Stratosphere Temperature Watch 2015/2016

[Singularity]

8 minutes ago, SN0WM4N said:

Seeing as warmings work clockwise I would think that if it has enough umpf after the GL > Scandi > GL would it then push itself back to the Scandi locale?

 

That's what GFS keeps trying to do, though it seems a little slower with each new run. The model may be jumping the gun a bit with the second effort.

[Nick F]

Yesterday's EC strat charts on Berlin site showing a reversal in the zonal winds at 1hPa, 10hPa and 30 hPa - though remains to be seen if it will be sustained:

Clear displacement of the strat PV from wave 1

Remains to be seen how the trop behaves to this shift in the strat vortex, a look at the 150hPa level sees a dipolar vortex, with a centre over Greenland and centre over central Siberia at 24hrs, the Greenland centre shifting to Svalbard by 240hrs an becoming the dominant centre while other centre shifts east across eastern Siberia.

There does appear to be a similar response in the trop with regards to the trop PV shifting from Greenland to Svalbard

Can't see a SSW yet, but certainly a stratospheric warming taking place.

[chionomaniac]

The problem with displacements is that unless we see a full stratospheric destruction of the PV then we are unlikely to benefit from the slight stratospheric upheaval at the top of the strat. All signs with this displacement at this point are that it will not create a SSW and certainly not a vortex destroying one, and any propagation down to the trop of the displacement is looking stilted to say the least. We are still seeing tropospherically the increased strength vortex that occurs before the displacement, and it may take some time before this washes out of the system. I think the winter will need some tropospheric (GWO) feedback systems in place in the meantime and there is no sign of that help for a little while too! Those relying on the strat to save this winter may be disappointed, as, even if we still get a SSW and even if it does eventually propagate, it is still very uncertain that blocking would appear in the correct place. That was the fear before winter started and it still remains.

 

There, now I have said what I have been thinking for a while, hopefully I will be proved totally wrong!

[Abyss]

So to summarise no chance of a SSW then Chio. Confused thought it was likely reading posts from a couple of days ago. Oh well

[Nouska]

The two super Ninos of the known archive did not see a SSW but the three classified under the strong category all did - in February. Is there a tale therein that we don't know the reason for as yet?

I don't see a solar signal - 1958 was a very strong max. Suggestions that the anomalous warmth across the tropical basins may be a reason - don't see  that either - the IOBW was even warmer than now in late 1972. QBO was west in both the super category events but also west in 1958 - does west at solar max have an influence?

There may still be a technical SSW in February but the failure of the modelling, so far, to progress the strong warming through time steps is not leading to any confidence.

Whatever the rest of winter brings, it has already provided a number of extremes that will be the subject of research and maybe even some revisions of previous theories.

Sources.

http://ggweather.com/enso/oni.htm

http://ds.data.jma.go.jp/tcc/tcc/products/elnino/index/sstindex/sliding_30year_period/IOBW/deviation

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html

[karyo]

I have to say, when I read Ian Pennell's 27th December 2015 post on the seasonal forecast thread I felt quite disheartened and it appears that it is likely he will be proved right once more.

He said: for Sudden Stratospheric Warming (SST) to occur over the high-arctic there needs to be some predisposition towards weaker mid-latitude jet-streams that will allow upper ridges of warm air to buckle far to the north and most such SSTs it seems there is a pre-requisite for strong upper westerlies to impact hard on the Himalayas or high Pamirs of central southern Asia so that the fast-flowing air is forced upwards over great heights leading to ridges extending north over Siberia and into the Arctic.  Currently the Cuircumpolar Vortex is blowing too strongly and too far north for these developments to unfold.

The gfs has settled in the idea of a less pronounced second warming (less compared to the forecast of a few days ago).

Edited January 25, 2016 by karyo

[Chris1986]

I can't see the vortex taking this much of a beating and not going pop. I think by the time we get to the squeeze on the vortex things may be a little more interesting... Hopefully.

[Singularity]

As wary as I am of taking such long-range GFS output at face value, it has at least been very consistent with the idea of a wave 1 attack that's stronger than the one we're seeing as we begin Feb, and moves toward the U.S. in very similar fashion. A few runs have toyed with splitting the vortex and having the daughter vortex end up in the vicinity of Newfoundland, but from a wave 1 a stretch in that direction seems more likely to be as far as it goes.

As opposed to a technical SSW, it may be worth looking at the progression of that warming across the U.S. as a target to hope that we land on. Certainly it would play nicely with a stable high AAM orbit, assuming that is achieved.

 

I do have a feeling it will get a whole lot colder just when some people would rather it warmed up and we got on with spring! If it proves exceptional enough to produce lying snow in the far south (big ask), I'll love it. Otherwise, I will loath it. Man, the stakes are high! 

[Dennis]

10Hpa zonal wind  changes dramaticly .....

[Chris1986]

9 minutes ago, Dennis said:

10Hpa zonal wind  changes dramaticly .....

Definitely something to watch!!  

[Singularity]

35 minutes ago, Dennis said:

10Hpa zonal wind  changes dramaticly .....

Well that's an eyebrow-raiser. Implications for the AO at least (it's still a displacement event).

[Weather-history]

For a layman, like myself, find it all confusing. Here is Dr Cohen saying there is likely to be a SSW in his latest blog

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

 

[bluearmy]

Extended gfs op shows the stretched vortex dumbelling around and likely returning to a decent axis for europe to receive a x polar flow around mid month. now if the strat/trop remains with decent coupling at that stage then could be game on, depending on what is left upstream.

[Duane S.]

This could be one to watch to see if it gathers pace. A wave2 squeeze on the vortex appearing at D10.

[Interitus]

According to the MERRA data, the 60°N 10mb wind speed achieved its 3rd highest value (data since 1979) on 22/01/16 of 75.31 m/s behind 75.65 and 75.35 m/s on 16th and 21st of January 1989.

The good news - these 1989 winds were followed by a split SSW.

The bad news - it was a month later on 21st February.

[bluearmy]

1 hour ago, s4lancia said:

This could be one to watch to see if it gathers pace. A wave2 squeeze on the vortex appearing at D10.

Whenever I have checked ECM day 10 and gfs day 10, they have been pretty close at 10hpa 

no reason to believe that gfs fi that high up isn't giving a decent steer

[Dennis]

30Hpa - some nice pressure on the PV - split possible  

[knocker]

https://twitter.com/MJVentrice

Debatable, but I'm getting more excited about the stratosphere warming.

Edited January 26, 2016 by knocker

[bluearmy]

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

 

 

[feb1991blizzard]

20 minutes ago, 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

 

 

There are hints though in GFS op FI that the vortex displacement to Siberian sector could re-occur after a brief flirtation with the Atlantic, I was wondering about the timing on the 30 day extended met text forecast but perhaps its the repeat pattern that is going to do the semi permanent displacement and with any luck be the beginning of the end of the Strat Vortex for this winter, could be an interesting mid feb - mid march period - just within the timeframe required to keep some level of enthusiasm going on these forums.

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2016012612&var=HGT&lev=10mb&hour=384

 

EDIT : Actually the Vortex never really makes it to the Atlantic which it was progged to do not so long ago, the worst it gets is back over the pole and doesn't look like staying there, I was agreeing with Ed's post the other day that the writing looks on the wall but on reflection I think at least another week of watching is required.

Edited January 26, 2016 by feb1991blizzard

[Snowman.]

1 hour ago, knocker said:

https://twitter.com/MJVentrice

Debatable, but I'm getting more excited about the stratosphere warming.

Thought those where your words knocker was confused for a brief moment.

[damianslaw]

13 hours ago, Interitus said:

According to the MERRA data, the 60°N 10mb wind speed achieved its 3rd highest value (data since 1979) on 22/01/16 of 75.31 m/s behind 75.65 and 75.35 m/s on 16th and 21st of January 1989.

The good news - these 1989 winds were followed by a split SSW.

The bad news - it was a month later on 21st February.

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..

I'm certainly not a fan of cold weather in April, but given how abnormally warm things have been since October - such warmth can't continue and there often tends to be a rapid shift normally when we don't want it in the spring and summer months.. it will be sods law it happens this year and we'll be talking about how conditions were warmer in Jan than during spring and summer!..

Edited January 26, 2016 by damianslaw

[Duane S.]

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. 

[Peter H]

The BBC long range forecast mentioned an SSW event by the second half of February and possible colder conditions.

Nothing on the latest model runs other than brief colder incursions between lows.

[Cloud 10]

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

today..yesterday..