Stratosphere Temperature Watch 2013/2014

[Snowy L]

Hmm, I'm not sure if this is an error, but the ECM has suddenly picked up on a massive increase in wave-2 breaking in 7-10 days time. I'm skeptical because this was nowhere to be seen in forecasts in the previous few days.

 

Can't post images yet sorry:

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=f240&var=ha2&lng=eng

[sebastiaan1973]

I thought CW are supposed to be in the early part of the winter? http://en.wikipedia.org/wiki/Sudden_stratospheric_warming

Edited November 11, 2013 by sebastiaan1973

[chionomaniac]

Hmm, I'm not sure if this is an error, but the ECM has suddenly picked up on a massive increase in wave-2 breaking in 7-10 days time. I'm skeptical because this was nowhere to be seen in forecasts in the previous few days.

 

Can't post images yet sorry:

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=f240&var=ha2&lng=eng

I have to admit that I was expecting to see a wave 1 type breaking event from around mid month, not wave 2, so this is great news because it means that rather than a displacement from the Pacific ridge the vortex will be under pressure in two areas - hence the Atlantic ridge coming into the forecast.

If I had thought about it properly I should have guessed that we should expect a wave 2 event because of the Atlantic ridge. Still live and learn!

 

Keep an eye on the MT analysis for the next few days.

 

Oh and Recretos, I agree with sebastiaan - the CW is an early season phenomenom. However, I am interested in the small chance of a wave 2 split SSW later on in the season. We can't rule it out completely!

Edited November 11, 2013 by chionomaniac

[summer blizzard]

I have to admit that I was expecting to see a wave 1 type breaking event from around mid month, not wave 2, so this is great news because it means that rather than a displacement from the Pacific ridge the vortex will be under pressure in two areas - hence the Atlantic ridge coming into the forecast.

If I had thought about it properly I should have guessed that we should expect a wave 2 event because of the Atlantic ridge. Still live and learn!

 

Keep an eye on the MT analysis for the next few days.

 

Oh and Recretos, I agree with sebastiaan - the CW is an early season phenomenom. However, I am interested in the small chance of a wave 2 split SSW later on in the season. We can't rule it out completely!

 

Would this wave 1 and 2 activity be in response to the collapse in angular momentum (assuming it's still low).

[lorenzo]

The zonal wind profile on Berlin site shows the GWO impact well. Had to double check the year at day 5 or so it looks like an easterly QBO.

That wave 2 plot is a great watch upwelling then completely across the grid.

 

Heights

 

Edited November 11, 2013 by lorenzo

[summer blizzard]

QBO not dissimilar to 2008 at the moment.

[MattH]

Keep an eye on this;

 

http://www.atmos.albany.edu/facstaff/roundy/waves/analogs/analogs.html

 

I find it produces some fascinating results, could be interesting in terms of the correlation and relationship between the trop and the strat (or vice versa!)...

 

Matt.

 

NB: Run through the sequence and note the clear signal for a +ve 300mb height anom to the W and NW of the UK in terms of the blocking pattern being signaled now.

Edited November 11, 2013 by MattHugo

[lorenzo]

Keep an eye on this;

 

http://www.atmos.albany.edu/facstaff/roundy/waves/analogs/analogs.html

 

I find it produces some fascinating results, could be interesting in terms of the correlation and relationship between the trop and the strat (or vice versa!)...

 

Matt.

 

NB: Run through the sequence and note the clear signal for a +ve 300mb height anom to the W and NW of the UK in terms of the blocking pattern being signaled now.

 

This page is also excellent within the Roundy pages, bit of a technical challenge to read !

 

Directory of MJO HovMoller plots - http://www.atmos.albany.edu/facstaff/roundy/waves/hovsdetmjo/

 

Current equatorial Plot - http://www.atmos.albany.edu/facstaff/roundy/waves/hovsdetmjo/0_7.5N/2013.png

 

[bluearmy]

the berlin plots seen to be dodgy at various points re the wave charts. i'd rather wait for tomorrows before i get too interested.

[Recretos]

 

Oh and Recretos, I agree with sebastiaan - the CW is an early season phenomenom. However, I am interested in the small chance of a wave 2 split SSW later on in the season. We can't rule it out completely!

 

I agree too. I wasn't pointing out that as an actual CW event by definition, but more like in a literal meaning "warming over Canada".

 

 

 

The zonal wind profile on Berlin site shows the GWO impact well. Had to double check the year at day 5 or so it looks like an easterly QBO.

ecmwfzm_u_f168.gif

 

 

 

I am calling this a run error for now. And an obvious one too. You cant really shift from +QBO to -QBO in one day. And all plots for day 7-10 seem out of context, so most if not all of the products in that range seem false to me. We will see what will happen with the new run.

Edited November 12, 2013 by Recretos

[bluearmy]

As suspected - erroneous.

[MattH]

Good call, unfortunately...

 

It's gone;

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ta2&lng=eng

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

 

Also for the record, despite some people often dismissing it, the latest EC32 shows a complete reverse of fortunes in terms of pressure anoms through the rest of NOvember and into early December. The significant +NAO pattern of late is reversed within a weak, or sorts, as pressure builds to the NW of the UK. Through week 3 and 4 which takes us into early December there is no evidence within this particular run for a significant polar vortex, in fact it highlights a weak +ve pressure anom over the pole, whilst pressure is lower either over or just to the south of the UK.

 

It'll be interesting to see if it verifies as it's far from a zonal/+AO/+NAO pattern.

 

Regards, Matt

[shaky]

Good call, unfortunately...It's gone;http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ta2&lng=enghttp://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ha2&lng=engAlso for the record, despite some people often dismissing it, the latest EC32 shows a complete reverse of fortunes in terms of pressure anoms through the rest of NOvember and into early December. The significant +NAO pattern of late is reversed within a weak, or sorts, as pressure builds to the NW of the UK. Through week 3 and 4 which takes us into early December there is no evidence within this particular run for a significant polar vortex, in fact it highlights a weak +ve pressure anom over the pole, whilst pressure is lower either over or just to the south of the UK.It'll be interesting to see if it verifies as it's far from a zonal/+AO/+NAO pattern.Brilliant matt!!which should hopefully mean cold and snow for us in the uk!!!Regards, Matt

[SMU]

Hi Matt-

 

I think this next 2-4 weeks will be an interesting time for the strat thread- no significant warming progged- infact quite the opposite, but tentative signs that the polar heights will increase with time-

certainly an unusual correlation.

 

S

[Ian Brown]

Good call, unfortunately...

 

It's gone;

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ta2&lng=eng

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

 

Also for the record, despite some people often dismissing it, the latest EC32 shows a complete reverse of fortunes in terms of pressure anoms through the rest of NOvember and into early December. The significant +NAO pattern of late is reversed within a weak, or sorts, as pressure builds to the NW of the UK. Through week 3 and 4 which takes us into early December there is no evidence within this particular run for a significant polar vortex, in fact it highlights a weak +ve pressure anom over the pole, whilst pressure is lower either over or just to the south of the UK.

 

It'll be interesting to see if it verifies as it's far from a zonal/+AO/+NAO pattern.

 

Regards, Matt

 

 

Thanks Matt, the same model did perform poorly this time last year though, continually modelling +ve anomalies over Greenland and Iceland that never materialised.

Edited November 12, 2013 by Ian Brown

[cooling climate]

Steve Murr, on 12 Nov 2013 - 11:37, said:Hi Matt-I think this next 2-4 weeks will be an interesting time for the strat thread- no significant warming progged- infact quite the opposite, but tentative signs that the polar heights will increase with time-certainly an unusual correlation.S

If we do see heights increase over the Arctic which I fully expect to seehappen hence my call for a mainly -AO winter then their will be interactionwith the stratosphere even if it is only at the lower levels.No stratosphere no heights.

[phil nw.]

Latest Stratosphere forecasts out to day 10 underline the interest in the model thread for a colder trend next week.

The recent wave activity has had some effect on the vortex with prominent Atlantic ridging apparent at the lower end.

 

A reduction in mean zonal wind speeds around 50-60N too reflective of some blocking there and showing a split flow.

 

Wave activity looks to be on the wane in the forecasts though

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ta1&lng=eng

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=ta2&lng=eng

 

and the core of the vortex still looks solidly placed over the Pole with cooling continuing apace.

 

The PV is taking some hits with the buckling at the edges for the next week or 2 but i think more wave activity will be needed to really make inroads or displace it from it's home i reckon.

 

[bluearmy]

was it winter 2010/2011 which saw a lack of coupling between the upper strat and lower strat/trop ? is my memory playing tricks ? i just remember seeing an ever cooling upper strat and vortex and lack of strong trop p/v. perhaps it was the neg QBO responsible

[MattH]

was it winter 2010/2011 which saw a lack of coupling between the upper strat and lower strat/trop ? is my memory playing tricks ? i just remember seeing an ever cooling upper strat and vortex and lack of strong trop p/v. perhaps it was the neg QBO responsible

 

I think I remember that as well. At times it was quite odd how there was a complete lack of any distinct connection and correlation between the two. The strat seemed to point towards a strong PV within the trop, yet, nothing, the opposite with northern blocking and quite cold conditions at times.

 

Thanks for the post Phil and agreed. My quick post the other day regarding the general November and December patterns, in broader terms, I still stand by at the moment and have no reason to change those thoughts. The ECM charts clearly teased us with some false info the other day with regards to wave 2 activity, which would have been a particularly decent step in the 'right direction'. However, the strat is cooling, as it should and despite the more meridional pattern next week, there's no major HLB activity on my 'radar' for the start of the winter.

 

Few pieces of information from the recent CFSv2 model of which may well be of some interest are as follows from the recent CFSv2 model. Clearly it's either well wide of the mark or it's on to something. You could say the NAO prediction isn't that impressive, but the AO, particularly compared with of late, is clearly persistently in a -ve state from the CFSv2 model. Just another model of course, but we are at that point of the 'strat season' when it is a case of 'no mans land'. A waiting game really.

 

 

 

NB: ECM seasonal update should be out on the 15th, I'll post a few comments on it when it becomes available...

Edited November 13, 2013 by MattHugo

[phil nw.]

Yes i seem to recall such a period ba although can't remember which year.

I am sure i read somewhere that downward propagation of waves in the Strat.vortex occur more readily in a +veQBO so that would explain that disconnect we experienced. (-ve QBO state).

 

Hopefully that's something in our favour this year- if of course i recall correctly.

Edited November 13, 2013 by phil nw.

[bluearmy]

Yes i seem to recall such a period ba although can't remember which year.I am sure i read somewhere that downward propagation of waves in the Strat.vortex occur more readily in a +veQBO so that would explain that disconnect we experienced. (-ve QBO state). Hopefully that's something in our favour this year- if of course i recall correctly.

Assuming that we have some wave propagation at the top to work down phil! at the moment we could do with the disconnect.

[cooling climate]

 

Yes i seem to recall such a period ba although can't remember which year.I am sure i read somewhere that downward propagation of waves in the Strat.vortex occur more readily in a +veQBO so that would explain that disconnect we experienced. (-ve QBO state). Hopefully that's something in our favour this year- if of course i recall correctly.

It was 2010 where we had a -ve QBO state in the lower strat and +ve QBOstate in the middle and upper stratosphere.local wave breaking in the upper troposphere and lower stratosphere similar(although weaker than then) to what we are seeing now.

[Interitus]

Just want to clarify some of these comments regarding the QBO - in the winters of 2009/10 and 2010/11 it was -ve in the higher strat at 10mb upwards and -ve then +ve in the 30mb-50mb range where it's typically measured.

If you're referring to a disconnect beneath the vortex, though it may have an effect, this isn't QBO - it isn't at these latitudes where the strat is strictly seasonal, the QBO cannot really be seen much further north than 15°N.

With regards to wave breaking, the North Poleward eddy heat flux (graph below) shows low activity at the moment, and the ECM forecasts show it to probably remain so for a while.

 

Edited November 14, 2013 by Interitus

[Catacol]

Can someone help me grow my knowledge a bit? The 120h chart of zonal wind forecast shows a strange looking reversal up towards the pole at trop level. It's nearly in reverse now - lasts about a week peaking at 120h and then returns to westerly flow again by 168/192.How does this sort of thing come about? I can grasp that warmth higher up causes a slow down and that this can become a reversal and downwell through the atmosphere, but how does a trop reversal like this come about in the trop first? Is it just the product of a pressure rise? And is it possible for a reversal at trop level to upwell regardless of a warming? Or is it linked hand in hand with warming via wave 1 activity? Apologies if that is a jumbled set of sentences - I'm really still trying to learn about the reality of the vertical significance of the atmosphere as a whole!

 

Edited November 14, 2013 by Catacol_Highlander

[Duane S.]

Interesting 10 day Wave 2 forecast chart. If not for its intensity the way it propogates downwards way into the troposphere with comparitive ease, I assume there is some sort of feedback mechanism going on here?