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Stratosphere Temperature Watch 2012/2013


chionomaniac

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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

I should also point out that from the stronger the mountain torque observed, we can forecast that the wave break into the stratosphere will be stronger. So that this is a useful guide as to what occurs down the line.

Also, in todays forecasts there is a strong 10 day trend to displace the polar vortex towards Baffin bay/ N Canada region. So will we see some kind of height rises in the Scandi region around this time tropospherically - not programmed as of yet!

(Edit - of course these height rises could be Eurasion placed)

Just for TEITS!

post-4523-0-35787300-1350159777_thumb.gi

Edited by chionomaniac
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Posted
  • Location: Peterborough N.Cambridgeshire
  • Location: Peterborough N.Cambridgeshire

Just for TEITS!

post-4523-0-35787300-1350159777_thumb.gi

Oh dear CH you really do take things personal.

Yes I can think of many occasions when you have been spot on but I can also think of many occasions when you have been wrong. So stop being so sensitive and taking any critical comments to heart. When I joined this forum I was told you have to accept negative comments aswell as positive comments when forecasting on a public forum and I took this advice on board. May I suggest you do the same!!

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Posted
  • Location: st albans
  • Location: st albans

Difficult to remember everything in detail but when the consequences of a strat forecast over the past few years have not materialised as predicted/hoped for, I think there was always a decent explanation for nw Europe. Apart from the strat forecast not being correct more than a week in advance (which can clearly occur) the subsequent tropospheric response of a verified strat situation will not always be straightforward. I remember the broken vortex several febs ago leaving an active piece around Newfoundland which spent many weeks firing up the Atlantic jet. Result was no freeze for us but further to our east, I think they did go cold. Could have easily been the other way around. of course it's only part of e jigsaw and can easily be overridden by other signals such as a strong ENSO or MJO but I think its clear that the strat is maybe the most important part of the winter jigsaw.

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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

Moving on back to the stratosphere....

We are still seeing a cooling of the mid stratosphere occurring in line with seasonal expectations.

It is still early and I would not expect anything other at this stage.

I suspect that the southern hemisphere situation will affect the northern hemisphere and we should now be looking for some strong NH wave activity to assist feedback into the stratosphere. On this point alone the GFS NH pattern from the 00Z would be very welcome.

post-4523-0-60436300-1350193748_thumb.gi

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Posted
  • Location: st albans
  • Location: st albans

Although quite varied over the past few days, that Aleutian/alaskan ridge seems to be one of the more consistent features modelled. Lets hope the oncoming depression really winds itself up and shoves that WAA into the central polar area. I note the other ridges around the hemisphere but these seem to be changing location with each run and are therefore probably less reliable re verification.

Edited by bluearmy
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Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.

A fascinating subject this one, and one that I was initially very sceptical of...But that was before three years' successful predictions.

So, my question is: what factor, or factors, cause the stratosphere to warm, in the first place?

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Posted
  • Location: Barnoldswick, Lancs, 500ft
  • Location: Barnoldswick, Lancs, 500ft

A fascinating subject this one, and one that I was initially very sceptical of...But that was before three years' successful predictions.

So, my question is: what factor, or factors, cause the stratosphere to warm, in the first place?

I recommend reading page 1, first post by C. That'll answer most of your questions....

M

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Posted
  • Location: Barnoldswick, Lancs, 500ft
  • Location: Barnoldswick, Lancs, 500ft

Please take a look overhere. http://www.wzforum.de/forum2/read.php?27,2519981 German written forecast for this winter, including SSW (most chance in January).

If you don't read German, you can use google translate.

Interesting and very comprehensive and pass on my regards to the author. The translation to English isn't great mind with some German words left over. That being said you can gauge the jist of the analysis especially from the images provided and it certainly supports current thoughts from most regarding a greater or heightened risk of more northern blocking this winter and hence a greater risk of cold outbreaks etc.

Cheers. M

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Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.

I recommend reading page 1, first post by C. That'll answer most of your questions....

M

Cheers Matt...Posted Image

And, after having done that, I'd recommend that others do the same.

Edited by Rybris Ponce
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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

Please take a look overhere. http://www.wzforum.d....php?27,2519981 German written forecast for this winter, including SSW (most chance in January).

If you don't read German, you can use google translate.

Thanks seb.

I still found it very difficult to read - even with google translate, but a very well thought out forecast. There is a good explanation of the GLAAM there which I will quote.

Global Integrated Angular Momentum Index: "The atmospheric angular momentum is the product of mass times the rotational velocity times the perpendicular distance from the axis of rotation. A rotating object will conserve its angular momentum unless a torque acts to change its rotation. The axial component is of interest in climate and is determined by the distribution of atmospheric mass and zonal wind relative .. to the earth's rotation axis Higher than normal surface pressure in the tropics or strong westerly flow there contributes to greater AAM

Also, if we are entering a neutral ENSO year then studies have shown that the chance of a SSW drop from around 70% during an El Nino to around 42% during a neutral year - so that is a brave call.

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Posted
  • Location: Epsom, Surrey, 100 Meters above sea level
  • Weather Preferences: Anything Extreme
  • Location: Epsom, Surrey, 100 Meters above sea level

Thanks seb.

I still found it very difficult to read - even with google translate, but a very well thought out forecast. There is a good explanation of the GLAAM there which I will quote.

Global Integrated Angular Momentum Index: "The atmospheric angular momentum is the product of mass times the rotational velocity times the perpendicular distance from the axis of rotation. A rotating object will conserve its angular momentum unless a torque acts to change its rotation. The axial component is of interest in climate and is determined by the distribution of atmospheric mass and zonal wind relative .. to the earth's rotation axis Higher than normal surface pressure in the tropics or strong westerly flow there contributes to greater AAM

Also, if we are entering a neutral ENSO year then studies have shown that the chance of a SSW drop from around 70% during an El Nino to around 42% during a neutral year - so that is a brave call.

Just out of interest Chino....what is the % for a SSW during a weak La Nina ?

Edited by EML Network
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Posted
  • Location: Barnoldswick, Lancs, 500ft
  • Location: Barnoldswick, Lancs, 500ft
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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

Just out of interest Chino....what is the % for a SSW during a weak La Nina ?

Interestingly around 70% as well. It is the Enso neutral years that have less events.

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Posted
  • Location: Epsom, Surrey, 100 Meters above sea level
  • Weather Preferences: Anything Extreme
  • Location: Epsom, Surrey, 100 Meters above sea level

Forgive me if this should have been posted elsewhere, thought it might be relevant to the posts directly above, 2012 ENSO bears a STRIKING resemblance to 2006 !....(in fact it's almost identical)..and the projected forecast going into Winter falls in line with what happened in 2006 as well...feel free to delete this post if it's not in the correct thread.

Posted Image

Edited by EML Network
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Posted
  • Location: Netherlands
  • Location: Netherlands

http://www.eps.jhu.edu/~cig4/mjosswv6.pdf thanks to Karel for this suggestion

The effect of the Madden-Julian Oscillation (MJO) on the Northern Hemisphere wintertime stratospheric polar vortex and major, midwinter stratospheric sudden warmings (SSWs) is evaluated using a meteorological reanalysis dataset. The MJO influences the tropospheric North Pacific, and in particular the region in the North Pacific most strongly associated with a SSW.

Consistent with this, SSWs in the reanalysis record have tended to follow certain MJO phases. The magnitude of the influence of the MJO on the vortex is comparable to that associated with the Quasi-Biennial Oscillation and El NiËœno. The MJO could be used to improve intra-seasonal projections of the Northern Hemisphere high latitude circulation, and in particular of the tropospheric Northern Annular Mode, at lags exceeding one month.

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

Forgive me if this should have been posted elsewhere, thought it might be relevant to the posts directly above, 2012 ENSO bears a STRIKING resemblance to 2006 !....(in fact it's almost identical)..and the projected forecast going into Winter falls in line with what happened in 2006 as well...feel free to delete this post if it's not in the correct thread.

Posted Image

Its no longer an applicable analogue in my opinion, the PDO has stayed deeply negative and the QBO is effectively in a polar opposite state.

Additionally the chart below coupled with a September MEI reading of just 0.2 indicates that if anything we may be leaning towards La Nina..

Posted Image

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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

http://www.eps.jhu.e...g4/mjosswv6.pdf thanks to Karel for this suggestion

The effect of the Madden-Julian Oscillation (MJO) on the Northern Hemisphere wintertime stratospheric polar vortex and major, midwinter stratospheric sudden warmings (SSWs) is evaluated using a meteorological reanalysis dataset. The MJO influences the tropospheric North Pacific, and in particular the region in the North Pacific most strongly associated with a SSW.

Consistent with this, SSWs in the reanalysis record have tended to follow certain MJO phases. The magnitude of the influence of the MJO on the vortex is comparable to that associated with the Quasi-Biennial Oscillation and El NiËœno. The MJO could be used to improve intra-seasonal projections of the Northern Hemisphere high latitude circulation, and in particular of the tropospheric Northern Annular Mode, at lags exceeding one month.

Thanks once again Seb.

This is quoted in the paper

45 Fig. 6 shows that about 10 days after the MJO passes its phase with reduced (enhanced)

46 convection over the western Paciï¬c (Indian) Ocean [phase 1 as deï¬ned by Wheeler and

47 Hendon, 2004], warm anomalies are established in the polar lower stratosphere.

and the current MJO forecast:

post-4523-0-36714300-1350209943_thumb.gi

Let's watch and learn!

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Posted
  • Location: @scotlandwx
  • Weather Preferences: Crystal Clear High Pressure & Blue Skies
  • Location: @scotlandwx

2006 monthly pattern for ENSO up until now does mirror this year very well, taken in isolation it is a good analog. Unfortunately the other factors over ride this somewhat, the solar state is quite different, as mentioned QBO is vitally different.

Guidance still favours development of weak Nino conditions on a deterministic basis, the background climatological conditions have some leaning to Nina. Leaving us in a bit of a stalemate with ENSO and back to square one with neutral.

http://iri.columbia.edu/climate/ENSO/currentinfo/technical.html

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Posted
  • Location: Leeds (Roundhay) 135m
  • Location: Leeds (Roundhay) 135m

Thanks once again Seb.

This is quoted in the paper

45 Fig. 6 shows that about 10 days after the MJO passes its phase with reduced (enhanced)

46 convection over the western Paciï¬c (Indian) Ocean [phase 1 as deï¬ned by Wheeler and

47 Hendon, 2004], warm anomalies are established in the polar lower stratosphere.

and the current MJO forecast:

post-4523-0-36714300-1350209943_thumb.gi

Let's watch and learn!

48 In contrast, anomalous cooling occurs in the stratosphere about 10 days after MJO phase 5,

49 which has convective anomalies of opposite sign to that of phase 1

So if im reading this correctly, the paper states that there is link between some MJO phases and the state of the stratosphere in that if we see a higher amplitude phase one event, there is a link between that and a possible warming event, and phase five and possible cooling?

Edited by Mark Bayley
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Posted
  • Location: @scotlandwx
  • Weather Preferences: Crystal Clear High Pressure & Blue Skies
  • Location: @scotlandwx

In respect of the MJO if I remember rightly from 2009/10 winter I tended to notice a 4-6 lag from when exiting phase 1 into early phase 2 as one that favoured a more easterly set up for us here, not always definitive hence began following the strat thread as better guidance as to future trend. Think that year the MJO was getting heavily analysed for impacts.

If I remember correctly January this year there was some disconnect between ECM and GFS programming into NH models the potential OLR associated with MJO event and this led to some cracking debate between which would go where.

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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

So if im reading this correctly, the paper states that there is link between some MJO phases and the state of the stratosphere in that if we see a higher amplitude phase one event, there is a link between that and a possible warming event, and phase five and possible cooling?

Yes

It is all interlinked I suspect through the processes of wave breaking due to mountain torques - all part of the GWO cycle!

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Posted
  • Location: @scotlandwx
  • Weather Preferences: Crystal Clear High Pressure & Blue Skies
  • Location: @scotlandwx

Cannot attach this one as 7mb, sorry the links are massive for some reason..

Link included some re-analysis by ECMWF on MJO predictability specifically in winter.

http://www.google.co...5LH7SoS3Dpn-Q

Prediction of the Madden-Julian Oscillation

and its impact on the European weather

in the ECMWF monthly forecasts

Annual Seminar ECMWF - 8 September 2010

Frédéric Vitart

European Centre for Medium-Range Weather Forecasts

ECMWF Training Seminar on MJO and Strat PPT File

http://www.google.co...-sHxNcas_u6Gw

post-7292-0-08611200-1350211566_thumb.pn

Edited by lorenzo
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