Stratosphere Temperature Watch 2014/2015

[MattH]

Morning all...

 

Just a few updated thoughts given that at least some of the charts from the Berlin site are back up but there remain a lot missing, hopefully these will appear overnight and into tomorrow now. The setup we have at the moment within the troposphere doesn't really tally with what is going in the stratosphere and clearly the developments there at the moment, on face value, look interesting with the projected split expected within the next few days. However, what does seem to be the case now is that despite what looks to be quite a decent split, at least for a time, really doesn't lead us anywhere significant with the vortex consolidating back over the pole once again by the end of the forecast period (240hrs). This processes continues to re-inforce the thoughts that an official SSW, as it is currently known at least, will probably not occur now until mid to late January at the earliest. Clearly depending on your own thoughts this may well seem quite late in the season, equally if you go off Cohen and his SAI index, then that could be about right. The process of a decent split and then consolidation is evident well at 30hPa...

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ec.php?alert=1&level=30&forecast=all&lng=eng

 

Down at 100hPa the split is also evident but so is the process of re-development and beyond the opening few days of the forecast period the U60N is generally on the increase throughout the forecast period and by the 240hr chart we end up with a quite well organised and established vortex at the bottom of the strat.

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ec.php?alert=1&level=100&forecast=all&lng=eng

 

Clearly any further 'attacks' on the vortex, as we have at the moment aren't a bad thing but clearly we are still going to need additional wave 1 and 2 developments to properly knock this 'bird of its perch' and as ever it is often wave 2 activity that can really do the damage, so has it has been all winter it is a further waiting game. There are some interesting signs within the tropospheric models, particularly the GFS towards mid-month for the vortex to split and perhaps get a greater risk of a meridional pattern with possible Greenland blocks. This is highlighted by the 00Z GFS Det, Control and parallel below...

 

 

Now whether you could connect the dots and say that the up coming stratospheric split which does occur at all levels within the next few days is likely to then have an influence on the troposphere within 7 to 14 days, which clearly takes us towards the 16th, 17th and 18th of the month, may well be a stretch. Clearly the signs from the GFS may well have been gone tomorrow, but equally it's at least something to keep an eye on.

 

Personally, I don't believe what is happening now within the stratosphere is what the GFS is trying to model approx 2 weeks away. There are some signs that the MJO may just about get into phase 6 which is certianly a progression towards a greater risk of a more blocked and meridional pattern compared with phase 4 and 5 that we are in at the moment, so it could be related to this too. It is, as ever, difficult to say.

 

Clearly the winter isn't going to plan, overall, in terms of the stratospheric conditions and the tropospheric conditions depending on what your initial thoughts were for the winter based on the various forecasts that were published. I always try and use February and March 2013 as a perfect example of how, under the right synoptics, late winter weather can still be of significance even then, but clearly solar influences counterbalance things unless it really is a 'proper' cold synoptic setup. My own feeling is that the zonal pattern through to the middle of the month will not be a repeat of last year and changes will take place into the second half of the month. In terms of the stratosphere I really do think we have ended up with the short straw this year despite such excellent background conditions for a SSW. It's going to take time, one may well happen but it could well, as mentioned above, be late in January now which leaves the late winter as the most likely period for any significant and sustained cold weather.

 

I know after such a long wait that if February 2015 turns out to be one of the coldest February's in a number of years then I would take that, but as ever as the weeks tick by impatience grows and confidences drop for anything significant happening. So far it is definitely a case of UKMO (seasonal models, ie; ECM and EUROSIP) 1 v early signs and signals 0

 

The wait goes on....

 

Matt.

 

 

[beng]

So is the MJO one of the main reasons some of the forecasts have gone awry, or are there other more important factors that have made the vortex hard to split this winter, e.g solar factors ( solar max conditions are not helpful given the who state I believe)? Would be good to try and understand the learning points so we can take them onboard for future seasons. Just to be clear, I'm not having a dig as I know written text can get misconstrued sometimes - I'm genuinely interested in what we can learn here because these threads are terrific and have moved things forwards so much over the last few years.

On the MJO, I'd think the warm SSTs around Australia are not helping since these are no doubt helping prevent the atmosphere from coupling with the weakfish El Niño SST pattern off S America. The other thing (although I don't understand the mechanism) that may not be helping is the current warm PDO pattern. I can't think of any cold Uk winters off the top of my head that occurred with both a warm PDO and warm AMO; there may be the odd exception, but certainly these patterns don't seem to have favoured us in the past.

Just on the warm PDO that we're in, the same thing happened in the late 50s with a short lived warm blip in the long term cold cycle. This occurred just prior to the flip in the Atlantic cycle so it's possible we're seeing indications that the AMO will go negative over the next 4-5 years.

[Gustywind]

It would be good to understand why the polar vortex is so strong again this year, with that temp graph showing below average polar temps currently?

I thought an easterly QBO was supposed to inhibit pv strength, if so, how strong would it have got in a westerly phase this year...a repeat of last year perhaps!

[bluearmy]

Berlin updated now and reveals, as many expected, a dearth of wave activity by the end of the ten day period.

Add to that a negative zonal area in the mid/upper strat 30/50N and I would say it's not too positive a starting point! The zonal flow up there has to be concentrated at a latitude which we would like to see blocked.

Edited January 3, 2015 by bluearmy

[karyo]

Berlin updated now and reveals, as many expected, a dearth of wave activity by the end of the ten day period.

Add to that a negative zonal area in the mid/upper strat 30/50N and I would say it's not too positive a starting point! The zonal flow up there has to be concentrated at a latitude which we would like to see blocked.

image.jpg

That's dreary especially combined with the gfs stratospheric output which shows a re-organisation of the vortex.

[bluearmy]

I guess it depends how significant you think the strat is this season karyo. I haven't noticed it being the driver of what happens in the trop.

A proper flow reversing SSW may change that but can't see where that's coming from.

[karyo]

That's why we need a SSW or a more significant warming at least.

 

I suppose we could focus on the MJO but that's for another thread.

[CanadaAl]

Very tasty warming on the Navgem. Shame it's unlikely to verify 

[IDO]

That's dreary especially combined with the gfs stratospheric output which shows a re-organisation of the vortex.

 

Yes I have given up on a Major SSW as it is frustrating with false dawn after false dawn. I think it is telling us that something bigger is going on within the variables that is counteracting that possibility.

 

Dr Cohen's blog will be updated soon and I will be interested if his predictions are just for a Minor SSW or a Major one because if it is the former it is a bit misleading for followers? It appears from his latest musings: "is the sudden stratospheric warming (SSW) predicted to take place by the models the end of the first week of January (Figure 4)." that his idea of a SSW is not the Major variety (his definition is a PV split rather than wind reversal). He then predicts 6 weeks of blocking from the upcoming warming, after some sort of delay in downwelling from strat to trop. This upcoming warming IMO may not even effect the trop, let alone cause blocking or last for 6 weeks, so I am a bit confused. Or is it that he believed the over amped ECM over the more reasonable GFS strat and jumped the gun? Interesting to see!

[karyo]

Yes I have given up on a Major SSW as it is frustrating with false dawn after false dawn. I think it is telling us that something bigger is going on within the variables that is counteracting that possibility.

 

Dr Cohen's blog will be updated soon and I will be interested if his predictions are just for a Minor SSW or a Major one because if it is the former it is a bit misleading for followers? It appears from his latest musings: "is the sudden stratospheric warming (SSW) predicted to take place by the models the end of the first week of January (Figure 4)." that his idea of a SSW is not the Major variety (his definition is a PV split rather than wind reversal). He then predicts 6 weeks of blocking from the upcoming warming, after some sort of delay in downwelling from strat to trop. This upcoming warming IMO may not even effect the trop, let alone cause blocking or last for 6 weeks, so I am a bit confused. Or is it that he believed the over amped ECM over the more reasonable GFS strat and jumped the gun? Interesting to see!

Maybe he got carried away like Chris Fawkes with his tweets.

 

But yes, something is working against the stratosphere and is also preventing the MJO from progressing in the 7 and 8 phase this year.

Edited January 3, 2015 by karyo

[Dennis]

Hi I'm new to this forum : my name is Dennis and live in the Netherlands .I follow this very interesting forum about two years now.

Hope the winter2015 is a GREAT one - signs are hopefull

 

Greets Dennis

[KyleHenry]

Maybe he got carried away like Chris Fawkes with his tweets.

 

But yes, something is working against the stratosphere and is also preventing the MJO from progressing in the 7 and 8 phase this year.

http://www.swpc.noaa.gov/products/solar-cycle-progression

[sebastiaan1973]

Hi I'm new to this forum : my name is Dennis and live in the Netherlands .I follow this very interesting forum about two years now.

Hope the winter2015 is a GREAT one - signs are hopefull

 

Greets Dennis

 

Hi Dennis, welcome to the forum. The chart you show is 300 hours plus, I don't think that's a great sign. The stratospheric warming doesn't seem to effect the troposhere in a favourite way. So in my opinion right now there aren´t any good signs.

[Dennis]

Yes, I did see the GFS 0z run shortly after it come out but just looked at the ECM now, looking at the 10mb profile I did expect the wave 2 charts to show an increase, the EP flux prediction looks just about as poleward as ive ever seen.

 

 

 

The problem is that by now you would expect to see much more blocking in the extended ensembles.

pls could u post a new chart ? Gr Dennis

[sebastiaan1973]

HI Dennis you can find them over here http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html

[Dennis]

HI Dennis you can find them over here http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html

Thnx found it 

[Snowman.]

Hi Dennis, welcome to the forum. The chart you show is 300 hours plus, I don't think that's a great sign. The stratospheric warming doesn't seem to effect the troposhere in a favourite way. So in my opinion right now there aren´t any good signs.

 

The GFS Twins disagree on that.

[bluearmy]

The GFS Twins disagree on that.

Is is the strat that done it then snowman?

Would love the greeny ridge to verify and then see if we trace anything back to this weeks warming high up.

[Dennis]

SSW model

[AWD]

A couple of images taken from Twitter that I've asked for more info on but yet to receive a reply.

A 3.5sigma warning event over Siberia. I understand a Siberian warming event is one of the more saught after geographical locations for a stratospheric warming to occur?

Would this leave the vortex in a more favourable position in our part of the NH?

[bluearmy]

A couple of images taken from Twitter that I've asked for more info on but yet to receive a reply.

image.jpgimage.jpg

A 3.5sigma warning event over Siberia. I understand a Siberian warming event is one of the more saught after geographical locations for a stratospheric warming to occur?

Would this leave the vortex in a more favourable position in our part of the NH?

That's happening today AWD. all the forecasts predicted it and go on to rebuild the split vortex so I'm afraid not.

[Skin]

Berlin model is acting strange. not sure whats going on. Goes from a split PV at 10hpa at 00hr

 

 

To a reformed PV 24 hours later. 

 

 

Am I missing something? 

[MR EXTREMES]

Berlin model is acting strange. not sure whats going on. Goes from a split PV at 10hpa at 00hr

 

 

To a reformed PV 24 hours later. 

 

 

Am I missing something? 

i think the bottom line is that the recent warming and wave breaking has been a fail.

although for the members that have put alot of effort into this study they pretty much said there be a warming at some point this winter and they pretty much nailed it.

 

as for its effects well you can see it looks like a fail this perhaps could be the back ground feed back from high solar activity possibly.

 

if this had happened when the sun is at its most minimum then i suspect it would have totally been a different story.

its all getting rather frustrating but its also an extremely interesting winter with i suspect a lot of extra info for learning.

[bluearmy]

IGNORE THE BERLIN OUTPUT TODAY

ITS WRONG!

I wonder if it's from this time last year?

[knocker]

Correct me if I'm wrong ba but the ECM at weatherbell seems to going for strengthening of the vortex over Greenland by the 14th.