Model Output Discussion - Into 2024

[MattStoke]

19 minutes ago, Martz86 said:

It would be nice to have a model group just for those that know what their talking about, reading through this one is very confusing, shame really as I quite like reading the knowledgeable posts but it's becoming tedious filtering through it all. 

Model highlights thread shows only the most informative posts based on reactions.
 

 

[Met4Cast]

Just now, Chrisover93 said:

What are your thoughts in terms southern coastal counties in terms of lows bumping into cold air will it all fall as rain 

 

and I agree GFS is actually ending it before it gets going with progressive lows 

It's far too early to look at that kind of detail, the polar boundary will still be shifting 100-200 miles across varying runs & modelling until we start getting to much shorter lead times. 

The risk is there but naturally the further south you are the more likely you are to see transient snow events vs all snow events, that's just the way it often goes. A decent channel/N France runner though could deliver even to the south coast so.. in short, potentially, but also potentially not.

[MATTWOLVES 3]

2 minutes ago, Buzz said:

Do as I have done - add all of the problematic posters to your ignore list. It'll take a while but it's well worth it - I now mainly only see those posts which are actually useful. Reading this thread is now a pleasure, not a chore.

In addition to that there is of course the very useful Highlights thread, but that does rely on others actually marking posts from here as Insightful and not abusing the feature.

I can't see the point tbh mate..its only valid if you log in..you can still read everyone's posts when not logged in. And tbh it's good to hear those that lose there heads every second of the day as it brightens up my rather sad life

[Jason M]

I've just looked through the GEFS at 216 hours.

There are some stonkers in amongst them. The 00Z GEFS were dreadful but this set is much better around that timescale.

This is going to be an extremely tight run thing. A difference of a couple of hundred miles in the pattern is going to have very big ramifications.  

[Cymro]

1 hour ago, Battleground Snow said:

I think to stop us going mad, it's better to just look at ukmo and ecm up to 144 at the moment, doesn't seem to  swing wildly from run to run

That's a brave call re the ECM following this week's colder uppers and snowfall fiasco with the ECM. 

[Chrisover93]

1 minute ago, Met4Cast said:

It's far too early to look at that kind of detail, the polar boundary will still be shifting 100-200 miles across varying runs & modelling until we start getting to much shorter lead times. 

The risk is there but naturally the further south you are the more likely you are to see transient snow events vs all snow events, that's just the way it often goes. A decent channel/N France runner though could deliver even to the south coast so.. in short, potentially, but also potentially not.

For an experienced forecaster like yourself I’m still learning things but what do you see the scenario looking like for your next experience?

[MattStoke]

1 minute ago, Met4Cast said:

It's far too early to look at that kind of detail, the polar boundary will still be shifting 100-200 miles across varying runs & modelling until we start getting to much shorter lead times. 

The risk is there but naturally the further south you are the more likely you are to see transient snow events vs all snow events, that's just the way it often goes. A decent channel/N France runner though could deliver even to the south coast so.. in short, potentially, but also potentially not.

It's also often though not always the case that these lows end up further south than initially modelled, so if anything those in the south would almost want lows to be modelled fairly far north this far out.

[jmp223]

Bit of a concerted trend towards warmer 850s after the 15th. Control a bit of a stinker

 

 

Edited January 9 by jmp223

[Gizzy]

1 minute ago, MATTWOLVES 3 said:

I can't see the point tbh mate..its only valid if you log in..you can still read everyone's posts when not logged in. And tbh it's good to hear those that lose there heads every second of the day as it brightens up my rather sad life

Long time lurker on here, with the odd Post thrown in, but I always like your posts Matt, always seem sensible, balanced and on point.

I know nothing about models so it's good to hear from the sad person as we chase and chase the white gold, keep it up mate.

[TSNWK]

4 minutes ago, MATTWOLVES 3 said:

I can't see the point tbh mate..its only valid if you log in..you can still read everyone's posts when not logged in. And tbh it's good to hear those that lose there heads every second of the day as it brightens up my rather sad life

Also blocked posters still pop up in quoted posts...

[northwestsnow]

6z mean is an upgrade at day 10

Edited January 9 by northwestsnow

[Ali1977]

1 minute ago, northwestsnow said:

6z mean is an upgrade at day 10

Looks slidey and full of snow opportunities

[Rain All Night]

2 minutes ago, northwestsnow said:

6z mean is an upgrade at day 10

Is it? The Atlantic LP is closer to the UK

[Met4Cast]

5 minutes ago, Chrisover93 said:

For an experienced forecaster like yourself I’m still learning things but what do you see the scenario looking like for your next experience?

These lows tend to trend further south so I would expect models to occasionally barrel them through and bring in mild weather quickly but the reality will likely be a much slower transition. I.E more than 1 attempt to bring in milder weather with the potential for multiple snow events. Again though, where that boundary lies wont be known for a while.

It's possible northern areas will remain in cold air throughout (mentioned this in the above quoted tweet)

5 minutes ago, MattStoke said:

It's also often though not always the case that these lows end up further south than initially modelled, so if anything those in the south would almost want lows to be modelled fairly far north this far out.

Indeed! Fully expecting that which is why I'm not entirely buying the modelling around the 17th at the moment bringing those lows in, suspect it'll be more delayed than that. (though, it doesn't ALWAYS trend south as you say, not something we can 100% rely on!)

[johnholmes]

I suppose I will be talking to myself but comparing 06 to 00 at extended distances really is a waste of time. Compare like with like and you will get a better idea of where the particular model seems to be heading.

I'm in the middle of doing my usual 500MB output, will post it before long but they seem to agree with the overall outlook of cold returning over the coming weekend, but with differences in how cold.

re the how far north will any low get. Almost always IF the cold has been in place for 3 days or more then the initial modelling suggesting the Atlantic pushing the ridge/cold air away is very often too quick. The direction of travel of the depression at the surface and in the 3 dimension is fairly critical and is usually only seen accurately 24-48 hours out. Even then it can be several days before there is a real breakdown into genuinely milder gets there.

Edited January 9 by johnholmes

[Battleground Snow]

9 minutes ago, Cymro said:

That's a brave call re the ECM following this week's colder uppers and snowfall fiasco with the ECM. 

Perhaps, but ukmo and ecm agreement at 96 hours is a strong combo 

[WolfeEire]

The forecast deep pool of cold over North America invariably fires up the jetstream and allows for rapid movement across the Atlantic as seen in the GEFS mean. The only positive is that the jetstream isn't aimed right at us but carrying systems more toward western france, which sets up the potential for some parts of UK to be on the right side of sliding lows. Whether there will be enough of a colder airmass to the north of these sliders to produce snow here is another matter.

[Chrisover93]

3 minutes ago, Met4Cast said:

These lows tend to trend further south so I would expect models to occasionally barrel them through and bring in mild weather quickly but the reality will likely be a much slower transition. I.E more than 1 attempt to bring in milder weather with the potential for multiple snow events. Again though, where that boundary lies wont be known for a while.

It's possible northern areas will remain in cold air throughout (mentioned this in the above quoted tweet)

Indeed! Fully expecting that which is why I'm not entirely buying the modelling around the 17th at the moment bringing those lows in, suspect it'll be more delayed than that. (though, it doesn't ALWAYS trend south as you say, not something we can 100% rely on!)

Thank you really informative never go wrong when asking you question 

 

 

[Alexis]

10 minutes ago, jmp223 said:

Bit of a concerted trend towards warmer 850s after the 15th. Control a bit of a stinker

 

 

Both the operational and control are above the mean as soon as we hit the unreliable.

[northwestsnow]

6 minutes ago, RainAllNight said:

Is it? The Atlantic LP is closer to the UK

Day 11 was a disappointment it looked better at 10 I thought..

more slidey perhaps..?

day 12 

[Frigid]

GEFS and EPS still solid up to day 10. I wouldn't be worried with the GFS outcomes atm, look how much they differ to the mean with it being a major outlier. Meanwhile, ECM op and control closely resembles the mean. Solid agreement with the EPS, along with an encouraging UKMO 0z is much favoured imo.  

  

 

[northwestsnow]

I suspect t the Exeter update will reveal if they are going with GFS/GEM V UKMO /EC..

I'd suggest the envelope for the sweet spot is  somewhere around the Scottish Borders to Birmingham as it stands - 

That might move north or south as the envelope narrows ..

[Mark Bayley]

7 minutes ago, Met4Cast said:

These lows tend to trend further south so I would expect models to occasionally barrel them through and bring in mild weather quickly but the reality will likely be a much slower transition. I.E more than 1 attempt to bring in milder weather with the potential for multiple snow events. Again though, where that boundary lies wont be known for a while.

It's possible northern areas will remain in cold air throughout (mentioned this in the above quoted tweet)

Indeed! Fully expecting that which is why I'm not entirely buying the modelling around the 17th at the moment bringing those lows in, suspect it'll be more delayed than that. (though, it doesn't ALWAYS trend south as you say, not something we can 100% rely on!)

Not often i comment in the model thread in recent years, but having been here for nearly 17 years experience has suggested more often than not these lows track south (and the GFS tends to over blow them / track too far north), and it is usually the second or third attempt that makes in inroads north. That's potentially the best scenario for the UK as a whole, with battle ground snow to the south, snow showers to north. Sadly someone will always miss out, but this scenario offers the greatest widespread snow potential. Will be intriguing to see how this evolves over the coming days!

[Rob 79812010]

9 minutes ago, Mark Bayley said:

Not often i comment in the model thread in recent years, but having been here for nearly 17 years experience has suggested more often than not these lows track south (and the GFS tends to over blow them / track too far north), and it is usually the second or third attempt that makes in inroads north. That's potentially the best scenario for the UK as a whole, with battle ground snow to the south, snow showers to north. Sadly someone will always miss out, but this scenario offers the greatest widespread snow potential. Will be intriguing to see how this evolves over the coming days!

The lows will eventually get through but suspect it will be a relatively short period before back to cold. So, probably slightly below average Jan and I'm gagging for Feb to come 

[Malarky]

Interesting thing found on the internet… some temperature difference.