Stratosphere Temperature Watch 2012/2013

[MattH]

Didn't want to clog this thread up, so find attached link to some info on EC32 and general thoughts...What a difference a week makes!

M.

[chionomaniac]

Didn't want to clog this thread up, so find attached link to some info on EC32 and general thoughts...What a difference a week makes!

http://forum.netweat...40#entry2442820

M.

Thanks for the update, Matt.

I think that we will have to 'do a bit of time' with the trough situated across the UK after this cold spell is brought to an end. It is very frusttrating to see a cut off trough from the rest of the polar vortex - but with not enough forcing to squeeze in enough northern blocking above. Interestingly, this does to some extent fit in with recent MJO forecasts which increase amplitude and hover between phases 1 and 2.

This also fits in with the translocation of the stratospjheric polar vortex between Canada and Siberia. Originally most of the energy transfer was directed away from the Atlantic - but there is just enough showing in recent forecasts to back up the NWS stance.

However, that leaves me still looking further ahead and I don't trust the long range ECM 32 dayer. The situation in 2-3 weeks could be similar but hopefully tilted more in our favour.

We are now seeing the increase of forecast wave 1 activity that will help push the PV over to Siberia.

This in turn helps reduce the mean zonal winds as forecast here:

and also sets off a chain at 10 hPa which has been shown for a few days now.

This is so far forecast to be a significant warming - will it be enough to destroy the polar vortex?

In the meantime I just don't think that we can rule out pressure rises to the North west once the polar Vortex has relocated to Siberia. The one nagging thing is that the Siberian block is not reducing in intensity enough to allow a trough to drop through Scandi. But this could also come as a double edged sword- because like a snow leopard waiting in wings, it (the Siberian block) will pounce if and when the PV gets destroyed by a SSW?

Edited December 11, 2012 by chionomaniac

[MattH]

Agreed, the EC32 has shifted just like the the other models. The EC32 was persistent in keeping the low pressure that is forecast to be over us further south and west and the northern blocking which is still there clearly was forecast/expected to be dominant to the north or north-east and hence the risk or signal for an E or NE'ly flow, but clearly that's disappeared down the 'pan'.

I'm edgy about all models at the moment, operationally speaking, despite once getting into this cut-off low scenario it becoming almost a semi-permanent feature simply because of the higher pressure at more northern latitudes which is still clearly there and as you highlight that is the most frustrating thing. It's heading unsettled but without being properly zonal.

The consistency within the discussion and charts in this thread regarding the relocation of the main strat vortex is promising and clearly, with time, hopefully it'll produce the goods, but I have a feeling we're going to have to wait some time, but here's hoping for a change the other way just as quickly as the E or NE'ly was taken away from us.

Cheers, Matt.

[chionomaniac]

And again from the GFS 06Z run 10hPa,

This is the best forecast yet, The forecasts are extremely consistent even this far out and the warming is now propagated (forecast) down to the 30 hpa level.

Remember, we need to see the warming intergrate into the core of the vortex to see a major breakdown which will occur some days following this.

I expect to see this to be showing signs on the ECM in 3-4 days time.

It fits in nicely with Judah Cohens articles wrt feedback from the gain of Eurasion snow cover in October - that is why that was so important.

Edited December 11, 2012 by chionomaniac

[kold weather]

Even stronger warming on the 12z GFS this run, and importantly signs of it starting to rotate into the arctic at the very end of the run. Good signs, if nothing else for now.

[chionomaniac]

Even stronger warming on the 12z GFS this run, and importantly signs of it starting to rotate into the arctic at the very end of the run. Good signs, if nothing else for now.

Agreed.

We will need something to knock the jet stream. It seems that the PFJ and STJ have joined forces. Great, they are south of the UK, but we have absolutely no amplification in the current pattern to change the weak ridging above the UK and the Siberian block. I think that we will need an amplification and movement of the MJO to get the ball rolling and disturb that jet.

[Weather-history]

The Instant weather maps conveniently show the max and min - in this case it is -11.1

http://i.imgur.com/cIUDn.gif

Latest chart now says it is up to -1.5

At 1mb, it is high as 11.4

[chionomaniac]

Latest chart now says it is up to -1.5

At 1mb, it is high as 11.4

Which when the mean is calculated would lead to an incredible warming. We just don't know the mean from those charts. Will look back to 2009 thread to see if I kept a record of the max temp when I have a chance.

10 hPa temps to compare.

Edited December 11, 2012 by chionomaniac

[Isolated Frost]

A lot of (annoying) talk belittling the effects of the stratosphere and further teleconnections- purely because persistent and long-lasting cold isn't affecting all parts of the UK.

Not only is the warming events prior to now and the GWO signal merely a precursor to the upcoming event- but the extent of northern blocking has been pretty incredible so far.

I think that it's pretty cold and we should all look at the wider picture !

[Panayiotis]

Is the stratosphere cold enough in this image for the UK to see Nacreous clouds?

http://forum.netweather.tv/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=148467

Edited December 11, 2012 by panayiotis

[Great Plum]

The GFS seems to show the pv setting up shop over Greenland in deep FI... (To my untrained eye at least...) is this baloney or is the pv not expected to take a holiday to deepest Siberia now?

[chionomaniac]

Latest run 18Z

max temp 4.1ºC at 10 hPa.

[Tim Bland]

Come on GP throw us a bone here! Do you still expect northern blocking to take hold?

[chionomaniac]

The GFS seems to show the pv setting up shop over Greenland in deep FI... (To my untrained eye at least...) is this baloney or is the pv not expected to take a holiday to deepest Siberia now?

FI forecasts for lower strat suggest main vortex over Siberia with a weaker lobe stretching out towards East Canada. Too early to see where this signal leads.

[TEITS]

FI forecasts for lower strat suggest main vortex over Siberia with a weaker lobe stretching out towards East Canada. Too early to see where this signal leads.

I fear Greenland rather than East Canada at the moment.

Have to be honest im not liking the model output in distant F.I!

[Panayiotis]

The GFS seems to show the pv setting up shop over Greenland in deep FI... (To my untrained eye at least...) is this baloney or is the pv not expected to take a holiday to deepest Siberia now?

The GFS has a tendency of moving the PV to its default location (Greenland) but for all we know it could be right! However as stated above by the more knowledgeable, they are suggesting its going to move to Siberia. Edited December 11, 2012 by panayiotis

[lorenzo]

What polar vortex....

[bradymk]

FI forecasts for lower strat suggest main vortex over Siberia with a weaker lobe stretching out towards East Canada. Too early to see where this signal leads.

Hi Ed, you still thinking a possible northerly around Xmas? I thought this was a plausible outcome but im having second thoughts today. Also, still good consistency for that warming in FI, lets hope it shows on ECM in a few days, i think it will with how consistent GFS has been with it.

[If Wishes made Weather]

What is the expected effect of the vortex warming over the far east? Is the idea that it will reduce winds giving less energy to the jet?

[LomondSnowstorm]

A lot of (annoying) talk belittling the effects of the stratosphere and further teleconnections- purely because persistent and long-lasting cold isn't affecting all parts of the UK.

Not only is the warming events prior to now and the GWO signal merely a precursor to the upcoming event- but the extent of northern blocking has been pretty incredible so far.

I think that it's pretty cold and we should all look at the wider picture !

People are talking of Stewart's forecast being bust because of the lack of a positive height anomaly over Greenland:

And then we have the final ten days, wherever we're going to end up with that, but for the first 20 days it doesn't look like being all that far off. People forget that a positive anomaly over Greenland, even a fairly significant one, doesn't guarantee a full blown Greenland high, and so it has proven once again. Very interesting developments in the stratosphere though for January.

[kold weather]

Man that is some real strong warming at the end of that 18z run, the type that will likely destroy any re-organising PV. There are hints that a PV lobe will set-up shop over Greenland at some point and it does look like it may well strengthen for a time.

BUT if that 18z is even close, then odds are as Chino has been saying, by the New Year the PV is going to be just about ready to bite the dust completely...and probably see an offical SSW with it.

[bluearmy]

The location of the russian block is close to where it sat late nov. as i recall, that drove wave 1 energy for later this month. Given its sitting there again, are we looking at more wave 1 activity early jan just as the warming begins to fire up?

[Recretos]

Here is an animation I made, containing the potential vorticity from 27th November to 10th December, on the 600K theta level, which is roughly around 23km or 30mb. Images are from http://www.pa.op.dlr...tic/index.html.

It shows nice dynamics with the split, and an interesting energy transfer and reformation of the vortex.

And here is an image, that will help you understand the height of the theta levels.

Best regards.

[chionomaniac]

Latest run 00Z

http://nwstatic.co.uk/viewimage.pbx?type=gfs;date=20121212;time=00;ext=384;file=npst10;sess=43c7c4c244e923a48c71bb287b563b13;

[Great Plum]

There are some thoughts in the model thread that the strat has been 'trolling' and the strat pv in FI is relocating to Greenland... That's not what your last image shows though is it C?