Stratosphere Temperature Watch 2012/2013

[MattH]

I think that suggests that we are very much at a crossroad Matt, for what is likely to occur for the final third of autumn.

And I think that that is very much the case stratospherically as well. We are seeing strong cooling of the middle stratosphere forecast with an upper strengthening vortex. Will the tropospheric vortex disturbances be able to have any impact on this?

It's certainly one that I am not going to try to call presently, though I imagine that we will need to see the northern arm of the BDC increase if the middle strat is to be warmed up!

Yeah, you're right and I agree. The output from the ECMWF 32 day model is often quite smooth in transition from a week by week period, primarily I believe to what is overall a very good medium/long range model, but this update and more recent updates have been showing some wild swings and that is the case with this update. As ever it'll be interesting to see how the UKMO interpret this into their 15 to 30 day update on their website, as it'll be a tricky one to summarise in my opinion.

There's still clearly a solid 3 or 4 weeks to go before we can get a better understanding of how things will pan out in the early winter etc. Clearly last Oct/Nov went down a particularly bleak path for those after a more blocked pattern and December was clearly a text book example of one particular stratospheric/tropospheric condition. It would seem, looking at the below image, the average temp on that chart has just dropped below average as well;

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/html_e/pole30_n.html

Clearly a very long way to go, but with such positive variables evident up to present to signal a more blocked and potentially colder winter, if we get a repeat performance of the first half of last winter, this winter, it'll be a major sucker-punch in the gut in my opinion. But hey, that's meteorology and the stratosphere for you!

Cheers, Matt.

[Summer Sun]

Latest ECMWF 32 day from overnight shows a very changeable and almost near impossible synoptic trend to track really. From clearly a spell of very unsettled conditions short term, but to completely the opposite potentially by late October and into early November with a strong signal for higher pressure to build across the UK and other areas of Europe.

In essence, it really shows an 'almost anything is possible' scenario really in the coming 2 to 4 weeks, from active, potentially deep autumnal lows, to perhaps far more anticyclonic conditions as well...Little sign however for below or well below average temperatures, in fact, the opposite.

Cheers,

M.

Very interesting all most anything could happen but warm weather looks more likely than cold weather going by that

[UV-RAY]

Very interesting all most anything could happen but warm weather looks more likely than cold weather going by that

It won't be warm Gavin whatever the outcome, but it appears RJS may have called the early part of winter correctly. Still a long way to go though.

[chionomaniac]

It won't be warm Gavin whatever the outcome, but it appears RJS may have called the early part of winter correctly. Still a long way to go though.

Err - winter is still 49 days away!

[UV-RAY]

Err - winter is still 49 days away!

Hence my still early days comment!

[Glacier Point]

I'd advise an extreme amount of caution in interpreting current stratospheric temperatures and projecting forward on this basis. For this day last year, 30mb temperatures over the Pole were slightly above normal.

Was that a good guide as to what was to come ?

It's not until the backend of this month and more particulalry next month that the stratospheric responses to tropospheric events begin to take hold.

GFS in the extended range continues to take my eye in displacing the core cold towards NE Atlantic and some limited warming developing over Asia (which is where we should be looking for embryonic warming).

[UV-RAY]

Thanks for the advice GP, I guess last years horror show is still effecting my judgement.

[johnholmes]

A very sensible post from GP

Without wanting to upset one or two, I do advise learning to walk before trying to run in any sphere, meteorology or anything else, and this thread perhaps more than some others. It is a hugely complex topic and I take my lead from GP and chio as I find it still a pretty baffling area of meteorology.

[richwatson00]

Southern hemisphere polar stratosphere at 30mb has reached a record high temperature whilst the tropical stratosphere plunges..

This may have a knock on effect for the Northern Hemisphere, allowing for greater penetration of surface fluxes poleward and upward.

Hey Guys,bit of a lurker i'm afraid and as you'll clearly see i'm still scraping the surface in terms of knowledge.

Here are my questions based on what i have read in this thread, isn't this a positive point for future vortex disruption from a downward warming in the NH due the increase in the transport of ozone to the pole? or, do i have it the wrong way around?

If the above is correct. Based on Mountain torque events and where they originate (asian,US etc) at first glance they have appear to have downstream impact on specific regions? Can the same be said for the top down warmings that are associated with increased ozone, or is the impact from this increase so small it becomes irrelevant due to the more major and shorter lead time factors?

I look forward to your responses, either way.

Rich

[arcticadventurer]

32 day ECM output leads to the 12th of November? Surely early days?

[BLAST FROM THE PAST]

I'd advise an extreme amount of caution in interpreting current stratospheric temperatures and projecting forward on this basis. For this day last year, 30mb temperatures over the Pole were slightly above normal.

Was that a good guide as to what was to come ?

It's not until the backend of this month and more particulalry next month that the stratospheric responses to tropospheric events begin to take hold.

GFS in the extended range continues to take my eye in displacing the core cold towards NE Atlantic and some limited warming developing over Asia (which is where we should be looking for embryonic warming).

So lets try again for GP and C please or anyone else that knows the answer. If pronounced cooling is starting is it 'usual' for it to continue full steam ahead and once started is very hard to reverse?

Many thanks..............BFTP

Edited October 12, 2012 by BLAST FROM THE PAST

[chionomaniac]

So lets try again for GP and C please or anyone else that knows the answer. If pronounced cooling is starting is it 'usual' for it to continue full steam ahead and once started is very hard to reverse?

Many thanks..............BFTP

The short answer is that it is usual for cooling to continue until themodynamic equilibrium is reached. There are factors such as ozone levels from the BDC and wave breaking that can upset that thermodynamic equilibrium.

Edited October 12, 2012 by chionomaniac

[Glacier Point]

This decade has seen an unusually cool stratosphere during the late autumn and winter, especially so at the 10hPa and higher layers. This cooling has been most pronounced over the tropical stratosphere.

Cooling is to be expected at this stage.

What either arrests this cooling or works with it are IMO the key factors:

- relative state of the BDC during the autumn (ENSO and QBO driven);

- state of the QBO against the solar cycle;

- troposhperic drivers - sea ice, snow cover, tropical convection and general 'state' of the atmosphere, especially mountain torque events associated with atmosphere moving from La Nina to El Nino type pattern.

Bear in mind, stratospheric time scales are extremely long, several months to start and complete processes. Thus stuff that's going on now within the lower part of the atmosphere will ultimatley have a bearing on the stratosphere in 2-3 months time.

If I were doing an assessment of these factors, it would go something like this...

- relative state of the BDC during the autumn (ENSO and QBO driven); no ENSO signal to interfer; cooler tropical stratosphere relative to polar stratosphere, (enhanced of late); likely favourable to development of weaker than normal vortex;

- state of the QBO against the solar cycle; favourable to warming with weakening east QBO (second season), potential interest in early season warming event;

- troposhperic drivers - sea ice, snow cover, tropical convection and general 'state' of the atmosphere; favourable to weaker than normal vortex with record exposure of surface water during autumn, likely rapid advance in Siberian snowcover weeks 2-3 October, notable anomaly pattern in H5 field appearing over Arctic region during October and teleconnective pattern in mid latitudes developing.

Edit: last bit bolded to tie in with Steve Murr's posting re. 4-wave pattern. The last time we saw one of these in the autumn was November 2009. I recall the speculation at the time what that might lead to...

Edited October 12, 2012 by Glacier Point

[BLAST FROM THE PAST]

Thank you guys. Just responded to a post on the model thread, the last time a rare SH SSW took place was in October 2002. There was some very tempting blocking showing up and southerly tracking LPs particularly in Dec and early Jan....but it was a nearly winter. Wonder if the SSW down there has a bearing on NH and if so I am a tad hopeful that with solar cycle/s currently being experienced nearly could turn into achievement.

BFTP

[Skyraker]

Forgive me if this is a daft question or posted in the wrong thread, but is there any correlation between the reduced ozone seen before the ban on CFC gasses and a colder stratosphere ?

[Cheshire Freeze]

To be honest, we can only go on what we see at present- and that's a strat that has now cooled to below average. No ifs, buts, or maybe change that fact. I think, if we're honest with ourselves, us cold lovers would rather be sat here with an above normal strat temp with factors potentially going for us than below average strat temps with factors which *may* help us warm the strat at a later date.

Not the most auspicious of starts it has to be said.

Edited October 12, 2012 by CreweCold

[chionomaniac]

Forgive me if this is a daft question or posted in the wrong thread, but is there any correlation between the reduced ozone seen before the ban on CFC gasses and a colder stratosphere ?

I suspect that is very much the case, though we are dealing with a comparatively small data sample.

[Skyraker]

I guess it's another piece of the jigsaw.

A quick glance of wikipedia contains the following;

Since the adoption and strengthening of the Montreal Protocol has led to reductions in the emissions of CFCs, atmospheric concentrations of the most significant compounds have been declining. These substances are being gradually removed from the atmosphere—since peaking in 1994, the Effective Equivalent Chlorine (EECl) level in the atmosphere had dropped about 10% by 2008. It is estimated that by 2015, the Antarctic ozone hole will have reduced by 1 million km² out of 25 (Newman et al., 2004); complete recovery of the Antarctic ozone layer is not expected to occur until the year 2050 or later. Work has suggested that a detectable (and statistically significant) recovery will not occur until around 2024, with ozone levels recovering to 1980 levels by around 2068

I suspect that is very much the case, though we are dealing with a comparatively small data sample.

[Glacier Point]

To be honest, we can only go on what we see at present- and that's a strat that has now cooled to below average. No ifs, buts, or maybe change that fact. I think, if we're honest with ourselves, us cold lovers would rather be sat here with an above normal strat temp with factors potentially going for us than below average strat temps with factors which *may* help us warm the strat at a later date.

Not the most auspicious of starts it has to be said.

....... Ice in november to bear a duck... We don't want strato running hot now

[shedhead]

....... Ice in november to bear a duck... We don't want strato running hot now

There's an absolute plethora of lines to follow that one GP, but I assume the one you're alluding too involves slush and muck?

[SMU]

^^^

Following the mean decrease through October & into november with a canadian Warming late november thanks...

S

[Cheshire Freeze]

....... Ice in november to bear a duck... We don't want strato running hot now

So you don't see the current state of play as an issue then Stewart?

[chionomaniac]

So you don't see the current state of play as an issue then Stewart?

It's still far too early in the season, Crewe. Normally this thread wouldn't open for another 19 days!

[Suburban Streamer]

So you don't see the current state of play as an issue then Stewart?

If I were doing an assessment of these factors, it would go something like this...

- relative state of the BDC during the autumn (ENSO and QBO driven); no ENSO signal to interfer; cooler tropical stratosphere relative to polar stratosphere, (enhanced of late); likely favourable to development of weaker than normal vortex;

- state of the QBO against the solar cycle; favourable to warming with weakening east QBO (second season), potential interest in early season warming event;

- troposhperic drivers - sea ice, snow cover, tropical convection and general 'state' of the atmosphere; favourable to weaker than normal vortex with record exposure of surface water during autumn, likely rapid advance in Siberian snowcover weeks 2-3 October, notable anomaly pattern in H5 field appearing over Arctic region during October and teleconnective pattern in mid latitudes developing.

Edit: last bit bolded to tie in with Steve Murr's posting re. 4-wave pattern. The last time we saw one of these in the autumn was November 2009. I recall the speculation at the time what that might lead to...

[snowstorm445]

Very interesting all most anything could happen but warm weather looks more likely than cold weather going by that

But it will probably mean wetter, windier weather with a Strong Jet Stream, which could cook up some nasty windstorms. I'm not bothered if it's mild or cold, but I'd prefer if it was calm than windy. A colder scenario would probably bring much more settled weather.