[Model Output Discussion - Into 2024]

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Thanks all.

 

[Model discussion highlights]

Looking at the latest fax T84 i think once we clear the slow moving low se into the continent by the end of the week,we well get a short term easterly as it clears but this was never the main course, as we realised days ago.

Never the less we can see the first injection of colder air heading in from the east by the weekend so from that pov the first stage of the pattern change shows up right on time that has been shown on countless ensemble charts and graphs for days.

It's not really an issue to me whether the high builds just to our north west or over us really.The main thing is it's the stepping stone to greater things a few days later when the retrogression towards Greenland is expected.

We can see this process underway by day 11 on the eps

Under the high we will be colder but more importantly drier(it's pouring down here again) with night frosts and hopefully some crisp winter sunshine while we wait for the main course.

We are in a good place with a great chance of something even more Wintery but it's several days away and i guess we will see more minor changes /disagreements between the models.It's ok to study every operational run but it does help to keep perspective and watch how the overall pattern is developing.

I am quite happy with the continual colder trends showing,including the later development of Greenland heights .

Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4991825

[Model Output Discussion - Into 2024]

Looking at the latest fax T84 i think once we clear the slow moving low se into the continent by the end of the week,we well get a short term easterly as it clears but this was never the main course, as we realised days ago.

Never the less we can see the first injection of colder air heading in from the east by the weekend so from that pov the first stage of the pattern change shows up right on time that has been shown on countless ensemble charts and graphs for days.

It's not really an issue to me whether the high builds just to our north west or over us really.The main thing is it's the stepping stone to greater things a few days later when the retrogression towards Greenland is expected.

We can see this process underway by day 11 on the eps

Under the high we will be colder but more importantly drier(it's pouring down here again) with night frosts and hopefully some crisp winter sunshine while we wait for the main course.

We are in a good place with a great chance of something even more Wintery but it's several days away and i guess we will see more minor changes /disagreements between the models.It's ok to study every operational run but it does help to keep perspective and watch how the overall pattern is developing.

I am quite happy with the continual colder trends showing,including the later development of Greenland heights .

[Model Output Discussion - Into 2024]

We still get the colder air in at the weekend as the high edges in but the main push of cold is further south on both uk and gfs on these runs.

Looking much further ahead at this point is probably unhelpful as modeling the jet split is inevitably going to undergo further adjusments.

I would hope more energy is drained from the northern arm as go further on as we rely on that to see any second reamplification get further north than mid-latitude.

[Model Output Discussion - Into 2024]

Happy new year everyone.

A good start to the day with GFS starting to close the gap with the Euro models after giving some folks the jitters.

The ensembles looking cold as we head into the weekend and beyond as we see the -5 uppers head in from the east.

Let's see how the pattern develops now but it looks very promising for cold to extend into next week.

[Model discussion highlights]

Still some details to iron out within the operational runs but  the ensembles are starting to clear the uncertainties for the end of this week.The combined 850 ensemble graph for Warwickshire showing the average forecasts from the GEFS/ECM/MOgreps .Good agreement that cold air  is in by day 7 .

So the  suggestion is that the high will build just far enough north west to usher in the first cold wave from the east over next weekend.

Eps T168

I take that as the first hurdle overcome,get the cold in and then accept further forward remains uncertain on how the pattern develops.In the worst case under a UK high we retain quite cold air but  looking a few days further on the eps and gefs we  have another go at reamplifying the Atlantic pattern.

This looks much better with an extension of a European trough underneath so based on this an extension of the cold looks quite possible beyond the initial high.Likely we will get better snow chances from that setup.

The most unlikely scenario is any early return of the westerlies so plenty to be optimistic about going into January for cold seekers.

Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4989166

[Model Output Discussion - Into 2024]

The ups and downs of the model runs and the roller coaster of views are well represented in the thread this evening.

At least we have  a pattern change and a break from this relentless chain of Atlantic lows to come.

By the end of the week it will be colder under high pressure dry with frosts,a decent change from all the wet.It will be much more pleasant.i will put the extra layer on and get out and enjoy a walk in the fresh air.

Stay positive for something even more wintery later on.

Whatever your preference i hope you all have a happy new year.

[Model discussion highlights]

Over the years it is uncanny how many times the split flow of the jet upstream causes disagreements within the operational runs.

Further it is uncanny how on many of these occasions the GFS is proved to have thrown too much energy into the northern arm of the jet.

Just saying...

Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4989478

[Model Output Discussion - Into 2024]

Over the years it is uncanny how many times the split flow of the jet upstream causes disagreements within the operational runs.

Further it is uncanny how on many of these occasions the GFS is proved to have thrown too much energy into the northern arm of the jet.

Just saying...

[Model discussion highlights]

Still some details to iron out within the operational runs but  the ensembles are starting to clear the uncertainties for the end of this week.The combined 850 ensemble graph for Warwickshire showing the average forecasts from the GEFS/ECM/MOgreps .Good agreement that cold air  is in by day 7 .

So the  suggestion is that the high will build just far enough north west to usher in the first cold wave from the east over next weekend.

Eps T168

I take that as the first hurdle overcome,get the cold in and then accept further forward remains uncertain on how the pattern develops.In the worst case under a UK high we retain quite cold air but  looking a few days further on the eps and gefs we  have another go at reamplifying the Atlantic pattern.

This looks much better with an extension of a European trough underneath so based on this an extension of the cold looks quite possible beyond the initial high.Likely we will get better snow chances from that setup.

The most unlikely scenario is any early return of the westerlies so plenty to be optimistic about going into January for cold seekers.

Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4989166

[Model Output Discussion - Into 2024]

Just a little request to folk who are doubtful over telecommunications ie background signals please show a little respect  for the members who spend time and have gained knowledge to enlighten the rest of us on this accepted form of meteorology.

It all adds to enrich the forum and it would be a shame if unfriendly posts put these folk off from posting.

I myself have gained much more understanding of what causes certain patterns to develop and i am 75years old but you can never stop learning about this great hobby if you keep an open mind.

[Model Output Discussion - Into 2024]

Still some details to iron out within the operational runs but  the ensembles are starting to clear the uncertainties for the end of this week.The combined 850 ensemble graph for Warwickshire showing the average forecasts from the GEFS/ECM/MOgreps .Good agreement that cold air  is in by day 7 .

So the  suggestion is that the high will build just far enough north west to usher in the first cold wave from the east over next weekend.

Eps T168

I take that as the first hurdle overcome,get the cold in and then accept further forward remains uncertain on how the pattern develops.In the worst case under a UK high we retain quite cold air but  looking a few days further on the eps and gefs we  have another go at reamplifying the Atlantic pattern.

This looks much better with an extension of a European trough underneath so based on this an extension of the cold looks quite possible beyond the initial high.Likely we will get better snow chances from that setup.

The most unlikely scenario is any early return of the westerlies so plenty to be optimistic about going into January for cold seekers.

[Model Output Discussion - Into Winter]

We have moved a couple of posts here

I have a feeling it will be busy in here soon so please make sure that posts refer to the model outputs,any moans or one liners etc please use the moans thread linked above.

Thanks all.

[Model Output Discussion - Into Winter]

19 minutes ago, northwestsnow said:

Acc to MOGREPS we should be looking at around the 4th/5th as a potential starting point for a switch to colder weather conditions ...

Fingers crossed Exeter keep the faith..

Yes flicking through the ensembles we can get an idea of cold becoming more of a feature around day 7.

Around this time we see Atlantic pressure rising so at least now we are seeing something tangible well within 10 days.

Noticeable too in the next week that deep cold buildup over Scandinavia.We just need those heights building further then we are in business.

[Model Output Discussion - Into Winter]

Morning all,

Unfortunately a couple of off topic posts have been removed.

Just a reminder people are entitled to different views on the models as long as they are supported in the outputs.

Please report any problems to the team rather than complain in off topic posts.

Thanks.

[Model Output Discussion - Into Winter]

1 minute ago, Kasim Iberian Heights Awan said:

If this winter is going to deliver we need cold weather firmly within 240H. Today's ECM would likely go on to produce further mild conditions.

We don't know that.Given the chaos in the changing pattern before day 10 maybe it's best to comment on what we can see.

[Model Output Discussion - Into Winter]

2 minutes ago, nick sussex said:

The rapid drop in zonal winds is likely to cause a lot of model variability. 

If the trend to correct the pattern west gathers pace then things could get quite interesting .

Yes indeed once the Atlantic push dies away under a weakening jet we can see those wedges of heights popping up further north.This picture will vary until we get closer but we can see the effects of the weakening pv starting to filter into later frames.

[Model Output Discussion - Into Winter]

Firstly a nod to the here and now to say this really is a depressingly wet and windy spell with dark heavy clouds lowering the light even further and it looks like we have a number of days of low after low coming in right through the weekend.

Latest fax t84    

the effects of a strong jet and low pressures heading well into Scandinavia and Russia show up with the milder temperatures.

Current obs.     

The cold very much locked up to the north east currently  however with the forecasted pattern change to come hopefully this will look quite different next month.

Certainly the ensembles are moving the mean jet further south in the outlook gradually bringing more of the UK into colder air which currently only the north of Scotland are seeing.

EPS  days 11-15 mean 850s anomalies.

 

[Autumn & Winter 2023---2024 Stratospheric Polar Vortex. Events, Analysis, Discussions AND Outlooks]

24 minutes ago, Mike Poole said:

Zonal mean zonal winds - the mean means (sic) average round the globe at the 60N zone, not across realisations.  I think the Berlin charts are yesterday’s ECM op 12z.  Would be great if they could do the control now out to 15 days, but for the moment it is the op to 10 days.

Thanks Mike

[Autumn & Winter 2023---2024 Stratospheric Polar Vortex. Events, Analysis, Discussions AND Outlooks]

1 minute ago, bluearmy said:

I’m pretty sure that the Berlin model is ecm op 12z Phil?

Also note that the 06z gfs op is the first run I can recall for a long time that doesn’t see an Atlantic high anomoly in the upper strat 

as a result the spv drifts towards Greenland 

but it does find a renewed Asian warming at the very end 

As it says mean zonal winds at the top of the chart I took it as a picture of the average of all the members of that run Nick?

[Autumn & Winter 2023---2024 Stratospheric Polar Vortex. Events, Analysis, Discussions AND Outlooks]

1 hour ago, bluearmy said:

yesterday’s op even closer - looks like todays 00z is a tech reversal 

what I would say about that profile yesterday is that it doesn’t look very strong but then the Berlin flow data seems to be v questionable in its measurement so going to have to assume the -5 are nearer to  -10 

Some continuity at least.

I do prefer this site for hopefully counting this down to day 1.

Rather this ensemble output once a day than the ups and downs of each operational run.

[Autumn & Winter 2023---2024 Stratospheric Polar Vortex. Events, Analysis, Discussions AND Outlooks]

The Berlin site,yesterdays ecm chart, showing reversal of zonal winds downwelling towards 10hPa by day 10.

      

good to see ecm on board now within 10 day range.Along side the gefs zonal wind reversal  chart issued today also forecasting this around a similar timeframe ,so all looking promising to see a technical SSW around the first week of January.

We then wait to see how long it will take to see effects lower down. 

 

[Model Output Discussion - Into Winter]

6 minutes ago, TSNWK said:

Will be back on the first duff run from the pack...

Im looking forward to settling down with a nice whisky on Christmas night as 18z rolls.

I have already settled down with a couple of drams so forgive me if I don't go into detail tonight. 

I see that earlier post from Lorenzo sums things up perfectly.

Everything is coming together  for a complete change over to a -ve AO/NAO pattern in January.

This has been trending in the week 2 ensembles for a few days now and today they continue to strengthen.

Anyway I hope Christmas has been good for everyone and my thoughts are with matt3wolves and others who have had sadness or poor health at this time.Best wishes for a brighter outlook in the New Year.

 

[Model Output Discussion - Into Winter]

I think we will have to wait a little to see the effects of the  strat.warmings imprinting onto the 500 pattern.

For the time being it continues to look quite unsettled -rather colder at times,with further transitional snowfall up north as the lows pass across  towards Scandinavia, bringing the polar further south at times. 

The ensembles still show height anomalies increasing towards the pole as we progress towards the end of week 2  along with a Scandinavia low anomaly so at least there is consistency in the trend to move away from a +ve AO.

Reasons to be optimistic for a different pattern i think further into the NY.

Anyway in the meantime i wish all of you a very happy Christmas and here's  to a snowy new year.

[Model Output Discussion - Into Winter]

On the gefs06z we can see the pattern change by NY day.

Agrees pretty well with the 10 day trend on the eps

Both building heights from the Atlantic and Siberian sectors towards the pole as the low anomalies are being removed.Mean jet further south too.

Early days yet but  good trends and it seems the ensembles are starting to factor in the warmings and increasing amplification of the NH pattern expected into the NY.