Stratosphere Temperature Watch 2013/2014

[Cloud 10]

Day 10 10 hpa chart for reference.

 

 

 

 

Quite an improvement on the current situation if it verifies.

 

[Severe Siberian icy blast]

Day 10 10 hpa chart for reference.

 

ecmwf10f240.gif

 

 

 

Quite an improvement on the current situation if it verifies.

 

ecmwf10a12.gif

Yes it looks quite interesting there , looks like the main part is over Siberia and the other toward northwestern Greenland.

Maybe we can squeeze high pressure toward Iceland ? Looks similar to last January when we had the immediate trop response to the MMW ? May be completely wrong !

[Catacol]

Yes it looks quite interesting there , looks like the main part is over Siberia and the other toward northwestern Greenland.Maybe we can squeeze high pressure toward Iceland ? Looks similar to last January when we had the immediate trop response to the MMW ? May be completely wrong !

 

Yes - I hinted at this in the model thread. I do not have confidence in the models' handling of the trop impact of pressure on the vortex: it seems to me that beyond about 144h they lose the plot entirely if there is something going on in the strat - though I have no evidence of that and only subjective observations over a few years to base it on.

 

The new ECM might get a better handle of it (is the whole ECM suite of products in line for this upgrade? Someone said in the model thread that the op run is not...?) but I am not unhappy at the current situation. Going back a couple of weeks it looked like westerlies in control and talk was of analogues pointing to late winter strat events - if any. We have now had a block in the atlantic develop somewhat against that train of thought, and 2 small warming episodes in November (inc 1 coming up) which although they look unlikely to break up the core of a strong vortex too much are at least putting some pressure on it.

 

I think the scene is set for an atlantic block to come and go throughout December provided this situation continues and the building of pressure in the northern pacific is maintained. Chance of a decent northern shot at some point? I am not expert enough yet to be able to suggest a mid to late winter warming as some have hinted at... but its been a very good first 19 days of November so far for model and data watching, that's for sure.

[feb1991blizzard]

You lot are making my head hurt. I am getting too old so have thrown in the towel on this area of meteorology I am afraid. But there is certainly a huge amount of work being done by some of you-keep going, it may well bring some further light on this fascinating topic. I'll stick to my very amateurish look at the 30mb temperature profile.

 

Was thinking the same thing, I got to learn a bit last year but now realise this is a fascinating but really complex subject, wish I had more time and a better retention span, not being able to view pdf's doesn't help either!

Day 10 10 hpa chart for reference.

 

ecmwf10f240.gif

 

 

 

Quite an improvement on the current situation if it verifies.

 

ecmwf10a12.gif

 

True but the warm really needs to get right into the core or the vortex will soon re-phase.

[Recretos]

On a side note, how has your MJO reanalysis/composite project gone? That one looked quite interesting as well. 

 

 

 

Well, I was about 60% done (or around there somewhere), when I had some other priorities, thinking I can just go back to it when I will have time. Turned out that my methodology was just as complicated as it was efficient, so I totally forgot the system I was using in just two weeks (yes it was that complicated but very efficient, as I said). Later I got a new computer, delaying it even more, so I gave it a shot two weeks ago but I just couldn't figure it out (changed excel versions in between too). I will just try to salvage the finished data, and complete the rest when I create a new methodology for the efficient data extraction from the dataset. Talking about GWO composites of course. MJO is also in plan. 

 

This is brilliant work.

I know you gave the time line but is there anyway you could add that to the animations?

Not a criticism at all, one again great work and thank you.

 

 

Well, that's a funny story actually. Yes of course I tried that, but got my RAM almost up in flames because when I changed the name macros it started to reload the whole datasets for all layers.  Gotta get around this first, and then tweak my methodology a bit, to start with the names before I have a XY amount of layers and data that starts reloading. It was too late yesterday to start layering from beginning just to add the time stamps. So I decided to post the animations just for the sake of the feeling how a 3D SSW visualisation looks like. So the time stamps are definitely a priority in this case. Animations like these just don't look professional enough without it. Thank you.

 

It is late, so just a quickie from me, too keep this post on topic:

 

GFS and EC are generally on terms, with EC looking better actually, because of that wave 2 which seem more defined on EC. GEFS 10mb mean, is kinda closer to EC than GFS actually (tho I plotted CFS instead). 

 

 

 

 

Further on, we might see that Aleutian high picking up the pace (as the CFS was also suggesting at some point), as it is also suggested on the ECM 15day ensembles. These are normalized anomalies, so you wont get confused.

 

 

 

Best regards.

 

edit;
Lets also not forget to look at possible MT upticks in the near future.

 

 

 

Edited November 20, 2013 by Recretos

[blizzardof96]

Asian pattern looking very interesting in the medium range wrt potentially adding additional HF anoms towards the upper strat. We are seeing an overall pattern shift from a +VE anomaly north of India to a major lowering in SLP across Siberia and areas to the West of the Tibetan Plateau according to the ECMWF and its ensemble suite.

Notice the northeastward momentum flux across northern and western europe. This is helping setup equatorward propagation of -AAM and a -EAMT response.

OLR, 850mb stream function and wave flux:

SLP response across asia is unsupportive of significant heat flux transport

Big changes going on by D9. This pattern will help amplify the current positive temp anoms showing up at 10mb in a poleward fashion.  Significant warming took place at 10mb  as a result of the last EAMT spike in the Nov 6-14th period but these warm anoms are stationary at the moment.  The usual EAMT-->HF feedback response should show up in the 6-10 which will help enhance the Wave 2 setup the euro is showing by day 15.

Edited November 20, 2013 by blizzardof96

[MattH]

Just a quick one, but bit of a downgrade this morning given yesterday's 12Z ECM, the split is no more and the wave 2 activity is nowhere near as significant as the last few days;

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ha2&lng=eng

 

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

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ec.php?alert=1&level=10&forecast=all&lng=eng

 

To an extent after this up coming prolonged spell of anticyclonic conditions, in a way, there is only really one way to progress, at least for a time and that is towards a more active Atlantic.

 

Looking forward to the EC32 update later in the week after it's upgrade this week because its continuously shown high pressure well into December for some time, but that looks increasingly unlikely now.

 

Matt.

[Interitus]

Just a quick one, but bit of a downgrade this morning given yesterday's 12Z ECM, the split is no more and the wave 2 activity is nowhere near as significant as the last few days;

 

 

The possible split was a geopotential response to cross-polar ridging in the troposphere and the ECM has gradually backed away from this in the last few runs while the GFS wasn't really feeling it from the start.

[Tamara]

It looks to me as if rather than a split in the vortex (as recently suggested by the ECM) there is simply a shift in the coldest section of the vortex towards Siberia. This in itself is still a good thing to be talking about for the time of year even though there is still a lobe of vortex remaining towards the Canadian sector which is sufficient to flatten things out in the nearer time period.

 

I still think that whilst it will require harder work from below to disturb what is a consolidated and stable winter polar vortex higher up,  it is a matter of time before the pattern re-amplifies with further wave activity likely as the Pacific High builds once more and the cycle repeats. Therefore potentially another atlantic ridge scenario ahead imo after a spell of westerlies.

Edited November 20, 2013 by Tamara תָּמָר

[chionomaniac]

Just a quick one, but bit of a downgrade this morning given yesterday's 12Z ECM, the split is no more and the wave 2 activity is nowhere near as significant as the last few days;

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ha2&lng=eng

 

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

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ec.php?alert=1&level=10&forecast=all&lng=eng

 

To an extent after this up coming prolonged spell of anticyclonic conditions, in a way, there is only really one way to progress, at least for a time and that is towards a more active Atlantic.

 

Looking forward to the EC32 update later in the week after it's upgrade this week because its continuously shown high pressure well into December for some time, but that looks increasingly unlikely now.

 

Matt.

I have to say that this is not really a surprise given the lack of consistent support from the GFS. Still need to keep an eye on the future wave activity, but as I suggested in an earlier post, it is going to have to be mighty strong to overcome the vortex.

[Cecil Hogmanay Melchett]

Drat this most excellent thread is my 'port of call' when the models look mediocre.

Not really the news i was hoping for this morning but as C says,probably to be expected.

Keep up the phenominal work guys.

[shaky]

All the bloody charts are rubbish at the moment.just yesterday it looked like we were gona get some strong wave 2 activity and now we practically looking at zilch!!kudos to gfs cos it always gets slated.amazing how things have changed!!

[Catacol]

All the bloody charts are rubbish at the moment.just yesterday it looked like we were gona get some strong wave 2 activity and now we practically looking at zilch!!kudos to gfs cos it always gets slated.amazing how things have changed!!

 

But the more knowledgeable I think were always cautious about our current "cold" spell as it was not supported by other signals.

 

However all is not lost. Read the post a few back from Blizzard - way too knowledgeable for me! tho I get the jist - and also read the repeated references by some to ongoing amplification and consequent impact back and forward into the vortex. The aleutian high is set to rebuild and that will help amplfy the pattern. Add to that Blizzard's point about torque events possibly from day 9 and you have a pattern that may just about flatten out as our current ridge wanes only then to be pumped back up early in December. As MattHugo also stated - the EC32 update with new improved resolution will be interesting in terms of the blocking prediction. I still cant see consistent HLB in December - but I am optimistic regarding developments during mid winter and after.

 

We are all waiting to see the vortex put under proper pressure, but for now be happy with the odd cold outbreak.

Edited November 20, 2013 by Catacol_Highlander

[Catacol]

I would like to ask another dull question to follow on from the one yesterday that got me such a good response. Mountain Torque. I understand what it is (I think) but in terms of global weather patterns where are the "hotspots" so to speak for usual impact on the NH? Are we talking Himalayas and Rockies? Or a longer list?

[mountain shadow]

I'm no expert Catacol but I would have thought a poleward Rockies Mountain Torque event coupled with the presence of the Alutian High would serve to exert some extra pressure on the vortex in that local, displacing it to the other side of the pole.

Whilst the vortex is strong it is unlikely we will see any HLB, however we might see a bit more fluctuations in the jet stream, certainly not flat zonal and perhaps the chance of a northerly as the vortex gets pushed towards Siberia due to the MT (if it occurs) and Aleutian High.

One thing is clear in my view, the vortex strength was underplayed by the ECM resulting in the failed HLB. Remember when Steve was saying it was worth noting that the HLB was happening despite the strong vortex? It turns out of course that the HLB never occurred.

[Catacol]

Thanks MS - agree with all that. Just wondering how big the mountains have to be to precipitate a reasonable torque event. SM hasnt quite latched on to the strat thread yet... it's a pity because I think his powers of sequential analysis are strong and his mind would be very useful if he bought into it more. I still count myself a novice, but I'm not sure I have seen a major winter outbreak in the UK for lowlying areas in the last few years that hasnt been connected to strat disruption.

 

I'm in the camp that see NW and occasional SW influence for most of December once this pattern flattens out - Blast just posted the same in another thread - but charts like this still show there is interest to be had.

 

 

 

 

Note the amplification at 100hPa on this 192 chart over on the pacific side. While the Aleutian High continues to be a big player and we get this kind of upstream amplification I dont think December will be too dull. Some toppling ridges at this very least and I wouldnt rule out a northerly at some point. While ECM strat forecasts have drifted away from a split Blizzard's post early suggests additional pressure on the vortex beyond day 9. I didnt understand everything he posted, but that much I gleaned...!

Edited November 20, 2013 by Catacol_Highlander

[bluearmy]

I'm no expert Catacol but I would have thought a poleward Rockies Mountain Torque event coupled with the presence of the Alutian High would serve to exert some extra pressure on the vortex in that local, displacing it to the other side of the pole.Whilst the vortex is strong it is unlikely we will see any HLB, however we might see a bit more fluctuations in the jet stream, certainly not flat zonal and perhaps the chance of a northerly as the vortex gets pushed towards Siberia due to the MT (if it occurs) and Aleutian High.One thing is clear in my view, the vortex strength was underplayed by the ECM resulting in the failed HLB. Remember when Steve was saying it was worth noting that the HLB was happening despite the strong vortex? It turns out of course that the HLB never occurred.

 

chicken and egg. if the trop amplification had developed as modelled by ecm op, then the strat vortex would likely have split somewhat under wave 2 attack. anyway, the lesson to be drawn from this is that without ncep strat modelling support, we should be ultra cautious re berlin charts and vica versa.

 

having looked through the wave charts myself, its not as if the activity has gone. also, we still see some reduction in zonal wind speed below 10 hpa for a time.

Edited November 20, 2013 by bluearmy

[Tamara]

chicken and egg. if the trop amplification had developed as modelled by ecm op, then the strat vortex would likely have split somewhat under wave 2 attack. anyway, the lesson to be drawn from this is that without ncep strat modelling support, we should be ultra cautious re berlin charts and vica versa.

 

having looked through the wave charts myself, its not as if the activity has gone. also, we still see some reduction in zonal wind speed below 10 hpa for a time.

Taking the overall stratosphere environment into account, and the stability of the upper vortex, then an atlantic ridge was exactly what was to be expected from this wave activity I think. It was simply the amount of amplification of the jet stream that was in question. In that respect there are no surprises or disappointments because we got the ridge and some amplification on the macro NH scale, albeit less than some modelling suggested, but simply not enough on the micro scale because it only takes small adjustments to make quite a big difference to an island the size of the UK.

Edited November 21, 2013 by Tamara תָּמָר

[Interitus]

Apologies if this has been linked before but the NASA Merra satellite reanalysis is very good - http://acdb-ext.gsfc.nasa.gov/Data_services/met/ann_data.html

There is a range of temperature, flux, wave data etc for a range of stratospheric heights, dating back to 1979, which can be compared ready graphed with extremes and percentiles.

The graphs are nice, and using the request form at the bottom returns daily data which is only a couple of days old ready to paste into the spreadsheet of your choice.

I'm going to be wasting time with this for sure!

Edited November 21, 2013 by Interitus

[sebastiaan1973]

http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/glob-seas-prob

new forecast is out. If I interpretate correctly around 50% chance for colder than normal for  the South of the UK. But more importantly are the 500hPa charts.

[cooling climate]

http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/glob-seas-prob

new forecast is out. If I interpretate correctly around 50% chance for colder than normal for  the South of the UK. But more importantly are the 500hPa charts.

850 temps look promising also. Although in reality I think it will be colder.

[Catacol]

850 temps look promising also. Although in reality I think it will be colder.

 

You refer to your forecast frequently. Where have you posted it? What methods do you use?

[Recretos]

Ensemble FI, but still, very decent tropospheric setups appearing on the ECM EPS lately. 

 

 

 

[Duane S.]

A bit more interest again this morning from the ECM as maybe signs of Wave1 pepping up at the end of the run

 

Moderate Wave 2 breaking still on course over the next few days and again at D10, maybe one to watch...

 

 

But we are going to see a bit more this this to greatly impact the growing vortex, graphically shown at 5 days where it comes under pressure

 

To D10, fully re-formed

 

But looking a bit further ahead stll ,the trend to keep the main vortex more East than West based continues and with a West Atlantic Based High also likely to be in situ for a while yet, that is less steps to cold from that point. Got a feeling we could start seeing some very decent charts show up soon for Early-Mid December. Of course merely charts and it actually occuring are two different things...

[MattH]

A bit more interest again this morning from the ECM as maybe signs of Wave1 pepping up at the end of the run

ecmwfzm_ha1_f240.gif

 

Moderate Wave 2 breaking still on course over the next few days and again at D10, maybe one to watch...

ecmwfzm_ha2_f240.gif

 

 

But we are going to see a bit more this this to greatly impact the growing vortex, graphically shown at 5 days where it comes under pressure

ecmwf10f144.gif

 

To D10, fully re-formed

ecmwf10f240.gif

 

But looking a bit further ahead stll ,the trend to keep the main vortex more East than West based continues and with a West Atlantic Based High also likely to be in situ for a while yet, that is less steps to cold from that point. Got a feeling we could start seeing some very decent charts show up soon for Early-Mid December. Of course merely charts and it actually occuring are two different things...

 

Just a quick follow on from this, but the EC32 has had its upgrade and changes are evident for December. However, the signals for December are particularly weak on this last run. There doesn't seem to be a signal for a +NAO nor does there seem to be a signal for significantly -ve height anoms to the NW, in fact there is a weak signal for higher than average pressure over Greenland by mid-December. That being said, the signals are particularly weak so it's anyone's guess what December will produce, but 'raging zonality' doesn't seem on the cards. What is also interesting is the continued complete lack of any significant MJO phase. For at least 2 weeks running now the EC32 EPS MJO prediction maintains near 'neutral' conditions throughout the forecast period. It just doesn't seem to want to get going and this variable is likely to remain rather useless for medium/long range predictions for now.

 

As usual, it's just a case of watching and waiting to see if anything materialises...

 

Cheers, Matt.