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1 hour ago, I remember Atlantic 252 said:

Tuesdays and Wednesdays here, then broken down on Thursdays, here no true hot spell last 2 summers, 2013 July last time

It's been pretty dire here as well for the past couple of years, April normally delivers some warm dry sunshine but once you get towards the end of may the Atlantic rolls in and our traditional summer rain appears until september

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2 minutes ago, More Snow said:

Maybe we should have a winter tweet thread... would save all this nonsense every time a tweet is put in here.. ban tweets being posted in here and keep them to a specific thread, then anybody that wants to get involved in tweets can do so at there own will...

It would also save a lot of nonsense if you didn't post things like that in the model discussion thread. 

I have never seen so much rubbish in that thread as I have done today. I struggled to find a handful of genuine model discussion posts in three or four pages. What does it take to get the message in to peoples heads?

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I see that the "potential" may now be shifting to late February, in real terms that probably means a toppler at best which is no better than offerings from recent winters.

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3 minutes ago, Mapantz said:

It would also save a lot of nonsense if you didn't post things like that in the model discussion thread. 

I have never seen so much rubbish in that thread as I have done today. I struggled to find a handful of genuine model discussion posts in three or four pages. What does it take to get the message in to peoples heads?

Have you quoted all of them having a dig or have you just decided to have a pop at me?? i agree the thread is painful to be in most of the time and is full of non model post, just wonder why you have jumped on my post and not any from the more senior well respected members...

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10 minutes ago, Mapantz said:

It would also save a lot of nonsense if you didn't post things like that in the model discussion thread. 

I have never seen so much rubbish in that thread as I have done today. I struggled to find a handful of genuine model discussion posts in three or four pages. What does it take to get the message in to peoples heads?

I think today has been so frustrating for all. However today has been absolute carnage in the thread and trying to syphen out the good and informative posts. from someone who is still learning it  has been exauasting in itself . The worst days for posts in the thread since I joined and by a country mile too. 

Edit - more snow I wasn't particularly bothered by your post at all . What I mean is the knee jerk reactions also the emergence of some trolling by some. I think we all know who those couple of people are.

Edited by Mark wheeler
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2 minutes ago, Mark wheeler said:

I think today has been so frustrating for all. However today has been a isolate carnage in the thread and trying to syphen out the good and informative posts. from someone who is still learning it  has been exauasting in itself . The worst days for posts in the thread since I joined and by a country mile too.

Agree with you totally.. terribly hard to learn from anything written in there today, but rather peeved that my post out of hundreds was the one to get jumped on.. plenty of more senior and well respected members have been at it today but out of all of them im the one getting dug out..

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2 minutes ago, Anon90 said:

I see that the "potential" may now be shifting to late February, in real terms that probably means a toppler at best which is no better than offerings from recent winters.

Potential can be very elusive...It usually appears at T+384, sometime in late Autumn; from then on, it's usually somewhere between day 5 and day 12. It's rather like tomorrow, in that it never comes?:D

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8 minutes ago, More Snow said:

Have you quoted all of them having a dig or have you just decided to have a pop at me?? i agree the thread is painful to be in most of the time and is full of non model post, just wonder why you have jumped on my post and not any from the more senior well respected members...

Trust me, the report button was used many many times! I now have my index and middle finger taped up to a splint.

I'm just pointing out, that I don't particularly want to read about you wanting to ban tweets, in the mod thread. It should be discussed with a mod, or asked about in the site suggestions thread.

I personally don't have an issue with tweets being shown, if they are relative to the thread. The thing I can't understand is, why do people have to hit the quote, then reply button and start an irrelevant topic? All they need to do, is hit the "MultiQuote" + sign next to quote - it will store it in a cache, and then go to a relevant thread and use the "Quote 1 post" button to paste the quote in to the edit box? In the words of Jezza Clarkson, how hard can it be?

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8 minutes ago, Mapantz said:

Trust me, the report button was used many many times! I now have my index and middle finger taped up to a splint.

I'm just pointing out, that I don't particularly want to read about you wanting to ban tweets, in the mod thread. It should be discussed with a mod, or asked about in the site suggestions thread.

I personally don't have an issue with tweets being shown, if they are relative to the thread. The thing I can't understand is, why do people have to hit the quote, then reply button and start an irrelevant topic? All they need to do, is hit the "MultiQuote" + sign next to quote - it will store it in a cache, and then go to a relevant thread and use the "Quote 1 post" button to paste the quote in to the edit box? In the words of Jezza Clarkson, how hard can it be?

Very hard if you dont know how to do something like that.. we are not all blessed with computer know how etc.. i simply said ban tweets in the model thread would save you me and others the trouble of dealing with the nonsense they cause... surly if we have a thread especially for tweets and tweet chat that would be better for us all, i simply do not know how or where to post to get my point across.. no need to have a go at me about it.. and the advice you offered is welcome but the sarcasim is not..

And also did you quote each and every post you reported or do you only feel fit to have a go at newer members as i dont see you digging out Nick S or anybody else of his standing...

Edited by More Snow

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So it looks like this 'cold spell' is being eroded with it becoming less cold as early as Sunday as opposed to next week!

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10 minutes ago, Don said:

So it looks like this 'cold spell' is being eroded with it becoming less cold as early as Sunday as opposed to next week!

Yep, more like a cool snap lol. All sounds a bit boring, might see a snow grain if I'm lucky. Hopefully at least there'll be some crisp winter sunshine to enjoy. Signs of a Greenland high  in FI but a way away so best ignored for now.

Edited by stainesbloke
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3 minutes ago, stainesbloke said:

Yep, more like a cool snap lol. All sounds a bit boring, might see a snow grain if I'm lucky. Hopefully at least there'll be some crisp winter sunshine to enjoy. Signs of a Greenland high  in FI but a way away so best ignored for now.

To be honest I've given up on this winter now!  Hopefully we'll get some better winters during the next few years as we approach solar minimum.

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14 minutes ago, Don said:

So it looks like this 'cold spell' is being eroded with it becoming less cold as early as Sunday as opposed to next week!

Indeed. A watered down, mostly dry, short cold snap. I'm sure ECM Day 10 will be "full of potential" in another couple of runs....

Bah. At this point I'd rather just get on with Spring! This has been a tedious winter.

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1 minute ago, Don said:

To be honest I've given up on this winter now!  Hopefully we'll get some better winters during the next few years as we approach solar minimum.

Understandable, it's that time of year where thoughts of spring and a bit of warmth are beginning to surface. Still a good few weeks of winter and possible cold and snow to go though, anything possible. Very frustrating winter for snow lovers, always just out of reach. I've enjoyed most of this winter personally but am too looking forward to spring.

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2 minutes ago, stainesbloke said:

Understandable, it's that time of year where thoughts of spring and a bit of warmth are beginning to surface. Still a good few weeks of winter and possible cold and snow to go though, anything possible. Very frustrating winter for snow lovers, always just out of reach. I've enjoyed most of this winter personally but am too looking forward to spring.

I feel this winter has been better than the last three with a greater incidence of frosts.  However, it's been a rather 'close but no cigar' winter in my view and although background signals now look more favourable, I feel any real cold and snow prospects will probably continue just out of reach.

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4 hours ago, I remember Atlantic 252 said:

so have I but still want snow! may see some Fri and Sat, but please no more frost and rain, if rain is on the way, nothing worse than a frosty -3 morning, might as well be 12°

I love the snow, nothing would make me happier but it just feels like another one of those winters and time is ticking. Mar13 was not great for my neck of the woods so I've had it!  Hope for better next winter!

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There was a queen wasp fresh out of hibernation buzzing around my kitchen today, that's it, winter is over!

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1 hour ago, stainesbloke said:

Understandable, it's that time of year where thoughts of spring and a bit of warmth are beginning to surface. Still a good few weeks of winter and possible cold and snow to go though, anything possible. Very frustrating winter for snow lovers, always just out of reach. I've enjoyed most of this winter personally but am too looking forward to spring.

There still a chance of something but that would probably come at time when things are more marginal and most people are already over it ala February 2005.

Edited by Anon90

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I'm never going to believe weather models past 5 days ever again. ( not sure how many times I've said this!)

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still early Spring showing, 10° light winds from Tuesday, could feel like proper Spring if any sun

h850t850eu.png

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8 hours ago, stainesbloke said:

There was a queen wasp fresh out of hibernation buzzing around my kitchen today, that's it, winter is over!

Queen wasp fell out of roof hatch when I opened it. Now got a squashed queen wasp. Seem to be quite a lot have secreted themselves about the place. Have to keep an eye out for nests next summer. 

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Deary deary me half the forum chasing this Easterly since Nov miss after miss then land it on Feb to be water-down and be forecasted rain on Sunday, west is best greenie high that is dont want to hear about another scandi high again from the deluded east.

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Really hoping the forecasted cool to cold March buggers off soon, nothing worse than looking forward to switching the heating off and mild mornings, only to be confronted with a fourth month of faux-winter.

Sod's law it'll be bloody freezing all month... 

 

 

 

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51 minutes ago, Fozfoster said:

I'm never going to believe weather models past 5 days ever again. ( not sure how many times I've said this!)

I came to that conclusion a few years ago and said so in here. I got derided for suggesting it. Too many variables in weather-related factors across the globe. Data models cant handle it all at times.

Add in the UK pos to the Atlantic and gulf stream and there you have it.

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      2014/2015 https://forum.netweather.tv/topic/81567-stratosphere-temperature-watch-20142015/
      2013/2014 https://forum.netweather.tv/topic/78161-stratosphere-temperature-watch-20132014/
      2012/2013 https://forum.netweather.tv/topic/74587-stratosphere-temperature-watch-20122013/
      2011/2012 https://forum.netweather.tv/topic/71340-stratosphere-temperature-watch-20112012/
      2010/2012 https://forum.netweather.tv/topic/64621-stratosphere-temperature-watch/?hl=%20stratosphere%20%20temperature%20%20watch
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      ------------------------------
      Ed's opener from 2015/16
      As ever, the first post will become both a reference thread and basic learning thread for those wanting to understand how the stratosphere may affect the winter tropospheric pattern, so forgive me for some repeat from previous years, but it is important that those new to the stratosphere have a place that they can be directed to in order to achieve a basic grasp of the subject.
      The stratosphere is the layer of the atmosphere situated between 10km and 50km above the earth. It is situated directly above the troposphere, the first layer of the atmosphere and the layer that is directly responsible for the weather that we receive at the surface. The boundary between the stratosphere and the troposphere is known as the tropopause. The air pressure ranges from around 100hPa at the lower levels of the stratosphere to below 1hPa at the upper levels. The middle stratosphere is often considered to be around the 10-30hPa level.

      Every winter the stratosphere cools down dramatically as less solar UV radiation is absorbed by the ozone content in the stratosphere. The increasing difference in the temperature between the North Pole and the latitudes further south creates a strong vortex – the wintertime stratospheric polar vortex. The colder the polar stratosphere in relation to that at mid latitudes, the stronger this vortex becomes. The stratospheric vortex has a strong relationship with the tropospheric vortex below. A strong stratospheric vortex will lead to a strong tropospheric vortex. This relationship is interdependent; conditions in the stratosphere will influence the troposphere whilst tropospheric atmospheric and wave conditions will influence the stratospheric state.
      At the surface the strength and position of the tropospheric vortex influences the type of weather that we are likely to experience. A strong polar vortex is more likely to herald a positive AO with the resultant jet stream track bringing warmer and wet southwesterly winds. A weaker polar vortex can contribute to a negative AO with the resultant mild wet weather tracking further south and a more blocked pattern the result. A negative AO will lead to a greater chance of colder air spreading to latitudes further south such as the UK.
       AO chart

      The stratosphere is a far more stable environment then the troposphere below it.
      However, the state of the stratosphere can be influenced by numerous factors – the current solar state, the Quasi Biennial Oscillation (QBO), the ozone content and distribution and transport mechanism, the snow cover and extent indices and the ENSO state to name the most significant. These factors can influence whether large tropospheric waves that can be deflected into the stratosphere can disrupt the stratospheric polar vortex to such an extent that it feeds back into the troposphere.
      Ozone Content in the stratosphere
       Ozone is important because it absorbs UV radiation in a process that warms the stratosphere. The Ozone is formed in the tropical stratosphere and transported to the polar stratosphere by a system known as the Brewer-Dobson-Circulation (the BDC). The strength of this circulation varies from year to year and can in turn be dictated by other influences. The ozone content in the polar stratosphere has been shown to be destroyed by CFC's permeating to the stratosphere from the troposphere. The overall ozone content in the polar stratosphere will help determine the underlying polar stratospheric temperature, with higher contents of ozone leading to a warmer polar stratosphere. The ozone levels can be monitored here: 
      http://www.cpc.ncep.noaa.gov/products/stratosphere/sbuv2to/index.shtml
      One of the main influences on the stratospheric state is the QBO. This is a tropical stratospheric wind that descends in an easterly then westerly direction over a period of around 28 months. This can have a direct influence on the strength of the polar vortex in itself. The easterly (negative) phase is thought to contribute to a weakening of the stratospheric polar vortex, whilst a westerly (positive) phase is thought to increase the strength of the stratospheric vortex. However, in reality the exact timing and positioning of the QBO is not precise and the timing of the descending wave can be critical throughout the winter.
      Diagram of the descending phases of the QBO: (with thanks from http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/qbo/index.html )

      The QBO has been shown to influence the strength of the BDC, depending upon what phase it is in. The tropical upward momentum of ozone is stronger in the eQBO , whereas in the wQBO ozone transport is stronger into the lower mid latitudes, so less ozone will enter the upper tropical stratosphere to be transported to the polar stratosphere as can be seen in the following diagram.

      http://www.atmos-chem-phys.net/13/4563/2013/acp-13-4563-2013.pdf
      However, the direction of the QBO when combined with the level of solar flux has also been shown to influence the BDC. When the QBO is in a west phase during solar maximum there are more warming events in the stratosphere, as there is also during an easterly phase QBO during solar minimum, so the strength of the BDC is also affected by this – also known as the Holton Tan effect .
      http://strat-www.met.fu-berlin.de/labitzke/moreqbo/MZ-Labitzke-et-al-2006.pdf
      http://onlinelibrary.wiley.com/doi/10.1002/jgrd.50424/abstract  
      http://onlinelibrary.wiley.com/doi/10.1002/2013JD021352/abstract
      The QBO is measured at 30 hPa and has entered a westerly phase for this winter. As mentioned warming events are more likely during solar maximum when in this westerly phase – with the solar flux below 110 units. Currently, we have just experienced a weak solar maximum and the solar flux heading into winter is still around this mark. This doesn’t rule out warming events, but they will not be as likely – perhaps if the solar flux surges then the chance will increase.
      Latest solar flux F10.7cm:

      http://www.swpc.noaa.gov/products/solar-cycle-progression
      Sudden Stratospheric Warmings:
      One warming event that can occur in the stratospheric winter is a Sudden Stratospheric Warming (SSW) or also known as a Major Midwinter Warming (MMW). This, as the name suggests is a rather dramatic event. Normally the polar night jet at the boundary of the polar vortex demarcates the boundary between warmer mid latitude and colder polar stratospheric air (and ozone levels) and this is very difficult to penetrate. SSWs can be caused by large-scale planetary tropospheric (Rossby) waves being deflected up into the stratosphere and towards the North Pole, often after a strong mountain torque event. These waves can introduce warmer temperatures into the polar stratosphere which can seriously disrupt the stratospheric vortex, leading to a slowing or even reversal of the vortex.
      Any SSW will be triggered by the preceding tropospheric pattern - in fact the preceding troposheric pattern is important in disturbing the stratospheric vortex even without creating a SSW.  Consider a tropospheric pattern where the flow is very zonal - rather like the positive AO phase in the diagram above. There has to be a mechanism to achieve a more negative AO or meridional pattern from this scenario and there is but it is not straightforward.  It just doesn't occur without some type of driving mechanism. Yes, we need to look at the stratosphere - but if the stratosphere is already cold and a strong polar vortex established, then we need to look back into the troposphere. In some years the stratosphere will be more receptive to tropospheric interactions than others but we will still need a kickstart from the troposphere to feedback into the stratosphere. This kickstart will often come from the tropics in the form of pulses and patterns of convection. These can help determine the position and amplitude of the long wave undulations – Rossby waves - that are formed at the barrier between the tropospheric polar and Ferrel cells. The exact positioning of the Rossby waves will be influenced by (amongst other things) the pulses of tropical convection – such as the phase of the Madden Jullian Oscillation and the background ENSO state and that is why we monitor that so closely. These waves will interact with land masses and mountain ranges which can absorb or deflect the Rossby waves disrupting the wave pattern further - and this interaction and feedback between the tropical and polar systems is the basis of how the Global Wind Oscillation influences the global patterns.
      If the deflection of the Rossby Wave then a wave breaking event occurs – similar to a wave breaking on a beach – except this time the break is of atmospheric air masses. Rossby wave breaks that are directed poleward can have a greater influence on the stratosphere. The Rossby wave breaks in the troposphere can be demonstrated by this diagram below –
      RWB diagram:

      https://www.jstage.jst.go.jp/article/jmsj/86/5/86_5_613/_pdf
       This occurs a number of times during a typical winter and is more pronounced in the Northern Hemisphere due to the greater land mass area. Most wave deflections into the stratosphere do change the stratospheric vortex flow pattern - this will be greater if the stratosphere is more receptive to these wave breaks (and if they are substantial enough, then a SSW can occur). The change in the stratospheric flow pattern can then start to feedback into the troposphere - changing the zonal flow pattern into something with more undulations and perhaps ultimately to a very meridional flow pattern especially if a SSW occurs - but not always. If the wave breaking occurs in one place then we see a wave 1 type displacement of the stratospheric vortex, and if the wave breaking occurs in two places at once then we will see a wave 2 type disturbance of the vortex which could ultimately squeeze the vortex on half and split it – and if these are strong enough then we would see a displacement SSW and split SSW respectively. The SSW is defined by a reversal of mean zonal mean winds from westerly to easterly at 60ºN and 10hPa. This definition is under review as there have been suggestions that other warmings of the stratosphere that cause severe disruption to the vortex could and should be included. http://birner.atmos.colostate.edu/papers/Butleretal_BAMS2014_submit.pdf
      A demonstration of the late January 2009 SSW that was witnessed in the first strat thread has been brilliantly formulated by Andrej (recretos) and can be seen below:
       
      The effects of a SSW can be transmitted into the troposphere as the downward propagation of the SSW occurs and this can have a number of consequences. There is a higher incidence of northern blocking after SSW’s but we are all aware that not every SSW leads to northern blocking. Any northern blocking can lead to cold air from the tropospheric Arctic flooding south and colder conditions to latitudes further south can ensue. There is often thought to be a time lag between a SSW and northern blocking from any downward propagation of negative mean zonal winds from the stratosphere. This has been quoted as up to 6 weeks though it can be a lot quicker if the polar vortex is ripped in two following a split SSW. A recent paper has shown how the modelling of SSW and strong vortex conditions have been modelled over a 4 week period. This has shown that there is an increase in accuracy following weak or strong vortex events – though the one area that the ECM overestimates blocking events following an SSW at week 4 is over Northwestern Eurasia.
      http://iopscience.iop.org/article/10.1088/1748-9326/10/10/104007
      One noticeable aspect of the recent previous winters is how the stratosphere has been susceptible to wave breaking from the troposphere through the lower reaches of the polar stratosphere - not over the top as seen in the SSWs. This has led to periods of sustained tropospheric high latitude blocking and repeated lower disruption of the stratospheric polar vortex. This has coincided with a warmer stratosphere where the mean zonal winds have been reduced and has led to some of the most potent winter spells witnessed in recent years.
      We have also seen in recent years following Cohen's work the importance of the rate of Eurasian snow gain and coverage during October at latitudes below 60ºN. If this is above average then there is enhanced feedback from the troposphere into the stratosphere through the Rossby wave breaking pattern described above and diagrammatically below.
      Six stage Cohen Process:

      The effect of warming of the Arctic ocean leading to colder continents with anomalous wave activity penetrating the stratosphere has also been postulated
      http://www.tos.org/oceanography/archive/26-4_cohen.pdf
      Last year we saw a large snow gain but unfortunately tropospheric atmospheric patterns prevented the full potential of these being unleashed on the stratosphere – hence no SSW, but this winter could be different, but we will have to wait until the end of October.
       ENSO Influences
      One of the main influences in the global atmospheric state this winter will be the upcoming El Nino, and that is forecast to be the strongest since 1997. Studies have shown that SSW’s are more likely during strong ENSO events ( http://www.columbia.edu/~lmp/paps/butler+polvani-GRL-2011.pdf) 
       but also that there is a particular pattern of upward propagating waves. During El Nino events wave formation is suppressed over the Indian Ocean Basin whilst it is enhanced over the Pacific Ocean
      http://link.springer.com/article/10.1007%2Fs00382-015-2797-5
      The ENSO pathway taken may be all critical this year as can be demonstrated by this paper  http://www.columbia.edu/~lmp/paps/butler+polvani+deser-ERL-2014.pdf
      This can lead us to suggest that a rather distinctive wave 1 pattern is likely this winter with the trigger zone likely to be over the north Pacific in the form of a quasi stationary enhanced wave 1 – a traditional Aleutian low SSW trigger pattern is suggested by Garfinkel et al ( http://www.columbia.edu/~lmp/paps/garfinkel+etal-JGR-2012.pdf ) and this should be expected at some point this winter.
       

      The reported incidence of SSW in EL Nino years is roughly around 60%  - which is more than ENSO neutral years.  A big question remains however, whether the ENSO wave 1 pattern will override the negative HT effect that the wQBO with the reducing solar ouput link brings. And even if it does, and we do achieve a displacement SSW, the next question is how will this affect the Atlantic sector of the Northern Hemisphere? My suspicion is that even if we do achieve a SSW this winter it will be in the second half, and also any subsequent blocking may not be quite right for the UK and, that if we were to achieve a –ve NAO, any block will be nearer Canada than Iceland, leaving the Atlantic door ajar.  It is still too early this winter to be making any definitive forecasts – the next 6 weeks are very important stratospherically, determining in what vein winter will start. Already we are seeing a forecast of weak wave activity disrupting the growing vortex and it will be interesting to see if this is repeated during November.
      And it will be especially interesting to see what occurs in November and what is forecast for December before winter starts because typical strong El nino wQBO stratospheric composite analogues tell an opposite story. They suggest that the stratospheric vortex will be disrupted and weaker early in the winter before gaining in strength by February.
      December:

      January

      February

      The mean zonal winds are already forecast to be below average so perhaps an early disrupted vortex is more likely this year!

      As ever, I will supply links to various stratospheric websites were forecasts and data can be retrieved and hope for another fascinating year of monitoring the stratosphere.
      GFS: http://www.cpc.ncep.noaa.gov/products/stratosphere/strat_a_f/
      ECM/Berlin Site: http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html  
      Netweather: http://www.netweather.tv/index.cgi?action=stratosphere;sess=75784a98eafe97c5977e66aa65ae7d28
      Instant weather maps: http://www.instantweathermaps.com/GFS-php/strat.php
       NASA Merra site: http://acdb-ext.gsfc.nasa.gov/Data_services/met/ann_data.html
      Previous stratosphere monitoring threads:
      2015/16 https://www.netweather.tv/forum/topic/84231-stratosphere-temperature-watch-20152016/
      2014/2015 https://forum.netweather.tv/topic/81567-stratosphere-temperature-watch-20142015/
      2013/2014 https://forum.netweather.tv/topic/78161-stratosphere-temperature-watch-20132014/
      2012/2013 https://forum.netweather.tv/topic/74587-stratosphere-temperature-watch-20122013/
      2011/2012 https://forum.netweather.tv/topic/71340-stratosphere-temperature-watch-20112012/
      2010/2012 https://forum.netweather.tv/topic/64621-stratosphere-temperature-watch/?hl=%20stratosphere%20%20temperature%20%20watch
      2009/2010 https://forum.netweather.tv/topic/57364-stratosphere-temperature-watch/
      2008/2009 https://forum.netweather.tv/topic/50299-stratosphere-temperature-watch/
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