Model Output Discussion - Deeper into Autumn

[ANYWEATHER]

La Nina, pattern set up as I said a few days ago seems very faint, or non- existent . Why? There must be many other factors over riding  this . It's really why long range forecasts goes belly -up, I'm not being critical. Anyway,  back to normal service next week , High winds at times , heavy rain, and feeling much colder in the strong winds. Hopefully there will be some sunshine to compensate , in which we are now entering the most darkest time of year.

[Frigid]

1 hour ago, northwestsnow said:

EC joins GFS and gives up on any idea of drying out.

As zonal as it gets out to day 10 ,and beyond.

I guess its best to get all the zonal crud out of the way, unless its perpetual like Winter 19/20 then we worry. I'm expecting 2/3rd week to show some interest. 

Edited October 29, 2022 by Frigid

[damianslaw]

We've had a meredional jet for much of 2022, any zonal flow has been very short lived and the background state hasn't changed, I would not be surprised to see a flip to settled, once the flow pushes east, as said think this is the trigger, we need the zonality to shake things to a more La Nina state.. keep an eye on the azores high, one positioned further west indicates the change. 

[johncam]

Latest GFS another horror show , out to mid November and not a frost in sight , the total opposite very mild , yuk 

[DavidS]

South Westerlies for ever on the 6z GFS

[damianslaw]

Just now, DavidS said:

South Westerlies for ever on the 6z GFS

Possibly GFS deafaulting to its over eagerness to maintain a zonal flow, once one appears, has a habit of doing this. Recent runs have been all over the place.

[northwestsnow]

17 minutes ago, damianslaw said:

Possibly GFS deafaulting to its over eagerness to maintain a zonal flow, once one appears, has a habit of doing this. Recent runs have been all over the place.

Agreed.

EC 00Z does seem to have ditched any high pressure influence though ..

[TSNWK]

25 minutes ago, DavidS said:

South Westerlies for ever on the 6z GFS

Good.. keep the heating off for another two weeks.. 

[ItNeverSnowsInWindsor]

11 minutes ago, TSNWK said:

Good.. keep the heating off for another two weeks.. 

Surely the pattern has to change at some point ?

Not sure what can bring about the change.

[Cambrian]

The current conundrum of the models is nicely captured by the 0z ECM mean and anomaly charts. 

The progression from the beginning of the new month at day 3

 

to day 8 involves the attempt to cut off of the low at the base of the Atlantic trough

 

- the low deepens as it’s nudged south, so a more lively spell of weather around bonfire night and a colder burst of polar maritime air likely to be wrapping around it from the west. 

The same direction of travel continues for the broad picture through to day 10.

 

Heights maintained to the east, and over the western side of the North Atlantic, always tempting the northern link-up through Svalbard and Greenland - slow traffic, no real cold supply in the offing - but with a lack of any sustained energising from the jet stream to shift it east, the stubborn Atlantic low in a slow cycle of deepening and filling for at least another couple of weeks, then perhaps ultimately drifting and fading?

But here’s the conundrum - we don’t really know. The Northern Hemisphere has settled back by then into another elegantly symmetrical but pedestrian 4-wave pattern, which looks like the same pattern we have seen for months, and evidently very hard to break out of. Adding to our conundrum, the lowest Arctic heights are solidly on the Canadian side, continuing to feed lower heights southeast into the Atlantic trough. This is in effect balancing out the build in heights north through Scandinavia and into the Arctic.

This leaves us in no man’s land for any cold any time soon - we can’t confidently look to the northwest, even with the hope that with the centre of the low inching its way southeast towards the north of Scotland, it might occasionally bring a more sustained direct feed of some of that cold air from Greenland - and we can’t yet confidently see the way to heights building strongly enough in the right places to bring us some anticyclonic based cold. 

Though not favoured by the 16 day model runs yet at all, with everything being so slow, there’s a possible route to something colder from the north / northeast for later in November if the Newfoundland and Svalbard heights do link up through Greenland, and with the heights over Iberia fading, the low could well head down through the North Sea before moving into Europe. 

By then, the slowness of the pattern might become the friend of northwest European cold, but looking well into November from where we are now, it’s the resilience of the balance of this 4-wave symmetry that is the basis to our conundrum.

Have a great weekend. 

[damianslaw]

6 minutes ago, Cambrian said:

The current conundrum of the models is nicely captured by the 0z ECM mean and anomaly charts. 

The progression from the beginning of the new month at day 3

 

to day 8 involves the attempt to cut off of the low at the base of the Atlantic trough

 

- the low deepens as it’s nudged south, so a more lively spell of weather around bonfire night and a colder burst of polar maritime air likely to be wrapping around it from the west. 

The same direction of travel continues for the broad picture through to day 10.

 

Heights maintained to the east, and over the western side of the North Atlantic, always tempting the northern link-up through Svalbard and Greenland - slow traffic, no real cold supply in the offing - but with a lack of any sustained energising from the jet stream to shift it east, the stubborn Atlantic low in a slow cycle of deepening and filling for at least another couple of weeks, then perhaps ultimately drifting and fading?

But here’s the conundrum - we don’t really know. The Northern Hemisphere has settled back by then into another elegantly symmetrical but pedestrian 4-wave pattern, which looks like the same pattern we have seen for months, and evidently very hard to break out of. Adding to our conundrum, the lowest Arctic heights are solidly on the Canadian side, continuing to feed lower heights southeast into the Atlantic trough. This is in effect balancing out the build in heights north through Scandinavia and into the Arctic.

This leaves us in no man’s land for any cold any time soon - we can’t confidently look to the northwest, even with the hope that with the centre of the low inching its way southeast towards the north of Scotland, it might occasionally bring a more sustained direct feed of some of that cold air from Greenland - and we can’t yet confidently see the way to heights building strongly enough in the right places to bring us some anticyclonic based cold. 

Though not favoured by the 16 day model runs yet at all, with everything being so slow, there’s a possible route to something colder from the north / northeast for later in November if the Newfoundland and Svalbard heights do link up through Greenland, and with the heights over Iberia fading, the low could well head down through the North Sea before moving into Europe. 

By then, the slowness of the pattern might become the friend of northwest European cold, but looking well into November from where we are now, it’s the resilience of the balance of this 4-wave symmetry that is the basis to our conundrum.

Have a great weekend. 

Very good post, yes the likely evolution to something more settled at least, will come courtesy of the trough digging further south into Europe this should be enough to allow for pressure rises to occur to our north and north west, low pressure becomes cut off so to speak - something we've seen alot of this year, but generally to our SW, for something colder needs to happen to our south. A slow evolution through November it seems, patience is a virtue they say!

[mushymanrob]

4 hours ago, damianslaw said:

Its the opposite to expected La Nina imprint, which really does seem to be outflanked by other factors last couple of years, should have ridge to west and trough to east.

Alas there is a path to this scenario, should the azores high link over the top with the trough cut off and shunted south, heights then transfer west... the high to the NE needs to ridge further west though for this to happen.

This is the 3rd consecutive La Nina Winter.... the last two didnt support that Western ridge/Eastern trough either..

From my very limited knowledge understanding of the enso signal, im far from convinced there is any pattern/correlation.

 

[MATTWOLVES 3]

Long time no post folks...let me just dust down the cobwebs that have gathered on my bonce and I will give it me best shot.

Firstly I would like to say the cold chase begins for me on the 1st of November.. more especially mid November...what comes before then matters not a jot...I accept no Winters over posts from any of you until at least end of February let's enjoy the chase and let's not forget we are becoming long overdue something memorable! Will this be the Year? To early so say but I'm looking forward to it for sure.

Back to the here and now and its looks rather mixed for the next week or so with bands of rain and showers and strong winds for many at times. It could be a rather windy Bonfire night for sure..so do take care with any Rocket launches

My interest becomes more intense towards mid month because I feel there are some substantial hints of pressure rises around the Scandinavian vicinity...we are long overdue Height rises in those areas as they feel a thing of the past. But I do feel that colder more settled conditions look an increasing prospect come then. And it will pay to keep an eye on those Height rises towards the NE as we move further into next month.

Right gang much love to ya...have a Stirling Weekend ..if your out trick or treating please stay away from my home as you may be in for a very scary sight when I answer the door

 

[Mike Poole]

It’s a good question, what will bring about a change to the current status quo…

Looking farthest ahead on the ECM clusters, and the trough out west and concomitant southwesterly flow is still there at day 11 on all clusters (indicated in purple, ok cluster 1 has it pushed east).  It just will not ‘go with the (zonal) flow’ because there isn’t any!

By day 15, there is some change for sure, but it is by no means obvious what to!  And it could just be ECM ‘noise’ at that range.

At this stage we now look for hints in the operational models and ensembles as to what will be the starting gate for winter, to go alongside the predictions from the long-rangers and soothsayers…

I take a Bayesian view of such things, and my prior for winter is this:  that the best chance of UK cold weather is early on in winter, there is a decreasing chance of stratospheric disturbance as winter progresses this year (as per La Niña and west QBO), and while the seasonal models favour a +NAO zonal pattern by the end of winter, they all suggest quite the opposite early doors.

So…unless this is to be a bust, something has to change significantly during November, and I think this is what we will see, but it will be (prediction) beyond mid month and will come from the north, not east.  I don’t buy into the idea that current patterns will last, it is autumn, a transitional season, the clue’s there.  But of course, it could be that the seasonal models will shift in the November update of course.

Some thoughts about the imminent winter chase.  It has been, for most of the time I’ve been on Netweather (since 2013), a hard slog, particularly to get snow in the south, with few rewards.  Notable of course was the BFTE March 2018, but particularly so from a model watching point of view as the strat events that caused it, we were watching from before the new year.  Pieces fell into place like clockwork.  

It can be like that again.  But, here’s the thing, we are now reliant on lower probability, longer sequences of events to get the winter weather many want, that’s not to say they can’t happen, they can, but it does mean backing the outside chance on occasions to ‘predict’ them.  I could say to you at the start of winter, that there will be no significant lying snow in Oxfordshire all winter, and 3 times out of 4 now, I would be right.  But where’s the fun in that!  The thrill of the case, is getting increasingly confined to identifying those lower probability scenarios that might just deliver.  Which is what I will look for.  Some others will I’m sure write off winter before it has started, I think some even have now .

But we do need that pattern change in the second half of November.  On with the 12z’s…

 

 

Edited October 29, 2022 by Mike Poole
Wrong quoted post removed

[E17boy]

[Don]

38 minutes ago, Mike Poole said:

I take a Bayesian view of such things, and my prior for winter is this:  that the best chance of UK cold weather is early on in winter, there is a decreasing chance of stratospheric disturbance as winter progresses this year (as per La Niña and west QBO), and while the seasonal models favour a +NAO zonal pattern by the end of winter, they all suggest quite the opposite early doors.

So…unless this is to be a bust, something has to change significantly during November, and I think this is what we will see, but it will be (prediction) beyond mid month and will come from the north, not east.  I don’t buy into the idea that current patterns will last, it is autumn, a transitional season, the clue’s there.  But of course, it could be that the seasonal models will shift in the November update of course.

This is why I believe the November LRF updates will be pivotal for the coming winter.  Worth mentioning also that 2020/21 had a W-QBO and La Nina but still produced a SSW early January.  Not to say that will be the case this time of course!

In the meantime, more mild weather to come for the next couple of weeks at least!

[johncam]

Oh dear  , just when you think the GFS csnt get any worse , it looks even milder if thats possible , dreadful 

[North-Easterly Blast]

3 minutes ago, Don said:

This is why I believe the November LRF updates will be pivotal for the coming winter.  Worth mentioning also that 2020/21 had a W-QBO and La Nina but still produced a SSW early January.  Not to say that will be the case this time of course!

In the meantime, more mild weather to come for the next couple of weeks at least!

For a westerly QBO winter 2020-21 was actually a fairly decent winter for cold - at least by the standards of recent years - obviously nowhere near as cold as 2009-10 but it was colder and a bit different to most, if not all winters since 2012-13.  The only other winter since 2012-13 that was as cold as 2020-21 was 2017-18.

[KTtom]

39 minutes ago, johncam said:

Oh dear  , just when you think the GFS csnt get any worse , it looks even milder if thats possible , dreadful 

On the plus side, IF the latest runs do come to fruition it shows the Met have diddly squat idea past day 10 as the rest of us! They have been consistant over a colder settled spell week 1, then week 2 November even forcasting snow in the west a few days ago! Goes to show, and worth remembering in winter,  anything can happen post day 10.....no one knows

[Kirkcaldy Weather]

Nice way the 12z GFS finishes

 

[johncam]

22 minutes ago, Kirkcaldy Weather said:

Nice way the 12z GFS finishes

 

Would the high not just collapse into Europe once again and back to rinse and repeat

[Don]

50 minutes ago, KTtom said:

On the plus side, IF the latest runs do come to fruition it shows the Met have diddly squat idea past day 10 as the rest of us! They have been consistant over a colder settled spell week 1, then week 2 November even forcasting snow in the west a few days ago! Goes to show, and worth remembering in winter,  anything can happen post day 10.....no one knows

As I have said recently, when colder weather starts getting put back, it's a concern!  However, on the plus side it's still October, but need to see a significant pattern change soon if we are to get an early cold winter period.

[North-Easterly Blast]

36 minutes ago, Don said:

As I have said recently, when colder weather starts getting put back, it's a concern!  However, on the plus side it's still October, but need to see a significant pattern change soon if we are to get an early cold winter period.

It is very worrying that many of the charts are now showing a flat jet and mostly mild zonal.  I am not saying that it is likely that we shall see anything like December 2010 at the start of this winter, but many would have hoped that a weak to moderate La Nina would help the chances to be better than they have been for a number of years, of early cold spells this winter season.

[damianslaw]

59 minutes ago, johncam said:

Would the high not just collapse into Europe once again and back to rinse and repeat

No, its a classic scandi high, atlantic forcing would most likely see it retrogress.. 

2 minutes ago, North-Easterly Blast said:

It is very worrying that many of the charts are now showing a flat jet and mostly mild zonal.  I am not saying that it is likely that we shall see anything like December 2010 at the start of this winter, but many would have hoped that a weak to moderate La Nina would help the chances to be better than they have been for a number of years, of early cold spells this winter season.

GFS 12z ends with a classic scandi high, yes way in long range but shows a route out of the mild and wet. GFS hardly ever shows scandi highs at such range.  I must be viewing different charts?

Edited October 29, 2022 by damianslaw

[Allseasons-Si]

Just to reiterate on just how quick the models can flip from a strong pv to the north with Euro heights to the south to strong heights to the northwest,...yes i have picked out the 2010 Reanalysis achived charts from meteociel just to give you an example...

who would of thought that we was going to see a memorable cold spell from this chart on the 15th Nov eh!

well i was fooled but look what happens seven days later onwards

now come on guys we are still in Autumn and so lets sit out this mild spell and see what transpires over the coming days/weeks,...chins up boys and girls,...a looooooong way to go yet

oooh!!!,just checked out the 12z gfs,...this is what we want to see in terms of punching that tpv against the ropes

Edited October 29, 2022 by Allseasons-si
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