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Stratosphere temperature watch - 2016/17


Paul

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Posted
  • Location: bingley,west yorks. 100 asl
  • Location: bingley,west yorks. 100 asl

Will the very active hurricane season have any impact on the Strat through the autumn into winter?

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Posted
  • Location: Ripon , North Yorkshire 41m/135ft ASL
  • Weather Preferences: heat and cold, storms and blizzards...zonal a no no
  • Location: Ripon , North Yorkshire 41m/135ft ASL
1 hour ago, joggs said:

Will the very active hurricane season have any impact on the Strat through the autumn into winter?

No Idea Joggs, some folk say an active hurricane season does have some sort of bearing on the type of winter we may get,

But this is just one of those things that make you go HHmmmmm .. coincidence or just one of those things ! :) 

 

https://twitter.com/severeweatherEU/status/905783359359606785

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Posted
  • Location: Longden, Shropshire
  • Location: Longden, Shropshire
2 hours ago, joggs said:

Will the very active hurricane season have any impact on the Strat through the autumn into winter?

There is a connection between active hurricane seasons and increased chances of northern blocking during the following winters.  However, just one piece of a very large jigsaw!

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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
On 9/8/2017 at 19:29, joggs said:

Will the very active hurricane season have any impact on the Strat through the autumn into winter?

I suspect the correlation is pretty weak but there is evidence that seasons with high ACE totals increase the amount of Ozone and encourage stratospheric warmings. At any rate this season is certain to be declared a hyperactive ACE season given that we are above the seasonal average already. 

 

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Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl
3 hours ago, summer blizzard said:

I suspect the correlation is pretty weak but there is evidence that seasons with high ACE totals increase the amount of Ozone and encourage stratospheric warmings. At any rate this season is certain to be declared a hyperactive ACE season given that we are above the seasonal average already. 

 

The last 4 seasons were very weak - so there could be some creedance in this. The last active season I think was 2012, and 2010 was also quite active..

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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
9 hours ago, damianslaw said:

The last 4 seasons were very weak - so there could be some creedance in this. The last active season I think was 2012, and 2010 was also quite active..

In terms of ACE 2011, 2012 and 2016 were all comfortably average about the same level (2010 the last to be close to hyperactive). 

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Posted
  • Location: Slovenia, Central Europe 1050m ASL
  • Location: Slovenia, Central Europe 1050m ASL

That is an interesting topic, and some studies were done about it, but i cant remember the authors or titles. 

Anyhow, I decided to take a look myself at the basic raw data. Making a correlation of DJF 500mb and the atlantic ACE index prior to the winter, looking at years 1980-2016. The obvious -ve NAO tendency falls out. The correlation factor is not too high for great confidence, but its enough to show a potential signal. 

hgt-in-correlation923734.png

So I decided to make a graphic with ACE, AO and NAO, for future reference. It is to be used to look at any specific years. There are some years that have high ACE/-ve NAO and vice versa. 

ace.png

So I decided to make a scatter plot. Here we can see that lower ACE years are pretty random with AO and NAO. But, as we go higher, especially above 150, the tendency for more negative -AO/NAO increases. The exceptions are 98 and 99, being strong La Nina years. 

acec2.png

This is just raw data and a lot could be analysed further down the line. 

And a bonus graphic, a correlation of autumn polar vortex with ACE. This basically shows a small indication that the polar vortex might tend to be weaker with higher the ACE goes.

25372.png

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Posted
  • Location: Netherlands
  • Location: Netherlands

Latetst GLOSEA5 update shows a postive NAO/AO this winter. In the northern part of the Pacific pressure tends to be higher than normal. In the northern part of Atl. Ocean low pressure seems to be the king. Still time for a change....

http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/ens-mean

Thanks Recretos

 

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Posted
  • Location: Inbhir Nis / Inverness - 636 ft asl
  • Weather Preferences: Freezing fog, frost, snow, sunshine.
  • Location: Inbhir Nis / Inverness - 636 ft asl
12 minutes ago, sebastiaan1973 said:

Latetst GLOSEA5 update shows a postive NAO/AO this winter. In the northern part of the Pacific pressure tends to be higher than normal. In the northern part of Atl. Ocean low pressure seems to be the king. Still time for a change....

http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/ens-mean

Thanks Recretos

 

 

Looks a tad windy for Scotland...

 

2cat_20170901_mslp_months46_global_deter

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Posted
  • Location: Slovenia, Central Europe 1050m ASL
  • Location: Slovenia, Central Europe 1050m ASL

As far as teleconnections go, someone has stated we are in a similar situation like winters 07/08 and 95/96. Tho the difference in winter patterns was enormous. Kinda shows we are still open for business and nothing is finalised yet. 

ncltrgc9fujttmpqq.png    nclh69v47bdrhtmpqq.png

ncl9ywci0qn67tmpqq.png     sssssss.png
 

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Posted
  • Location: Longden, Shropshire
  • Location: Longden, Shropshire
On 10/09/2017 at 16:48, sebastiaan1973 said:

@Don, do you know some publications about this subject?

I don't know of any publications but it is explained in Gavs Weather Vids Winter updates.

 

Edited by Don
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Just as a slight nod of interest here is the GFS ensembles & the CFS runs relating to the 10MB zonal wind

The GFS continues to show a surpressed zonal wind with it running mainly below the average for the time of year-

Its not that significant & wouldnt be 'that' significant until we land in December as we found last year !!

What raised my eyebrow is the CFS control run which brings the zonal mean into negative territory which it would be well outside the 'norm'

here it is

IMG_9333.thumb.PNG.e2a058c4993ef517bb4e2a4332bf451e.PNG

 

S

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Posted
  • Location: Netherlands
  • Location: Netherlands

Interesting Steve. Perhaps a trend. Thanks Don.

An inverse relationship between aggregate northern hemisphere tropical cyclone activity and subsequent winter climate

http://moe.met.fsu.edu/~rhart/papers-hart/2010HartGRL.pdf

Edited by sebastiaan1973
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Posted
  • Location: Netherlands
  • Location: Netherlands

Understanding the linkage between El Niño Southern Oscillation (ENSO) and Northern Hemisphere climate has found to be one of the key mechanisms to improve the predictability skill in extratropical regions. The El Niño signal propagates poleward via Rossby wave trains in the upper troposphere. In the North Pacific, this contributes to a deepening of the winter Aleutian low pressure system (AL), and hence to a strengthening of the Pacific North America (PNA) pattern. As a consequence, the strengthened wave anomaly interacts constructively with the climatological planetary wave and thereby enhances upward propagation of planetary waves into the stratosphere. This can lead to Sudden Stratospheric Warming (SSW) events, which can then have a lasting impact on the North Atlantic and Europe by projecting onto the North Atlantic Oscillation (NAO) pattern, thereby influencing weather over Europe. Pressure anomalies in the North Pacific can also propagate to the North Atlantic and Eurasia through the mid- and upper troposphere as a Rossby wave train, but the relative importance of the tropospheric and stratospheric pathways is still not resolved. In this study, we evaluate the relative importance and the role of both pathways. We use a 3D wave activity flux to identify the propagating Rossby waves in the troposphere and in the stratosphere. On the one hand, that the stratospheric pathway can be due to planetary wave reflection or absorption, exhibiting different surface responses and different time scales. On the other hand, when the stratosphere is less active, in neutral Vortex events, we show that the tropospheric pathway is dominant leading to a negative(positive) NAO during El Niño(La Niña) years. We also investigate the role of the synoptic eddies, which play a significant role in maintaining the southward(northward) shift of the storm track in the Atlantic during El Niño(La Niña) conditions. https://ams.confex.com/ams/21Fluid19Middle/webprogram/Paper318786.html

Please notice the presentations of this conference https://ams.confex.com/ams/21Fluid19Middle/webprogram/Paper319446.html.

E.g. https://ams.confex.com/ams/21Fluid19Middle/webprogram/Paper318618.html

Or https://ams.confex.com/ams/21Fluid19Middle/webprogram/Paper319446.html

The Madden-Julian Oscillation (MJO), also known as the 30-60 day oscillation, represents a major fraction of convective variability in the tropics and is the strongest of the intraseasonal climate oscillations. The MJO has important derivative effects on extratropical circulation and intraseasonal climate (e.g., Zhang [2013]).

Recently, a number of authors, beginning with Yoo and Son [2016], have shown that the stratospheric quasi-biennial oscillation (QBO) modulates the amplitude of the boreal winter MJO such that MJO amplitudes are larger on average during the easterly phase (QBOE) than during the westerly phase (QBOW). A major possible mechanism is the decrease in static stability in the lowermost stratosphere under QBOE conditions resulting from relative upwelling associated with the QBO induced meridional circulation. Marshall et al. [2016] have further shown that the observed QBO influence on the MJO should result in improved predictability of the MJO and its convective anomalies in the Pacific during QBOE relative to QBOW.

Here, evidence is presented that tropical upwelling changes related to the 11-year solar cycle also modulate the boreal winter MJO. Using outgoing longwave radiation (OLR)-based MJO index (OMI) amplitude data covering the 1979-2016.3 period (37.3 years), it is found that the increase in MJO occurrence rate and mean amplitude during December, January, and February (DJF) under QBOE conditions is especially large under solar minimum (SMIN) conditions while the decrease in MJO amplitude under QBOW conditions is largest under solar maximum (SMAX) conditions. Consistently, the DJF mean static stability calculated from ERA-Interim reanalysis data in the lowermost stratosphere over the warm pool region is especially high under QBOW/SMAX conditions and is lowest under QBOE/SMIN conditions. Specifically, while the mean MJO amplitude in DJF is ~ 42% larger in QBOE than in QBOW, it is ~ 88% larger in QBOE/SMIN than in QBOW/SMAX. Conversely, the mean MJO amplitude in DJF is only ~ 27% larger in QBOE/SMAX than in QBOW/SMIN. Similarly, while the occurrence rate of daily MJO amplitudes in DJF exceeding unity is ~ 34% larger under QBOE conditions than under QBOW conditions, it is ~ 88% larger in QBOE/SMIN than in QBOW/SMAX. On the other hand, it is only ~ 17% larger in QBOE/SMAX than in QBOW/SMIN. This dependence on the solar cycle is consistent with a solar-induced increase in relative tropical upwelling under SMIN conditions and a decrease (relative downwelling) under SMAX conditions (e.g., Matthes et al. [2004]).

However, these results are based on a limited time record. For example, only 4 to 6 winters qualify for the QBOE/SMIN category while 7 to 9 winters qualify for the QBOW/SMAX category, depending on adopted limits for the QBO and solar phases. During the coming solar minimum, at least one additional winter in the QBOE/SMIN category should occur (possibly as early as the 2017/2018 winter), during which a larger-than-average number of higher-amplitude MJO events is to be expected and an initial test of the proposed relationship will be possible.

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Posted
  • Location: Netherlands
  • Location: Netherlands

Interannual variation of seasonal-mean tropical convection over the Indo-Pacific region is primarily controlled by El Niño–Southern Oscillation (ENSO). For example, during El Niño winters, seasonal-mean convection around the Maritime Continent becomes weaker than normal, while that over the central to eastern Pacific is strengthened. Similarly, subseasonal convective activity, which is associated with the Madden–Julian oscillation (MJO), is influenced by ENSO. The MJO activity tends to extend farther eastward to the date line during El Niño winters and contract toward the western Pacific during La Niña winters. However, the overall level of MJO activity across the Maritime Continent does not change much in response to the ENSO. It is shown that the boreal winter MJO amplitude is closely linked with the stratospheric quasi-biennial oscillation (QBO) rather than with ENSO. The MJO activity around the Maritime Continent becomes stronger and more organized during the easterly QBO winters. The QBO-related MJO change explains up to 40% of interannual variation of the boreal winter MJO amplitude. This result suggests that variability of the MJO and the related tropical–extratropical teleconnections can be better understood and predicted by taking not only the tropospheric circulation but also the stratospheric mean state into account. The seasonality of the QBOMJO link and the possible mechanism are also discussed.

http://journals.ametsoc.org/doi/full/10.1175/JCLI-D-16-0620.1

Edited by sebastiaan1973
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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks
1 hour ago, sebastiaan1973 said:

gawd, my head hurst, but thank you I will try again in a bit

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks
1 hour ago, Paul said:

For those wanting to learn about the strat, and what it's all about, Matt's blog is well worth a read

It's Back - The Stratospheric Polar Vortex

 

ah, hopefully this might help me understand a bit better, although I suspect my old brain is now just about able to keep track of synoptic meteorology, never mind here goes

Yep that is more my standard, 'various factors' helps me to realise that it may be best for me to stick with how the Polar Vortex is developing rather than what is causing it in the post from s1973. Each of us to our own level, good luck to all the cold lovers, I am one but not for 3 solid months of it thank you. &-10 days two or three times during meteorological winter will do me. I just hope we can all keep our posts polite and respect other folk's point of view without the team having to spend many hours sorting things out.

NB:- If the team feel any of the above needs deleting please do so just me rambling on!

Edited by johnholmes
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Posted
  • Location: Drayton, Portsmouth
  • Location: Drayton, Portsmouth
On 12/09/2017 at 10:46, NorthernRab said:

 

Looks a tad windy for Scotland...

 

2cat_20170901_mslp_months46_global_deter

So here we go again!!!

The chart above is, of course, the form horse for recent winters. The strat warmings will need to be pretty decent to break us out of this!! 

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Posted
  • Location: Longden, Shropshire
  • Location: Longden, Shropshire
7 minutes ago, Man With Beard said:

So here we go again!!!

The chart above is, of course, the form horse for recent winters. The strat warmings will need to be pretty decent to break us out of this!! 

Yes and unfortunately the GloSea 5 is not on its own with both the latest CFSv2 and EC seasonal models also pointing towards a similar pattern for winter.

Edited by Don
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Posted
  • Location: weston-super-mare, UK
  • Location: weston-super-mare, UK
20 minutes ago, Don said:

Yes and unfortunately the GloSea 5 is not on its own with both the latest CFSv2 and EC seasonal models also pointing towards a similar pattern for winter.

I personally refuse to believe it. I reckon they've gone for the mild option because we have had four in a row from 2013-2017. These things can't be reliable and it takes a couple of things to throw it. 

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