Stratosphere Temperature Watch 2015/2016

[Abyss]

Thanks. I'm no longer confused 

[Recretos]

Good discussion, and let me be of assistance. The big reason why the models, and ENS generally are going for a more zonal period, does indeed also happen to be stratosphere based (among other stuff). I have made a new animation, showing the polar vortex core dynamics during the SSW and after it. You can see right away how the wave 1 itself helps to bring that cold shot into E USA, but that is about it. The vortex core tries to re-spin, and in the later frames of the forecast we can see the top-down NAM re-linkage of the mid strat vortex core down into the upper troposphere, causing a pattern supportive for positive AO and NAO. 

I recommend watching in full screen. 

 

Stratosphere is not only of importance during SSWs, but all the time...

Edited February 3, 2016 by Recretos

[fergieweather]

2 minutes ago, Recretos said:

Good discussion, and let me be of assistance. The big reason why the models, and ENS generally are going for a more zonal period, does indeed also happen to be stratosphere based (among other stuff). I have made a new animation, showing the polar vortex core dynamics during the SSW and after it. You can see right away how the wave 1 itself helps to bring that cold shot into E USA, but that is about it. The vortex core tries to re-spin, and in the later frames of the forecast we can see the top-down NAM re-linkage of the mid strat vortex core down into the upper troposphere, causing a pattern supportive for positive AO and NAO. 

 

Sooper-dooper. And there we have it: the rationale behind the GloSea signal in glorious 3-D! Thanks as ever, Recretos.

[mountain shadow]

Indeed there we have it, any possible cold end to Winter scuppered by a Strat Warming. 

Remember that for next Winter folks. A Strat warming can be both an aid and a hindrance to Northerly blocking even over riding an amplified favourable MJO phase.

[fergieweather]

Just now, mountain shadow said:

Indeed there we have it, any possible cold end to Winter scuppered by a Strat Warming. 

Remember that for next Winter folks. A Strat warming can be both an aid and a hindrance to Northerly blocking even over riding an amplified favourable MJO phase.

Ha! Indeed.... and next winter, perhaps La Nina by then, easterly QBO; what could possibly go wrong? ;-)

[Recretos]

Dont forget low solar activity. We have it all covered. 

Let me just say while at it, that I hope this years SSW, minor or not, was a good reality check for the future. I (we) have said to be careful about not only this one, but every warming in the stratosphere has to be analysed individually. Seeing the warming at 10mb is not nearly enough of a reason to start the hype train and to celebrate. This SSW was an obvious no-game-changer before it even began, and everyone could see it if they would want to, even without the fancy 3D animations and graphics. Trust me, if this whole event would be worth the attention, I would write about it and hype it myself. 

Now Dr. Cohen still believes in negative AO mid Feb onwards into March, so we will see how everything pans out. I will finish off with another animation, this time its EPV at 10mb, from the NASA GEOS-5 model, showing the SSW wave1 dynamics and the recovery attempt. 

 

 

[Recretos]

One more thing. Look at this, how there is a lagged response between 10mb and 300mb. And also notice how the MSLP responds also. Most notably in the second part, when the strat-trop coupling increases.

 

Adding PA 850mb temperature to the mix, since it is under direct SSW response via the cold shot. Notice also here how the strat fastly couples with the trop, showing decent correlations also here, not only in 3D animations.

Edited February 3, 2016 by Recretos

[Snowman.]

2 hours ago, mountain shadow said:

Indeed there we have it, any possible cold end to Winter scuppered by a Strat Warming. 

Remember that for next Winter folks. A Strat warming can be both an aid and a hindrance to Northerly blocking even over riding an amplified favourable MJO phase.

Between this and the hurricane in Jan I hope I will wake up one day look at my clock and see that is in fact November still and all of this was just a bad dream.

But more importantly it has proved to those who regularly fall back on a SSW delivering the goods is not always the case.

Edited February 3, 2016 by SN0WM4N

[Singularity]

@fergieweather @Recretos; thank you for all of your responses/input. It appears the vortex is being an absolute *phrase withheld* this season and I imagine it will take a decent amplitude MJO to make a difference. We did see in mid-Jan, though, that it can produce some results even when the vortex is raging away.

Surely it will be at least a bit weaker as the MJO comes around again... therein lies the last real hope for fans of sustained lowland lying snow Feb-Mar.

Could be some 'surprise' events next week but with accumulations short-lived away from high ground, especially in the south.

It's been a weird sort of winter really. Fascinating from a scientific perspective but also dreadful in terms of things not quite cutting the mustard or whatever the phrase is . Next winter might be fun though, if we see a low solar activity, negative QBO, neutral/weak ENSO combination. Of those the first is the most likely I should think, with the QBO not certain and ENSO highly uncertain (range of outcomes cover strong La Nina to a rebounding El Nino reaching the strong threshold again!).

[phil nw.]

Really useful and informative discussion thanks guys.

We havent had the full blown SSW with zonal wind reversals at 10hPa when we would have preferred it for best Winter cold chances- more a displacement which worked against us pushing the vortex this way.

We have seen plenty of wave 1 action through the season but it has been such a beast of a vortex this time with very cold temps. at 30hPa.

I suppose we all thought it would be an uphill struggle this year to see extensive blocking but we always live in hope!

[Allseasons-Si]

Yesterdays 30 hpa and 10 hpa

today's

could this go further,we will find out tomorrow,now looking at them charts,they suggest that downwelling will be mid-late feb,but have read that it could downwell in the wrong place,is this right?,still learning and this is a tough subject.

 

[damianslaw]

Been a good read so far this winter.. as others have said, there are plenty of uncertainties when it comes to forecasting Stratospheric warming and consequently its likely potential effects, all dynamics are affected by other factors.

This winter it seems it has all been about the effect on the Polar Vortex which has been at record cold levels I think since early November - in an average year it usually takes until late Dec to reach its cold core, this year it was on super turbo charge even before we started the winter. If the predictions are right the minor SSW?? will displace the PV in an unfavourable position for any high latitude blocking to affect us at least through the remainder of the meteorological winter, its a pity because I think many of us would just like to see some settled conditions as opposed to more wind, rain and cloud.

We still can't be sure what may happen, will PV displacement be a shortlived affair, might we finally see some higher latitude blocking as we enter Spring.. might the PV implode on itself during Spring.. who knows.. but I suspect whatever happens this thread is probably going to go into shutdown over the next week or so..

Edited February 3, 2016 by damianslaw

[Daniel*]

Boosh quite extraordinary 

 

Things are heating up...

 

 

Edited February 4, 2016 by Daniel*
Typo

[Recretos]

A little verification of the Glosea5 model. It runs 4 members per day,  perturbations + 1 control. So I decided to take 5 days worth of data, from 9 to 14 January. That is total of 5 days, which means 20 ens members. Generally, it had a good idea of how the strat dynamics will evolve, with the drop and everything. But it was a bit far out and it had quite a spread. But generally I wouldn't say that it is too bad at all. It did miss out on the recovery period, but some ens have it.

edit:

Gonna add GEOS5 forecast of changes. Further reveals where the SSW linkage goes and where not.

   

Edited February 4, 2016 by Recretos

[Harsh Climate]

So from looking at the net weather gfs strat forecast we see those red colours from the 5th februrary all the way to the 10th februrary.

Surely this would have a major effect on the lower atmosphere (Troposphere.)? Would any one stick there heads out and say this would produce major blocking or an easterly late februrary/early march if these forecasts are correct?

[feb1991blizzard]

16 minutes ago, Harsh Climate said:

So from looking at the net weather gfs strat forecast we see those red colours from the 5th februrary all the way to the 10th februrary.

Surely this would have a major effect on the lower atmosphere (Troposphere.)? Would any one stick there heads out and say this would produce major blocking or an easterly late februrary/early march if these forecasts are correct?

I am no expert but I would categorically say that they would not produce proper blocking, for any blocking to occur, you need to either see a split vortex (preferably far and wide with the ridge over Greenland), or the displacement shown on the first chart persist for a good length of time and not just revert back to its default position over the pole.

[karyo]

50 minutes ago, Harsh Climate said:

So from looking at the net weather gfs strat forecast we see those red colours from the 5th februrary all the way to the 10th februrary.

Surely this would have a major effect on the lower atmosphere (Troposphere.)? Would any one stick there heads out and say this would produce major blocking or an easterly late februrary/early march if these forecasts are correct?

Westerlies for us! The vortex is reluctant to leave Greenland and there is no split.

[Snowman.]

1 hour ago, Harsh Climate said:

So from looking at the net weather gfs strat forecast we see those red colours from the 5th februrary all the way to the 10th februrary.

Surely this would have a major effect on the lower atmosphere (Troposphere.)? Would any one stick there heads out and say this would produce major blocking or an easterly late februrary/early march if these forecasts are correct?

If anything the attempted SSW has probably hindered us more as it pushes the vortex further south in our sector which is why where looking at the potential for a stormy period of weather in the south of the UK.

[Harsh Climate]

Thanks for the replies :). Yeah what you have all said seems to make sense, it seems the strat warming alone isn't enough to produce the goods for the UK. My knowledge on the strat isn't great lol so this a great thread to learn.

[joggs]

If it comes about re the predicted NASA warming,could this be powerful enough to break the vortex?

And what's the lag time?

And why does the vortex cling to Greenland like a limpet most winters?.

To the more knowledgeable,thanks.

[Singularity]

Well unless the imminent warming does something unexpected, the next period of interest is perhaps near the end of the third week in Feb.

Not much to look at yet I know. It could nudge the vortex further from the pole toward Europe I suppose.

As I'm expecting a lot more forcing of amplification from the tropical Pacific by that time than the model has been seeing, there's a lot of room for change so this is just pondering for the sake of pondering 

[WINTRY WALES]

43 minutes ago, joggs said:

If it comes about re the predicted NASA warming,could this be powerful enough to break the vortex?

And what's the lag time?

And why does the vortex cling to Greenland like a limpet most winters?.

To the more knowledgeable,thanks.

I have always wondered why the vortex positions itself here...can anyone explain?

Thanks

[knocker]

Very apt

[Singularity]

27 minutes ago, knocker said:

Very apt

Funny that, it bears resemblance to a splitting vortex. Relatively low down, of course. Seems to me there are increasing suggestions from the models that the troposphere and lower-strat. will again diverge considerably from the picture higher up.

[KyleHenry]

2 hours ago, WINTRY WALES said:

I have always wondered why the vortex positions itself here...can anyone explain?

Thanks

Temperatures, ice sheet,altitude, geographical position.