Model Output Discussion - the cold has arrived

[SLEETY]

I think ECM is wrong,before the start of the current cold-spell it threw out a similiar mild run and it turned out to be miles wrong.

Next runs were cold after that rogue run.Its been chucking out mild op runs for days,always at the top of the pack or a big mild outlier for not just UK but much of Europe.

[Kasim Awan]

23 minutes ago, Catacol said:

Zonal is a flow parallel to the equator. A meridional flow runs north to south. This chart is misleading for anyone looking to learn. Quite simply this is not a zonal chart. The reason we have never heard of loco zonality before is because it does not exist.

Zonal = west to east

Local zonality = west to east air flow localized to a small area

Different from widespread zonality

[SqueakheartLW]

Everyone looking for cold should be focused on the period just after Christmas.

Last 4 GFS runs

18z                                                              00z

18z - Av 850hpa cold peak -6.5C           00z - Av 850hpa cold peak -6.3C

06z                                                              12z

06z - Av 850hpa cold peak -6.0C           12z - Av 850hpa cold peak -7.3C

A good consistent signal there from the GFS with the current peak of the cold around the 27th

00z ECM

00z - Av 850hpa cold peak -5.1C

A relatively decent signal from the 00z but not as strong as GFS is

00z and 12z GEM

00z                                                              12z

00z - Av 850hpa cold peak -4.1C           12z - Av 850hpa cold peak -4.1C

GEM least on board with this potential colder snap/spell but the dip is still there.

Summary

Which way will the models end up going.

Will they water down the cold signal and follow GEM?

Will they converge on the middle of the road signal from ECM?

Or will they head colder and follow the GFS?

 

I know which outcome I'd prefer

[The Enforcer]

I understand that the Low pressure would be blocked by the Greenland High to the north and the Euro High to the south (see red lines added to chart below) and so can't go in those directions. However, with the black arrows indicating squeezing by those Highs, surely the Low would become more 'frisbee-shaped' and move eastwards in the gap between the two Highs following the path of the previous Low along the Jetstream, as indicated by the green arrow?

[Derecho]

10 minutes ago, mulzy said:

It can be consistently wrong.  The king (ECM) says no and the UKMO says no - history has taught us coldies that if the UKMO is not in board, you can forget it.

Let’s wait for the better ensemble suites (EPS and MOGREPS) to confirm or otherwise the increasingly milder outlook.

Mogreps 12z appear substantially colder then the 06z, the OP is at least amongst the mildest.

Either the OPS are picking up on a feature that the ensembles aren't spotting yet, or the OPs are making too much off the feature and the ensembles are a better guide.

EDIT: You beat me to it Matt

Edited December 18, 2022 by Quicksilver1989

[Mark wheeler]

9 minutes ago, MATTWOLVES said:

The colder runs gather pace and this proves that things are far from done and dusted. This clearly shows both milder and colder options are on the table. But it certainly doesn't show the outcome is guaranteed mild.

I'm quite shocked by some folks reactions in here this evening...its worse than towell throwing its throwing everything but the kitchen sink. Considering we've already had a very good chunk of this month cold.. yet some will never be happy. 

It's nearly Xmas and I'm not having the best of times so i aint gonna cause arguments with anyone..your all entitled to your opinions after all.

BUT THIS IS FAR FROM SETTLED!

The 12z to my eye have certainly trended colder compared to the 6z.

as @Quicksilver1989says above .

Edited December 18, 2022 by Mark wheeler

[Cold Winter Night]

EPS ensemble does not support the EC HRES Operational.
The EPS 0z was colder than before, with the Op as a mild outlier, now the 12z is maybe slightly less cold, but certainly not mild, with the Op once more as an outlier.

London:

De Bilt:

Considering the GFS and GEFS trending notably colder, joined by an EPS that at that lead time should be leading the High resolution run, I’d cautiously lean towards the colder solutions.

Edited December 18, 2022 by Cold Winter Night

[The Enforcer]

7 minutes ago, Stuie W said:

Regardless of snow chasing, at the minute Xmas day is far from warm. I hope the people who posted about blips and bbq`s have a fun day.

 

I agree. And the temperatures have been constantly overplayed by models during the cold spell, with both daytime maxima and nightime minima several degrees out even at very short range and by now it was supposed to be well into double figures and I'm still registering below 8C.

[tight isobar]

1 minute ago, Cold Winter Night said:

EPS ensemble does not support the HRES Operational.
The EPS 0z was colder than before, with the Op as a mild outlier, now the 12z is maybe slightly less cold, but certainly not mild, with the Op once more as an outlier.

London:

De Bilt:

Considering the GFS and GEFS trending notably colder, joined by an EPS that at that lead time should be leading the High resolution run, I’d cautiously lean towards the colder solutions.

Makes perfect sense- and I’ll reiterate.. the ecm raw- and even ukmo are lagging behind their sister suites GFS/GEFS....

[Snowmadsam]

Just now, Ali1977 said:

The majority of us on this forum want cold and snow, but this year I’m sure many people will be looking at the silver lining should the opposite Synoptics transpire. It’s been an expensive 10 days through this cold spell for sure. 

Sod’s Law would suggest this winter will be cold  

I thought we’d have a pretty robust solution for Xmas day by this evening but we are well off!!  
 

I'm six of one half a dozen in terms of a favourable weather pattern at this time of year. For a change I would like it to be seasonably cold, but from what teleconnections have been suggesting the milder part of winter COULD come around later Jan/feb time. But to predict that atm feels difficult. 

The ECM op being a frequent outlier in its own ens does worry me in longer term trend spotting in general as it has been doing this too often for my liking as of late....

Regarding cold, I'll await the GFS and the GEFS 18z tonight to see if that offers consistency from the 12z and then progress from there

[MATTWOLVES 3]

8 minutes ago, Mark wheeler said:

The 12z to my eye have certainly trended colder compared to the 6z.

as @Quicksilver1989says above .

Mark I pointed out the 0z runs were going colder compared to previous days and i was accused of getting peoples hopes up.. now the 12s have trended colder still! 

I may have this wrong...I may have it correct..but at the moment I feel like I'm beating my head against a telegraph pole.

Some side with the det,some with the ens! But the inconsistencies are glaring and for all too see. At the moment you can't say its definitely trending milder for Xmas,and you can't say for sure it's trending colder! But what concerns me is if things don't improve with the det before much longer,i have a feeling some folks Xmas dinner will be ruined by it.

It us the season to be jolly,and we should all participate in this hobbie with a smile on our faces. Life is short and the weather will do want it wants to do..we can't change that! 

So I think becoming colder again from midweek further North...this could spill further South towards Xmas. Beyond that nobody really knows for sure...if the models can't work it out...then how the hell are we supposed to.

What I will say though is each and everyone of you have a great Xmas and prosperous New Year...and spare a thought for those much more unfortunate than yourselves.

Here's hoping to a New Year of cold Arctic shots.

[marksp]

16 minutes ago, The Enforcer said:

I agree. And the temperatures have been constantly overplayed by models during the cold spell, with both daytime maxima and nightime minima several degrees out even at very short range and by now it was supposed to be well into double figures and I'm still registering below 8C.

i would concur, its just reached 3.6c here not the double figs that may have been projected.

[Mike Poole]

ECM clusters, first the key timescale T120-T168:

Well, the ghastly ECM op is represented in the minority cluster 3 (14 members).  GFS solution or similar in cluster 1 (22 members).  Cluster 2 is somewhere in the middle, but probably mild for the majority of the UK.

T192-T240:

Rooting for cluster 2 here (22 members) which sucks the euro heights into an Atlantic ridge scenario.  Nice destination, this, after all the drama, should it come off.

[northwestsnow]

EC det ANOTHER run right at the top of the suite.

I give up with this model.( mainly because it stubbornly refuses to show what I want ).

[Rain All Night]

48 minutes ago, NewEra21 said:

Hasn't the ECM been really poor recently, always playing catchup to the GFS? And UKMO doesn't really fill you with confidence whatever it shows of late.

I could be completely wrong, but my faith in the ECM has gone down a lot recently. And not just because it's not showing what we want to see in cold. 

Just to plagiarise my own very unscientific and blindingly colourful post from last night... "Who nailed the northerly"? (at T+168 hours)

The answer:

Balanced guesses:

Overplayed:

Underplayed:

Edited December 18, 2022 by RainAllNight

[offerman]

27 minutes ago, MATTWOLVES said:

The colder runs gather pace and this proves that things are far from done and dusted. This clearly shows both milder and colder options are on the table. But it certainly doesn't show the outcome is guaranteed mild.

I'm quite shocked by some folks reactions in here this evening...its worse than towell throwing its throwing everything but the kitchen sink. Considering we've already had a very good chunk of this month cold.. yet some will never be happy. 

It's nearly Xmas and I'm not having the best of times so i aint gonna cause arguments with anyone..your all entitled to your opinions after all.

BUT THIS IS FAR FROM SETTLED!

Hi Matt, I'm sorry you’re not having the best of times. I share your pain, my mum just passed away three weeks ago  just before her birthday ( no words to describe the pain/ loss sadness)  , I’m ill and my boy has scarlotte fever  .  
i hope you’re situation improves Matt. 

[Eskimo]

6 minutes ago, marksp said:

i would concur, its just reached 3.6c here not the double figs that may have been projected.

I mean, the models weren't showing double digits until well into the mid-morning hours of tomorrow anyway. 

In fact, all models show the Peak District at about 4-5C by 9pm. Bang on. 



By 9am...double digits!

Edited December 18, 2022 by Eskimo

[Stuie]

10 minutes ago, marksp said:

i would concur, its just reached 3.6c here not the double figs that may have been projected.

it`s tomorrow you will see higher temps.

Edited December 18, 2022 by Stuie W

[snowbob]

I do believe gfs has sniffed out a pattern now but I don’t believe it will be for Xmas I think it’s jumped the gun somewhat and will keep showing a day late then a day late and so on.

ecm and ukmo are I believe correct but will soon show cold around boxing day onwards.

Edited December 18, 2022 by Polar Maritime
To move discussion on..

[Kentish Snowman in Yorks]

Well if you looked only at the GFS ensembles tonight for guidance as to conditions over the Christmas period you would think another cold spell was nailed on between 24th and 28th December

Model watching is a funny old game though...

[Allseasons-Si]

Guess who's back in town,...me and good evening all

a horrible trip back from Skegness this evening in all the rain and spray and so glad to be back

I see everyone's getting edgy with the models at present but i see nothing wrong with the gefs ens for here or London over the festive period

the ECM was an outlier again

and the latest from NOAA/CPC shows Atlantic height's to our W/NW and Scandi trough in the ext'd 8-14 day outlook

tis the season of good will so let's keep it friendly eh guys

C U l8ter for the 18z.

 

 

 

 

Edited December 18, 2022 by Allseasons-si
typo

[Don]

7 minutes ago, Allseasons-si said:

and the latest from NOAA/CPC shows Atlantic height's to our W/NW and Scandi trough in the ext'd 8-14 day outlook

 

That looks like a decent chart if it wasn't for that pesky high pressure to the south!!

[Singularity]

1 hour ago, Kasim Awan said:

Zonal = west to east

Local zonality = west to east air flow localized to a small area

Different from widespread zonality

Localised zonal flow is a thing, west-east wind.

Localised zonality isn’t because zonality refers to planetary scale waves (Rossby waves) progressing west-east. I.e the broad troughs that we see within the jet stream. That can never be a local scale event.

 

Anyway back to the models - EPS are about 29 to 22 against GFS but those 22 are all in one cluster… the largest one. Very clarifying… not!

[TSNWK]

13 minutes ago, Allseasons-si said:

Guess who's back in town,...me and good evening all

a horrible trip back from Skegness this evening in all the rain and spray and so glad to be back

I see everyone's getting edgy with the models at present but i see nothing wrong with the gefs ens for here or London over the festive period

the ECM was an outlier again

and the latest from NOAA/CPC shows Atlantic height's to our W/NW and Scandi trough in the ext'd 8-14 day outlook

tis the season of good will so let's keep it friendly eh guys

C U l8ter for the 18z.

 

 

 

 

And euro heights... which kinda makes the greenie heights and scandi trough moot! 

[london-snow]

11 minutes ago, Allseasons-si said:

Guess who's back in town,...me and good evening all

a horrible trip back from Skegness this evening in all the rain and spray and so glad to be back

I see everyone's getting edgy with the models at present but i see nothing wrong with the gefs ens for here or London over the festive period

the ECM was an outlier again

and the latest from NOAA/CPC shows Atlantic height's to our W/NW and Scandi trough in the ext'd 8-14 day outlook

tis the season of good will so let's keep it friendly eh guys

C U l8ter for the 18z.

 

 

 

 

Those charts may look misleading to those who glance, At best that’s a brief if not very brief fleeting northerly with nothing but mild upticks thereafter. Pretty poor outlook going by those ensembles.