Model Output Discussion - Into 2024

[Eagle Eye]

Some of the best overall pattern charts being predicted now, w/the Greenland high supported to be a bit stronger and less transient and varied. Could well still change but for now, the overall pattern is very good, every chance for upgrades still w/just miles between stronger 850's further south and not. General pattern a week away is likely to happen, exact 850's aren't and people know that. Note the 850's in the SE yesterday just kept getting continuously upgraded but that probably won't get mentioned by the moaners who say models always downgrade from this point. There is a flip side to what Im saying but what is the point of thinking that? To avoid disappointment? Is it worth moaning for a whole week to avoid a bit of cold and snow downgrading, it's fun when you get it but if it's life or death to you, a reminder that most people here have lived through way more big Winters than me, I don't even remember 2010, I only have 2018. The weather doesn't owe anyone anything. 

[Chesil View]

2 minutes ago, Catacol said:

A fair point - but I'm not sure the prognosis at the moment has really deviated from the overall shape of things that was probably best expressed by Tamara a couple of her posts ago. We have the wave break now that is being pushed up to high latitude at the end of the week, we then have the cold trough dropping in. We will likely have a slower breakdown from this than the models predict (because observationally models speed up breakdowns than is usually the case once it happens) and then we have - with the less favourable MJO phases and a drop in AAM - an anomaly chart like this to wrestle with:

First of all it is a very long way off - but if we take it at face value it reflects the progression of the drivers stated above but does not really give us a scooby as to what the synoptics will be. There is certainly a pressure contrast that is still suggestive of weak -NAO but quite where the cold/warm boundary will sit is very uncertain.

Then -  looking at the latest GEPS that, to my eye, has been a bit more accurate than GEFS from the 00z run we get this out in the very far reaches of ensemble modelling:

High pressure starting to build back into Greenland in line with the Nino background and drivers pointing to renewed momentum and amplification which then ties in with the EC weekly move back towards this:

So - some degree of relaxation of the cold was inevitable at the end of next week, but it does look temporary and - in any case - quite where the boundary between the warm and cold air will be is utterly impossible to nail down now. I think the overall pattern as described in that post of Tamara's remains solid.

Good post Catacol. It's easy for people to say thus has not worked or so .ych for that driver. Because they purely look at it from a snow I  my backyard point of view but the overall global picture is very much as the drivers predicted. Local backyard stuff within that global pattern is down to nuance and if its snow you want a bit of luck. But the overall pattern is very much as was suggested.

[MattStoke]

5 minutes ago, CoventryWeather said:

Don't get why everyone is panicking - the models have shifted north, but these battleground events are hard for modelling to get right. It will be uncertain right down to 48/72 hours, where it will most likely go right through France, as models overestimate the strength of the Atlantic compared to the cold airmass. 

Also it's one set of operational runs and ensembles. It will change back and forth in the next week, some to good runs and some to bad runs. No need to stress on every run. 

Longer range modelling shows the cold leaving briefly at the end of next week, but there is a risk of severe snow events on that boundary. Like I said above, it won't be known where this is until a day or two beforehand. Such an interesting period of weather, don't really know why people aren't happy about it...some bias from southern regions I believe 

Spot on. 

[Lampostwatcher]

European computer model is saying 

Buy a new sledge gloves and hat winter is arriving with atleast 1 snow event 🌨

[Mike Poole]

ECM clusters this morning do not help much because there is again only one cluster during the key T192-T240 timeframe.

T120-T168:

Here I find it very reassuring that the op is in cluster 1, because cluster 2 is better!  It retains more of a ridge between the UK and the Azores low, which should keep them separate and allow the cold air further south.

T192-T240, doesn’t tell us much, on the member shown, the UK remains cold:

T264+:

There is still the suggestion in cluster 1 and 4 of a shift towards Scandi heights but nothing definitive.  Clusters 2 and 3 show a gradual return to mobility as the block recedes.

[Zero Visibility]

6 minutes ago, CoventryWeather said:

Don't get why everyone is panicking - the models have shifted north, but these battleground events are hard for modelling to get right. It will be uncertain right down to 48/72 hours, where it will most likely go right through France, as models overestimate the strength of the Atlantic compared to the cold airmass. 

Also it's one set of operational runs and ensembles. It will change back and forth in the next week, some to good runs and some to bad runs. No need to stress on every run. 

Longer range modelling shows the cold leaving briefly at the end of next week, but there is a risk of severe snow events on that boundary. Like I said above, it won't be known where this is until a day or two beforehand. Such an interesting period of weather, don't really know why people aren't happy about it...some bias from southern regions I believe 

This is a great level minded post and highlights why we are all here in the first place. Yes we would all love to see that winter wonderland but if other fellow members on here are forecast snow tomorrow and I was not, I would be made up for them. I have been watching and learning on this forum for many years, and what I will say is this is one of the most interesting and exciting periods of seeing how the models play out in years.

[jamesthemonkeh]

12 hours ago, Biggin said:

Yep. you are.

Look at those tasty uppers coming into Spain late next week!

 

The trend does not appear the coldie's friend, though I think you can still be heartened by the ECM.

If we get the cold in first, then the background scenario could be fun levels of snow for many, though that remains an if, to my possibly misguided eyes.

Though the temporary end to the cold spell, as backed up by more knowledgeable posters on here in terms of MJO, etc, now does seem to be signalled for some point next week/next weekend - can we get some fun first?  (slight south/central England bias here so apologies)

[AdrianHull]

I really hope this Low pressure late next week moves much much further south.

I know the snow precipitation charts look great for the Midlands and south but for the UK as a whole it's not the best outcome early on into a cold spell.

Fingers crossed we can maintain the Northly feed so we can get even more cold in.

Some people are a little too happy on eating the first sweet they are given where I tend to save mine.

Either outcomes are interesting but with different risks whatever happens. 

Edited January 9 by AdrianHull

[TEITS]

Have to say regardless of your location the current output is excellent and to be fair you will never get a set up that will deliver for everyone. Only the likes of 1947 do this when blocking alternates between Scandi & Greenland.

So the initial surge of cold N,lys around 14th/15th Jan looks likely despite some dodgy ECM runs a few days ago. At this stage snowfall looks limited but you never know what will develop in the N,ly flow.

Now onto my favourite part which reminds me of the late 1970s, 80s. The classic old skool situation of a blizzard for some, snow to rain for others, and then some seeing snow to rain and then back to snow again. At the moment impossible to say who will hit the jackpot but based on the current output and my own personal experiences I would say the bullseye is slightly further S than the ECM has this.

My reasoning is this. Note for my location the ECM operational is very close to the mean.

Now look for the S coast of England. This is way higher than the operational.

 

So the above combined with my own personal experience of these set ups suggest the main risk of heavy snow is further S with the N limit being around 30miles N of London. Subject to change though!!

[Gowon]

The ICON looks a downgrade compared to the 0h run

[bluearmy]

Incidentally, the main 3 AI models seem less interested in bringing the Azores lows as far north as the U.K. 

Yesterday they were inconsistent so not deducing too much from this yet 

[Kasim Awan]

24 minutes ago, Eagle Eye said:

Some of the best overall pattern charts being predicted now, w/the Greenland high supported to be a bit stronger and less transient and varied. Could well still change but for now, the overall pattern is very good, every chance for upgrades still w/just miles between stronger 850's further south and not. General pattern a week away is likely to happen, exact 850's aren't and people know that. Note the 850's in the SE yesterday just kept getting continuously upgraded but that probably won't get mentioned by the moaners who say models always downgrade from this point. There is a flip side to what Im saying but what is the point of thinking that? To avoid disappointment? Is it worth moaning for a whole week to avoid a bit of cold and snow downgrading, it's fun when you get it but if it's life or death to you, a reminder that most people here have lived through way more big Winters than me, I don't even remember 2010, I only have 2018. The weather doesn't owe anyone anything. 

Not sure about this I think the Greenland high signal looks less amplified and robust than a few days ago.

[The Enforcer]

Having looked at the 00z ensembles suites, I subjectively rank the stinker run %s as follows:

1. GEM - 41% (includes the operational & control)

2. GFS - 28% (includes the operational & control)

3. ECMWF - 25%

 

Certainly room for improvement.

Edited January 9 by The Enforcer

[Eagle Eye]

Just now, Kasim Awan said:

Not sure about this I think the Greenland high signal looks less amplified and robust than a few days ago.

Depends when you take it, the shortwaves were often interfering w/the signal so it got watered down. Especially w/the Northern extent it could push to, often it was just a wedge in south Greenland. 

[Alexis]

4 minutes ago, Gowon said:

The ICON looks a downgrade compared to the 0h run

If you get your magnifying glass out
Think it's more of a few hours delay looking at the 850s so far.

[Nick123]

For my own sanity I'm taking a break till the weekend. I dunno how you guys Do it!

[Ice Day]

1 hour ago, Continental Climate said:

A good post in my view. If you look at the output say 5 days ago there was a much more robust signal for greenie blocking and the infamous shuffling high to the north was meant to just meander around giving us a prolonged cold period. That signal has evaporated. I've not heard a single mention of a shuffling high for days. Some people are quite rightly frustrated this signal has been dropped. This spell has been watered down last few days in my opinion. Will it get colder yes, will people get snow yes, will this be a period of snowy weather lasting longer than 6 days unlikely now in my opinion. There is no denying the blocking signal has faded last few days. 

Excellent post CC.  I think the optimism by some of the more knowledgeable posters this morning is great, but the blocking signal has changed and faded over the last few days.  I'm still cautiously optimistic, but my confidence for the south of the UK has dropped a little over the last couple of days. Lots of changes to come, the funny thing is we *could* be on the cusp of a notable UK snowstorm for early next week, but as of yet I certainly won't be counting any chickens.  The 12z's tonight will be extremely informative.

[TEITS]

6 minutes ago, Nick123 said:

For my own sanity I'm taking a break till the weekend. I dunno how you guys Do it!

Simple for me. There was a time when I used to view all model runs as they come out and view each individual ensemble member. I was also dreadfully biased towards cold weather. Now I try and take a more balanced approach to viewing the models but I also have less time to look at them like I used.

Also with all the pain and suffering in the world I tend to put the UK getting snow into perspective.

[booferking]

14 minutes ago, TEITS said:

Have to say regardless of your location the current output is excellent and to be fair you will never get a set up that will deliver for everyone. Only the likes of 1947 do this when blocking alternates between Scandi & Greenland.

So the initial surge of cold N,lys around 14th/15th Jan looks likely despite some dodgy ECM runs a few days ago. At this stage snowfall looks limited but you never know what will develop in the N,ly flow.

Now onto my favourite part which reminds me of the late 1970s, 80s. The classic old skool situation of a blizzard for some, snow to rain for others, and then some seeing snow to rain and then back to snow again. At the moment impossible to say who will hit the jackpot but based on the current output and my own personal experiences I would say the bullseye is slightly further S than the ECM has this.

My reasoning is this. Note for my location the ECM operational is very close to the mean.

Now look for the S coast of England. This is way higher than the operational.

 

So the above combined with my own personal experience of these set ups suggest the main risk of heavy snow is further S with the N limit being around 30miles N of London. Subject to change though!!

More like france main risk for heavy snow for me.

[Battleground Snow]

Gfs has took a big step to the euros early on,

Look for the high to get sucked up from Uk towards greenland because the low is still enclosed in the Atlantic 

Edited January 9 by Battleground Snow

[TSNWK]

Just now, Battleground Snow said:

Gfs has took a big step to the euros early on,

Look for the high to get sucked up from Uk because the low is still enclosed in the Atlantic 

I still don't understand this closed in low resolution you have mentioned  

[Battleground Snow]

3 minutes ago, TSNWK said:

I still don't understand this closed in low resolution you have mentioned  

Haha I'm not explaining it again, I've already done it twice, just  it will prop the block up better and will send the cold plunge more south rather than south west

Edited January 9 by Battleground Snow

[Captain Shortwave]

Well the good news is the cold plunge from the north is almost certainly going to occur on Sunday and into Monday. However it is hard to not feel a little concerned when models toy with this push of cold air into the Atlantic because that brings the risk of a chain reaction that can literally turn the Atlantic profile from blocked to a positive NAO in a couple of days. We do want the models and track back towards something a little more safe in the coming runs.

[feb1991blizzard]

6z looking like a better run than 0z, i actually prefer the Atlantic trough nearer as the last run it attracted the cold trough to the NE to spill too far into the Atlantic

Edited January 9 by feb1991blizzard

[Zero Visibility]

 

Icon v GFS 120