Model Output Discussion - New Year and Beyond

[alexisj9]

1 hour ago, nick sussex said:

The problem is the high isn’t orientated favourably. It needs a ne sw alignment to face head on the  troughing .

The ECM at day 5 was quite encouraging and had the best set up . The UKMO the worst as it blows up the shortwave over the UK day 4 and doesn’t easily absorb the one to the north day 5 .

 

What I've noticed is we are still talking day 5 with the high, however it now shows weak before day five and strengthens, also the pattern behind still has the same lows, so the high does hold things up, behind it changes slightly every run, as in what the lows do. I'm not sure it's at the full resolution yet, but time is running out. I hope it doesn't get pushed aside, cold wise. But if I'm honest, it would be better for my pocket.

[Ali1977]

FI definitely improving, the mean heading to -5c and finally some -10c (even -15c) cold options.

Edited January 2, 2023 by Ali1977

[Mike Poole]

39 minutes ago, nick sussex said:

Regarding the Scandi high .

I think one more days outputs should decide whether even though unable to directly influence the weather on the ground as it edges east it could hang on in a more favourable position and add more forcing to direct the jet more se into the UK.

After the Scandi high moves  east the models paint an unsettled picture . Some variation though in how much suppression we see of the Euro high .

By day ten the ECM has the more favourable upstream pattern with a better chance of a more potent PM shot .

I’d remain wary though of the Euro high in the later outputs as the models seem to going on recent performance have been premature in either flattening it or displacing it further west and north .

The movement of the MJO does though favour some change so I’d say the odds slightly favour the more amplified upstream solutions .

 

 

I don’t think this early scandi high is going to result in UK cold directly, I think that was always a big ask.  

What it does do potentially, is demonstrate that the atmosphere as of now is perhaps more prone to northern blocking than it appeared because the high has been underestimated by the models.

It also, as it moves east, puts pressure on the strat vortex in combination with the Aleutian low.

But, I think the model runs that have it stronger, also slow the movement east of the big low in the Atlantic, which delays any meaningful PM shot, and also delays eroding the euro high.  But I think these are both delays rather than substantially changing the picture we previously had from several ensemble suites of low heights moving eventually in the direction of Italy.  

If you look at the extended clusters T264+ you still see the euro heights gone on all 3 (apart from the first chart of cluster 1), and - again apart form the first chart of cluster 1, no further +NAO charts, with Scandi high, Atlantic ridge and Greenland block represented. 

Edited January 2, 2023 by Mike Poole

[bluearmy]

The upper trough that is going to barrel into the Atlantic sector is currently forming in the base of the pv extension far n of Canada. You would expect the models to have a good handle on this feature but there is still some wriggle room on its evolution and subsequent interaction with the sceuro ridge thrown up ahead of it.  As nick says, perhaps another couple runs to be certain of how that is most likely to play out. (Although the models do seem pretty sure) 

beyond this it looks pretty mobile zonal but mid month begins to smell a little interesting. There are more gefs members than I have seen for some time with notable solutions for that timescale. Awaiting to see if the eps are similar in that respect. The clusters show that they could be. 

[BlueHedgehog074]

2 hours ago, Eagle Eye said:

I'm going to copy over my pretty much non-biased (hopefully) texted forecast long-term to one of my friends...

Firstly, we have the Atmospheric Angular Momentum (AAM) which is the amount of torque or rotational force in the atmosphere… Positive AAM (+VE means positive… 

We do for sure have some incredible model output and chart analyser’s in here. The knowledge by some is just out of this world! (Although I appreciate all the posts people do in here no matter how big, small, technical, non-technical they are).

If you were to write a book about the weather, and/or some kind of guide to the models, I bet it would get sold out faster than a flash of lightning.

[Chesil View]

It's always a trade off having a Scandi. Scuero high place that doesn't directly bring cold to the UK.

The downside is that they simply hold a mild wet trough in place over the UK or they just aid the barrelling of lows across the UK and up past Northern scandi in a perpetual mild wet and windy regime for us.

The upside is that they allow very cold air to build in the Scandi locale so that when the next bout of sufficient amplification  comes round there is at least some cold air in place to advected southwest towards th UK.

The key is getting that next bout of amplification into play.

Edited January 2, 2023 by Chesil View

[Stuie]

Mogreps hasn`t deviated too much from it`s output on the 31st. 1st chart goes to Jan 8th, 0Z Jan 2nd does show possibly a trend cooler by the 10th but nothing eye catching.

1st image is a jpeg output from here, other a screenshot. Same stuff.

[bluearmy]

The eps control shows that if the first push of the trough is less clean then things aren’t that far from being interesting- were still likely to fall short though with things as they currently look
 

[Duane S.]

It does seem that, whilst there is little appetite for a full on SSW any time soon, the forecast warmings up top could start playing havoc with the SPV, stretching it here and pushing it there.

A slow down up top coming into view. Yes, nothing significant, but maybe it won’t need to be?

And, last but not least,  you’d have to assume this won’t be without huge consequence with regards to the NH atmosphere, off the scale…

My take away is a mobile first half of January but literally anything goes as we get past mid month. 

[nick sussex]

The GFS 06 hrs run T114 hrs is quite similar to the ECM 00hrs run to T120 hrs although the former makes more of that very annoying shortwave off the coast of Norway .

[ANYWEATHER]

Dare I say it but I think we are going to be stuck in this rut for the rest of the month, can't see any other trend or backround signals to convince me otherwise...

[bluearmy]

7 minutes ago, ANYWEATHER said:

Dare I say it but I think we are going to be stuck in this rut for the rest of the month, can't see any other trend or backround signals to convince me otherwise...

Just the 30 days then ………

[johncam]

20 minutes ago, ANYWEATHER said:

Dare I say it but I think we are going to be stuck in this rut for the rest of the month, can't see any other trend or backround signals to convince me otherwise...

Sad to say you could be right , latest model output also seem to be downgrading any PM shots 

[Chesil View]

58 minutes ago, s4lancia said:

It does seem that, whilst there is little appetite for a full on SSW any time soon, the forecast warmings up top could start playing havoc with the SPV, stretching it here and pushing it there.

A slow down up top coming into view. Yes, nothing significant, but maybe it won’t need to be?

And, last but not least,  you’d have to assume this won’t be without huge consequence with regards to the NH atmosphere, off the scale…

My take away is a mobile first half of January but literally anything goes as we get past mid month. 

My thoughts are along a similar line S4L. Writing off the whole of January on the second day of the month because the current outlook is mobile would foolish.

Edited January 2, 2023 by Chesil View

[Battleground Snow]

3 minutes ago, johncam said:

Sad to say you could be right , latest model output also seem to be downgrading any PM shots 

Yep charts like this and repeating warmings scream normal January mild weather... 

[KTtom]

28 minutes ago, ANYWEATHER said:

Dare I say it but I think we are going to be stuck in this rut for the rest of the month, can't see any other trend or backround signals to convince me otherwise...

I feel for your pain with the comments comming your way after that statement

Can see where you are comming from tho...I personally think something may crop up after or around mid month similar to what gfs 06z is trying to do with heights forming around Iceland.  

Edited January 2, 2023 by KTtom

[johncam]

2 minutes ago, Battleground Snow said:

Yep charts like this and repeating warmings scream normal January mild weather... 

I no longer look at the new GFS as it has been terrible 

[Methuselah]

1 minute ago, KTtom said:

I feel for your pain with the comments comming your way after that statement

Can see where you are comming from tho...I personally think something may crop up after or around mid month similar to what gfs 06z is trying to do with heights forming around Iceland.  

Indeed. And not being able to see where the next cold, snowy spell is going to come from, isn't quite the same as writing off the entire month of January... I can't see where it's going to come from either, But I ain't writing anything off.

[Lampostwatcher]

Gfs 6z

Scandi building day 12 

[Ali1977]

23 minutes ago, ANYWEATHER said:

Dare I say it but I think we are going to be stuck in this rut for the rest of the month, can't see any other trend or backround signals to convince me otherwise...

This could get us out of the rut. 

[Mike Poole]

GFS 6z has the sort of evolution we want to see after the PM shot in FI, due to increased amplification.  No point looking at the detail this far out (the UK isn’t that cold on this run) but this sort of change is what I am looking for mid-month:

The MJO is already in phase 7 now, with greater amplitude than models have predicted, so with the lag, this sort of evolution is plausible on that timescale in my view.

Edited January 2, 2023 by Mike Poole

[nick sussex]

Encouraging GEFS so far to day 7 with the Euro high either flattened or displaced further west.

European ski resorts will be praying this trend continues as it’s been a horror show for the last few weeks especially for lower altitude stations .

[Battleground Snow]

11 minutes ago, johncam said:

I no longer look at the new GFS as it has been terrible 

Will agree with that the last 6 weeks, but it's the only OP we get to see past day 10

[Lukesluckybunch]

Well Well more of the same from the gfs..mild throughout it would appear!even them transient shots from the north and northwest look out the picture now..not very good for cold the next two weeks! All of this after a rubbish ECM also

[MP-R]

25 minutes ago, nick sussex said:

Encouraging GEFS so far to day 7 with the Euro high either flattened or displaced further west.

European ski resorts will be praying this trend continues as it’s been a horror show for the last few weeks especially for lower altitude stations .

Yes! I’m due to ski in the Pyrenees from the 20th. You’d think between now and then we could get some precipitation down there! 

The same necessity down there is what we need up here to shift this pattern along i.e. low pressure to the south. Although, some potent Pm shots heading SE would also do the trick! The last time I skied down there was Jan 2013 and the snow was excellent but the month featured a lot of low pressure over Spain.