Stratosphere Temperature Watch 2015/2016

[NoTraction]

Hello peeps! Im no expert, infact the polar opposite, lol, but as far as im aware a technical SSW is reversal winds at 10hpa/30hpa for the majoraty of the northern hemisphere. which means at a specific hight if you average the total wind direction/speed at 60n  the result is reverse to the norm. looking at the gfs 18z and nothing else, this surely reaches SSW status in FI convincingly for the first time that i have noticed (not every run observed, but always daily) based purely on the size of the secondary warming compared to the size/location of the PV the northen hemisphere has a larger area of warming over the pole with the pv shunted and squashed to lower latitudes!

it may not follow the script but is really taking abuse!

[Singularity]

9 hours ago, Cloud 10 said:

18z a bit "hotter" than yesterday's run for the same time.

today..yesterday..

 

 

 

Retained by the 00z. It seems (to me) that initial overestimation by the long-range is now being countered at the mid-range by upgrades to the amplification signal from the tropical Pacific, this enhancing the magnitude of the wave break from the MT event. 

Longer-term, with the usual caveats of course, GFS continues to entertain the idea that while a lot of the anomalously high temperatures become caught up in the stratospheric ridge across the Pacific, some of it does manage to ride into the vortex - or something like that, causing a dramatic rise in the minimum temps associated with it:

 

There's no split at that level, though. Weirdly there is one at 30 hPa and it leaves the bigger of the offspring near Greenland, which is not helpful - but also a marked departure from the previous few runs which had a displacement similar to what's going on at 10 hPa.

Anyway, it seems a split would be a risky game to play unless we saw more of a Pacific-Atlantic alignment to the stretch beforehand. If the warming in 8-10 days time could upgrade further, it might help in that regard. 

[Nouska]

11 hours ago, s4lancia said:

The one I have been watching is 1983. Some striking similarities.

It shared a very similar ENSO and QBO base state to 15/16 and we experienced increasingly strong zonal winds with wave activity through January 83 putting severe pressure on the vortex (aka Jan 16) before we started to see the consequences not long after in early Feb...

 It may seem a mile off from most FI charts of present but personally I think it won't be long before charts like this start showing up and eventually verifying. 

I wonder what the forcing was for that turn of fortunes - no SSW listed and having checked the MJO archive, a very typical Nino-esque low amplitude dalliance near neutral.

Historic model run, starting mid January.

http://www.meteociel.com/modeles/archives/archives.php?day=15&month=1&hour=0&year=1983&map=4&mode=2

Edited January 27, 2016 by Nouska

[Dennis]

Wow all warming - what you think ?

[Norway Nut]

http://ds.data.jma.go.jp/gmd/tcc/tcc/products/clisys/STRAT/index.html

 

This shows ( hopefully!) that the strat temp is not following the normal path of returning to a less negative temp. if you click on southern hemisphere, you will notice that the southern strat temp hasn't yet started to decline to its winter temp. To me, this suggests that the northern BDC has stopped and all the ozone is being transported south to Antarctica. My question to you learned folk is - What is the ramifications  if the strat temps stay as they are for the next 10 months or so ( as if they will) ?

 

[SnowManClan]

Hey guys,

Some weeks ago I found an article with plots of northern hemisphere stratospheric temperature deviation from normal during winter time (think it was Dec-Mar) through history. Think it was about 1980 to present.

Cant seem to find it again, any help? : )

[Lewisian Lass]

I have been watching the GFS really closely the past 5 or so days. it is sticking to its guns about that SSW around the 5th of Feb +220hrs onwards. I know it is still way off, but the GFS seems to be great at picking up events, they then disappear and then come back again, such as some of the deep lows that have bombarded our shorelines.I  have a feeling it is onto something.

 

[chionomaniac]

18 minutes ago, Lewisian Lass said:

I have been watching the GFS really closely the past 5 or so days. it is sticking to its guns about that SSW around the 5th of Feb +220hrs onwards. I know it is still way off, but the GFS seems to be great at picking up events, they then disappear and then come back again, such as some of the deep lows that have bombarded our shorelines.I  have a feeling it is onto something.

 

No SSW ( using the technical major warming description here) has been forecast yet and as much as the warming around day 10 is quite large, it is not strong enough to reverse the mean zonal flow at 60ºN and 10hPA - with u wind staying above 20m/s at this point. The forecast displacement may have some trop affect with the vortex positioning, and with possible MJO and GWO alignment at the same time,  forecasts like the ECM op have a good chance of occurring. But I would say that this is primarily trop induced with a little help from the strat. 

The vortex at 10hPa will still be ripe for further 'attack' but the GFS has suggested that the vortex will quite possibly regain strength.

I know that Judah Cohen has been tweeting that he considers a SSW to be on the cards - but not by the definition that currently exists for a major one in my book, so caution should be used when reading these tweets.

(Amy Butler has suggested via twitter that the summer meeting of SPARC will reconsider the SSW definition question further)

[NorthYorksWeather]

Thanks for the update @chionomaniac. 

I follow this thread and the conversations on twitter but unfortunately have little understandings on the meanings and implications of the warmings/displacements etc and do find it quite confusing when trying to learn when some are touting this is a major SSW event. I feel like unless the likes of yourself, Tony and Andrej get excited then I won't be getting excited myself. Hopefully thought as you suggest we will still see some positive trop affect. 

[damianslaw]

This continues to be a good thread to read - interesting to note possible comparisons with Fe 83 which incidentally didn't see a SSW effect, yet we saw a cold month with northerlies in full ascendancy. A change to cold conditions isn't reliant on a SSW, much as some seem to think is what is needed - it certainly helps and stacks things in a more favourable state, but its not needed as such.

[Duane S.]

11 hours ago, Nouska said:

I wonder what the forcing was for that turn of fortunes - no SSW listed and having checked the MJO archive, a very typical Nino-esque low amplitude dalliance near neutral.

Historic model run, starting mid January.

http://www.meteociel.com/modeles/archives/archives.php?day=15&month=1&hour=0&year=1983&map=4&mode=2

I would say the MJO may possibly have played a bit part? Even though the amplitude was no great shakes, any atmospheric coupling present (I may be wrong but I thought this is more likely mid-tail end of winter in a Nino) could have been the catalyst for the Mid Atlantic ridge with the MJO coming out of the Pacific and into phase 8. 

My hunch would be though that it must have been aided by the very strong upper-strat wave2 spike that occurred at the end of Jan. This following on from a good period of persistent wave1 activity that would have ground down the previously raging vortex. Maybe it was a case that the timing was perfect with MJO as well? 

MJO aside, this seems to tie in quite nicely to where we are now with renewed and strong wave1 already underway and signs afoot that a wave2 attack may be on the cards as we head into early Feb. 

[Interitus]

On 1/26/2016 at 9:02 PM, damianslaw said:

No coincidence that winter 88/89 was one of the mildest on record... April 1989 was unusually cold mind. Did we have  SSW in Feb 98? this winter has shown similiarities with 97/98 which was also very mild with unusual warmth.. things cooled in March and we had a rather chilly April..

 

At face value 97/98 like this year was a strong El Nino, but stratosphere wise 97/8 was quite different and there was no SSW in Feb 98. After a strong early season in October and first half of November a series of warmings nearly caused technical SSW on 7th January, down to 2 m/s from which the vortex never properly recovered. The maximum 10mb 60°N speed of the whole season was on November 30th at just under 47m/s while the average from December 1st to today 28th January was 21.7 m/s.

Contrast with 1988/9 where the winter average to 28th Jan of 54 m/s was higher than the 97/98 max, and the second strongest to this point almost identical to 1980/81. This year is 3rd to this point just a little less on about 53.7 m/s so a similar strat, but here's a thing, 1988/9 was a strong La Nina.

[David Morse]

On 26/01/2016 at 5:48 PM, bluearmy said:

that displacement isn't great for nw Europe unless it manages to force the jet far enough south to leave us under the extended broad vortex (v unlikely)

more probable is that the warming continues to push the vortex around broadly to the position it occupies around T240 but with the main warming on the Canadian side

then we have to hope that the Canadian vortex is less well positioned to keep the PFJ flat across the atlantic and that a mid atlantic ridge can form.

all the above assumes a trop/strat coupling which, whilst absent in early January, seems to be establishing thanks to the strong upsurge in zonal flow downwelling at the moment

 

 

 

Hi @bluearmy I'm sure that the location and position of the displacement is not reflected directly in the trop? That the effects are transmitted down and in the chaos the eventual outcome in 6 to 12 days after is not possible to model, particularly on how it will exactly effect the jet or the location of pressure cells? And as snow conditions over Ireland and The UK are always so marginal its impossible in my view to say that this is a bad set up or a good one!

Can you point to any examples which show the position(s) of a wave1 SSW event and how it always transmits into the trop? 

If I follow the same logic you're employing, surely this set up would deflect the jet far south over North America and accelerate it north easterly over Iberia?

[Singularity]

As far as I understand it, the circulation at base of the stratospheric vortex - at the tropopause - drives zonal motion in the troposphere along its flanks, but with the more mixed and chaotic nature of the atmosphere resulting in less regular circulation patterns especially near the Earth's surface, which are sometimes heavily distorted by strong WAA events or blocking highs. There is also modification by forcing from the surface or troposphere (e.g. extensive areas of snow cover or modes of tropical convection). Often though, the surface weather will keep trending back toward westerlies in the region below the base of the periphery of the stratospheric vortex.

So there is truth in the notion that we'd like to see the vortex displaced as far from the pole as possible if it is to be in our sector of the hemisphere, as this would encourage the westerly winds - such as the jet stream - to move south. Weakening also helps, as you have less of a drive toward zonal momentum even when the periphery of the strat. vortex is overhead.

 

The way that warm anomalies associated with displacement events in the stratosphere propagate down is one of the main limitations to using changes in that layer to produce long-range projections for surface weather patterns; the models struggle to capture the extent of that propagation and how well it is able to move the vortex about. The vertical path also seems to display some uncertainty, this affecting the orientation of vortex displacement.

Vortex splitting events are arguably a different beast entirely. You pretty much know the vortex remnants will be send well away from the pole, with high latitude blocking dominating the polar region, and it becomes more a question of where exactly those remnants end up.

 

This is my take on things, mostly based on observations of model behaviour and actual outcomes. Research does come into it, but I'm not yet finished in that respect - which means I must add the caveat that I might not yet have it all right. If anyone reading this has spotted a misinterpretation, I hope that you will enlighten me 

[Vorticity0123]

The ongoing stratospheric polar vortex displacement is not only seen in the charts. In fact, one of the possible consequences is that polar stratospheric clouds will form over Europe, especially Scandinavia! For these to form temperatures at about 25 km need to be below -80*C. And this appears to be going to happen.

10 hPa (about 25 km) geopotential heights and temperatures (colours) for today 12 UTC. Courtesy: FU Berlin.

As can be seen here, in a region ecompassing the east of the UK and the northern parts of the Netherlands, temperatures are below -80*C, which might result in polar stratospheric clouds becoming visible just after sunset (so a few hours ago by now).

And this is - if they are visible- how they should look like. It would be pretty amazing to see them in this way in real life!

A beautiful example of a polar stratospheric cloud. Courtesy: Wikipedia.

 

 

Edited January 28, 2016 by Vorticity0123
Updated to remove unwanted emoticon

[David Morse]

2 hours ago, Vorticity0123 said:

As can be seen here, in a region ecompassing the east of the UK and the northern parts of the Netherlands, temperatures are below -80*C, which might result in polar stratospheric clouds becoming visible just after sunset (so around now ).

I've seen Noctilucent clouds in Dublin, but on in the summer; similar but perhaps not as colourful?

[Methuselah]

I remember seeing nacreous cloud, in Fife, sometime around the Millennium. What a beautiful sight - everyone was outside enjoying the spectacle!

Edited January 28, 2016 by Ed Stone

[knocker]

https://twitter.com/MJVentrice

The stratosphere to light on fire! (Not really) but HUGE displacement event likely in the medium range forecast.

[Weather-history]

A

A comparison a week apart for the same time frame

 

Edited January 29, 2016 by Weather-history
try again

[JeffC]

Morning Good People!

Not claiming any specific knowledge of things stratospheric, but I always take a look at this when warming is mentioned.

http://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-4.14,93.90,292/loc=158.140,77.927

By playing with different pressures and clicking, temp differences at 10 hpa are shown quite graphically...

Well...I like it!

Edited January 29, 2016 by JeffC
kindle spell check didn't like hpa!

[Duane S.]

The epv forecast at day10 is quite something. If it could verify and be followed by a bit more of the same, preferably slightly more polewards heading, the FI chart outputs could suddenly start becoming full of HLB promise I would imagine

[Allseasons-Si]

And........

we have lift off

 

30hpa10hpa

 

[mountain shadow]

1 minute ago, Allseasons-si said:

And........

we have lift off

 

30hpa10hpa

 

That looks like a pretty sudden warming to me. FINALLY.

[phil nw.]

12 minutes ago, Allseasons-si said:

And........

we have lift off

 

30hpa10hpa

 

Probably that rise coincides with vortex displacement away from the pole rather than a SSW.

[Faronstream]

On ‎2016‎-‎01‎-‎23 at 5:48 PM, KyleHenry said:

Although not as strong as initial.

The ECMWF supports GEFS on this forecast. GEFS forecast double phase approximately 7 days ago which at the time appeared to be an error.