Model output discussion - is the beast awakening?

[sukayuonsensnow]

There has been a signal for an area of snow over N France/Belgium and/or south/south east England next Sunday.

Is it worth watching or too early to say at this stage? Some of the models have moved away from it but it has been a trend for next Sunday in various recent model runs.

[bluearmy]

Interesting to see if the gem can snatch a victory from being 2 down at half time again ......

[Continental Climate]

UKMO a downgrade this afternoon but hardly surprising as it was 9/10 this morning. None of the charts so far deliver a UK wide snow event. Ususl suspects will do well again. 

[SLEETY]

17 minutes ago, mountain shadow said:

Really? What's wrong with it exactly?

Looks like setting up a very long draw Easterly to me.

was comparing its run from 12 hours ago, last two frames totally different ,but looking like the final outcome is going to be ok ,thankfully!

[Methuselah]

I must be hallucinating: the -10C T850 isotherm lies over North Norfolk, the -5 down over the English Channel... as a near gale-force easterly undercut rattles across the South... And that's a downgrade?!

    

[Pembroke Dangler]

Looks like day 10 onwards on gfs high retrogresses to Greenland allowing the motherload to drop from the north east cone on you can do it

[Sweatyman]

2 minutes ago, Mike Poole said:

GFS T198, what a time to get the link with the arctic high, excellent alignment and pressure not too high over UK.  Cold in place and on tap to reload.  What’s not to like?

Well you know some wont like it

[Froze were the Days]

2 minutes ago, D.V.R said:

You're always pessimistic, so it's no surprise you're disappointed with the UKMO.

Let's see what the rest of the models do and we can judge later at 7pm.

Yep! years of experience has taught me that with the UK winter climate!...GFS 12z looks fine no quarms but the 1M$ question is it correct or even near correct?...it does differ from the UKMO and hugely from the ECM.

[kold weather]

So at the moment my conclusion is kind of two fold based on the models:

1: The evolution between 72-120hrs is getting increasingly iffy. For those of us who have been on here a while I don't like to see a situation where the trigger low takes longer and longer to get to the south. That is a path that can quite often lead to easterly whiffing away totally down the line. 12z GEM is the logical conclusion of that trend by 144hrs...

2: IF we can get the easterly in, then its going to be cold enough for snow, and there is certainly plenty of chances for snow events. The models post 144hrs look very good tonight. The UKMO is weakest thus far, though it to may get there in the end, especially the further north you go. 

Edited January 31, 2021 by kold weather

[goosey007]

6 minutes ago, Eskimo said:

Yeah..so about those 'downgrades'

Sure some members want the models to keep upgrading until there's icicles hanging from there noses! ...we live in the UK not Antarctica. The general pattern is for cold to arrive next weekend I had  heavy snow today with -2 850s  ...i am sure lots of places will get the snow in this set up with -8 850s ......raging easterly or not.

[tight isobar]

Cracking cracking cracking and the anti will up as we gain...bang and boom gfs 12z✌

[Singularity]

For what it’s worth, because the cold air is Arctic maritime rather than polar, I.e. sourced from further north than we usually see and in fact being continental until late on, the UKMO 12z setup at +144 should be conducive for snow across most of the UK - albeit with the precipitation focused in the northeast.

[MJB]

The OP is very similar to the 6z Control

[Snowman.]

GEM is a horror show...

[tight isobar]

Just now, Singularity said:

For what it’s worth, because the cold air is Arctic maritime rather than polar, I.e. sourced from further north than we usually see and in fact being continental until late on, the UKMO 12z setup at +144 should be conducive for snow across most of the UK - albeit with the precipitation focused in the northeast.

Agree @polar continental feefeed #later on but my point was that the sourcing will inevitably be...just that!!.✌@polarconti

[phil nw.]

We could do a lot worse than GFS.By t144 the low has cleared to the south thanks to the forcing from that robust Arctic high.Much quicker cleaner than the UK run at day 6.

So we then go into a bitter easterly with -12c uppers in the mix and with low pressure over France strong winds with snow streamers setting up down the east coast/Possible more prolonged snow across the south from this setup.

We quickly go into a classic bitter beast if this verified.

Edited January 31, 2021 by phil nw.

[kold weather]

Remember I highlighted the areas I was concerned about with the 12z GEM earlier...

This is what is leads to:

The UKMO really isn't all that far removed from that pattern either, it would only take another 12-24hrs delay in its motion eastwards and thats what it would evolve into.

I'm getting very iffy feelings about this entire set-up now, my dodo alert is going full blast!

This is a set-up where its going to be more or less all or nothing. 

Hopefully that atlantic low disrupts enough to pull the whole boundary further south.

Edited January 31, 2021 by kold weather

[nick sussex]

Looks like the UKMO is a sort of ECM hybrid and just about avoids a calamity phasing incident .

I think you need that low over the UK much further se to increase the margin for error after day 6 .  The block to the ne has good alignment , as long as you don’t get too much seepage west of heights at day 7. 

What this shows however is the models are still uncertain as to which evolution to take where once again as in the UKMO it’s now onto a different one .

No resolution this evening I’m afraid regardless of what the ECM shows .

It wouldn’t surprise me to see that embark on yet a different set up. 

 

[Geordiesnow]

6 minutes ago, northwestsnow said:

Ukmo is lovely mate.

As is icon and GFS...

We may have to accept the low takes a bit longer than desired to clear however...

 

 

I think that is the issue in the  outputs, does the trigger low clear away allowing the colder air to be pulled in or will it stall over the UK keeping the colder air largely away. Either way, the further north and east you are, the likelyhood the colder air will remain. 

[Duncan McAlister]

<-20C temperatures for the Highlands if the GFS comes off, but dry as a bone for the most part.

Edited January 31, 2021 by Duncan McAlister

[Mike Poole]

1 minute ago, Snowman. said:

GEM is a horror show...

It is vile, worse than 0z ECM, here T138:

Thing is, that envelope of uncertainty I spoke of earlier obviously does include this evolution, we just hope it doesn’t happen.  This may be the one bad model this set of runs, and the ECM may show better, just the way the cookie crumbles.

[Sweatyman]

4 minutes ago, tight isobar said:

Cracking cracking cracking and the anti will up as we gain...bang and boom gfs 12z✌

thats the 6z !

[Gowon]

1 minute ago, Froze were the Days said:

Yep! years of experience has taught me that with the UK winter climate!...GFS 12z looks fine no quarms but the 1M$ question is it correct or even near correct?...it does differ from the UKMO and hugely from the ECM.

Same, but I'm not waving the white flag yet.

Just because the ECM is the number one, doesn't mean it's right - let's see what happens.. 

[Matt H]

The GEFS 12z ensemble mean is still clearing the low far quicker than the operational run and has us in an easterly wind by t120.

[MJB]

2 minutes ago, kold weather said:

Remember I highlighted the areas I was concerned about with the 12z GEM earlier...

This is what is leads to:

The UKMO really isn't all that far removed from that pattern either, it would only take another 12-24hrs delay in its motion eastwards and thats what it would evolve into.

I'm getting very iffy feelings about this entire set-up now, my dodo alert is going full blast!

GEM will end up delivering , just delayed