Stratosphere watch 2018/19

BLIZZARD7 · 12-12-2018 9:06am

GEFS now has the zonal wind (@65N, 10hpa) dropping below 0 m/s before the end of the month - thats a reversal

Just a comment on the ECM run mentioned above, the GFS para and ECM day 10 charts are not all that far apart...

sryanbruen · 12-12-2018 12:29pm

hatrickpatrick wrote: »

Major upgrade by the FV3 0z tonight, still showing the warming beginning on the 21st / 22nd and for the first time, staying in the red (and even sometimes the dark red!) throughout the entire rest of the run.

Meanwhile, FI pressure charts for the same period show a serious block appearing in the Atlantic and a potential Easterly for Ireland and the UK - presumably this is too soon to be a direct consequence of the forecasted strat warming, but if it were to verify, with the effects of the strat disruption filtering down as we move towards New Years, we could get very lucky with this:

As an aside, now that the beginnings of the warming have moved into the purview of the ECM, does anyone know of anywhere one can look at 10 hpa temperature charts from the ECM? Meteociel doesn't have them and every link I've found only shows current analysis of the start at that level, not a forecast out to 240h as with other ECM charts. Does this exist?

University of Berlin. Simply search up University of Berlin ECM strat and you’ll find each of the forecast charts - also the wind/fluxes chart that I posted in a tweet here.

BLIZZARD7 · 12-12-2018 7:23pm

https://mobile.twitter.com/MJVentrice/status/1072883878300475393

DuOmJ5kXQAARV_t?format=jpg&name=900x900

The red colours on far right of the this representing the warming propagating down towards the Troposphere

sryanbruen · 12-12-2018 9:58pm

https://twitter.com/splillo/status/1072915440920354818

BLIZZARD7 · 13-12-2018 8:50am

Good agreement here still today, mean doesn't show quite as sharp a drop but thats normal variation, a few more extreme gefs members appearing also - as you were all things considered.

sryanbruen · 13-12-2018 5:44pm

https://twitter.com/Met_Set_UK/status/1073257111461789698

Artane2002 · 13-12-2018 7:52pm

GFS Para is really going for an extreme stratospheric warming, up to 12c in the stratosphere!! And it's "only" 11 days away ie. not stuck at the perpetual 16 days.

sryanbruen · 13-12-2018 8:26pm

In further response from the above tweet I posted which is of the UKMO Glosea5 showing this SSW event being similar to that of 2012-13 (which culminated in the coldest March since at least 1962), it goes onto show this stratospheric warming becoming a split at latter dates similar to 2012-13. Here's a GIF of reanalysed charts of how the 2012-13 warming evolved. Note at first it was a displacement before becoming a split and an obliteration of the Polar Vortex.

sryanbruen · 14-12-2018 12:07am

GFS 18z really going IN on the second warming displacing the Polar Vortex further to North America. Still no sign of a split on the model.

Lucreto · 14-12-2018 12:26am

sryanbruen wrote: »

GFS 18z really going IN on the second warming displacing the Polar Vortex further to North America. Still no sign of a split on the model.

If this were to happen would it power up the Jet stream and continue to throw low pressure systems in our general direction?

hatrickpatrick · 14-12-2018 1:11am

The first appearance of the -20 isotherm has now moved up slightly to 7PM on December 20th, as per tonight's FV3 18Z. If this continues, a warming event of some kind will have cleared FI and entered the reliable timeframe in just two days, or specifically by the time Monday night's 18Z and 0z are rolled out.

Whatever the eventual effects of the warming, it's getting very hard to imagine that this could fall apart before clearing FI. FI is always dodgy, yes, but this warming event has been extraordinarily consistent for almost a week, now - and the only changes the FV3 has made over time have been bringing it slightly earlier and intensifying it. The strat isn't my area of weather knowledge, but given the ongoing consistency in both GFS models, I'd be hugely surprised if a warming event didn't take place beginning at some point between the 20th and 22nd of December.

EDIT:

sryanbruen wrote: »

Still no sign of a split on the model.

Obviously you know far more about this than me (or most likely anyone else on this forum), but just looking at the GIF you posted, in the last few frames it looks to me as if the edge of the warm blob is trying to extend directly into the centre of the cold blob - see the "pointy" edge of the boundary between the two, encroaching on the edge of the cold blob - could this be the very beginning stages of an attempted split?

sryanbruen · 14-12-2018 2:16pm

hatrickpatrick wrote: »

Obviously you know far more about this than me (or most likely anyone else on this forum), but just looking at the GIF you posted, in the last few frames it looks to me as if the edge of the warm blob is trying to extend directly into the centre of the cold blob - see the "pointy" edge of the boundary between the two, encroaching on the edge of the cold blob - could this be the very beginning stages of an attempted split?

It's really a case of wait and see. All we know right now is that the UKMO Glosea5 is going for a split. Still no sign on the GFS today so far but it continues to emphasise that second warming displacing the Polar Vortex into North America although not as extreme of a displacement as the 18z was.

ECM starting to come into view.

sryanbruen · 14-12-2018 2:18pm

Lucreto wrote: »

If this were to happen would it power up the Jet stream and continue to throw low pressure systems in our general direction?

Not totally sure if it's as straightforward as that. All we can say is that displacements are the less favourable type to delivering high latitude blocking on our side of the pole.

nacho libre · 14-12-2018 4:13pm

sryanbruen wrote: »

Not totally sure if it's as straightforward as that. All we can say is that displacements are the less favourable type to delivering high latitude blocking on our side of the pole.

Your man over on netweather, GP, does not forsee a split taking place till mid January on wards, this is broadly in line with the glosea model, which seems to have a better handle on these things than the GFS. As regards a displacement lets hope we get lucky and a lobe of vortex does not end up back in Greenland.

Artane2002 · 14-12-2018 6:41pm

Here is the GFS 12z strat warming for 24 December:

It is going for an even more extreme secondary warming, again up to 12c in the strat.

nacho libre · 14-12-2018 7:55pm

Sorry to have to ask this, but how high did the temperature get at that level (10hpa)during the second warming last Feburary?

Artane2002 · 14-12-2018 8:45pm

nacho libre wrote: »

Sorry to have to ask this, but how high did the temperature get at that level (10hpa)during the second warming last Feburary?

I think it got to 0c but I'm sure someone like Sryan can confirm.

EDIT: Just seen you said the second warming, can't answer that with much confidence. From what the archive charts show, it got to -16c but I dunno if that is really what happened.

nacho libre · 14-12-2018 8:53pm

Artane2002 wrote: »

I think it got to 0c but I'm sure someone like Sryan can confirm.

EDIT: Just seen you said the second warming, can't answer that with much confidence. From what the archive charts show, it got to -16c but I dunno if that is really what happened.

Yeah, if i remember correctly, there were two warmings-the second one was even more significant than the first one- in fact without it we might not have gotten the beast from the east.

Artane2002 · 14-12-2018 9:25pm

nacho libre wrote: »

Yeah, if i remember correctly, there were two warmings-the second one was even more significant than the first one- in fact without it we might not have gotten the beast from the east.

I think there may have even been a third warming. If we do get a SSW, then that would be our 4th one in a year!

Artane2002 · 14-12-2018 9:29pm

https://twitter.com/MJVentrice/status/1073674103410831361

Impressive indeed.

Carol25 · 14-12-2018 10:40pm

Artane2002 wrote: »

I think there may have even been a third warming. If we do get a SSW, then that would be our 4th one in a year!

Are we more likely to get SSW during solar minimums?

Artane2002 · 14-12-2018 10:51pm

Carol25 wrote: »

Are we more likely to get SSW during solar minimums?

That is a good question. I am not sure what the answer, I'm not even sure if there's a correlation with SSWs and solar minimum. However, transitioning from easterly QBO to westerly QBO does increase the chances of a SSW, like this season.

BLIZZARD7 · 15-12-2018 9:01am

GFS(P)/FV3 going for a split at the end of 00z - but the Trop charts are bleak across the board this morning though, No sign of any Strat affects on either the ECM or GFS.

Zonal wind forecasts are very good - Destruction of the PV isn't far away-

Expect the Model output for the Troposphere to improve rapidly, I'd be a bit shocked if they don't change to a more blocked outlook in the next few days.

sryanbruen · 15-12-2018 1:50pm

BLIZZARD7 wrote: »

Expect the Model output for the Troposphere to improve rapidly, I'd be a bit shocked if they don't change to a more blocked outlook in the next few days.

I'd have to kinda disagree with you there. I do not expect to see any tropospheric responses on our side of the pole until at least another week and even then, the tropospheric response would appear way into Fantasy Island stages.

Let's look back at February 2018 for comparison sakes. The warming of the stratosphere began to show its hand on the GFS at the end of January. This became a consistent signal on the model with some flips and flops on different runs. As we got closer to the second week of February, both the GFS and ECM started picking up on a subsequent stratospheric warming which would be more intense than the first and split the Polar Vortex into two. It was a similar evolution to that of the early 1985 warming (which funnily enough was at a similar point in the solar cycle to February 2018). The last week of February i.e. the Beast from the East period, started coming into view on the GFS during the end of that second week when the stratosphere had just completed its first warming and going onto the second one (which would reverse the zonal winds a second time). If it were to be similar now, we'd have to wait minimum to Christmas week to see any signs on model output of tropospheric responses.

Keep in mind, one could say we're already seeing some signs of tropospheric responses from analogues and seasonal models such as the UKMO Glosea5 with the second half of Winter really promising for coldies.

Look at my post below I did on 25 January (click onto the original post if you wish to see the charts in the post). Those open two sentences and the closing sentence, god I was such a tease!

sryanbruen wrote: »

The question on our minds at the moment is that will the beast be unleashed in February 2018? When it comes to the bigger picture - i.e. my methodology I use to make my forecasts - it does look pretty compelling.

The significant stratosphere warming (again not a SSW though) is still up for grabs in early February on the GFS runs, see the latest 12z for example below. Even the ECM is showing some warming going on in the stratosphere (though only at 10hPa and not at 30hPa at all).

I will not put any bets (you should never do gambling on weather anyway) on the Beast From the East coming but what I can say is that something is certainly up in the air here.

GFS 06z was another run that showed a split in the Polar Vortex. Let's see this theme continue. The model is showing warming propagating down to 30hPa in the stratosphere now too.

nacho libre · 15-12-2018 3:07pm

the glosea5 strat chart for early January is something special- the vortex is seemingly out for the count.

BE58065F-BB96-45BA-8B77-A13E36BCEEE9.jpeg.ca6d7ca6d2ea0eb45ca1b72e7fba4aa7.jpeg

BE58065F-BB96-45BA-8B77-A13E36BCEEE9.jpeg.ca6d7ca6d2ea0eb45ca1b72e7fba4aa7.jpeg

I think our siberian friend will arrive around around the middle of January. Clonmel1000, no doubt, will have his arms wide open at that point;)

sryanbruen · 15-12-2018 4:20pm

https://twitter.com/MJVentrice/status/1073957385360826368

sryanbruen · 15-12-2018 5:43pm

nacho libre wrote: »

the glosea5 strat chart for early January is something special- the vortex is seemingly out for the count.
I think our siberian friend will arrive around around the middle of January. Clonmel1000, no doubt, will have his arms wide open at that point;)

Where did you get that chart from out of curiosity?

Artane2002 · 15-12-2018 6:06pm

sryanbruen wrote: »

Where did you get that chart from out of curiosity?

Someone tweeted it (Met-Set or something?). Someone on Netweather posted it too.

nacho libre · 15-12-2018 6:09pm

sryanbruen wrote: »

Where did you get that chart from out of curiosity?

It was posted in the Stratosphere thread over on Netweather. The latest UK Met office update is bullish, it must be that their stratosphere experts are confident of a split taking place. In terms of how warm it is projected to get at 10 hpa(assuming it does pan out), how does it compare to the second warming last February?

sryanbruen · 15-12-2018 11:32pm

nacho libre wrote: »

Sorry to have to ask this, but how high did the temperature get at that level (10hpa)during the second warming last Feburary?

It got just above freezing over Canada.

Here's what the stratosphere charts from the JMA looked like over the North Pole at both 10hPa and 30hPa.

Check out actual temperature data here: https://acd-ext.gsfc.nasa.gov/Data_services/met/ann_data.html

sryanbruen · 15-12-2018 11:42pm

GFS 12z OP backtracked on the split being non-existent whilst the parallel just about showed signs of a split at the very end of its run (not getting any closer). We'll see what the 18z has to say shortly.

sryanbruen · 16-12-2018 11:46am

18z showed no split on the OP again whilst the parallel was similar to the 12z.

0z showed no split on the OP and the warming was more intense over the Arctic with the PV getting displaced over Europe. Parallel did show signs of a split at the very end but again not getting any closer to the reliable timeframe so not sure of how serious we can take it.

06z is running at the moment.

hatrickpatrick · 16-12-2018 1:24pm

The -20 degree isotherm, which is marked as a major temperature shift in the charts and thus I'm considering the proper beginning of the warming (correct me if I'm incorrect in doing this?) has finally moved into the reliable timeframe at 120h on the 6z:

gfsnh-10-120.png?6

It's officially game on, folks :cool:

The end of the run seems to be suggestive of a potential split further down the line once again:

Certainly all to play for at this stage, very exciting few weeks ahead!

sryanbruen · 16-12-2018 4:12pm

https://twitter.com/MJVentrice/status/1074320625345413120

https://twitter.com/MetmanJames/status/1074321968948760576

https://twitter.com/DrAHButler/status/1074342805114302464

Artane2002 · 16-12-2018 10:10pm

I know it isn't gonna happen so I won't even bother posting the chart but the JMA yesterday showed the strat temperature reaching a toasty 16c on Christmas Day. That is warmer than some summer days here in Ireland. Today it is showing 12c.

Artane2002 · 16-12-2018 10:40pm

Artane2002 wrote: »

I know it isn't gonna happen so I won't even bother posting the chart but the JMA yesterday showed the strat temperature reaching a toasty 16c on Christmas Day. That is warmer than some summer days here in Ireland. Today it is showing 12c.

Actually that's not as crazy as I thought... apparently the ECM is showing 8c for the same timeframe.

sryanbruen · 17-12-2018 3:23pm

https://twitter.com/SimonLeeWx/status/1074641538125316103

https://twitter.com/jhomenuk/status/1074644762093858816

sryanbruen · 17-12-2018 6:09pm

Excellent signs here!

https://twitter.com/griteater/status/1074712726096789506

sryanbruen · 17-12-2018 8:09pm

No PV split on the GFS 12z parallel now. Operational is still going for displacement and has been the consistent one out of the two. Some positivity is the high levels of heat flux mentioned above that is being signalled by the model at the same time.

hatrickpatrick · 17-12-2018 8:39pm

sryanbruen wrote: »

No PV split on the GFS 12z parallel now. Operational is still going for displacement and has been the consistent one out of the two. Some positivity is the high levels of heat flux mentioned above that is being signalled by the model at the same time.

Last frame of FI, but does this chart from the FV3 signify the beginning of the end for the warming? Or could it reload even if this chart were to verify? Still getting to grips with how to read these

sryanbruen · 17-12-2018 8:41pm

hatrickpatrick wrote: »

Last frame of FI, but does this chart from the FV3 signify the beginning of the end for the warming? Or could it reload even if this chart were to verify? Still getting to grips with how to read these

There is some warmer temperatures just over the med which with the heat flux signalled by the model would likely intensify and cause a split in the Polar Vortex or a subsequent major warming. If there wasn't that heat flux, I would probably say it'd be the end of the warming.

nacho libre · 18-12-2018 3:22am

sryanbruen wrote: »

There is some warmer temperatures just over the med which with the heat flux signalled by the model would likely intensify and cause a split in the Polar Vortex or a subsequent major warming. If there wasn't that heat flux, I would probably say it'd be the end of the warming.

Yes, this is what Stuart Rampling and others have suggested, we will initially get a vortex displacement, but he expects the subsequent warming to finish off(split) the Vortex- though i think he does not foresee a split till Mid January- which would be great for your winter forecast

sryanbruen · 18-12-2018 1:02pm

Amazing amplification of the reversed zonal winds on the GEFS this morning. Getting close to February 2018 standards.

sryanbruen · 18-12-2018 1:07pm

More on the heat flux.

https://twitter.com/simonleewx/status/1074998921414524928?s=21

Really loving these strat signals.

https://twitter.com/jhomenuk/status/1075000633680384005?s=21

sryanbruen · 18-12-2018 3:40pm

The ECM forecast for the 10hPa and 30hPa zonal winds is getting very close to reversal levels.

https://twitter.com/TheSteveCop/status/1075037711231262721

sryanbruen · 18-12-2018 3:55pm

nacho libre wrote: »

Yes, this is what Stuart Rampling and others have suggested, we will initially get a vortex displacement, but he expects the subsequent warming to finish off(split) the Vortex- though i think he does not foresee a split till Mid January- which would be great for your winter forecast

Cohen seems to be along the same lines.

https://twitter.com/judah47/status/1075040398928723968

sryanbruen · 18-12-2018 6:38pm

https://twitter.com/DrAHButler/status/1075064716316344320

hatrickpatrick · 19-12-2018 9:05am

I know I've mentioned this before, but the temperature figure spam on the FV3 is getting seriously out of hand

It only appears for a few frames on the 0z so I'm assuming it's just a glitch, but all the same... Great Jaysus

Regardless, the warming is now forecast to begin within the next three days :cool:

FI continues to show the potential for the beginnings of a split, building from January 1st:

Villain · 19-12-2018 12:09pm

A little change now with winds not quite reversing

Image is live so will update as it changes.

sryanbruen · 19-12-2018 12:24pm

Villain wrote: »

A little change now with winds not quite reversing

Image is live so will update as it changes.

Very strange. ECM 10hPa zonal winds are now reversing in its forecast.

If the zonal winds do not reverse, this won’t be a technical SSW. Albeit, that chart is 65 degrees North, it’s 60 degrees North we look at (I only noticed I made that mistake yesterday).

Stratosphere watch 2018/19

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