Model output discussion - Winter has arrived

[mountain shadow]

19 minutes ago, northwestsnow said:

Phew!!

EC det looks very progressive compared to the mean.

Mean looks slidersville to me !!

There's nothing more annoying than an Op being out of kilter with the mean.

Hopefully tonight's ECM extended comes on board. 

[bluearmy]

2 minutes ago, mountain shadow said:

There's nothing more annoying than an Op being out of kilter with the mean.

Hopefully tonight's ECM extended comes on board. 

The op is in a cluster of 26% .....it’s not an outlier at all ..... well it’s a tad extreme with its rise on 850’s and a bit overdone on heights late on so it’s on the high side of its cluster envelope .....

Edited December 4, 2020 by bluearmy

[That ECM]

14 minutes ago, bluearmy said:

Largest extended cluster looks winterville....... unless the op is leading the way (and hemispherically that would be going somewhere interesting anyway) we should stay busy in here .....

NW or NE block suggested? TIA

[mountain shadow]

1 minute ago, bluearmy said:

The op is in a cluster of 26% .....it’s not an outlier at all 

Cheers blue.

What was the percentage for slidersville?

[bluearmy]

1 minute ago, That ECM said:

NW or NE block suggested? TIA

[bluearmy]

2 minutes ago, mountain shadow said:

Cheers blue.

What was the percentage for slidersville?

Around 60%

[bluearmy]

Just now, bluearmy said:

Around 60%

Tough to assess how sliders will behave though ....the lw trough could edge further north as per gfs op in the mid term this morning 

[ICE COLD]

18 minutes ago, bluearmy said:

Largest extended cluster looks winterville....... unless the op is leading the way (and hemispherically that would be going somewhere interesting anyway) we should stay busy in here .....

Oh thank god for that, been getting worried about the past 2 EC op runs. They’ve been dreadful. 

[sebastiaan1973]

Latest plume for De Bilt. Indeed control and oper on the high end of things (at the end).

[bluearmy]

Please dont get carried away with my last few posts - all I’m saying is that in respect of the extended ens (and that’s all three big models) we remain in the game for winter 

[nick sussex]

The UKMO looks the pick of the big 3 at day 6 followed by the GFS and the ECM in the naughty corner for delivering that underwhelming output .

The ECM has delivered two similar op runs in a row , that really needs to change course this evening because eventually the majority of the ensembles will start jumping to that solution.

Even if we do get a slider lots of uncertainty remains over how much cold will be available to undercut any precip.

At this point though the first hurdle is for the ECM to change course .

[Anthony Burden]

ECM 6 days out keen on firing up Atlantic and pushing continental air away, GFS not so keen

to rush it .The second half of December still up for grabs but looking unfortunately more likely 

to return to Atlantic domination.

[Sky Full]

These charts from the main models at +144hrs do demonstrate a reasonable degree of agreement with low pressure around the Med in Southern Europe and the Atlantic being kept at bay for the time being.  

                                                500s.                                     850s

UKMO       

ECM          

GFS            

GEM          

This is not really a poor set up for mid-December especially compared with some recent years but we know that things can radically alter for the better or for the worse, so we’ll have to keep watching.... ️

 

 

[phil nw.]

It's always the same when modelling the Atlantic v a block.

A set up that can go either way. We see different solutions posed at quite short notice as in the overnight operational runs. 

It is not unusual to see a run removing the block too easily. The ECM reluctant to cut off the trough at day 5 which halts the ht rises towards Iceland showing on the UK and GFS chartsg- this seems to be the key issue. 

Overall not a bad set though and the Ecm mean output is less progressive than its operational run. 

This should be resolved by tonight as the difference is at such a short time frame. 

[SMU]

ICON 06z out to its usual early stop time 120 has reduced the amount of forward motion on that atlantic low & by 120 it looks rather like the UKMO

[northwestsnow]

1 minute ago, Steve Murr said:

ICON 06z out to its usual early stop time 120 has reduced the amount of forward motion on that atlantic low & by 120 it looks rather like the UKMO

I'm praying EC is wrong Steve.

[carinthian]

Morning all the Russian High still dominates the HN profile in all models at 144t. Beyond that the GFS now shows some resilience  against the zonal flow from the Atlantic with possible stalling of frontal systems over Western Britain. The feeling from the experts over here is the ECM is far too progress with its milder runs out to 240t. So from a wintry perspective to extend the colder conditions, the UKMO is best this morning as it shows a stronger ridge west from the Russian High and profiles a slightly more deeper cold air mass over much of Western Europe including the British Isles.  Although the start of our ski-ing season out here has been delayed until Christmas Eve, we have access to forecast portal service from Dec 1st as the piste team still need to prepare in advance. This mornings latest chat with specifics towards the British Isles still holds out for a extended colder spell for you guys with the risk of snow continuing into next week. The snow model out perimeter results would favour higher ground in the west, which would indicate some type of slider or frontal movement into colder air. But no percentage rates that far out. The team still think 60/40 in favour of colder conditions out to 10 days . Hope that helps.

 C

 

 

Edited December 4, 2020 by carinthian

[mushymanrob]

Erm.... no comments on this yet? we may be under a slack westerly flow but these latest charts have certainly developed ridging to our north... Itll be interesting to see if this is consolodated tonight and tomorrow .
 

[Penicuikblizzard]

57 minutes ago, Anthony Burden said:

ECM 6 days out keen on firing up Atlantic and pushing continental air away, GFS not so keen

to rush it .The second half of December still up for grabs but looking unfortunately more likely 

to return to Atlantic domination.

The Atlantic wins out more often that not my money will be on a return to milder weather and a return to winter proper in February

[Anthony Burden]

Matt Hugo on Twitter very confident that cold to rather cold to remain for sometime yet,

and ECM 00 being an outlier.

[northwestsnow]

18 minutes ago, mushymanrob said:

Erm.... no comments on this yet? we may be under a slack westerly flow but these latest charts have certainly developed ridging to our north... Itll be interesting to see if this is consolodated tonight and tomorrow .
 

That looks good Mushy !!

[Skullzrulerz]

35 minutes ago, mushymanrob said:

Erm.... no comments on this yet? we may be under a slack westerly flow but these latest charts have certainly developed ridging to our north... Itll be interesting to see if this is consolodated tonight and tomorrow .
 

How accurate are these charts?

[nick sussex]

How the models handle the shortwave over the UK at day 5 is important .

The UKMO clears that se at day 6 and doesn’t phase that with the upstream low . The GFS has a shallow feature which gets absorbed by that low .

Preferably you want that out of the way but if it’s going to phase you want it to remain a shallow feature .

 

[SMU]

GFS means sees more ridging at 108

[Weather-history]

How this for a Christmas Eve chart? One of the extended GFS ensembles. A UK record breaking high pressure (record is 1053.6mb) and a frigid easterly to go with it