Stratosphere Temperature Watch

[chionomaniac]

Still no set pattern or agreement with the stratospheric forecasts, which makes it difficult to determine the influence that the stratosphere will have on the troposphere.

Firstly we still see that the GFS at the lower levels of the stratosphere is suggesting another split in the vortex (at T+240) but we see nothing along these lines from the ECM. This makes it extremely difficult to put forward any suggestion whether we will see another period of northern blocking or a return to a more regularly positioned vortex.

This may be driven (the vortex shape that is) by the upper stratospheric pattern. At the T+240 timescale at the 10hPa level the GFS is still insisting on a warming event, driving temperatures above -20ºC. However, the ECM keeps any warming temperatures far less than that which will have a far less effect of any pressure squeeze on the vortex.

I have a feeling that until these differences are resolved that we are likely to the large differences in the tropospheric model outputs especially in the 5-10 day timeframe. There will have to be a climbdown or meet in the middle between these two outputs and I wouldn't like to say which way that will go just yet.

I certainly don't like not knowing which way to jump!

[chionomaniac]

Ho Ho Ho! I have just had a look at the ECM stratospheric T+240 100hPa forecast and found this staring back at me!

The warming at 10 hPa is now more in line with the GFS as well.

Need I say any more other than I know which way to jump now.

Second week in Jan is my guess for another severe Arctic outbreak.

edit in fact it could be a touch sooner than that.

Edited December 22, 2010 by chionomaniac

[Mark Bayley]

Ho Ho Ho! I have just had a look at the ECM stratospheric T+240 100hPa forecast and found this staring back at me!

The warming at 10 hPa is now more in line with the GFS as well.

Need I say any more other than I know which way to jump now.

Second week in Jan is my guess for another severe Arctic outbreak.

edit in fact it could be a touch sooner than that.

I don't really understand the above chart as I'm only used ot using the 30hpa graphs. Would the above chart suggest heights rebuilding over southern Greenland like the NAEFS has been suggesting?

http://www.meteociel...e=0&ech=192= (will upload chart in a second has it doesn't seem to be working)

Is there any guides or explanations to the chart above? I'm guessing the orange is where the warming event is predicted to happen and the two large circles of the Arctic indicating a split PV (although i could be completely wrong) ?

Thanks

Edited December 22, 2010 by Mark Bayley

[chionomaniac]

I don't really understand the above chart as I'm only used ot using the 30hpa graphs. Would the above chart suggest heights rebuilding over southern Greenland like the NAEFS has been suggesting?

http://www.meteociel...e=0&ech=192= (will upload chart in a second has it doesn't seem to be working)

Is there any guides or explanations to the chart above? I'm guessing the orange is where the warming event is predicted to happen and the two large circles of the Arctic indicating a split PV (although i could be completely wrong) ?

Thanks

The 100 hPa level is really at the tropospheric interface. Do not look here for the warming, it is far further above at the 10 hPa level. The main thing I wanted to show, you have correctly identified - the split in the vortex. This will hopefully allow another episode of northern blocking to occur in the heart of winter. We will have to wait to see where the exact loction for is though.

Edited December 22, 2010 by chionomaniac

[Mark Bayley]

The 100 hPa level is really at the tropospheric interface. Do not look here for the warming, it is far further above at the 10 hPa level. The main thing I wanted to show, you have correctly identified - the split in the vortex. This will hopefully allow another episode of northern blocking to occur in the heart of winter. We will have to wait to see where the exact location for is though.

Thanks for the reply, I enjoy following this thread during the winter as I find it a fascinating subject. Hopefully I will continue to build my knowledge! It would be good have January follow on from December's impressive weather, however perhaps not as cold!

[bluearmy]

chio, the NAEFS has been pointing to a strong anomolous greeny height rise around 4th jan for many days now. now the strat is pointing to a split vortex a few days later. question would be - are the models able to forecast this strat warming. is something occuring which the models are taking into account in their runs which is leading to the warming taking place ??? you're looking at a strat forecast for last 10 days dec/beginning jan. have the models been factoring in a longer range foreacst (which we dont see) and generating a split vortex in their far off fi's as a result??

[gottolovethisweather]

Second week in Jan is my guess for another severe Arctic outbreak.

edit in fact it could be a touch sooner than that.

Interesting that you note that period Chiono because this winter is following a very similar to the lasts.

The period we are in now (as in 2009) slowly got slightly more mild and then cold returned with a vengeance come the 6th January as we all well remember.

It's also interesting in the fact that the media seem to forget the tales of woe from this time last year and that it happens every bloody year but they still hype hype hype. Ok the good thing to come out of all the mayhem and chaos is the WEATHER IS BEING TALKED ABOUT, which can only be good for those hoping for a career in this field.

These cycles often seem to come into the play but maybe this time around we should be anticipating something EVEN MORE EXTREME IN 2 WEEKS TIME in terms of snow and bitter cold.

Cheers

gottolovethisweather

[johnholmes]

Ho Ho Ho! I have just had a look at the ECM stratospheric T+240 100hPa forecast and found this staring back at me!

The warming at 10 hPa is now more in line with the GFS as well.

Need I say any more other than I know which way to jump now.

Second week in Jan is my guess for another severe Arctic outbreak.

edit in fact it could be a touch sooner than that.

It is beginning to look as if events 'up top' so to speak may have another cold influence 'below stairs' !

post your thoughts into the model section-in plain English mind you, and best warn the mods of what you are about to do as it could cause a melt down.

[chionomaniac]

chio, the NAEFS has been pointing to a strong anomolous greeny height rise around 4th jan for many days now. now the strat is pointing to a split vortex a few days later. question would be - are the models able to forecast this strat warming. is something occuring which the models are taking into account in their runs which is leading to the warming taking place ??? you're looking at a strat forecast for last 10 days dec/beginning jan. have the models been factoring in a longer range foreacst (which we dont see) and generating a split vortex in their far off fi's as a result??

It is difficult to know whether that would be the case. Yet again we see an upper warming avoiding the middle stratosphere but potentially still have an effect on the vortex to allow a bottom up split (potentially). This has been the theme of the last two winters and I amsure that there is a link. I do not know wheteher there is a further outreach from past T+240 that we are not privy to, but that is factored into tropospheric modelling.

It is beginning to look as if events 'up top' so to speak may have another cold influence 'below stairs' !

post your thoughts into the model section-in plain English mind you, and best warn the mods of what you are about to do as it could cause a melt down.

No chance!

[Winter Monsoon]

Chino i love you man ....after the depressing despaire in the mod thread i came in here saw your ho ho ho and though yes yes yes. This happened last yer didnt it?

[Rustynailer]

Should win todays best thread award IMO :smiliz19:

Thanks for keeping us informed CH, very interesting. Something I will perhaps read up on during the holiday period.

Russ

[Winter Monsoon]

Can i ask a question/s?? Has the vortex always been prone to split, for instance in the 90's early 2k was it common then or is what happened last year and this extremly rare? Is it the norm for the strat to warm during winter months and is this proccess repeated for the southern hemisphere?

Edited December 22, 2010 by Winter Monsoon

[chionomaniac]

WM, I will try and answer your questions when I have more time.

Quick update.

Today the GFS and ECM stratospheric models have pulled away from the idea a vortex split. Typical! This has been replaced with an idea of a mid latitude block situated over the UK.

Of note is the considerable warming at the 10hPa level which is now forecast to affect the 30 hPa level. This could yet cause a split - so much to monitor.

Edited December 23, 2010 by chionomaniac

[Kentish Kiwi]

WM, I will try and answer your questions when I have more time.

Quick update.

Today the GFS and ECM stratospheric models have pulled away from the idea a vortex split. Typical! This has been replaced with an idea of a mid latitude block situated over the UK.

Of note is the considerable warming at the 10hPa level which is now forecast to affect the 30 hPa level. This could yet cause a split - so much to monitor.

The idea of a mid latitude high over, or very close to, the UK seems to fit in nicely with GP's thoughts for January.

[Winter Monsoon]

WM, I will try and answer your questions when I have more time.

Quick update.

Today the GFS and ECM stratospheric models have pulled away from the idea a vortex split. Typical! This has been replaced with an idea of a mid latitude block situated over the UK.

Of note is the considerable warming at the 10hPa level which is now forecast to affect the 30 hPa level. This could yet cause a split - so much to monitor.

Cheers mate. Shame about the split not being forcast anymore would have been nice to see that again still its looking cold for jan if i read GP right and you never know the vortx still might split/displace

[knocker]

Does the pool of very cold air lying to the north and east of Britain at 30 and 10mb have any significant influence on the tropospheric circulation patterns that currently exist?

[Duane S.]

WM, I will try and answer your questions when I have more time.

Quick update.

Today the GFS and ECM stratospheric models have pulled away from the idea a vortex split. Typical! This has been replaced with an idea of a mid latitude block situated over the UK.

Of note is the considerable warming at the 10hPa level which is now forecast to affect the 30 hPa level. This could yet cause a split - so much to monitor.

Hi Chiono, where are you seeing that warming at 10hPa? Probably just me but I am struggling to see any warming currently going on at that level.

[knocker]

Hi Chiono, where are you seeing that warming at 10hPa? Probably just me but I am struggling to see any warming currently going on at that level.

Is this a possibilty? Chiono will hopefully correct my assumption.

[chionomaniac]

Does the pool of very cold air lying to the north and east of Britain at 30 and 10mb have any significant influence on the tropospheric circulation patterns that currently exist?

Again, I have very little time to update.

Yes, is the answer to this by reducing the blocking that we have seen during the early winter.

Hi Chiono, where are you seeing that warming at 10hPa? Probably just me but I am struggling to see any warming currently going on at that level.

Is this a possibilty? Chiono will hopefully correct my assumption.

That is right weather ship. And more dramatically seen on the GFS forecast chart.

Also look how the average polar vortex speed is set to reduce at the 100hPa level over the coming days even without the forecast split.

http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ec.php?alert=1&level=100&forecast=all&lng=eng

[Winter Monsoon]

Is this a possibilty? Chiono will hopefully correct my assumption.

Not sure i understand what those charts mean for us?? Does the 2nd one suggest cold??

[chionomaniac]

Not sure i understand what those charts mean for us?? Does the 2nd one suggest cold??

Have you read the first post WM? This gives a beginners guide to the stratosphere.

[Winter Monsoon]

I have now :smiliz23: and those charts are making abit more sense now. Those 2 charts that WS just posted look similar to some form last year .

[chionomaniac]

Merry Christmas all. Wouldn't it be nice to have a SSW as a Christmas present?

c

[Uncle_Barty]

Is that being hinted at then, C?

[chionomaniac]

Is that being hinted at then, C?

Yep, this to me, has SSW written all over it.

A major mid-winter warming is defined to occur when the zonal mean zonal winds at 60N and 10hPa become easterly during winter (NDJFM). The first day on which the daily mean zonal mean zonal wind at 60N and 10hPa is easterly is defined as the central date of the warming. -

http://www.columbia.edu/~lmp/paps/charlton+polvani-JCLIM-2007.pdf

The amount of warming suggested is very promising for a SSW (MMW)..

The blocking already seen is a perfect precursor /preconditioning. The only concern is that the stratosphere would be in an upwelling phase - similar to Feb 2009.. Even if we don't get a MMW I still see enough evidence of polar vortex disruption. The 1hPa mean zonal wind speed is already forecast to be reduced by 50%!

c

Edited December 25, 2010 by chionomaniac