Model Output Discussion - Into Winter

[BartyHater]

Not really sure we any closer to resolving the first few days of the new year yet and in it’s latter stages the ECM looks rudderless, with a S Scandi High and a massive N Atlantic dartboard Low.

The ENS from GFS still show plenty of scatter, but the mean never drifts to far from average in the new year and the Op still manages to be one of the coldest members later in the run.

As for the minor models all show a variation on the ‘colder’ theme without demonstrating any kind of inter run consistency, so imo the 12 suite continues to ask more questions than it answers…. and I suspect that situation will persist for several days yet.

Edited December 26, 2023 by BartyHater

[TSNWK]

Just now, Dorsetbred said:

Sorry could you say that again, and again and again...

And post some charts please @BartyHater

[Froze were the Days]

26 minutes ago, Ali1977 said:

now we just need to correct set up

And there lies the problem - easterlies becoming less and less common, warmer sst's aiding short waves becoming of note of recent years.

[ItNeverSnowsInWindsor]

45 minutes ago, Catacol said:

I love it when the models struggle for coherence. ECM toward the end of the run is a mess - doesn’t know if it is coming or going. Sure sign that things are becoming more than a little interesting…

We could very easily end up with nothing cold wise. As has more often than not been the case.

Need the GFS and ensembles to agree on the cold solutions.

[Scott Ingham]

1 minute ago, prolongedSnowLover said:

We could very easily end up with nothing cold wise. As has more often than not been the case.

Need the GFS and ensembles to agree on the cold solutions.

Correct. Although this is the overwhelming outside chance with what’s about to go off in the atmosphere this next 2 weeks!

[January Snowstorm]

So while we look forward to a promise of wintry conditions in January worth commenting that most will have endured yet another snowless December. It must be around the 10th mild Bland Christmas here in a row, which rivals anything the 90s threw at us...

Now the positive stuff, it's clear to me the Strat is going to have a major impact as we move into the New Year. All of the big weather guru's including the Met Office seem to be going for this one!! When last did we get a decent January cold spell?? I genuinely can't remember one other than the tail end of '09

If we were gambling we'd be bankrupt long ago, a royal flush in January would be sweet

Edited December 26, 2023 by January Snowstorm

[Djdazzle]

4 minutes ago, Scott Ingham said:

Correct. Although this is the overwhelming outside chance with what’s about to go off in the atmosphere this next 2 weeks!

We’ve had that before - and still ended up with nothing.

I wouldn’t go any further than a 10% chance of a significant cold spell. We need a lot more runs yet.

[Ali1977]

1 minute ago, January Snowstorm said:

So while we look forward to a promise of wintry conditions in January worth commenting that most will have endured yet another snowless December. It must be around the 10th mild Bland Christmas here in a row, which rivals anything the 90s threw at us...

Now the positive stuff, it's clear to me the Strat is going to have a major impact as we move into the New Year. All of the big weather guru's including the Met Office seem to be going for this one!! When last did we get a decent January cold spell?? I genuinely can't remember one other than the tail end of '09

Yeah, I was overseas for the 2009 Jan cold spell - and the Nov/Dec 2010 spell for that matter  - and poorly fur the 2018 BFTE - I feel like I deserve a proper prolonged winter period - and an SSW early Jan is just about perfect timing in relation to the coldest point of winter a few weeks later

[Scott Ingham]

2 minutes ago, Djdazzle said:

We’ve had that before - and still ended up with nothing.

I wouldn’t go any further than a 10% chance of a significant cold spell. We need a lot more runs yet.

The stratospheric warming is 85% certain to happen and 60% of these produce wintry spells of significance so that 10% figure is a wild assumption backed by no discernible evidence.

This isn’t your regular background signal stab in the dark. The weight of evidence for this time period is as high as you’re likely to get to make a prediction for this timeframe. Strong enough in my mind to state it’s way more likely to be a wintry spell than a damp squib

Edited December 26, 2023 by Scott Ingham

[ItNeverSnowsInWindsor]

5 minutes ago, January Snowstorm said:

So while we look forward to a promise of wintry conditions in January worth commenting that most will have endured yet another snowless December. It must be around the 10th mild Bland Christmas here in a row, which rivals anything the 90s threw at us...

Now the positive stuff, it's clear to me the Strat is going to have a major impact as we move into the New Year. All of the big weather guru's including the Met Office seem to be going for this one!! When last did we get a decent January cold spell?? I genuinely can't remember one other than the tail end of '09

If we were gambling we'd be bankrupt long ago, a royal flush in January would be sweet

The Met Office are going for drier and more settled cold conditions which may not include widespread snow though.

[tight isobar]

Now that’s an interesting ensemble. And strays yet stays within its realm b4 base dropping!. The perturbations plots will tell more ..

[Djdazzle]

1 minute ago, Scott Ingham said:

The stratospheric warming is 85% certain to happen and 60% of these produce wintry spells of significance so that 10% figure is a wild assumption backed by no discernible evidence

60% may produce wintry spells but there’s no guarantee that we will be in the right place to benefit.

I’m just trying to ground people’s expectations. And we also know that the vast majority of modelled cold spells go wrong.

So my 10% is based on many years of model watching experience.

 

[Norrance]

8 minutes ago, January Snowstorm said:

So while we look forward to a promise of wintry conditions in January worth commenting that most will have endured yet another snowless December. It must be around the 10th mild Bland Christmas here in a row, which rivals anything the 90s threw at us...

Now the positive stuff, it's clear to me the Strat is going to have a major impact as we move into the New Year. All of the big weather guru's including the Met Office seem to be going for this one!! When last did we get a decent January cold spell?? I genuinely can't remember one other than the tail end of '09

If we were gambling we'd be bankrupt long ago, a royal flush in January would be sweet

Mid Jan 2013 was pretty good. Don't know about Cork but my home area had 18 inches of snow by the 22nd.

[January Snowstorm]

3 minutes ago, BartyHater said:

With a couple of obvious exceptions, December has pretty much become a late Autumn month across much of the last 20-30 years, with cold weather being far more likely in March.

Indeed but it's a different cold really isn't it. Mindsets have moved on to thinking of Spring in March. Cold spells are not disruptive in March compared to mid Winter. Your point is right though, March is statistically colder than Dec

[Ali1977]

6 minutes ago, prolongedSnowLover said:

The Met Office are going for drier and more settled cold conditions which may not include widespread snow though.

Any long range forecasting of an easterly will likely say it will be drier and more settled, it generally is on the whole but with bands of snow and times - and more showery on east facing coasts. Looking at the temps in Scandy, and some sea temps slightly higher than average for Jan; it could be the perfect scenario - should it materialise of course!! 

Edited December 26, 2023 by Ali1977

[bluearmy]

Ec chart viewer not working at present  

Edited December 26, 2023 by bluearmy

[MJB]

11 minutes ago, prolongedSnowLover said:

The Met Office are going for drier and more settled cold conditions which may not include widespread snow though.

yes but you can still have a good covering of snow and it be classed as dry. You need a fair bit of snow to be the equivalent of  1" of rain 

[Scott Ingham]

7 minutes ago, Djdazzle said:

60% may produce wintry spells but there’s no guarantee that we will be in the right place to benefit.

I’m just trying to ground people’s expectations. And we also know that the vast majority of modelled cold spells go wrong.

So my 10% is based on many years of model watching experience.

 

They only go wrong the vast majority of time if you follow every chase without counter proofing the chances of these cold model spells happening against any known forecasting science. I’m just saying this time and this chase has an overwhelming amount of scientific theory/fact and weather sense to make it more likely than other chases. A considerable number higher than 10% of it happening anyway! Haha! I respect your viewpoint if you like to forecast based on past model experience but I have to politely disagree with your view point mate. As ever all will be known come week 2 in January onwards and we will have a post mortem regardless of good or bad outcome wise in order to drive future self improvement and knowledge

[Drifter]

Something to worry about?

https://x.com/raleighwx/status/1739737310273343778?s=46

[feb1991blizzard]

3 minutes ago, Drifter said:

Something to worry about?

https://x.com/raleighwx/status/1739737310273343778?s=46

I must admit i feared this after the eps 0z mean 10mb height chart but more particularly GFS suites, although 12z GFS op was an improvement on 00 and 06.

Edited December 26, 2023 by feb1991blizzard

[Ali1977]

4 minutes ago, Drifter said:

Something to worry about?

https://x.com/raleighwx/status/1739737310273343778?s=46

I bloody hope not, let’s hope that trend disappears quickly

[Daniel*]

24 hour change in 12z EPS for London this is start in right direction….

 

adding Birmingham

 

 

Edited December 26, 2023 by Daniel*

[Eagle Eye]

Not surprised we're trending away from a SSW on the EC46, it's gone from Wave-2 to Wave-1 and the members are struggling to work w/a strong Wave-1. However, the trend is looking towards a Wave-3 in the Trop later into the forecast which is where our potential cold spell also comes from. That Wave-3 should push into the Strat as a tripole beyond the current forecast time and I suspect a lot of those members don't have that signal yet. However, if we continue to move towards it then there's nothing to worry about, essentially it's a delay, which happens with most things forecasted. Anyway, the vortex is likely to stay weaker than average throughout the next while, meaning a better chance of cold even w/out or a delayed SSW. 

 

Could still get a SSW first time if the Wave-2 is stronger (mainly the wave around Greenland needs more strength) than its currently forecasted. It's been forecasted to be stronger than it currently is being forecasted to be to be fair. 

Edited December 26, 2023 by Eagle Eye

[Kasim Awan]

50 minutes ago, Djdazzle said:

We’ve had that before - and still ended up with nothing.

I wouldn’t go any further than a 10% chance of a significant cold spell. We need a lot more runs yet.

Unfortunately I would agree - 20 to 30% maximum.

[Bats32]

30 minutes ago, Drifter said:

Something to worry about?

https://x.com/raleighwx/status/1739737310273343778?s=46

Oh oh!