Stratosphere Temperature Watch 2015/2016

[feb1991blizzard]

20 hours ago, chionomaniac said:

I think the ball is rolling....

This early? have to say I didn't expect it yet.

[feb1991blizzard]

15 hours ago, chionomaniac said:

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

 

Any chance you could post a link please to those pre cursor patterns? thank you in advance.

[Woollymummy]

Here you are Feb1991blizzard:

http://www.columbia.edu/~lmp/paps/martius+polvani+davies-GRL-2009.pdf

[chionomaniac]

13 hours 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.

Simple answer is yes. Go to martineau's website and watch the SSW's. Some vortices get pushed off the throne only to jump back on. Others take their time. 

 

Feb91. Go to tweet and link is on the following tweet. On my phone so can't link sorry. 

[lorenzo]

Couple of charts from the usual places.

Don't think I have ever seen a 100 on the u-wind plot on Berlin!

 

Well - it's thinking about it..

Current Wave 1 impacts - watch this loop... http://acdb-ext.gsfc.nasa.gov/Data_services/arctic/anim_T_0010.html

Regarding the tilt and split these two animations from Martineau lifted to compare with the C&P climatology.

1979  http://www.meteo.mcgill.ca/~pmartineau/updated_graphs/svw_anim/all_gif/1979_02_27

1984 http://www.meteo.mcgill.ca/~pmartineau/updated_graphs/svw_anim/all_gif/1984_03_03

Also if anyone wants a look through the archive to consider trop influence with respect to blocks and blocking pre-cursors / triggers to vortex events this table is useful.

Good to see more of the US guys get onboard with strat. monitoring. Levi Cowan added in some 10hPa material onto Tropical Tidbits as per tweet below.

A good time to start watching...

Bunched up EP FLux on the current plot, notice the similar look prior to the larger flux activity at the end of Dec > Jan last season.

Edited December 5, 2015 by lorenzo

[TomDav]

Still a consistent warming signal in upper strat around 20th

 

[aginob]

Hi to all

for User Tom Dav

Great Model but the Link alias Source not correct

not can find this URL ... ( wxmaps.co.uk )  ... Thanks !

Edited December 5, 2015 by aginob

[knocker]

 

Levi Cowan ‏@TropicalTidbits 17m17 minutes ago

Only planetary-scale Rossby waves propagate vertically into the stratosphere. GFS shows transition to wavenumber 1:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Edited December 5, 2015 by knocker

[Singularity]

 

GFS continues to drop hints - and they continue to be at around 16 days range. This often seems to happen as the model moves things along too swiftly, the hope is that it at least has the right idea about how the atmosphere will respond to tropical forcing. It sure is being consistent with the deep Aleutian trough now.

[chionomaniac]

2 minutes ago, Singularity said:

 

GFS continues to drop hints - and they continue to be at around 16 days range. This often seems to happen as the model moves things along too swiftly, the hope is that it at least has the right idea about how the atmosphere will respond to tropical forcing. It sure is being consistent with the deep Aleutian trough now.

That is a lot better for 30hPA. Hmmm

[Frank_Wx]

Here's another perspective from 12z GFS OP 10hPa

Edited December 5, 2015 by Frank_Wx

[Ruben Amsterdam]

The point Singularity raises I think is valid: significant warming so far only appears beyond +300 hrs. Although promising, we really need these charts to slowly but surely move to into the 240-300 hrs range. Recretos, any chance you can make us one of those artistic plots of the ensemble members one of these days? Then surely we can see whether warming/mean u decreases come closer or not. 

Edited December 6, 2015 by Ruben Amsterdam

[sebastiaan1973]

Recretos aka Mr Angerfist  Didn't know this kind of music was popular in eastern Europe.

Something else..

http://onlinelibrary.wiley.com/doi/10.1002/2014JD022022/full

Abstract

It has been suggested that the Sun may evolve into a period of lower activity over the 21st century. This study examines the potential climate impacts of the onset of an extreme “Maunder Minimum-like” grand solar minimum using a comprehensive global climate model. Over the second half of the 21st century, the scenario assumes a decrease in total solar irradiance of 0.12% compared to a reference Representative Concentration Pathway 8.5 experiment. The decrease in solar irradiance cools the stratopause (∼1 hPa) in the annual and global mean by 1.2 K. The impact on global mean near-surface temperature is small (∼−0.1 K), but larger changes in regional climate occur during the stratospheric dynamically active seasons. In Northern Hemisphere wintertime, there is a weakening of the stratospheric westerly jet by up to ∼3–4 m s⁻¹, with the largest changes occurring in January–February. This is accompanied by a deepening of the Aleutian Low at the surface and an increase in blocking over Northern Europe and the North Pacific. There is also an equatorward shift in the Southern Hemisphere midlatitude eddy-driven jet in austral spring. The occurrence of an amplified regional response during winter and spring suggests a contribution from a top-down pathway for solar-climate coupling; this is tested using an experiment in which ultraviolet (200–320 nm) radiation is decreased in isolation of other changes. The results show that a large decline in solar activity over the 21st century could have important impacts on the stratosphere and regional surface climate.

Edited December 6, 2015 by lorenzo
Reducing HUGE font size ;)

[chionomaniac]

Latest thoughts including much strat info here

Edited December 6, 2015 by chionomaniac

[Duane S.]

On 5 December 2015 11:27:46, lorenzo said:

Couple of charts from the usual places.

Don't think I have ever seen a 100 on the u-wind plot on Berlin!

 

The pesky W-QBO winter 13/14 vortex was producing similar strength wind, give or take the same time of year...

 

 

[chionomaniac]

Another run with a fair bit of wave 1 distortion by the end of it - we are not talking SSW here ( see winter forecast thread post) but the expected EN vortex displacement seen in the mid level strat at this juncture. Next thing to watch for is the Atlantic based tropospheric blocking - most likely around Scandi around Christmas time as this could act as a further trigger for a Jan SSW. Not too far away from expectations, but would like that wave 1 activity to show in the 10 day timeframe soon. The FI output is flirting with this for a good reason.

[chionomaniac]

 

[Singularity]

Some positive signs there, cheers for the update

I wonder, with the background El Nino state tending to enforce itself on the output at the nearer range having been underestimated at the longer range (in large part due to tropical forcing being handled incorrectly, I gather?) , could we see the wave 1 mechanism upgraded in magnitude as we move closer to the final week of Dec? Just a (wishful) thought.

[bryan629]

Cohen posted this on twitter not long after his blog up date this evening and i was wondering...Is this image highlighting a split in the vortex?

Edited December 7, 2015 by bryan629
missed words

[Duane S.]

Quite unusual u wind profile forecast at D10. Raging vortex but seemingly unable to filter down and getting confined to the top.

 

Talking of the top, best warming prediction I have seen so far this morning, a bit more of this will likely start to do some damage...

 

[Glacier Point]

I wonder, do we have a slow burner ? A slow burner that perhaps leads to a more assured route to a warming event in January ?

The pattern as of yesterday and for the next 7 days is within the envelope for generating Wave 1 activity in the upper stratosphere with a deep upper trough centred across the central North Pacific. The atmosphere is also reflecting a strong El Nino passage with relative angular momentum topping +2SD.

Both this morning's EC EPS and GEFS mean at 10 hPa show remarkable consistency on a big North Pacific ridge and slightly displaced upper vortex. We have also operational GFS showing warming at 1hPa, peaking around the 22nd-23rd December. That is much more in line with what we would expect given the tropospheric forcing right now and lagged impacts 12-21 days. It also underlines the operational GFS' propensity for rushing stratospheric responses.

A couple of things to consider where we might go from here.

The atmosphere is starting to take on a well defined rhythm tied into tropical forcing. A recent flare up of tropical convection in the Indian Ocean has generated a lagged El Nino response. We expect to see a slight waning of El Nino next week as the North Pacific ridge is pushed northwards and the atmosphere becomes more La Nina like for a time. As a result, the lagged stratospheric response will be for a backing off of the Wave 1. We can see this waxing and waning in tendency in relative angular momentum with pulses of westerly (red) and easterly (blue) tendency being fluxed poleward over time.

Thereafter, MJO forecasts are interesting in developing another eastward wave through the Indian Ocean and into the Maritime Continent. That should give the atmosphere another kick and develop a bigger upward trend in angular momentum and further wave 1 and possibly wave 2 forcing during the final third of December and into January.

EC monthly forecast very consistent with this, and should be reflected in the stratosphere during the first week of January. In other words, enjoy the current wave 1 period, but don't be surprised if it doesn't result in a warming event just yet. More focus I would suggest on the forecasts over Christmas week.

Edited December 8, 2015 by Glacier Point

[Recretos]

Here is the member dissection of the 06z GEFS for 10mb 60N zonal mean zonal wind. 

 

 

[Singularity]

Well, there's no mistaking the trend there

It will be interesting if the ECM projection for the MJO comes off. GEFS have basically been nowhere with the MJO lately, from what I've read over the past few days.

[Ruben Amsterdam]

Actually, this is the graph that Recretos made last thursday. By comparing it to the present one, one can only conclude that slowing down (is this English or Dunglish?) of the vortex did not really get in closer range. We need to see warming come into the +240hrs range really to get more excited (I think better charts will come in the EC range the coming days, but that's me being optimistic maybe).

 

[chionomaniac]

9 hours ago, Glacier Point said:

I wonder, do we have a slow burner ? A slow burner that perhaps leads to a more assured route to a warming event in January ?

The pattern as of yesterday and for the next 7 days is within the envelope for generating Wave 1 activity in the upper stratosphere with a deep upper trough centred across the central North Pacific. The atmosphere is also reflecting a strong El Nino passage with relative angular momentum topping +2SD.

Both this morning's EC EPS and GEFS mean at 10 hPa show remarkable consistency on a big North Pacific ridge and slightly displaced upper vortex. We have also operational GFS showing warming at 1hPa, peaking around the 22nd-23rd December. That is much more in line with what we would expect given the tropospheric forcing right now and lagged impacts 12-21 days. It also underlines the operational GFS' propensity for rushing stratospheric responses.

A couple of things to consider where we might go from here.

The atmosphere is starting to take on a well defined rhythm tied into tropical forcing. A recent flare up of tropical convection in the Indian Ocean has generated a lagged El Nino response. We expect to see a slight waning of El Nino next week as the North Pacific ridge is pushed northwards and the atmosphere becomes more La Nina like for a time. As a result, the lagged stratospheric response will be for a backing off of the Wave 1. We can see this waxing and waning in tendency in relative angular momentum with pulses of westerly (red) and easterly (blue) tendency being fluxed poleward over time.

Thereafter, MJO forecasts are interesting in developing another eastward wave through the Indian Ocean and into the Maritime Continent. That should give the atmosphere another kick and develop a bigger upward trend in angular momentum and further wave 1 and possibly wave 2 forcing during the final third of December and into January.

EC monthly forecast very consistent with this, and should be reflected in the stratosphere during the first week of January. In other words, enjoy the current wave 1 period, but don't be surprised if it doesn't result in a warming event just yet. More focus I would suggest on the forecasts over Christmas week.

Thanks for your thoughts Stewart.

I've always thought that we are onto a slow burner and the wave 1 displacement forecast for December will be our 25 day precursor to a stronger event in January. The question remains about how strong the wave 1 will be, but I am rather hoping that it will be strong enough to end the current VI state. The GFS propensity for rushing strat evolutions has been highlighted by Recretos two ensemble comparisons that look similar even though 5 days apart.

 

I am still hoping that we will see significant enough wave 1 activity around Christmas so that the expected full stratospheric response can be felt in January. Perhaps another surge in the angular momentum will be just what we need.