Stratosphere Temperature Watch 2014/2015

[bluearmy]

Well, the warming is still there on the 0z GFS but to me it doesn't look any better than the one we had in November. In fact, it doesn't seem to affect the strength of the vortex even if you look at the last frame (384 hours).

 

So the wait continues.

 

Karyo

 

give it a chance karyo !

[Snowman.]

Well, the warming is still there on the 0z GFS but to me it doesn't look any better than the one we had in November. In fact, it doesn't seem to affect the strength of the vortex even if you look at the last frame (384 hours).

 

So the wait continues.

 

Karyo

 

Anxiety is strong here! Do you ever stop panicking?

 

Patience is needed any a warming is better than none at all and it keeps the vortex on edge ready for the final push.

Edited December 7, 2014 by SN0WM4N

[karyo]

give it a chance karyo !

Are you expecting the forecasted warming to get upgraded? I would think a separate wave/warming would be needed after that.

 

Anxiety is strong here! Do you ever stop panicking?

 

Patience is needed any a warming is better than none at all and it keeps the vortex on edge ready for the final push.

Where is the panic? I just say what I see on the GFS.

[Snowman.]

Are you expecting the forecasted warming to get upgraded? I would think a separate wave/warming would be needed after that.

 

Where is the panic? I just say what I see on the GFS.

 

In a far away time-frame.

 

Specifics are going to chop and change especially when it nears higher resolution. For now just enjoy the fact that these things are showing and have a decent chance of materialising. 

[karyo]

I disagree, we had a downgrade yesterday 0z but a slight recovery on the 6z, then we have had upgrades, don't forget this warming was at 384  on Friday,  the start of it is now around 336 - 350 hours, im not sure what exactly you expected to see by now, im looking at the top of the stratosphere.

Yes, the warming is coming closer which is good but I think we will need to see the beginnings of a stronger event at the end of the run.

[Snowy L]

Are you expecting the forecasted warming to get upgraded? I would think a separate wave/warming would be needed after that.

 

With the Aleutian low going nowhere these next few weeks (thanks to El Nino) and heights over NW Eurasia there is no reason why we won't see multiple warmings over the next few weeks.

[bluearmy]

06z keeps the theme going.

[Duane S.]

Look at the 10hPa charts and look for mean zonal wind (u wind) reversal.

 

Or look at the fluxes chart on the Berlin site and watch for the blue line (10hPa u wind) be forecast to be below zero as demonstrated here 

 

 

fluxes.gif

 

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/ts.php?plot=fluxes&alert=1&lng=eng

 

This is what the early Jan 2013 SSW looked like on the fluxes chart.

 

fluxes-1.gif

Hi Chiono, is there an archive of these completed annual Berlin plots? Interesting on the 12/13, at the top of the Strat, u winds increasing prior to the sharp decrease and eventual reversal. We could be seeing similar starting to occur here, especially if that warming ramps up and comes to fruition in a couple of weeks.

[chionomaniac]

06z keeps the theme going.

Not only keeps the theme going but brings it forward at 10hPa and is the best yet at 1hPa. There is a lot of strat modeling to be completed in the next few weeks but some sort of strat disruption is likely around the turn of the year.

 

At 10hPa at T+312

 

 

 

At 1hPa renewed surge at T+384

 

 

Having tracked a few of these warmings now in the last few years anything above 20ºC at 1hPa is in SSW territory IF, and a big IF, the warming continues on this theme AND propagates downwards effectively.

 

In the first post on 11th Oct, I conjectured that we have an 80% chance of an SSW this year with the peak time around early January and I see no reason to change these thoughts. In fact, the FI forecast warming even though subject to a lot of change, reinforce these thoughts.

 

Keep the faith....

[nick sussex]

Andrew just itching to play with his new toys and a forecast SSW!

In the meantime, gfs currently consistent high up with the end week 2 warming and ECM at day 10 looks similar to gfs as the higher temps begin to show over Europe on their way to Asia. I wonder if we can expect to see some WSI tweets of the ECM ens strat picture later next week! Let's hope so.

the zonal flow strengthening in the meantime. if the upper zonal flow is strong immediately prior to a significant warming (note that is not necessarily a SSW), does that inhibit downwelling or exacerbate it ? Is it a case of 'the bigger they are?' I know that a reversal is often preceded by a flushing down of the zonal flow but that's usually nearer the time. what we see over the next fortnight is not that flushing down. Andrew - you referred to the strat Pv as being without any strong core compared to last year. Does the current data for two weeks hence show the same? your astonishing 3D representation yesterday seems to show a pretty big creature high up but I'm not convinced it looked too strong as a cross section.

BA I did look into this some time ago sadly though the research link met a bitter end as my last laptop imploded and with it the saved research. But from what I can remember is that the downwelling response is greater depending on the state of the AO at the time. In nutshell there was a greater response when the SSW took place ahead of a positive AO, the response became more muted as you went towards a negative AO.

 

I think this sort of makes sense as I'd view it as more explosive when in the positive AO phase as the pressure that's built up is likely to cause a bigger explosion post SSW, if you know what I mean!

[Severe Siberian icy blast]

BA I did look into this some time ago sadly though the research link met a bitter end as my last laptop imploded and with it the saved research. But from what I can remember is that the downwelling response is greater depending on the state of the AO at the time. In nutshell there was a greater response when the SSW took place ahead of a positive AO, the response became more muted as you went towards a negative AO.

I think this sort of makes sense as I'd view it as more explosive when in the positive AO phase as the pressure that's built up is likely to cause a bigger explosion post SSW, if you know what I mean!

Yes Iv read this aswell , If you get a compact vortex. With the AO in posit e territory , then a SSW as they are very dramatic with a sudden burst of heat in the middle of the vortex , it acts like a trigger bomb and can blow the vortex up , with fragments of the pv flying out and very difficult to predict where they land . Very similar to a bomb going off really .

Where's as if you get an already disorganised vortex , with warm high pressure cells in place in the artic , then a SSW will have much less of an impact , with warmer air already in place , there's less to blow up as it were .

Put a bomb in the middle of the city and watch it cause devestaion . Put a bomb in a field with nothing round it , much less of an impact will be evident !

Edited December 7, 2014 by Severe Siberian icy blast

[bluearmy]

BA I did look into this some time ago sadly though the research link met a bitter end as my last laptop imploded and with it the saved research. But from what I can remember is that the downwelling response is greater depending on the state of the AO at the time. In nutshell there was a greater response when the SSW took place ahead of a positive AO, the response became more muted as you went towards a negative AO.

 

I think this sort of makes sense as I'd view it as more explosive when in the positive AO phase as the pressure that's built up is likely to cause a bigger explosion post SSW, if you know what I mean!

My thoughts aswell nick. The careful side of me would prefer the -AO scenario as I expect any SSW would reinforce and deepen the existing pattern. The 'explosive' scenario would be fun but knowing our luck, a chunk of the Pv would end up in the Greenland/e Canada region as happened a few years ago and we would retain a +NAO keeping nw Europe on the 'warm side'.

[nick sussex]

Yes Iv read this aswell , If you get a compact vortex. With the AO in posit e territory , then a SSW as they are very dramatic with a sudden burst of heat in the middle of the vortex , it acts like a trigger bomb and can blow the vortex up , with fragments of the pv flying out and very difficult to predict where they land . Very similar to a bomb going off really .

It's a bit frustrating that I can't find the link to that research, I remember at the time it wasn't easy to find on the net. The link was pretty conclusive between the state of the AO and response.

 

I think its  logical as a SSW would have little energy to work with if the PV was already subdued and we were in a negative phase of the AO.

[nick sussex]

My thoughts aswell nick. The careful side of me would prefer the -AO scenario as I expect any SSW would reinforce and deepen the existing pattern. The 'explosive' scenario would be fun but knowing our luck, a chunk of the Pv would end up in the Greenland/e Canada region as happened a few years ago and we would retain a +NAO keeping nw Europe on the 'warm side'.

I totally agree with your post because you are trusting to luck with those chunks of the PV and the UK has often been unlucky in that regard. It would be great to see that SSW just cementing an already cold pattern.

[Severe Siberian icy blast]

My thoughts aswell nick. The careful side of me would prefer the -AO scenario as I expect any SSW would reinforce and deepen the existing pattern. The 'explosive' scenario would be fun but knowing our luck, a chunk of the Pv would end up in the Greenland/e Canada region as happened a few years ago and we would retain a +NAO keeping nw Europe on the 'warm side'.

I no it would be frustrating , the same happened in 2013 , with a segment left over Greenland , but as I remember once we can detach the low off the weak segment over Greenland then it has no fuel and simply runs out in the Atlantic , given the -QBO then you would think once we get into jan , the vortex weakens with seasonal movements , so even with weak high pressure cells AKA jan 2013 then it shouldn't be too difficult to have some fun ! Famous last words there !

[Weather-history]

My thoughts aswell nick. The careful side of me would prefer the -AO scenario as I expect any SSW would reinforce and deepen the existing pattern. The 'explosive' scenario would be fun but knowing our luck, a chunk of the Pv would end up in the Greenland/e Canada region as happened a few years ago and we would retain a +NAO keeping nw Europe on the 'warm side'.

I asked a question a year or two back, can a SSW/MWW knock the UK out of an existing a cold pattern?

I'm thinking of the first half of winter 1976-77 which was cold, a SSW event occurred in second week of January, it may have aided a cold outbreak for the UK, mid January but the second half of the winter was mild.

[nick sussex]

I asked a question a year or two back, can a SSW/MWW knock the UK out of an existing a cold pattern?

I'm thinking of the first half of winter 1976-77 which was cold, a SSW event occurred in second week of January, it may have aided a cold outbreak for the UK, mid January but the second half of the winter was mild.

Great question, I wonder if perhaps that SSW causes the PV chunks to move and so re-arranges the HLB pattern in the NH, so before say for example the PV was favourably located for cold into the UK and that SSW dislodged the PV to a different location which was less favourable.

 

The initial reversal of the zonal winds my have been that help for that cold spell but then once the full response occurred it shuffled the pack in a negative way for the UK.

[Interitus]

I asked a question a year or two back, can a SSW/MWW knock the UK out of an existing a cold pattern?

I'm thinking of the first half of winter 1976-77 which was cold, a SSW event occurred in second week of January, it may have aided a cold outbreak for the UK, mid January but the second half of the winter was mild.

 

I have posted regarding this possibility previously and there are a few good examples particularly concerning some of the supposed analogue years which are reeled out repeatedly.

 

1962-3 - the SSW was quite late in season on 11/02/63 with most of the cold already passed by the time any effects were felt, it is almost as though the SSW jilted the circulation away from the extreme set up that it was in previously and presaged the return to more normal conditions.

 

1978-9 - the SSW was near the end of February, around 22nd-27th. After an initial warming, this was followed by cold weather throughout March and into April, 15-45 day anomaly of -2.48. But this was relatively much warmer than the bitter spell that left a January CET of -0.37°C, over 4 degrees below normal.

 

1981-2 - the SSW of 27th January 1982 pretty much reversed the extreme conditions triggered by the earlier SSW on 4th December 1981.

 

1986-7 - SSW was between 23-26 of January and followed by prolonged cold weather with 15-45 day anomaly of -1.07°C but this was over 3 degrees warmer than the very cold spell beforehand.

 

2009-10 - the coldest weather occurred prior to the SSW on 09/02/2010 which was followed by a mild March.

 

Interesting ECMWF forecast charts from Berlin. If the latest from 06/12 is correct with the 60°N 10mb wind for 16/12 of 48.1 m/s then the earliest there has been an SSW from this strength in the MERRA dataset is 8 days in the case of the extreme 2009 reversal ~ so 24th December. Remove the 2009 outlier and the earliest is 16 days - Jan 2nd - and the 3rd highest is 22 days - Jan 8th.

[johnholmes]

I have posted regarding this possibility previously and there are a few good examples particularly concerning some of the supposed analogue years which are reeled out repeatedly.

 

1962-3 - the SSW was quite late in season on 11/02/63 with most of the cold already passed by the time any effects were felt, it is almost as though the SSW jilted the circulation away from the extreme set up that it was in previously and presaged the return to more normal conditions.

 

1978-9 - the SSW was near the end of February, around 22nd-27th. After an initial warming, this was followed by cold weather throughout March and into April, 15-45 day anomaly of -2.48. But this was relatively much warmer than the bitter spell that left a January CET of -0.37°C, over 4 degrees below normal.

 

1981-2 - the SSW of 27th January 1982 pretty much reversed the extreme conditions triggered by the earlier SSW on 4th December 1981.

 

1986-7 - SSW was between 23-26 of January and followed by prolonged cold weather with 15-45 day anomaly of -1.07°C but this was over 3 degrees warmer than the very cold spell beforehand.

 

2009-10 - the coldest weather occurred prior to the SSW on 09/02/2010 which was followed by a mild March.

 

Interesting ECMWF forecast charts from Berlin. If the latest from 06/12 is correct with the 60°N 10mb wind for 16/12 of 48.1 m/s then the earliest there has been an SSW from this strength in the MERRA dataset is 8 days in the case of the extreme 2009 reversal ~ so 24th December. Remove the 2009 outlier and the earliest is 16 days - Jan 2nd - and the 3rd highest is 22 days - Jan 8th.

 

a very interesting post that, food for thought I suppose. Most of I suspect with no great understanding of the main factors have, if you are like me, never really thought of it seeming to reverse already present cold. Maybe if I tried to read in a bit more depth it should be fairly obvious perhaps? What do our experts think about this post from Interitus please?

sorry I copied the whole post, but it is well worth reading in my view.

Edited December 7, 2014 by johnholmes

[Bristawl Si]

That's a really interesting post by Interitus.

All those severe winters or severe spells within the winter occured with no SSW beforehand.

[Nouska]

That's a really interesting post by Interitus.

All those severe winters or severe spells within the winter occured with no SSW beforehand.

 

I think we need to look at the post, from Interitus, in conjunction with the polar strat diagnostic archive.

 

The first three examples had an early winter Canadian warming so it is probable that would have the initial effect of disturbing/displacing the vortex to favourable positioning for our neck of the woods.

 

[Cloud 10]

Nice upgrade on the FI warming from the GFS 12z,and i would think higher up will be looking very toasty.

 

[radiohead]

Nice upgrade on the FI warming from the GFS 12z,and i would think higher up will be looking very toasty.

 

gfsnh-10-384.png

 

Indeed.

 

[ITSY]

looks significant on those two frames just posted. Clearly a long way to go but steps in the right direction to get the strat playing ball. Question is what if any impact will that have and when, and whether the trop can get into gear if it doesn't materialise. Neither of those things anyone can answer so here's hoping

[Snowman.]

looks significant on those two frames just posted. Clearly a long way to go but steps in the right direction to get the strat playing ball. Question is what if any impact will that have and when, and whether the trop can get into gear if it doesn't materialise. Neither of those things anyone can answer so here's hoping

 

The trop seems to be working it's way into gear anyway.

 

The strat is forecast to move it's way over to siberia which would slow down the atlantic and possibly promote ridging in the atlantic, however this is due to how amplified we get.

Edited December 7, 2014 by SN0WM4N