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Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)

No luck on the stratosphere front, the warming was small.

Yes, the cooling has resumed! However, at the moment we are not much below average.

http://acdb-ext.gsfc.nasa.gov/Data_services/met/metdata/annual/merra/t60_90n_30_2011_merra.pdf

Karyo

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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.

Yes, the cooling has resumed! However, at the moment we are not much below average.

http://acdb-ext.gsfc..._2011_merra.pdf

Karyo

And still nothing on the horizon.

post-4523-0-90100300-1320346455_thumb.gi

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

Quick look at this mornings update, nothing much to add really other than a continuation of the cooling at both the 10hpa and 30hpa level. This to me would suggest milder rather colder weather for the foreseeable future. Comparing this years and last stratospheric temperatures, there doesn't seem much difference so far, with last years temperatures remaining below the 30 year mean for most of the winter (we know what happened in December). Of course there are numerous other factors to consider, which i won't pretend to understand, and this years set up, is of course different to last year.

post-6181-0-84739100-1320408086_thumb.gi

post-6181-0-43267300-1320408087_thumb.gi

Saying that there is an indication from the GFS ensembles that we may see the AO and NAO trend negative as we progress through second half of November, it adds some support to a few peoples thoughts of a colder period of weather later on in the month.

http://www.cpc.ncep....ndex_ensm.shtml

http://www.cpc.ncep....ndex_ensm.shtml

Edited by Mark Bayley
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Posted
  • Location: hertfordshire
  • Location: hertfordshire

There was a decent warming at the 30 hpa level at the end of last October

and into the first few days of November at 90 degrees north, although the

graphs that you have shown do not show it that well.

Edited by cooling climate
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Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)

There was a decent warming at the 30 hpa level at the end of last October

and into the first few days of November at 90 degrees north, although the

graphs that you have shown do not show it that well.

That's true but unfortunately no warming on the horizon currently!

An unsettled and mild Nov and Dec look more than likely now and the CFS shows this also.

Karyo

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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.

Time for an update.

Firstly, an update on the Asian Mountain Torque event. There is a sustained mountain torque event which disrupts Rossby waves as they travel around the earth. The whole pattern and number of Rossby waves can change and be shifted.

One of the other affects is deflection of the wave into the stratosphere which can enter the polar vortex bringing in warmer air to the core as it does so. There is nothing so far to suggest that this MT is to create such an effect and I would have expected to see something of it in the forecasts were it to do so.

However, there is better news on the ECM forecasts at the troposphere/ stratosphere interface. so far this winter the stratospheric vortex has been positioned very much over towards the eastern Siberian segment and that looks set to continue. This has an effect on the positioning of the strongest tropospheric vortex which again has been towards the Pacific end. This has left an opportunity for a height rise in the Atlantic sector and for the first time this has been picked up at the 100hPA level with the ECM forecasts.

Here is the T+192 ECM forecast - very much an open door for Greenland height rises.

post-4523-0-71268700-1320658228_thumb.gi

Will the GFS follow suit or will we be left looking at a block more SEasterly placed over the UK?

c

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

Time for an update.

Firstly, an update on the Asian Mountain Torque event. There is a sustained mountain torque event which disrupts Rossby waves as they travel around the earth. The whole pattern and number of Rossby waves can change and be shifted.

One of the other affects is deflection of the wave into the stratosphere which can enter the polar vortex bringing in warmer air to the core as it does so. There is nothing so far to suggest that this MT is to create such an effect and I would have expected to see something of it in the forecasts were it to do so.

However, there is better news on the ECM forecasts at the troposphere/ stratosphere interface. so far this winter the stratospheric vortex has been positioned very much over towards the eastern Siberian segment and that looks set to continue. This has an effect on the positioning of the strongest tropospheric vortex which again has been towards the Pacific end. This has left an opportunity for a height rise in the Atlantic sector and for the first time this has been picked up at the 100hPA level with the ECM forecasts.

Here is the T+192 ECM forecast - very much an open door for Greenland height rises.

post-4523-0-71268700-1320658228_thumb.gi

Will the GFS follow suit or will we be left looking at a block more SEasterly placed over the UK?

c

I do think, to use the over used expression, building blocks, that more and more are slowly starting to drop into their needed position, they are not there yet as you rightly point out but I would be surprised if there is not a large change in the major wavelength pattern around the northern hemisphere before the end of the month.

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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 see that there is a forcast warming at 30 hpa 90 degrees

north on the ECM site. This could be worth watching.

For some reason I am not able to copy images at the moment

otherwise I would post it in here.

Keeping an eye on that for a day or two cc as the NH charts show that it is only a minor warming as the vortex slightly retreats to the Eastern Siberian sector. Ozone levels slowly on the increase.

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

I see that there is a forcast warming at 30 hpa 90 degrees

north on the ECM site. This could be worth watching.

For some reason I am not able to copy images at the moment

otherwise I would post it in here.

Here you go :)

Something worth watching over the coming days.

post-6181-0-21449400-1320692974_thumb.gi

Edit: Should now be recent one

Edited by Mark Bayley
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Posted
  • Location: Lincs
  • Location: Lincs

Hello i hardly ever post here as my knowledge is small compared to the majority on here but i am learning all the time from forums such as this, i was just wondering could you link me to those forecasts

Many thanks,

Ryan.

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

Hello i hardly ever post here as my knowledge is small compared to the majority on here but i am learning all the time from forums such as this, i was just wondering could you link me to those forecasts

Many thanks,

Ryan.

Hi, i'll point you towards CH's first post, this contains a number useful links, as well as an excellent overview of what is a very interesting area of meteorology :)

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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 checked everything stratospherically. Not an inkling of a break in the current cooling. There's always tomorrow!

(I think I may have a month and a half of this!)

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Posted
  • Location: Strathblane/Killearn nr Glasgow
  • Location: Strathblane/Killearn nr Glasgow

Isn't it a good thing [ based on GP's winter review ] that the vortex is most likely to set up shop over Canada this winter?

This will allow a trough over Scandi, and heights to build in the favourable locations and all the other jigsaw pieces?

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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.

Isn't it a good thing [ based on GP's winter review ] that the vortex is most likely to set up shop over Canada this winter?

This will allow a trough over Scandi, and heights to build in the favourable locations and all the other jigsaw pieces?

If the vortex is extremely strong it is more unlikely to be disturbed by HLB's no matter where the heart of it sets up. I know that the stratosphere is just one building block in winter - but imo it is a darn big one. Currently the mean zonal wind at 10 hPa is well above average and set to increase further. It is only a matter of time before this filters through to the troposphere.

http://acdb-ext.gsfc.nasa.gov/Data_services/met/metdata/annual/merra/u60n_10_2011_merra.pdf

I must admit I would truly love to see a Greenland block set up in these circumstances so that I can say the a powerful stratospheric vortex can be overridden. But I just can't see that happening. (Remember I am still on a big learning curve with the stratosphere! - and this may have occurred before without a warming event in a cold stratosphere).

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Posted
  • Location: Strathblane/Killearn nr Glasgow
  • Location: Strathblane/Killearn nr Glasgow

If the vortex is extremely strong it is more unlikely to be disturbed by HLB's no matter where the heart of it sets up. I know that the stratosphere is just one building block in winter - but imo it is a darn big one. Currently the mean zonal wind at 10 hPa is well above average and set to increase further. It is only a matter of time before this filters through to the troposphere.

http://acdb-ext.gsfc..._2011_merra.pdf

I must admit I would truly love to see a Greenland block set up in these circumstances so that I can say the a powerful stratospheric vortex can be overridden. But I just can't see that happening. (Remember I am still on a big learning curve with the stratosphere! - and this may have occurred before without a warming event in a cold stratosphere).

What factors do you think will be most responsible for a warming to occur this year?

At this stage, it looks like if we are to get a big freeze, the earliest it will now occur is the beginning of December - because last year, a warming was already happening by now, and is not this year?

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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.

What factors do you think will be most responsible for a warming to occur this year?

At this stage, it looks like if we are to get a big freeze, the earliest it will now occur is the beginning of December - because last year, a warming was already happening by now, and is not this year?

Last year we were assisted by Autumn warming during late October and November and it was nearly December before the mean zonal winds rose to normal values. This year we see the mean zonal winds running well above average already.

I am looking at this year the lower tropical westerly winds from the residual wQBO to be removed from the atmosphere. Also strong MT events can lead to stratospheric feedback, as can increased Autumnal NH snowcover. Also if we can see a cooling in subtropical stratospheric temperatures then the temperature gradient will not be quite as great. And of course an increase in polar ozone concentrations from a resultant enhanced BDC.

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Posted
  • Location: Strathblane/Killearn nr Glasgow
  • Location: Strathblane/Killearn nr Glasgow

Last year we were assisted by Autumn warming during late October and November and it was nearly December before the mean zonal winds rose to normal values. This year we see the mean zonal winds running well above average already.

I am looking at this year the lower tropical westerly winds from the residual wQBO to be removed from the atmosphere. Also strong MT events can lead to stratospheric feedback, as can increased Autumnal NH snowcover. Also if we can see a cooling in subtropical stratospheric temperatures then the temperature gradient will not be quite as great. And of course an increase in polar ozone concentrations from a resultant enhanced BDC.

How long does it take for residual winds to be removed from the atmosphere?

When did it start?

I remember last year after the freeze, GP told us that a downwelling of the QBO was occurring and would inhibit any further warmings - this year that is happening earlier, and is a good thing for this coming winter.

Sorry for all the questions, but I am doing so for the benefit of everyone else on this forum who wants to learn more about the stratosphere.

Edited by kilmannan27
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Posted
  • Location: Netherlands
  • Location: Netherlands

Last month achieved -3.05 for QBO.

According to this (http://www.usmessage...009-2010-a.html) little research the QBO will decline only slowly.

'The question now becomes.. when the phases switch, how long until the -10 threshold is reached? Historically, 20/24 (83%) -QBO events reached this point within 5 months of the phase switch. Assuming the worst case scenario happens, and September is when the phase switches, using just this, there is an 83% a negative QBO state of -10 or lower will be reached by February. but there's a twist. The atmosphere does not let the QBO trend from near neutral toward extreme negative readings in the Fall or Winter.

What time of the year the QBO change phases has a major impact on when this following -10 threshold is reached. Since 1953, the QBO has changed from positive to negative 6 times in April or May. Of these 6 times, every event was at -10 or greater within two months. June has seen a switch 5 times. Of these, there are 3 examples of it reaching -10 within 2 months, one example at 4 months, and at the extreme it didn't get there until 7 months. In the 7 month example, the QBO switched in the later half of June, which matches what comes next.. When switching phases in July or August, the average amount of time it takes for the QBO to reach -10 is over 8 months.

So basically, we need to from a +QBO to -QBO sometime before June 15th to achieve a -10 or lower anomaly by the Fall/Winter. Below is data showing the direct correlation between time of year the QBO phases switch, and how long it takes for a -10 point to be reached'

The QBO negative phase started in august of this year (http://www.esrl.noaa.gov/psd/data/correlation/qbo.data).

Edited by sebastiaan1973
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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.

How long does it take for residual winds to be removed from the atmosphere?

When did it start?

I remember last year after the freeze, GP told us that a downwelling of the QBO was occurring and would inhibit any further warmings - this year that is happening earlier, and is a good thing for this coming winter.

Sorry for all the questions, but I am doing so for the benefit of everyone else on this forum who wants to learn more about the stratosphere.

We are moving from knowns more towards theory from this point. If you watch GP's preliminary thoughts video, then you will see that he thinks that the next upwelling wave will begin early next year.

Last month achieved -3.05 for QBO.

According to this (http://www.usmessage...009-2010-a.html) little research the QBO will decline only slowly.

'The question now becomes.. when the phases switch, how long until the -10 threshold is reached? Historically, 20/24 (83%) -QBO events reached this point within 5 months of the phase switch. Assuming the worst case scenario happens, and September is when the phase switches, using just this, there is an 83% a negative QBO state of -10 or lower will be reached by February. but there's a twist. The atmosphere does not let the QBO trend from near neutral toward extreme negative readings in the Fall or Winter.

What time of the year the QBO change phases has a major impact on when this following -10 threshold is reached. Since 1953, the QBO has changed from positive to negative 6 times in April or May. Of these 6 times, every event was at -10 or greater within two months. June has seen a switch 5 times. Of these, there are 3 examples of it reaching -10 within 2 months, one example at 4 months, and at the extreme it didn't get there until 7 months. In the 7 month example, the QBO switched in the later half of June, which matches what comes next.. When switching phases in July or August, the average amount of time it takes for the QBO to reach -10 is over 8 months.

So basically, we need to from a +QBO to -QBO sometime before June 15th to achieve a -10 or lower anomaly by the Fall/Winter. Below is data showing the direct correlation between time of year the QBO phases switch, and how long it takes for a -10 point to be reached'

The QBO negative phase started in august of this year (http://www.esrl.noaa...lation/qbo.data).

Thanks Sebastiaan.

I think that the QBO has propagated further down the Troposphere within the last 10 days or so.

Here is the link to the post earlier in the thread - http://forum.netweat...watch-20112012/

This shows the west and east QBO positions.

Now compare it to today - http://wekuw.met.fu-...l&var=u&lng=eng

One can see that looking at the 30hPa level there certainly looks like a downwards propagation of the easterly winds has occurred - I suspect that we will be a lot closer to the -10 value.

The next can of worms involves analysing the QBO data to see how the exact timing of change of QBO cycle can affect NH winter patterns. Then compare this to low /high solar conditions, ENSO state, PDO cycle and so and so forth. Complex? You bet so!

Edited by chionomaniac
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Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)

If you are correct about the startosphere then it could be a long wait before the chance of a Greenland high Chino.

Thats a depressing thought

:sorry:

Since you mentioned the word depressing? Check this: http://www.cpc.ncep....s3/euT2mMon.gif

The CFS must be expecting a winter free of stratospheric warming events! lol

Karyo

Edited by karyo
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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.

If you are correct about the startosphere then it could be a long wait before the chance of a Greenland high Chino.

Thats a depressing thought

:sorry:

Let's hope I am wrong! I do have a suspicion that we will get a warming event in January. The recurring MJO pattern is encouraging, as is the lack of zonality.

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Since you mentioned the word depressing? Check this: http://www.cpc.ncep....s3/euT2mMon.gif

The CFS must be expecting a winter free of stratospheric warming events! lol

Karyo

Yes i really enjoyed the regional snow threads last 2 winters Karyo but do you think this year it might not be as fun for us? :sorry:

edit although there is no singal for the uk but very warm for scandy maybe they expect a big euro high pressure belt affecting europe

Edited by happy days
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