Model Output Discussion - Deeper into Autumn

[phil nw.]

1 minute ago, TSNWK said:

Agree. Is it me though as I tend to think ukm is less accurate than gfs and ecm at 144 and 168.. just a instinct I've created for myself over the years for ukm later stages

Yes an observation voiced before.

I just look at overall trends beyond a few days really including the anomaly means.

There is plenty of support for ridging to our east which seems harder to shift as we get closer to the time.

The UK model is not beyond a reasonable outlook even at day 7 .

Time will tell as they say.

[Tim Bland]

Nice cold pool Developing to our East.. let’s hope we can tap into that in early December !

[bluearmy]

Enough going on to keep us interested as extended modelling enters a period of the month where suitable coldie sypnotics would actually deliver coldie conditions 

despite some runs compacting the P/v, the majority are sticking with amplification.  The favoured spot, globally, being scandi 

[Methuselah]

So, today's GFS 06Z operational run continues playing with a potentially intense Russian-Scandinavian-European anticyclone?

    

    

    

And, as a bonus (and thus NOT TO BE TAKEN SERIOUSLY!) T+384 -- somewhat reminiscent of early January 2021; an easterly mixing with Mediterranean-sourced air? 

     

[LRD]

GFS 6z, 16 days away

What can possibly go wrong? Rolls eyes

Interesting to see how many ensembles show something similar

[bluearmy]

54 minutes ago, LRD said:

GFS 6z, 16 days away

What can possibly go wrong? Rolls eyes

Interesting to see how many ensembles show something similar

30% eps cluster not v far away from that 

[LRD]

14 minutes ago, bluearmy said:

30% eps cluster not v far away from that 

Thanks BA. Not bad odds. Models have a poor record of forecasting (correctly and incorrectly) scandi highs but better to be in the game than not, of course

[BlueHedgehog074]

Focussing around 144 hours on various 00Z operational models, it really feels as though the Atlantic trough and the block to the East of the UK will be in serious combat with each other, as they battle it out to see who will win! 

ICON

UKMO

 

GEM

 

ECMWF

 

GFS

 

UKMO possibly the highlight of the bunch at the 144 hour timeframe regarding the Scandinavian/European block having a bit more fighting power, and a good effort by the ECMWF too (even though the Atlantic trough does take more of the spotlight towards the end of the run). 

Saying that, however, most of the models above (except maybe the GEM) mark out some negative tilting to the Atlantic trough to our West suggesting it is lacking the full power needed to easily smash through further East.

Do feel overall, it’s hard to pick who will prove victorious. There has been many times where “we’ve been here before” and the Atlantic just breaks through. Equally, this could be one of those times that The Block comes out on top, even if it takes a while for it to succeed the battle, due to how the Atlantic seems to have been behaving in the last few months - never really having totally domination! 

For the time being, a big big battle could very well be commencing between both forces!

[mushymanrob]

This EPS chart for the 23rd is certainly of interest, that eastern block remains steadfast and theres hints of northern blocking developing too.. This must be a good sign for those wanting cold..

[TSNWK]

9 minutes ago, mushymanrob said:

This EPS chart for the 23rd is certainly of interest, that eastern block remains steadfast and theres hints of northern blocking developing too.. This must be a good sign for those wanting cold..

Any signals to support on the anomaly charts you kindly share with us.. and which I'm aligned with you in regards to their relative accuracy... as much you can be

[mushymanrob]

4 minutes ago, TSNWK said:

Any signals to support on the anomaly charts you kindly share with us.. and which I'm aligned with you in regards to their relative accuracy... as much you can be

i used this EPS chart because it goes out to the 23rd a little further than the NOAAs ... the NOAA 8-14 day chart is centred on the 19th but does strongly support the EPS, which strongly suggests that this pattern both suites illustrate is highly likely to be accurate.
But how they develop beyond that is uncertain, the GFS suggesting possible easterlies though IF the high builds further over Northern latitude  is certainly feasible.

Theres a lot of "ifs" and "buts" but from my pov, and im not a cold fan, theres a lot to be optimistic about if you are of a cold persuasion.

[jules216]

22 minutes ago, mushymanrob said:

This EPS chart for the 23rd is certainly of interest, that eastern block remains steadfast and theres hints of northern blocking developing too.. This must be a good sign for those wanting cold..

How is that good for cold if closest match to this pattern is of november 2020(persistant Sceuro high)and it brough very little even in december only few weeks of interest after January 2021 SSW.

[TSNWK]

Just now, mushymanrob said:

i used this EPS chart because it goes out to the 23rd a little further than the NOAAs ... the NOAA 8-14 day chart is centred on the 19th but does strongly support the EPS, which strongly suggests that this pattern both suites illustrate is highly likely to be accurate.
But how they develop beyond that is uncertain, the GFS suggesting possible easterlies though IF the high builds further over Northern latitude  is certainly feasible.

Theres a lot of "ifs" and "buts" but from my pov, and im not a cold fan, theres a lot to be optimistic about if you are of a cold persuasion.

Thank you for taking the time to provide a detailed response 

[Atleastitwillbemild]

2 hours ago, LRD said:

GFS 6z, 16 days away

What can possibly go wrong? Rolls eyes

Interesting to see how many ensembles show something similar

 When it comes to projected easterlies I'm as about as mistrusting and cynical as it gets. Big eye roll from me too.

[mushymanrob]

2 minutes ago, jules216 said:

How is that good for cold if closest match to this pattern is of november 2020(persistant Sceuro high)and it brough very little even in december only few weeks of interest after January 2021 SSW.

Firstly.... dont pattern match! just because a similar pattern failed to produce a desired result once, doesnt mean its bound to happen again.

Secondly ... what are you expecting? 1962/3? more realistically in a warming climate even a shorter Wintry spell would be welcome?

Thirdly .... Those charts suggest high pressure anomalies to our East and North.. that HAS to be good IF a cold synoptic pattern were to evolve, arent these the "building blocks"?.. lol, yes i hate that term too.

Forthly .... Surely that persistent mid/high latitude blocking will help disrupt the SPV as energy waves propagate upwards?

[jules216]

33 minutes ago, mushymanrob said:

Firstly.... dont pattern match! just because a similar pattern failed to produce a desired result once, doesnt mean its bound to happen again.

Secondly ... what are you expecting? 1962/3? more realistically in a warming climate even a shorter Wintry spell would be welcome?

Thirdly .... Those charts suggest high pressure anomalies to our East and North.. that HAS to be good IF a cold synoptic pattern were to evolve, arent these the "building blocks"?.. lol, yes i hate that term too.

Forthly .... Surely that persistent mid/high latitude blocking will help disrupt the SPV as energy waves propagate upwards?

The trouble with Sceuro high is that there is very fine line between Sceuro high and this, All you need is little injection in Atlantic energy, fór me its a sense of inevitability when I see one like now forecast.

[mushymanrob]

19 minutes ago, jules216 said:

The trouble with Sceuro high is that there is very fine line between Sceuro high and this, All you need is little injection in Atlantic energy, fór me its a sense of inevitability when I see one like now forecast.

True, but we are not seeing that. we are seeing a persistent high anomaly both to our east and north. Thats what the charts are suggesting, and as long as thats there, the first steps, then there is room for coldies to be optimistic. IMHO.
Im not sure what youd be happy with, as a first step?... surely the expectation of mid/high latitude blocking would be it?

 

[Kirkcaldy Weather]

Big differences on the Icon even as soon as Saturday 

6z  12z 

Higher pressure proving more dominant and that leads to a nicer evolution 

[TSNWK]

5 minutes ago, Kirkcaldy Weather said:

Big differences on the Icon even as soon as Saturday 

6z  12z 

Higher pressure proving more dominant and that leads to a nicer evolution 

That synoptic wise looks cold end of next week

[DavidS]

35 minutes ago, Kirkcaldy Weather said:

Big differences on the Icon even as soon as Saturday 

6z  12z 

Higher pressure proving more dominant and that leads to a nicer evolution 

Wow, the 12z ICON is really going for it and within the semi reliable. Will be interesting to see if it sticks with this on subsequent runs. It has been right before.

[sheikhy]

Latest gfs backs scandi high further west up to 168 hours aswell!!something to watch maybe!!!

[Kirkcaldy Weather]

GFS also better alignment with the high 

6z  12z 

We'll take that  

UKMO decent too 

 

[Derecho]

12 minutes ago, sheikhy said:

Latest gfs backs scandi high further west up to 168 hours aswell!!something to watch maybe!!!

Control run backing it up at T156 as well, there are also other interesting ensemble members to back it up.

Something more seasonal perhaps to end the month, if the Atlantic can be held at bay.

[northwestsnow]

2 hours ago, jules216 said:

How is that good for cold if closest match to this pattern is of november 2020(persistant Sceuro high)and it brough very little even in december only few weeks of interest after January 2021 SSW.

UKMO isn't far off Jules..

As usual we need to see energy into the Southern arm of the jet but I'm thinking there will be some cold Arctic air on the Eastern flank of the block heading your way,on this run at least.

[Daniel*]

Something could be brewing here this evening UKMO at day 6 really quite eye-catching falling pressure to south and a decent block to northeast. These short-term changes are often much more credible to see.