Stratosphere Temperature Watch 2015/2016

[Recretos]

2 hours ago, chionomaniac said:

Recretos, did you use a bit of ' artistic licence' to get each distinct ensemble member to look like they blend into each other? Also do you know the ensemble means at T+96 and T+384? Cheers 

Well, actually yes, just simple interpolation.  I know its kinda pointless since each member is a stand-alone forecast, but it looks better.  Will just leave the raw view next time.

As for the WAF, i dont have the formula for it to plot it. Some day perhaps.

While at ensembles, here are some CFSv2 ensemble trends. They are continuing what the GEFS has started, but given the time period, they feel too slow. 

 

 

  

[Methuselah]

How lucky we are to have you guys on netweather. Even with an 2.1 in Natural Sciences, I cannae get my head round more than a fraction of the stuff you provide for us...Though I do suspect I'm 100% correct in thinking that 'ageostatic flux' has no connection with a soldering iron!

[chionomaniac]

10 minutes ago, Glacier Point said:

Hi Ed. I'm sorry I don't have access to any WAF type forecast plots.

I'm not surprised in the least about the vortex this far. There are reasons outside of ENSO and the QBO which have flagged this for some time (although at this stage I'm unable to detail them).

Thus far, we do have a text book Cohen model response - October snow cover, November Siberian High, December Aleutian Low. Just need that to be sustained (and latest EC week 4 plot was good for that) and it's over to the strat response.

Yes, I think a lot are relying on the Cohen strat response in January to deliver something a bit more seasonal (Tony and I included), though the risk is there with the possible west based -ve NAO response and we end up with a flash in the pan. Good to see some strat wave interaction in the forecasts. 

 

Andrej - keep the artistic licence because I think that as long as everyone realises that, then the better look is worth it. Pity about the WAF!

[Recretos]

Btw, this is how it looks like without the artistic licence. 

 

 

[Cloud 10]

NAEFS raises a stratospheric eyebrow at max range,and may as well chuck the 12z gfs in there as well.

 

NAEFS..GFS..

[Recretos]

NAEFS is actually inferior to GEFS-alone. Yes, there is half of GEFS in the NAEFS, but the CMC ensembles just ruin the average. Given the configuration, GEFS is now the best freely available stratosphere ensemble forecasting system. It has a model top at 0.2mb, up from 2mb (CMC ensembles have the model top at 10mb btw), and it now has 64 vertical levels. Basically it now uses the same vertical system as the GFS. I also prefer to use the bias-corrected version when available, but given the new configuration, the normal output is sufficient. 

 

Edited December 3, 2015 by Recretos

[lorenzo]

3 hours ago, Recretos said:

Btw, this is how it looks like without the artistic licence. 

 

 

This reminded me of something, see attached. Both versions are excellent Andrew. Great work again.

Intriguing post Stewart re vortex intensification, hopefully you can share at some point. Another torque in the mix in the next week is a good thing.

Couple of more on topic attachments I found from last years folder, an image re Wave One and Wave two displacements and splits and also the different profiles across Vortex Onset, Growth, Maturity and Decay to compare to current position.

Let the take down commence....

[damianslaw]

I'm sensing the vortex may simply implode on itself given its forecasted strength, like a pressure cooker combusting.. a balloon inflated to max strength until it bursts... its started on all fires this year very very early in the season, unusually so.. only one way to go perhaps..

[Duane S.]

6 hours ago, Glacier Point said:

There are reasons outside of ENSO and the QBO which have flagged this for some time (although at this stage I'm unable to detail them).

Intriguing! Especially considering (I would have thought) that the current Enso state coupled with this W-QBO would have produced this response for early December anyway?  Interesting to think that another primary driver might be at play here.

[Woollymummy]

6 hours ago, Recretos said:

Btw, this is how it looks like without the artistic licence. 

 

 

That's ok, my kids like minecraft so I have become fond of little coloured squares.... Good graph. 

[Frank_Wx]

Too bad this is day 15, but cool to see. 

[Duane S.]

Starting to warm up nicely at the top, would be nice to see further increases in the coming days and, of course, it actually verifying...

[Glacier Point]

EC week 2 forecast relents wave 1 forcing a little during week 2, but really ramps it up again during weeks 3 and 4 with a very coherent N.Pacific pattern for displacement to continue.....

[chionomaniac]

I think the ball is rolling....

[Frank_Wx]

What type of impact does tropospheric ridging bring to the Stratosphere?

[chionomaniac]

1 hour ago, Frank_Wx said:

What type of impact does tropospheric ridging bring to the Stratosphere?

Hi Frank_wx - that pattern will lead to weak wave 2 - see tweet here on trop blocking precursor patterns prior to strat events

 

Edited December 4, 2015 by Paul
Sorted tweet embed - press enter after pasting the link in :-)

[Singularity]

A chance, then, that the stratospheric pathway will be able to help us escape the consequences of the tropospheric pathway i.e. a tendency toward a west-based -ve NAO late in the season.

A strong break down of the vortex looks to be essential for that, and perhaps the particularly vigorous state of the vortex at this early stage will prove to be helpful in that regard. This seems like a prime case of 'all or nothing' for the Jan-Feb period!

 

[Catacol]

45 minutes ago, Singularity said:

A chance, then, that the stratospheric pathway will be able to help us escape the consequences of the tropospheric pathway i.e. a tendency toward a west-based -ve NAO late in the season.

A strong break down of the vortex looks to be essential for that, and perhaps the particularly vigorous state of the vortex at this early stage will prove to be helpful in that regard. This seems like a prime case of 'all or nothing' for the Jan-Feb period!

 

Agreed. I think this winter is a pretty simple case of strat or bust. Cohen has it nailed too. Either we get some tropospheric induced strat warming in late Dec early Jan to knock the vortex off its stool, or we are looking at another 97/98, maybe even worse. Best we can hope for is that a record breaking vortex might shatter in a record breaking manner - more velocity, more damage done when the spanner is jammed into the spokes.... but more likely we will get a displacement and therefore a relatively short window for blocking and something seasonal. To my eye Ed's forecast of a single spell of cold weather looks a pretty good call at the moment based upon a displacement event - but I guess we will all hope that we get the right patterns for an almighty wave 2 pinch, and then something more dramatic a la Feb 2009

Edited December 4, 2015 by Catacol_Highlander

[Singularity]

On 11/23/2015, 9:06:57, Recretos said:

Oh trust me, a full on wave 1 can be a harder case for the vortex to handle than a wave 2. if the vortex is strong, it can take the "energy" of the 2-wave and use it to its own advantage, remaining firm in place, unless a strong enough temp. waves are following. While in a full blown wave 1 it will get shoved out of place before it can say "is that a wave1 coming at me...". Of course with the normal disclaimers, like each scenario is different and each situation is unique.

In response to CH's post here's what Recretos posted a couple of weeks back about wave 1 vs. wave 2.

This suggests to me that wave 1 is a lot more desirable than wave 2 with respect to the next 6 weeks or so. But we do need a mighty force, a big wrench for a big machine.

[phil nw.]

I always thought a wave 2 split would see a better blocking pattern and probably longer lasting?

A wave 1 displacement would push the vortex aside but would leave it bruised yes but basically intact only to push back and relocate over the pole.

 

[Singularity]

This leads me to ask a deceptively simple sounding question; can the polar vortex disintegrate following a heavy displacement?

I have seen displacements cause a vortex to become rather distorted with an elongated appearance, so to me it seems possible that the resulting imbalances might cause some degree of a breakdown, particularly if the vortex is particularly vigorous at the time of displacement.

[Catacol]

23 minutes ago, phil nw. said:

I always thought a wave 2 split would see a better blocking pattern and probably longer lasting?

A wave 1 displacement would push the vortex aside but would leave it bruised yes but basically intact only to push back and relocate over the pole.

 

My thoughts too. And the stronger the vortex, the tighter the elastic to pull it back into place. 

[Catacol]

19 minutes ago, Singularity said:

This leads me to ask a deceptively simple sounding question; can the polar vortex disintegrate following a heavy displacement?

I have seen displacements cause a vortex to become rather distorted with an elongated appearance, so to me it seems possible that the resulting imbalances might cause some degree of a breakdown, particularly if the vortex is particularly vigorous at the time of displacement.

Hmmm - a wave 1 induced full split? I'm out of my knowledge base here. Anyone care to comment as to whether a wave 1 attack can do this much damage? Interesting idea.

[KyleHenry]

On 3 December 2015 14:53:46, Glacier Point said:

.. and this little bomb is interesting...

Deep low pressure system tracking through the North Pacific trough, allied to around 10 days worth of low level wave forcing in the region. Very amplified Pacific sector as well, strong +dt/daam overlaying this, and +MT over N. America within 5 days.

That (little bomb) and the rest that follows it over next 14 days really is a tropospheric  clay      pigeon launcher of warm air  that fuels the upcoming MT event. 

Coinciding with Ozone concentrations in that launch area, the El Niño has possibly peaked. 

It does look like Winter Solstice 22nd Dec for SSW opportunity. 

[Skin]

On 12/3/2015, 6:03:24, s4lancia said:

Intriguing! Especially considering (I would have thought) that the current Enso state coupled with this W-QBO would have produced this response for early December anyway?  Interesting to think that another primary driver might be at play here.

The state of the PDO is helping negate the ENSO signals. Which I think allows the SSWEs to take precedence this winter. 

Positive PDO blocks or interferes with the propagation of the ENSO signal through the extratropics