Model Output Discussion - Into 2024

[ItNeverSnowsInWindsor]

1 hour ago, Scott Ingham said:

Please tell me you now aren’t happy with the ecm chart that has come round full circle to cold again! There’s lots of snow on that ecm where I am in Rotherham and there’s still more room for upgrades it’s a fabulous morning!  

The latest synoptics strongly favour Northern regions with the South at mercy of milder incursions.

Clearly nowhere near as good as the models were showing a few days ago with everything watered down.

[Chesil View]

Just now, Penrith Snow said:

If Netweather  existed 20,000 years ago some members would be complaining about how thin the glaciers were south of the M4 corridor compared to up north!

Indeed. But very strange that 20,000 years later the M4 corridor is still so often a demarcation line for snow events.  

[Grimplet]

2 minutes ago, prolongedSnowLover said:

The latest synoptics strongly favour Northern regions with the South at mercy of milder incursions.

Clearly nowhere near as good as the models were showing a few days ago with everything watered down.

No surprise really. Northerlies don't really produce much down south anyway.

[WinterOf47]

11 minutes ago, Chesil View said:

Models seem to be converging on a cold out come around day6/7 which is still too far out for comfort but definitely a step in the right direction.

Snow chances will be governed by day to day developments much closer to the time if the reality of the general forecast pattern materialises.

Still some  scope for milder nudging air into the south on current output which could lead to high risk/high reward snow chances here but that would be highly dependent on nuances much closer to the time.

Ideally now we want to see the models firming up or even upgrading the pattern on which they appear to be converging, over the next few days. That would decrease Nick Sussex's very sensible margin for error factor.

At the moment it seems as though Scotland and the North are pretty much guaranteed a few days with snow showers from Sat/Sun, but it is the south that could have a complete bust or cash in big time. Down here, just inland from the South Coast, there have been a number of times when the temperature has dropped like a stone as a low pressure trundles along the channel, starting with mild air dragged off the sea, then switching to cold North Easterlies tapping into cold inland air, but still pulling lots of moisture off the Chanel. Had a number of 6-10 inch dumplings like that in my lifetime. The set up next week at the moment allows for that opportunity, equally the lows could lurch south leaving cold and dry or track north and dump further up country. I prefer a set up like this to a dry bone-numbing “beast from the east” that last weeks but delivers little except to the East Coast.

[Chesil View]

7 minutes ago, prolongedSnowLover said:

The latest synoptics strongly favour Northern regions with the South at mercy of milder incursions.

Clearly nowhere near as good as the models were showing a few days ago with everything watered down.

That's always been the risk reward equation for the south from northerly sourced cold. The northerly source usually means dry for the south and therefore you need the risk of milder air nudging in to create snowfall chances.

Short of a polar low or very active cold front like the 2004 thundersnow event. Northerlies on their own are not great for southern snow chances

Edit. I see winter of 47 has said something similar above.

Edited January 8 by Chesil View

[Scott Ingham]

11 minutes ago, prolongedSnowLover said:

The latest synoptics strongly favour Northern regions with the South at mercy of milder incursions.

Clearly nowhere near as good as the models were showing a few days ago with everything watered down.

 

Compared to 48 hours ago they have upgraded run to run! They looked a lot worse over the weekend. These are amazing charts you must be hard to please! 

Edited January 8 by Scott Ingham

[Djdazzle]

I don't see everything being watered down?

[MJB]

13 minutes ago, prolongedSnowLover said:

The latest synoptics strongly favour Northern regions with the South at mercy of milder incursions.

Clearly nowhere near as good as the models were showing a few days ago with everything watered down.

I have experienced those scenarios and been left with 6" of wet lying snow before then turning colder, while the North were just getting frequent snow showers and nowhere near the covering but in a colder airmass.

 

EDIT

As per what Winter and Chesil have said

Edited January 8 by MJB

[Weathizard]

I see it’s got childish in here again this morning, there’s always going to be natural location bias when viewing the models, not sure why it’s taken so personally.

Northerlies aren’t particaurly favourable for southern areas but it also can be a very high reward IF we do get some moisture thrown in, I know the old adage is often said on here but get the cold air in place first then we can worry about exact forecasts later on, I’m a snow starved south coaster so I’m as hard done by as any  

[bluearmy]

32 minutes ago, Tim Bland said:

GEM may be a bit more risky but it’s a lot more rewarding…

If you check out the 850’s Tim the; you’ll find its mainly wet for you and me 

hence the need to get the trough further south before the Atlantic tries to slide in 

[bluearmy]

Not a great eps cluster choice from eps days 8/10. The op and control are in it so must be some spread in it 

[Lukesluckybunch]

9 minutes ago, bluearmy said:

If you check out the 850’s Tim the; you’ll find its mainly wet for you and me 

hence the need to get the trough further south before the Atlantic tries to slide in 

850's of -8 would do the trick surely!

[terrier]

Nothing wrong with this morning’s output Ukmo & gem spectacular gfs also good as is the ecm. Seems some imby’s going on today. Yes not so good further south but last time I looked this was the model output thread. Not the southern regionals lol.  

[kold weather]

I totally understand the worry and some are being very dismissive of it this morning.

That pattern needs to shift only a fraction north and its going to be a close but no cigar for at least  50% of the populace of the country. We literally *just* get away with it on several models.

Again I'd personally want a stronger pattern, get the cold in *then* relax into a LP attack rather than just skip the first stage and hope the cold even makes it in the first place. 

As it is though most runs are still very interesting, if as others have said, risking incursions of warmer air into the south.

[Mike Poole]

ECM clusters this morning.  Uncertainty now seems to be reduced once more, with just 2 or 3 clusters, which I prefer to 5 or 6, or even 1 (when it can’t distinguish 6 or less).

T120-T168:

Cross suite consensus that the heights get properly into Greenland now.  These clusters hardly differ, cluster 1 the extent of the high into the Arctic  slightly reduced.  Cluster 3 looks slightly faster with the cold to the UK.

T192-T240:

Cluster 1 looks like it is heading west-based -NAO by T240, but that cannot be the whole story because the op is in that cluster and that definitely did not do that.  Remember there is nothing special about the UK as far as the algorithm that does the clustering is concerned.  A look at the individual members is warranted later.  Cluster 2 remaining Atlantic ridge regime.

T264+:

A growing signal for extending the blocked period from 2 runs ago.  Cluster 1 maintains the Greenland high, cluster 2 shows a return to mobility, cluster 3 remains blocked, first hint at transition to Scandi - I know we are looking out for it!  One to watch.

[kold weather]

6 minutes ago, Lukesluckybunch said:

850's of -8 would do the trick surely!

Starts as snow then would transition to rain and melt it all away for far south where you are. You'd want a weaker low and maybe a little south still.

[frosty ground]

1 hour ago, JimBob said:

The next 2 to 3 days look the coldest for the south in the reliable time frame, just looks standard winter fare, even some double figure temperatures creeping in on some models at ten days time! 

Day ten double digit temps? Which model is that? Biggest question is it still dry?

[frosty ground]

1 hour ago, prolongedSnowLover said:

The problem is that we’re seeing a north based NAO!

 

I we at that stage where we create another NAO reference 

[Met4Cast]

The multi-model ensemble continues to highlight the broad evolution re mid month cold. A fair amount of spread but broadly cold air remains in place up to or after the 20th.

The NAEFS (GEFS & GEPS) continue to highlight the broader expected synoptic pattern well, been keeping an eye on this and it has generally been very consistent. 

Returning momentum in the form of the jet stream will likely begin to nudge northwards in the 20th-25th period and this is the period where we could see some high impact snowfall events, indeed the GEM highlights this scenario well with weather systems moving into some very cold & stagnant air across the UK, albeit perhaps a few days earlier than suggested above (probably too progressive in removing forcing from the high)

[northwestsnow]

Excellent runs this morning..

Trend is very good and its about ruddy time we saw a cold spell in the middle of January !!

[Lukesluckybunch]

Hopefully no more set backs..a nice clean passage into Greenland the period 120-168..that's generally what the models are agreeing on..hopefully some deep cold in the longer outlook

[DJ Fart]

18 minutes ago, terrier said:

Nothing wrong with this morning’s output Ukmo & gem spectacular gfs also good as is the ecm. Seems some imby’s going on today. Yes not so good further south but last time I looked this was the model output thread. Not the southern regionals lol.  

Seems to me it's gloating from northerners which has rubbed some up the wrong way. Still a long way to go before any of us see proper snow falling, with many more twists and turns to come. 

[Catacol]

Countdown to @Scott Inghamday is on - now 168 hours away.

For those interested, verification stats for 00z runs are quite a bit ahead of the 12z runs at the moment, and when it comes to 168h prediction from 00z runs there is very little between the models at the moment and that includes GEM. Don't diss it!

[Met4Cast]

1 minute ago, Catacol said:

Countdown to @Scott Inghamday is on - now 168 hours away.

For those interested, verification stats for 00z runs are quite a bit ahead of the 12z runs at the moment, and when it comes to 168h prediction from 00z runs there is very little between the models at the moment and that includes GEM. Don't diss it!

The GEM is absolutely a model I take more seriously these days, it used to be relegated to the cannon fodder folder alongside NAVGEM and JMA but it's come along way in recent years, absolutely a key player up there with the GFS, ECM and UKMO imo. 

[danm]

4 minutes ago, northwestsnow said:

Excellent runs this morning..

Trend is very good and its about ruddy time we saw a cold spell in the middle of January !!

11 years! 2013 was good, before that 2010. Nothing of significance since.