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Brian Gaze
30 December 2024 12:00:53
It's still difficult to be confident about how things will play out during the next couple of weeks. My reading of the data is we remain close to a tipping point. One thing to look out for is whether ECM ENS trends colder later today. 
MOGREPS also looks iffy. However, as I've mentioned the recommendation is to group the 00Z and 06Z together and the 12Z and 18Z together. At the time of writing the 06Z update isn't available. 

UserPostedImage 

UserPostedImage
Brian Gaze
Berkhamsted
TWO Buzz - get the latest news and views 
"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan
+1
Retron
30 December 2024 12:05:55
Copied from the last thread, as I posted it just after your closure warning, and I don't want the link to be missed! 😁

(Regarding the ECM ensembles)

Yes, they're not great. The EPS suite performed a massive flip overnight, with the median (not mean) noon temperature here on Sunday going from 3C (0z yesterday) to 4.5C (12z) to 11C this morning. And that's a very certain 11C as far as it's concerned, too, with the top 50% being squidged in between 11 and 12.

Hopefully it's confidently wrong, and the evidence from the other models suggests it may well be.

Incidentally the AIFS has ensembles too, and they can be seen in meteogram form here:

https://charts.ecmwf.int/products/aifs_opencharts_meteogram?base_time=202412300000&epsgram=aifs_classical_10d&lat=51.3973&lon=0.921564&station_name=Leysdown-on-Sea 

(Type in your own town, like the main ensembles it has points all over the place).

The AIFS has a median of 6C on Sunday, with the op towards the bottom at 2C. A remarkable difference between the two suites, and I would wager the AIFS will be closer to the mark (again, given the other models).
Leysdown, north Kent
+1
Rob K
30 December 2024 12:20:27
JFF, the CFS nine-monther 18Z run keeps it mostly cold or very cold right out to the beginning of March with just a few brief milder interludes!

PS the "Quick reply" button doesn't work and hasn't done for a long time - is it just me?
Yateley, NE Hampshire, 73m asl
"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome
Chunky Pea
30 December 2024 12:20:50

Copied from the last thread, as I posted it just after your closure warning, and I don't want the link to be missed! 😁

(Regarding the ECM ensembles)

Yes, they're not great. The EPS suite performed a massive flip overnight, with the median (not mean) noon temperature here on Sunday going from 3C (0z yesterday) to 4.5C (12z) to 11C this morning. And that's a very certain 11C as far as it's concerned, too, with the top 50% being squidged in between 11 and 12.

Hopefully it's confidently wrong, and the evidence from the other models suggests it may well be.

Incidentally the AIFS has ensembles too, and they can be seen in meteogram form here:

https://charts.ecmwf.int/products/aifs_opencharts_meteogram?base_time=202412300000&epsgram=aifs_classical_10d&lat=51.3973&lon=0.921564&station_name=Leysdown-on-Sea 

(Type in your own town, like the main ensembles it has points all over the place).

The AIFS has a median of 6C on Sunday, with the op towards the bottom at 2C. A remarkable difference between the two suites, and I would wager the AIFS will be closer to the mark (again, given the other models).

Originally Posted by: Retron 


Looking at the 'plume' charts for here from your link, and it still seems that the tightest cluster is on the cooler side of things in the longer term:, although, as you say, with much scatter overall. 

UserPostedImage
East Galway, Ireland.
Current Conditions
https://t.ly/MEYqg 

"You don't have to know anything to have an opinion"
Roger P, 12-Oct-2022
Gandalf The White
30 December 2024 12:25:28

It's still difficult to be confident about how things will play out during the next couple of weeks. My reading of the data is we remain close to a tipping point. One thing to look out for is whether ECM ENS trends colder later today. 
MOGREPS also looks iffy. However, as I've mentioned the recommendation is to group the 00Z and 06Z together and the 12Z and 18Z together. At the time of writing the 06Z update isn't available. 

UserPostedImage 

UserPostedImage

Originally Posted by: Brian Gaze 


A fairly consistent signal for the cold air to sink south during New Year’s Day and a chance/likelihood of a renewed push of milder air from the south-west over next weekend. As you go further north the number of members predicting that mild push becomes a diminishing minority. It’s a similar message going into next week; yet again the battleground appears to be setting up somewhere between The Channel and Southern Scotland.
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


Retron
30 December 2024 12:30:32

Looking at the 'plume' charts for here from your link, and it still seems that the tightest cluster is on the cooler side of things in the longer term:, although, as you say, with much scatter overall. 

Originally Posted by: Chunky Pea 


You can see the plumes from the normal EPS here: (again, modify the town)

https://charts.ecmwf.int/products/opencharts_meteogram?base_time=202412300000&epsgram=classical_plume&lat=51.3973&lon=0.921564&station_name=Leysdown-on-Sea 

I suspect that yours, like mine, will look much warmer on the regular EPS.
Leysdown, north Kent
Saint Snow
30 December 2024 12:42:23

A fairly consistent signal for the cold air to sink south during New Year’s Day and a chance/likelihood of a renewed push of milder air from the south-west over next weekend. As you go further north the number of members predicting that mild push becomes a diminishing minority

Originally Posted by: Gandalf The White 




Yes, the Manchester ENS mean stays below -5c through to 10th Jan (barring a small blip to around -4c on the 6th as a few members spike, presumably from tracking a/the low further north).

Op stays below -5c until 12th.

Martin
Home: St Helens (26m asl) Work: Manchester (75m asl)
A TWO addict since 14/12/01
"How can wealth persuade poverty to use its political freedom to keep wealth in power? Here lies the whole art of Conservative politics."
Aneurin Bevan
Chunky Pea
30 December 2024 12:48:13

You can see the plumes from the normal EPS here: (again, modify the town)

https://charts.ecmwf.int/products/opencharts_meteogram?base_time=202412300000&epsgram=classical_plume&lat=51.3973&lon=0.921564&station_name=Leysdown-on-Sea 

I suspect that yours, like mine, will look much warmer on the regular EPS.

Originally Posted by: Retron 


Yes, looks different, but only briefly. End of the set is much the same:

UserPostedImage
East Galway, Ireland.
Current Conditions
https://t.ly/MEYqg 

"You don't have to know anything to have an opinion"
Roger P, 12-Oct-2022
moomin75
30 December 2024 13:03:06
The stand-off between GFS/GEM and to a lesser extent UKMO v ICON/ECM must surely be resolved one way or another in the next 24 hours.
We've seen this a lot over countless years where the rogue model comes into line with the best, but more often than not, the rogue model is showing the cold while the others are going mild.
This is the other way around, and so one has to hope that ECM/ICON are barking up the wrong tree.
As ever, time will tell, but I do get a feeling in my loins that January 2025 may provide a lot more interest than recent January's. 
I'm sure a lot of you are pleased I haven't been posting much this year. Due to my dad falling very ill, I've not really been around the forum much, but I do still show a passing interest in the models, and suffice to say, it's looking very interesting this winter so far.
Thanks to those of you who have reached out privately with messages of support for me, as dad embarks on his cancer treatment journey, which has really put everything else into perspective for me.
Witney, Oxfordshire
100m ASL
+9
White Meadows
30 December 2024 13:05:57

JFF, the CFS nine-monther 18Z run keeps it mostly cold or very cold right out to the beginning of March with just a few brief milder interludes!

PS the "Quick reply" button doesn't work and hasn't done for a long time - is it just me?

Originally Posted by: Rob K 


Good ol’ CFS, you have to laugh. Like GFS on Prozac. 
Quick reply hasn’t worked for about a year for me. Since Brian’s ‘dark mode’ in fact. The whole thing seems buggy with posts often displaying in some kind of css coding. I have to edit and post again. 
nsrobins
30 December 2024 13:10:25
06Z GEFS steady after the wobbles yesterday. Control is interesting! 
I’m not too concerned with ECM as it’s a variation on the theme.
Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
Jiries
30 December 2024 13:24:59

Yes, the Manchester ENS mean stays below -5c through to 10th Jan (barring a small blip to around -4c on the 6th as a few members spike, presumably from tracking a/the low further north).

Op stays below -5c until 12th.

Originally Posted by: Saint Snow 


I zoomed in for Nuneaton ENS and there a slight spike on the 3-4th Jan with low uppers so there must be some form of feature or disturbance in the flow and not possible to be super severe bone dry under the unstable flow.  Had lot of rain from the recent HP that glad left now allowing sunny day today.  Should also see snow on NYD night as the peak of the spike at -5C uppers.  
doctormog
30 December 2024 13:45:01
The ECM 06z for what it’s worth is a bit different by day 6 compared with the previous run.

00z op run: 
https://www.wetterzentrale.de/maps/ECMOPEU00_150_1.png 

06z op run: 
https://www.wetterzentrale.de/maps/ECMOPEU06_144_1.png 

For comparison this is what the AIFS 06z shows at the same time point. 
https://www.wetterzentrale.de/maps/AIFSOPEU06_144_1.png 
Aberdeen
Current conditions (personal WS) 
Chunky Pea
30 December 2024 13:50:00

The ECM 06z for what it’s worth is a bit different by day 6 compared with the previous run.

00z op run: 
https://www.wetterzentrale.de/maps/ECMOPEU00_150_1.png 

06z op run: 
https://www.wetterzentrale.de/maps/ECMOPEU06_144_1.png 

For comparison this is what the AIFS 06z shows at the same time point. 
https://www.wetterzentrale.de/maps/AIFSOPEU06_144_1.png 

Originally Posted by: doctormog 


How do you get the AIF ECM on WetterZ? I can only see the regular version. 
East Galway, Ireland.
Current Conditions
https://t.ly/MEYqg 

"You don't have to know anything to have an opinion"
Roger P, 12-Oct-2022
doctormog
30 December 2024 13:55:57

How do you get the AIF ECM on WetterZ? I can only see the regular version. 

Originally Posted by: Chunky Pea 


It’s not on some of the main menus but is available here: https://www.wetterzentrale.de/en/topkarten.php?model=aifs&lid=OP 

Or, in the Topkarten drop down menu for the models it is under the subheading “Data-driven models”.
Aberdeen
Current conditions (personal WS) 
+2
Chunky Pea
30 December 2024 14:11:14

It’s not on some of the main menus but is available here: https://www.wetterzentrale.de/en/topkarten.php?model=aifs&lid=OP 

Or, in the Topkarten drop down menu for the models it is under the subheading “Data-driven models”.

Originally Posted by: doctormog 


Thanks DM for the link!

Whatever resolution this model is being run on on WZ, it seems about the same as the ERA reanalysis charts, giving a sort of historic feel to them. All the more so when it is showing those sub minus ten contours in over eastern Europe. 

UserPostedImage
East Galway, Ireland.
Current Conditions
https://t.ly/MEYqg 

"You don't have to know anything to have an opinion"
Roger P, 12-Oct-2022
White Meadows
30 December 2024 14:32:14
Met office mid term text update goes for rain and strong winds in the south after the first week of Jan. 
UncleAlbert
30 December 2024 14:58:48

Met office mid term text update goes for rain and strong winds in the south after the first week of Jan. 

Originally Posted by: White Meadows 


It actually says:

'The second week of January then looks rather varied, with high pressure, cold air and wintry showers more likely across the north, spells of rain and strong winds more likely in the south and an uncertain balance between these two regimes'

Which I would say seems about the most definitive way of putting it based on the output that is currently available to us.
+7
nsrobins
30 December 2024 14:59:09

Met office mid term text update goes for rain and strong winds in the south after the first week of Jan. 

Originally Posted by: White Meadows 


Which would fit the analogue ECM which they use primarily. The text changes ‘with the wind’ and if EC moves towards GFS/ECAI the MetO will adjust - but in small steps so they can hide the changes! 
Edit - and what Albert said.
Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
+1
DPower
30 December 2024 15:09:14
Could not give two hoots what the ECM det model shows these days. Its not even close to the model it once was, for our neck of the woods at least ( regardless of verification stats). You really need to take up another hobby other than nwp model watching if you have not cottoned on to this by now. 
I would cautiously say we are about to enter a lengthy  period of very cold weather that we have not seen for many a year, with the potential for many parts to see snow over the coming 10 to 15 days.
Hippydave
30 December 2024 15:17:02
Been trying to put some percentages to outcomes at the mo, entirely subjective and will vary depending on personal outlook, preferences and agendas! 
At the present time I'd go with 99% confidence of a significant cool down 1st/2nd Jan North to South and this lasting 2-3 days. 
After that and based on the last couple of days I'd go with:-
Extended spell of sub -5 850s affecting Scotland and possibly Northern England - 80%
Extended spell of sub -5 850s affecting England/Wales - 55%.

I'm a bit on the fence for the south purely because of 'the wobble' and that when the GEFS was first firming up on the idea of a possible colder spell, there was several runs with a big ens split between mild and colder.  It does seem like we're in one of those fun set ups where someone pointing a hairdryer in the wrong direction can make the difference between 1-3c and snow potential and 6-9c and cold rain for the southern part of the UK and that's the kind of thing that can cause flips at fairly short notice IMO.  If ECM comes back on board and the dissenting ens members diminish further on the GEFS, I'll feel more optimistic for MBY. 

In more general terms though the pattern regardless of IMBY looks like a cold one, which I guess shouldn't be a surprise given the tendency for HP to have more of an influence so far this winter, although in the context of recent climatology and most recent Januarys (2024 aside) is somewhat unusual. 

Home: Tunbridge Wells
Work: Tonbridge
+2
squish
30 December 2024 15:25:45
ICON back on board 
D.E.W on Dartmoor. 300m asl
Retron
30 December 2024 15:31:19

ICON back on board 

Originally Posted by: squish 


Not very impressive down here - there's some snow (which is a plus point), but it turns back to rain almost immediately and then it's gone within a day as 850s soon rise above zero. It's all due to a warm sector sitting over the SE, as the low is a bit too far north for us. Great if you're not in the far SE though!

It also illustrates the very IMBY nature of this sort of event, as the fronts that bring the snow (high reward) can also bring rain just a short distance away (which is the risk). The ideal for here (which is the ICON pattern about 50 miles further southeast) would be detrimental to those not far to the north.

The 12z ICON also ups the winds again, back into the 60s widely in the south.
Leysdown, north Kent
Retron
30 December 2024 15:34:40
The Met Office X'd this 40 minutes ago - the latest wind forecasts from their model for New Year's Day. Blustery, albeit less strong than is shown on the 12z ICON.
https://i.postimg.cc/WbNSTy8G/wind.jpg 
UserPostedImage
Leysdown, north Kent
Saint Snow
30 December 2024 15:41:29

ICON back on board 

Originally Posted by: squish 




If that's 'back on board', forgive me for being underwhelmed

Martin
Home: St Helens (26m asl) Work: Manchester (75m asl)
A TWO addict since 14/12/01
"How can wealth persuade poverty to use its political freedom to keep wealth in power? Here lies the whole art of Conservative politics."
Aneurin Bevan

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