the solar maximum and this is why that winter was severe. If that was the case why wasn't 1995-96, severer? Why wasn't 1984-85 colder? 1984-85 was closer to a minimum than 1978-79 but 1978-79 beats 1984-85 hands down.

There maybe colder winters clustering around solar minima, my question is why the really severe winters of at least the last130 or so years weren't. Some other factors must have played their part to make those winters particular severe.

Edited February 15, 2015 by Weather-history

[Nouska]

You say big style but as I pointed out, 5 of the last 7 great winters occured at or close to a solar maximum. Even 1962-63 wasn't at a solar minimum.

Why was this?

Some will say well there was a dip in the solar maximum and this is why that winter was severe. If that was the case why wasn't 1995-96, severer? Why wasn't 1984-85 colder? 1984-85 was closer to a minimum than 1978-79 but 1978-79 beats 1984-85 hands down.

There maybe colder winters clustering around solar minima, my question is why the really severe winters of at least the last130 or so years weren't. Some other factors must have played their part to make those winters particular severe.

 

I'm afraid I will have to take issue with the highlighted sentence - '62/'63 was about as close to minimum as it is possible to get, especially considering the intensity of the cycle.

 

 

Sorry, taking this off topic but it is part of the stratosphere dynamic.

[jonboy]

You say big style but as I pointed out, 5 of the last 7 great winters occured at or close to a solar maximum. Even 1962-63 wasn't at a solar minimum.

Why was this?

Some will say well there was a dip in the solar maximum and this is why that winter was severe. If that was the case why wasn't 1995-96, severer? Why wasn't 1984-85 colder? 1984-85 was closer to a minimum than 1978-79 but 1978-79 beats 1984-85 hands down.

There maybe colder winters clustering around solar minima, my question is why the really severe winters of at least the last130 or so years weren't. Some other factors must have played their part to make those winters particular severe.

Without looking in detail in would suggest that these tend to be just past maximum so on the down slope. I would not be surprised if the intensity of the drop off in activity didn't play a major factor in changing the atmospheric dynamics leading to the notable winters which intern led to cooler phases. 

[Weather-history]

I'm afraid I will have to take issue with the highlighted sentence - '62/'63 was about as close to minimum as it is possible to get, especially considering the intensity of the cycle.

 

 

Sorry, taking this off topic but it is part of the stratosphere dynamic.

OK even if I give you that, why weren't the following two winters severe? The base of that trough is in 1964, why was 1962-63, almost 3C to 4C colder than the following two winters?

Sunspot numbers alone can not explain that.

[Interitus]

Well looking at the Berlin North Pole data - http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html

January 1963 averaged a low 20 sunspot number, winter AO about -1.91

 

January 2007 averaged an even lower 17 - and this winter was the fourth warmest CET, winter AO about 1.0

 

But it had a west QBO.......

 

OK, take January 1975 with 19 sunspots and east QBO like 1963 - and this is the fifth warmest CET, winter AO about 0.78

 

Research shows that there are linkages relating AO and strat with QBO, enso, sunspots etc, but they seem far too tenuous to make any definitive predictive connection as to what would happen under any particular scenario.

Edited February 15, 2015 by Interitus

[Duane S.]

The OPI has failed and failed in a pretty big way. No glossing over it I'm afraid. There obviously is something to it but nothing in weather forecasting is as one-dimensional as it was, at times, portrayed to being. It's probably more of a case that the factors that generated the very low OPI figure ended up keeping the cap on what would have been another 13/14 winter. It is understanding exactly what those factors were that will be the challenge I guess. All well and good saying it was an anomalous low pressure sat in the Barents Sea that inhibited vertical wave activity and subsequent HLB but why was it not predicted and precisely what role does it play?

The computer doesn't yet exist that can come close to working out out how the primary drivers work with each other, couple with the atmosphere (or not) and successfully determine the outcome in terms of long range abilities.

The QBO, ENSO, solar influences, MJO, GLAAM, GWO and the PDO surely all play a role at times but how on earth can we tell by what degree and how one affects the other(s), couples with or cancels out. Throw in current tropospheric 'reflectors' such as the AO, NAO and the PNA and I can't say I am optimistic it will ever happen.

[Nouska]

OK even if I give you that, why weren't the following two winters severe? The base of that trough is in 1964, why was 1962-63, almost 3C to 4C colder than the following two winters?

Sunspot numbers alone can not explain that.

 

No one thing can work alone. As S4Lancia and Enteritus point out, a multiplicity of factors and how they all interact with or nullify each other makes any long range forecast an impossible goal.

 

What we can say is that certain factors predispose towards certain outcomes. Professor Lockwood (and others) talk about a low solar predisposition to blocked weather patterns in the N Atlantic regions. This comes about by a weak and displaced jet stream - for a location such as the UK, it is just as likely to be in the warm sector as the cold sector and even the cold sector can be modified substantially by oceanic influence.

[Weather-history]

Well looking at the Berlin North Pole data - http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html

January 1963 averaged a low 20 sunspot number, winter AO about -1.91

January 2007 averaged an even lower 17 - and this winter was the fourth warmest CET, winter AO about 1.0

But it had a west QBO.......

OK, take January 1975 with 19 sunspots and east QBO like 1963 - and this is the fifth warmest CET, winter AO about 0.78

Research shows that there are linkages relating AO and strat with QBO, enso, sunspots etc, but they seem far too tenuous to make any definitive predictive connection as to what would happen under any particular scenario.

The startling ones for me in that list is 1974-75 and 1978-79

1974-75 was east QBO and low sunspot numbers, was one of the mildest winters on record whilst 1978-79 had much higher sunspot numbers, a west QBO and was a severe winter. Both had Canadian warmings.

The question is why on face value did 1974-75 having more favourable background signals turned out so mild and 1978-79 having least favourable background signals turned out so cold?

1974-75 was a weak La Niña and 1978-79 was neutral by the looks of it.

Edited February 15, 2015 by Weather-history

[jonboy]

The startling ones for me in that list is 1974-75 and 1978-79

1974-75 was east QBO and low sunspot numbers, was one of the mildest winters on record whilst 1978-79 had much higher sunspot numbers, a west QBO and was a severe winter. Both had Canadian warmings.

The question is why on face value did 1974-75 having more favourable background signals turned out so mild and 1978-79 having least favourable background signals turned out so cold?

1974-75 was a weak La Niña and 1978-79 was neutral by the looks of it.

 

I personally think it could be due to the position in the cycle 74/5 was not long after the peak of cycle 20 whereas 78/9 was closer to the bottom. I think it is a cumulative effect and cycle 20 was lower than 19 and subsequent 21, 22. Sunspot numbers although important is showing the strength of a cycle its not what directly influences the atmosphere but the F10 and E flux levels and we don't have great records from these

[polar vortex]

I think -QBO works well with low solar and moderate Nino however if the QBO like this winter is to negative this can have 

a detrimental effect towards northern blocking. Just my opinion of course. 

One other point that may or may not be of relevance regarding the winter of 62/63 during the October of 1961 the largest 

detonated nuclear bomb (the Tzar bomba or king of bombs) was dropped over Novaya Zemlya with a yeild measurement 

of 50 megatons. This would have surely had a impact on the stratosphere remembering of course that the March of 62 

was very cold with extensive northern blocking. Maybe this had repercussions for the following winter as well.

[Nouska]

I personally think it could be due to the position in the cycle 74/5 was not long after the peak of cycle 20 whereas 78/9 was closer to the bottom. I think it is a cumulative effect and cycle 20 was lower than 19 and subsequent 21, 22. Sunspot numbers although important is showing the strength of a cycle its not what directly influences the atmosphere but the F10 and E flux levels and we don't have great records from these

 

The Finnish Met Institute have been doing some research on this factor and have a graph of winters 1958 to 2012.

 

 

http://journal.frontiersin.org/Journal/10.3389/fphy.2014.00025/full?utm_source=newsletter&utm_medium=web&utm_campaign=Physics-w18-2014