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There are certianly inklings of a FW that could be quite strong and not as late as is possible with such a cold and dominant pv.

 

Recent strong mountain torque has introduced a strong burst of westerlies into the equation.  A slight spike in AAM sending GWO into low amp phases 5-6-7. Wave 1 on the rise and likely to see yet another tag team with wave 2 into march.  I suspect another round of strong MT is required?

 

post-15445-0-43645600-1393346415_thumb.g  post-15445-0-80226000-1393346482_thumb.g post-15445-0-90849500-1393346699_thumb.p

 

Flux and temp forecasts suggestive of something similar to what we saw early Feb.  This time round, of course, the PV/zonal winds are weaker so perhaps potential for a meatier FW that may finally cause some lasting damage to the beastly PV?

 

post-15445-0-85261100-1393347471_thumb.g post-15445-0-68865500-1393347488_thumb.g post-15445-0-09880400-1393347829_thumb.g

 

 

Of course, i'm well aware that most of us monitor the strat because we pin our hopes of sustained cold weather on these events and a FW isnt exactly terribly exciting from that POV.  But i'm fascinated (as well as being equally frustrated) with this seasons remarkably strong PV and now my interests move towards how long into Spring it will persist etc etc, hence this post.  As well as the likelihood that a strong FW will have implications on our April weather patterns.

 

We still have some way to go, but there are the subtlest of hints at this early stage?  

 

Now if the FW does pan out favourably then I've got one eye on end march/early april 1967.

 

Lots of speculation, sorry!

 

EDIT: doh, just seen Chiono's post above...

Edited by Suburban Streamer
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I think that it is unlikely given the resistance of the mid to lower vortex to the wave activity. Take for example the latest forecast that shows a strong burst of wave 1 activity - this momentarily causes a 1hPa mean zonal mean wind reversal at 60N -but this is short lived and hardly creates an indent to 10-30hPA level vortex strength. I see a slow relaxing of the tropospheric polar vortex from now on into spring with the jet stream slowly receding northwards. No major meridional pattern likely, despite the MJO forecasts.

You are saying, then, that it is likely that summer will be as good as last year?

I know HLB is not the only factor, but you already know that HLB over Greenland means trough stuck like a limpet to the UK for summer.

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So do the experts think its worth me continuing  to scour the output daily for signs of a potent spring cyclonic North Easterly (the only synoptic worth bothering with once you get to the last third of March onwards).

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You are saying, then, that it is likely that summer will be as good as last year?

I know HLB is not the only factor, but you already know that HLB over Greenland means trough stuck like a limpet to the UK for summer.

 

he's basically saying that other forcings aside from the stratosphere influence our weather patterns in summer

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The stratospheric polar vortex is always a weak net easterly during summer and therefore the positioning of any ridges and troughs are liklely to be tropospheric led - not startospheric led. The tropospheric polar cell is still present in the summer - it is just a lot weaker than winter and one shouldn't confuse the underlying summer stratospheric conditions with that of the troposphere.

 

That was more or less how I understood it. The polar vortex doesn't create new modes of variability in the troposphere. It stimulates preexisting modes that are fundamental to the dynamics of the lower atmosphere. Thanks for your reply chio.

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I was reading through a paper on solar forcing and came across this paragraph about polar vortex condition in relation to QBO and solar cycle phase.

 

 

[60] In an attempt to refine this, Haigh and Roscoe [2009] carried out a multiple regression analysis of time series of the NAM and SAM indices throughout the depth of the atmosphere. A significant response to the 11 year SC was not evident if the solar and QBO terms were included separately, but when they were combined into a single term (solar multiplied by QBO) to represent their interaction, then a statistically significant response was found, particularly near the surface: the polar vortices were weaker and warmer in Smax–QBO-W and Smin–QBO-E years and stronger and colder in Smax–QBO-E and Smin–QBO-W years. This is consistent with the results shown in Figure 13. Nevertheless, volcanic aerosols also have a large impact on the annular modes. Given the timing of large eruptions during the late twentieth century (1982 and 1991), great care is required to avoid confusing the solar and volcanic signals during recent decades. Recent analysis using a data set extended to include the most recent Smax period during which there was no coincident volcanic eruption has enabled an improved separation of the two signals [Frame and Gray, 2010] and showed that the solar signal is statistically significant.

 

Does this not contradict the earlier comments about the vortex being very strong and cold because we are now in Smax/wQBO?

 

Full paper.

 

http://onlinelibrary.wiley.com/enhanced/doi/10.1029/2009RG000282/

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I was reading through a paper on solar forcing and came across this paragraph about polar vortex condition in relation to QBO and solar cycle phase.

 

 

Does this not contradict the earlier comments about the vortex being very strong and cold because we are now in Smax/wQBO?

 

Full paper.

 

http://onlinelibrary.wiley.com/enhanced/doi/10.1029/2009RG000282/

 

thats why some of us were glued to the 10.7 solar flux.  This winter was a Smax but it was still fairly low.  And on top of that we had the strongest wqbo on record. Perhaps if the wqbo had not been as strong, the flux would have been sufficient, and it came pretty close to an official ssw, which considering the strength of the PV, was quite remarkable in itself

 

http://solar.physics.montana.edu/SVECSE2008/pdf/labitzke_svecse.pdf

Edited by Suburban Streamer
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I was reading through a paper on solar forcing and came across this paragraph about polar vortex condition in relation to QBO and solar cycle phase.

 

 

Does this not contradict the earlier comments about the vortex being very strong and cold because we are now in Smax/wQBO?

 

Full paper.

 

http://onlinelibrary.wiley.com/enhanced/doi/10.1029/2009RG000282/

 

 

an interesting link there G_F, as with anything meteorological there are just so many possible variables. So far no one has yet managed to put them all together to give a reliable way of predicting changes months ahead.

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I was reading through a paper on solar forcing and came across this paragraph about polar vortex condition in relation to QBO and solar cycle phase.

 

 

Does this not contradict the earlier comments about the vortex being very strong and cold because we are now in Smax/wQBO?

 

Full paper.

 

http://onlinelibrary.wiley.com/enhanced/doi/10.1029/2009RG000282/

Near to the start of this winters strat thread I linked to a recent paper which challenges the theory that during solar max and w QBO sudden strat warmings are more common. I believe there is strong data to support the cold strat w QBO theory.

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Winter 88/89 has always stuck out for me as being a memorable winter for all the wrong reasons very mild,wet and windy but this winter has over shadowed that I think. Stratosphere wise though they were two very different winters.WInter89 the vortex was very strong and positioned in situ over Greenland and the pole. This winter the vortex has been displaced with one section as we know over south east Canada which is not such a bad position had we had a  negative QBOand more in the way of stratosphere warnings. We also saw persistent northeast Pacific ridges which is also a good synoptic (think 09/10 for example) to have had,had we seen greater warming and more in the way of blocking. An Alaskan vortex is normally a killer for winter as it promotes zonality across the state's which normally means similar for us.                                   I could be way off the mark here but I believe a moderate to high active sun this winter led to the very strong QBO which scuppered the chances for stronger stratosphere warnings and blocking.

Edited by cooling climate
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Could we have foreseen the record westerly based QBO? why was it so strong? It just feels every factor possible to prevent cold happening this winter happened. An extreme winter - but an exception I think... an oddity which occur from time to time - the apposite to the likes of winter 62/63 which synoptically was an oddity and exception again.

 

Lets hope fortunes change next winter and we see at least some decent frosts. Likewise our lowest temp of the winter has been a paltry -2/-3 degrees with a handful of air frosts only, we've had many a colder night in May!

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What are people's thoughts for March?

Looking at the 30hpa level, the vortex moves much closer to the UK as we progress in March and then there are indications of a final warming towards the end of the run.

The models are hinting at a period of high pressure for Central Europe and the UK but the stratosphere doresn't look like supporting this other than temprorarily.

Karyo

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What are people's thoughts for March?Looking at the 30hpa level, the vortex moves much closer to the UK as we progress in March and then there are indications of a final warming towards the end of the run.The models are hinting at a period of high pressure for Central Europe and the UK but the stratosphere doresn't look like supporting this other than temprorarily.Karyo

 

The location of the stratospheric vortex is somewhat irrelevant to the location of our tropospheric ridges if there's insufficient down-welling.

 

Looking at the ECWMF day 10 (last nights 12z) the stratosphere is warming but the vortex looks to be holding steady though displaced somewhat.

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The GFS starting to consistently model what looks very much like a final warming. This  May well be worth following as high latitude blocking can still deliver something  noteworthy and potent in mild to late March.

 

 

Yes I was thinking that over the last 24 hours, slightly worried though that still not even a mention in the Met further outlook, normally that wouldn't bother me but by all accounts the upgraded Met LRF models have been perforimg much better this year, the GFS 12z FI does look plausible to me, given the FW may only just have got underway by then, could be something decent, best synoptics late March and April in my opinion are cyclonic North Easterlies, with convective setups its a waste of time as its just shower-melt-shower-melt-shower-melt like last year, howerver, the low pressure snowfall late March last year delivered massive drifts around here.

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I think that it is unlikely given the resistance of the mid to lower vortex to the wave activity. Take for example the latest forecast that shows a strong burst of wave 1 activity - this momentarily causes a 1hPa mean zonal mean wind reversal at 60N -but this is short lived and hardly creates an indent to 10-30hPA level vortex strength. I see a slow relaxing of the tropospheric polar vortex from now on into spring with the jet stream slowly receding northwards. No major meridional pattern likely, despite the MJO forecasts.

 

I think that it is unlikely given the resistance of the mid to lower vortex to the wave activity. Take for example the latest forecast that shows a strong burst of wave 1 activity - this momentarily causes a 1hPa mean zonal mean wind reversal at 60N -but this is short lived and hardly creates an indent to 10-30hPA level vortex strength. I see a slow relaxing of the tropospheric polar vortex from now on into spring with the jet stream slowly receding northwards. No major meridional pattern likely, despite the MJO forecasts.

 

 

Any revision now there is a very significant warming (final) forecast inside the semi-reliable timeframe, im thinking of blocking maybe late March - early April, maybe a repeat of April 2012?

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Any revision now there is a very significant warming (final) forecast inside the semi-reliable timeframe, im thinking of blocking maybe late March - early April, maybe a repeat of April 2012?

There is no Final Warming (FW) forecast inside any relaible timeframe as far as I can see. Remember to acheive a FW we need to see zonal mean wind reversal at 10hPA and 60ºN that then doesn't return to positive until the next stratospheric winter. 

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There is no Final Warming (FW) forecast inside any relaible timeframe as far as I can see. Remember to acheive a FW we need to see zonal mean wind reversal at 10hPA and 60ºN that then doesn't return to positive until the next stratospheric winter. 

 

OK maybe not very reliable timeframe and not quite a reversal, will this end up as the FW down the line though or not?

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2014030218&var=HGT&lev=10mb&hour=336

Edited by feb1991blizzard
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Just wondering about prospects for next winter - given this year has not delivered any strat warming.. doesn't a warming normally occur every two years. The more I think about this year the more I think it has been a major anomaly - a entity of itself probability says unlikely to happen for a long time to come and therefore to be discarded,

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Just wondering about prospects for next winter - given this year has not delivered any strat warming.. doesn't a warming normally occur every two years. The more I think about this year the more I think it has been a major anomaly - a entity of itself probability says unlikely to happen for a long time to come and therefore to be discarded,

 

doesnt quite work like that but only 3 SSW's in 30 years worth of WQBO winters is telling! Not that this winter was entirely devoid of any strat warmings. There was wave activity and warming a plenty but not quite official SSW status and with the PV consolidating quickly soon after.

Winter 2014/15 looks like being EQBO which will help avoid the development of such a strong PV and likely to be el nino which is known to create warmer polar strat conditions.  SSW's more common in EQBO winters, as with both enso phases.

So a more promising outlook for next winter, though how the uk will fair, is of course anyones guess at this stage.

 

http://www.nws.noaa.gov/ost/climate/STIP/37CDPW/37cdpw-abutler.pdf

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There is no Final Warming (FW) forecast inside any relaible timeframe as far as I can see. Remember to acheive a FW we need to see zonal mean wind reversal at 10hPA and 60ºN that then doesn't return to positive until the next stratospheric winter. 

 

 It does kinda appear to be the case tho. Looking at GFS/GEFS recent scenarios, there is no way that the vortex can recover back to the extent that the zonal mean zonal component would be positive in the mid-upper strat. Posted Image

 

Posted Image Posted Image Posted Image

 

 

And the entire globe, and the south pole strat, that is way underway into the next cold season. Posted Image Note: The max/min data is for the global scale.

 

Posted Image Posted Image

 

Posted Image Posted Image

 

Best regards.

Edited by Recretos
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The Last 2 GFS runs are showing a full recovery of the +zonalwinds, Recretos, by the weekend. 

 

Posted Image

 

 

 It does kinda appear to be the case tho. Looking at GFS/GEFS recent scenarios, there is no way that the vortex can recover back to the extent that the zonal mean zonal component would be positive in the mid-upper strat. Posted Image

 

Posted Image Posted Image Posted Image

 

 

And the entire globe, and the south pole strat, that is way underway into the next cold season. Posted Image Note: The max/min data is for the global scale.

 

Posted Image Posted Image

 

Posted Image Posted Image

 

Best regards.

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The Last 2 GFS runs are showing a full recovery of the +zonalwinds, Recretos, by the weekend. 

 

Posted Image

 

 

I think he is referring to the timeframe after the projected warming starting at 200hrs+,  he means if that came of then the Stratospheric PV wouldn't be able to recover for the rest of the season.

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