Model Output Discussion - Into the new year

[Mike Poole]

49 minutes ago, Met4Cast said:

Hot off the press! The latest EC46 update has blocked the Arctic off right through until week 4. Strongest signal yet!

I can't remember ever seeing such a persistent signal.

Yes, mate, it is kind of an extension of the massive signal that has been in the ECM EPS for the last 3 runs now.  It is now, in my opinion, only a question of which way it happens...we will see...

[Ols500]

arome saying some snow might fall tmo

[I remember Atlantic 252]

3 minutes ago, Harsh Climate said:

You and smokeone are probably right regarding widespread snow. Maybe IMBY but with -4 uppers across a much longer draw across the North Atlantic we had sleet here with snowline about 750 feet yesterday. I'm sure with a shorter and dryer feed from the east that would make the world of difference here atleast. But I could be wrong haha

Mon 4th on EC, not a good chart, looks like mild sector and certainly looks less cold from the E

[Nick F]

40 minutes ago, Anthony Burden said:

High Nick,

thanks for your take on the current position,can I push you to ask your opinion of the positioning 

of northern blocking in the extended 5/6day period.

Current assumptions from today's output is for the amplified mid-Atlantic ridge to our west to extend NE over GIN corridor around day 6 for a time, inviting a NEly or even Ely over UK. Ensemble guidance then for this blocking ridge to retrograde back over the Atlantic- perhaps as far west as Baffin Bay / Davis Strait. How the surface pattern would evolve over UK as a result of this would be uncertain, if there is enough cold high pressure to the north and the jet tracks far enough south - we could maintain a NE flow.

Then again, a great deal of uncertainty past 6 days, as it's unclear how the models are reacting to constant changes in the troposphere at high latitudes that seem to be poorly modelled atm, against stratosphere forcings from the top down occuring over the coming 10 days, as we see the zonal reversal work down and possibly couple with the troposphere and how quick this occurs.

Edited December 28, 2020 by Nick F

[phil nw.]

ECM mean tonight looks very promising .

By day 10 a strong hint of an injection of Arctic cold via Scandinavian trough.By then we should be fast approaching retrogression (east to west)of the pv so would expect Greenland heights and a bitter n.e flow further on.

Based on these ht anomalies Euro low pressure is just far enough east to hold off any real Atlantic inroads from the sw i think.Odds are cold would bed in from here as that trough drops down.A close enough setup though to suggest the chance of a battleground snow event.

 

 

[Mr Frost]

Latest ECM monthly temperature (T2m) Anomalies! 

Weekly breakdown:

28/12 to 03/01

 

04/01 to 10/01

 

11/01 to 17/01

 

18/01 to 24/01

 

25/01 to 31/01

 

01/02 to 07/02

 

Edited December 28, 2020 by Mr Frost

[kold weather]

10 minutes ago, Mr Frost said:

Evening all

Squeaky bum time for you ladies and gents down South with regards to Wednesday night/early hours of Thursday - hopefully it trends further North so more of our Netweather members are at risk. 

Latest fax for 31/12 00:00

Interestingly the 12z global models shifted northwards, whilst the higher resolution models stayed a little further south.

This far out and given the feature hasn't even developed yet I'd favour the globals over the higher resolution models, though they should be getting a better grip one way or the other over the next 2-3 suites.

UKV is probably on the southern end of the range of options, though its well within the range of options.

Personally I'm not getting invested in snow events this year, so if it comes off then obviously huge bonus!

[Harsh Climate]

7 minutes ago, I remember Atlantic 252 said:

Mon 4th on EC, not a good chart, looks like mild sector and certainly looks less cold from the E

Day in question Tuesday is colder though, looks bitter

[Met4Cast]

5 minutes ago, Ols500 said:

arome saying some snow might fall tmo

Indeed, 12z AROME has this little feature moving through early tomorrow morning, though it doesn't appear to have a whole lot of support from other models so we'll see..

[bluearmy]

1 hour ago, Met4Cast said:

Showing snowfall? I can only find the MSLP stamps on the ECWMF website?

Sorry - mslp only but the track of the low dictates the location of the snowfall 

5 minutes ago, I remember Atlantic 252 said:

Mon 4th on EC, not a good chart, looks like mild sector and certainly looks less cold from the E

Yes there is precip associated with that feature and it’s mainly rain 

[Allseasons-Si]

The latest ICON for a 24 hr period shows the feature off the NE coast going through Yorkshire down into the west midlands south.

[kold weather]

1 minute ago, Allseasons-si said:

The latest ICON for a 24 hr period shows the feature off the NE coast going through Yorkshire down into the west midlands south.

Looking at the radar the 18z ICON looks about right which helps to be give some confidence to the above.

Interestingly the model is more keen to have any settling snow during the day, which rather goes against what I'd expect, however it looks like it allows snow to settle along the path of the strongest precipitation. 

 

[BlueHedgehog074]

2 minutes ago, Allseasons-si said:

The latest ICON for a 24 hr period shows the feature off the NE coast going through Yorkshire down into the west midlands south.

Interesting the way it intensifies as it sinks South through the West Midlands and down towards the South Coast. 

[phil nw.]

2 minutes ago, Allseasons-si said:

The latest ICON for a 24 hr period shows the feature off the NE coast going through Yorkshire down into the west midlands south.

Pretty much fits in with the fax for midday tomorrow si

By then the occlusion straddling the midlands drifting south.Plus the 2 small features in the channel.

[Matt H]

ICON 18z fairly good for snow prospects Wednesday night into Thursday in the south. A fair shift north from the 12z.

[kold weather]

Decent 18z ICON, as others have said its definately further north which does make it a little more marginal for the far south, but a decent band of settling snow either side of the M4. Nothing too extreme on this run, probably 1-3cms widely with maybe more on higher ground.

[Allseasons-Si]

Here is ICON's take on Wed system...

[BLAST FROM THE PAST]

27 minutes ago, I remember Atlantic 252 said:

Mon 4th on EC, not a good chart, looks like mild sector and certainly looks less cold from the E

Do you think though they’ve pinpointed a mild sector that small? It might be huge or it might be mightily cold at least on the surface

BFTP

[Tim Bland]

Icon a lot further north with the snow Weds / thurs compared with earlier run. Here’s the total accumulation by Thurs...

[I remember Atlantic 252]

1 minute ago, BLAST FROM THE PAST said:

Do you think though they’ve pinpointed a mild sector that small? It might be huge or it might be mightily cold at least on the surface

BFTP

FI anyway, GFS is much different, as is GEM

[bluearmy]

5 minutes ago, Tim Bland said:

Icon a lot further north with the snow Weds / thurs compared with earlier run. Here’s the total accumulation by Thurs...

That’s the total that’s fallen from the sky  Tim - ‘couche actuelle neige’ is lying snow ( both are likely nonsense!)

Edited December 28, 2020 by bluearmy

[ANYWEATHER]

Evening!  A very Blocked pattern across the UK  lots of cold and Ice and snow to look forward too....

[MKN]

2 minutes ago, bluearmy said:

That’s the total that’s fallen from the sky  Tim - ‘couche actuelle neige’ is lying snow ( both are likely nonsense!)

Icon performed the best for the snow that fell this morning so well worth keeping an eye on. 

[iowpompeylee]

45 minutes ago, Mr Frost said:

Evening all

Squeaky bum time for you ladies and gents down South with regards to Wednesday night/early hours of Thursday - hopefully it trends further North so more of our Netweather members are at risk. 

Latest fax for 31/12 00:00

 

Latest UKV snapshots for same date/time.

 

Bit of wintry/snowy potential also showing on the above for N/NE England at that timeframe.

All the above subject to change at this range of course! 

Hopefully it becomes reality as I do enjoy a browse through the regional threads to see the snowy scenes throughout the UK and Ireland! 

All the best!

So if I read that right, us snow starved isle of wighters will want the system to dive further south to increase our chances of having snow?? Always marginal for us!! Hope people post lots of tax charts this week as they will help a lot with small troughs etc 

[kold weather]

3 minutes ago, bluearmy said:

That’s the total that’s fallen from the sky  Tim - ‘couche actuelle neige’ is lying snow ( both are likely nonsense!)

Yeah something like 1-3cms mainly, maybe 5cms in hotspots if the 18z ICON is correct. mind you once it starts to snow the models may well underestimate the cooling that would occur within such a set-up from experience which may well help to give a little more snow on the ground.

Still definitely further north than the 12z run.

We will see what the 18z GFS comes out.