Stratosphere Temperature Watch 2012/2013

[MattH]

Latest run 00Z

http://nwstatic.co.u...71bb287b563b13;

I seriously hope the warming event comes to fruition and actually destroys the PV into early January, because every anomaly chart and N hem chart I've been looking at for work this morning shows a major drop in 500hPa heights over Greenland and surrounding regions towards the end of December with a really significant and noteworthy polar vortex evident in places. The main strat vortex seems to have been pulled back a bit as well on the last couple of runs and isn't over Siberia as far as it was.

Could be a long 2 or 3 weeks ahead for any cold fans....

M.

[Cecil Hogmanay Melchett]

I seriously hope the warming event comes to fruition and actually destroys the PV into early January, because every anomaly chart and N hem chart I've been looking at for work this morning shows a major drop in 500hPa heights over Greenland and surrounding regions towards the end of December with a really significant and noteworthy polar vortex evident in places. The main strat vortex seems to have been pulled back a bit as well on the last couple of runs and isn't over Siberia as far as it was.

Could be a long 2 or 3 weeks ahead for any cold fans....

M.

Thats a worrying signal! Like yourself i think its going to be a long waiting game now and already Dec looks slowless for the vast majority to mid month at the very least.We really don't want to be seeing a stron Vortex anywhere near Greenland in the extended timeframe.

[chionomaniac]

Have to admit, I am waiting for a SSW now - anything in the meantime will be a bonus. The lack of amplification in the pattern is the main concern and the only MJO signal is one that only reinforces the pattern.

[bluearmy]

interesting polar profiles re the trop vortex on the means. ecm, at day 10 seems to be struggling to get it quite as far into siberia as looked likely on yesterday's runs. meanwhile, naefs splits it back towards canada through week 2, leaving a splirt far ne canada/ne siberia. in tandem with another building aleutian ridge. if this is anything near accurate, i think there are a huge range of possibilities on offer post xmas.

[kold weather]

Indeed BA, but then again the GFS by in large (though not so much in its 06z run) has been pulling quite a tight PV into Greenland.

I suspect we WILL see a SSW but we may have a wait until that happens, anything major isa bonus, might have to put up with toppler set-ups and hope we luck out with one over Xmas.

[Ian Brown]

Have to admit, I am waiting for a SSW now - anything in the meantime will be a bonus. The lack of amplification in the pattern is the main concern and the only MJO signal is one that only reinforces the pattern.

Yes I believe a shift in the MJO may change the jet pattern. However I'm a bit confused re with PV, the GFS, admitttedly well in FI is really lowering heights at Northern latitides and bringing the PV to the Greenland area whereas I thought the talk was of the Vortex being 'smashed to pieces' by a probable warming event ?

[chionomaniac]

Yes I believe a shift in the MJO may change the jet pattern. However I'm a bit confused re with PV, the GFS, admitttedly well in FI is really lowering heights at Northern latitides and bringing the PV to the Greenland area whereas I thought the talk was of the Vortex being 'smashed to pieces' by a probable warming event ?

The warming won't occur until around the New Year with the vortex (hopefully) being destroyed at this point. From then on we hope that a piece of vortex doesn't land over us!

[kold weather]

Indeed I'm wondering whether the PV tigthening is actually a response to the warming that is starting to occur towards the back-end. IE the cold air aloft is getting contracted in size and that is shrinking but also strengthening the PV by its contraction.

Just a thought?

[bluearmy]

From then on we hope that a piece of vortex doesn't land over us!

doesnt't that rather depend from which direction its coming Ed and whats in place when it turns up !! (remember 2010?)

[chionomaniac]

doesnt't that rather depend from which direction its coming Ed and whats in place when it turns up !! (remember 2010?)

Feb 2009!!!

How can I forget after the initial easterly!

[bluearmy]

Feb 2009!!!

How can I forget after the initial easterly!

so thats two in two years !!

i made a post on the model thread this morning re the splitting vortex in week 2. do you think its plausible at all that the aleutian ridge could drive a -AO strong enough to send the chunk destination canada in the direction of nw scandi instead ??

[AWD]

This looks like a stronger warming than what some previous GFS output was suggesting;

http://cdn.nwstatic.co.uk/gfsimages/gfs.20121212/12/384/npst30.png

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=384&mode=10&carte=1

Also, isn't that warming helping the PV move over towards Siberia?

Edited December 12, 2012 by AWD

[Winter Monsoon]

Hi,

Been looking back through the pages on this forum trying to find the strat thread that went up in 2009. Im specifically looking to see if there was a split/displacement/warming towards the end of november of that year and the time delay to the 1st real cold snowy weather i had at around 18th December.

I cant find the thread though can anyone help?

[Gael_Force]

Looks to have been some activity at the beginning of December 2009. No other charts for then till somebody locates the 2009 thread if there was one?

[chionomaniac]

Here are the previous strat threads for info. I have dug them out so that I can go through and look for similarities from previous years. Remember anyone else who wants to look through - they were very much learning experiences!

2008/2009 http://forum.netweat...perature-watch/

2009 /2010 http://forum.netweat...perature-watch/

2010/2011 http://forum.netweat...perature watch

2011/2012 http://forum.netweat...watch-20112012/

I can't really believe we are into the 5th year this year and how long it took to convince others that the strat may have a bearing on trop weather.

Edited December 12, 2012 by chionomaniac

[chionomaniac]

Latest warming still forecast on 12Z GFS.

We want to see the warm air fully intergrate (as shown) with the vortex mixing with the cold air. Only then will we see the vortex completely disintergrate.

[chris55]

Latest warming still forecast on 12Z GFS.

We want to see the warm air fully intergrate (as shown) with the vortex mixing with the cold air. Only then will we see the vortex completely disintergrate.

Breaking through the surf zone??? Everybody's going surfing......breaking through the surf zone!! (or is that totally incorrect, still learning)

Edited December 12, 2012 by chris55

[chionomaniac]

Breaking through the surf zone??? Everybody's going surfing......breaking through the surf zone!! (or is that totally incorrect, still learning)

No, you are absolutely correct Chris. The surf zone can 'deflect' the warming - a favourable poleward ep flux comes in handy here.

[Snowman.]

Still looking good!

[chionomaniac]

Still looking good!

Yes, looking back to the record MMW in Jan 2009, the warmest 10 hPa temperature crept up to about 5ºC so we are getting close to those levels here ( BUT STILL FI!)

Very promising - however no guarantee that we may benefit tropospherically.

[bluearmy]

Note the slightly different ending to the 18z run as the warmer temps get oh so close to the 30 hpa vortex. recent runs have had a more rounded shape to the vortex at this level and the latter part of the trop run have been poorer for it. This run has a great shape to whats left of the vortex at 30hpa. I see 10hpa pushes the vortex closer to the pole on our side. This is a recent fi trend.

Edited December 12, 2012 by bluearmy

[Mark Bayley]

Yes, looking back to the record MMW in Jan 2009, the warmest 10 hPa temperature crept up to about 5ºC so we are getting close to those levels here ( BUT STILL FI!)

Very promising - however no guarantee that we may benefit tropospherically.

Yes, always something that is important to highlight, as i get the feeling some people think warming automatically equals cold and snow which it doesn't!

Edited December 12, 2012 by Mark Bayley

[bradymk]

Yes, something i feel is very important to highlight, as i get the feeling some people think warming automatically equals cold and snow!

Yes quite. I would love to know what the MetO are thinking about this potenitial warming right now. Be interesting to know whether they have more data about it and whether it is looking likely and what they are thinking its potential effects are for us come Jan. Unfortunately, we will probally never know.

[Panayiotis]

Yes, looking back to the record MMW in Jan 2009, the warmest 10 hPa temperature crept up to about 5ºC so we are getting close to those levels here ( BUT STILL FI!)

Very promising - however no guarantee that we may benefit tropospherically.

Does the stratosphere change a lot from when we preview now to see what the temperatures will be like in two weeks, because to me the GFS seems consistent on what temperatures the stratosphere will be like next week/week after, where as in the troposphere it can change a lot in this time period? Edited December 12, 2012 by panayiotis

[chris55]

I know the tropospheric pattern is much more chaotic than the stratospheric one, and using single charts at 384 to predict weather in the troposphere is pointless.

What influences, if any, from the troposphere affects what's being forecast in the stratosphere? We look to be having good consistency of this potential warming of the strat (for now) but obviously the tropospheric forecast at this range is changing all the time so I'm guessing the tropospheric pattern does not have a direct link to what's happening in the start. And it's signals higher up that dictate what happens up there?

Although I have heard GP talk about Strat/Troph feedback, so is there a link between the two when going from the ground up, as we obviously know there's a link from the strat down as a warm strat or SSW will impact the Tropospheric.

Also Ed when was the last time you saw such a strong warming forecast? Do these come up in FI often?

Edited December 13, 2012 by chris55