Model output discussion - winter proper underway

[Frosty.]

All I will say about the Ecm 12z is I hope the Gfs is right!!!!

[Summer Sun]

GEM looking very mild next week at times

ECM also trending milder

Edited December 11, 2017 by Summer Sun

[nick sussex]

The ECM is most progressive of the big 3. It does actually manage to eject the shortwave from Scotland to ne Spain between T144 and T168hrs. This would become the trigger if we had something that could lead to but too much energy upstream so no chance of developing any ridging to the ne.

There are differences between the big 3 upstream with views of the trough and how far east it gets. I still wouldn't rule out a GFS type outcome because its not really outlandish given the overall set up but its hard to see this as anything other than the dam holding a few more days before the Atlantic flood moves in.

It would need some bigger changes to develop a stronger ridge to the ne and sufficient trough disruption upstream.

 

[Frosty.]

5 minutes ago, Summer Sun said:

GEM looking very mild next week as times

ECM also trending milder

Where's the sick bag.. ...don't despair, we still have the Gfs 12z which holds on to the colder air for the early part of next week.

Edited December 11, 2017 by Frosty.

[Summer Sun]

Amazing how quickly the pattern is changing from what was looking like a cold month we could even end up above average yet the way ECM and GEM are going!

[booferking]

7 minutes ago, nick sussex said:

The ECM is most progressive of the big 3. It does actually manage to eject the shortwave from Scotland to ne Spain between T144 and T168hrs. This would become the trigger if we had something that could lead to but too much energy upstream so no chance of developing any ridging to the ne.

There are differences between the big 3 upstream with views of the trough and how far east it gets. I still wouldn't rule out a GFS type outcome because its not really outlandish given the overall set up but its hard to see this as anything other than the dam holding a few more days before the Atlantic flood moves in.

It would need some bigger changes to develop a stronger ridge to the ne and sufficient trough disruption upstream.

 

One thing iv notice about GFS this winter it has been more amplified this Winter than the EC which is strange usually the other way around, but sadly when the GFS has shown more amplification it slowly loses it run by run to be more inline with EC this has happened a few times during are Northerly outbreaks.

Edited December 11, 2017 by booferking

[The Weather Dragon]

looks like a pull on the atlantic is a given. I don’t think that cold will be too far away though - the models and the pros do indicate this ?

[chris55]

Haven't checked the models for a few days but flicked through the GFS 12z and thought, oh cold weather may well hang on. Just checked ensembles and can see it's a clear outlier in the mid term.

Is the op onto something or just simply out on its own.

A milder week next week would suit me personally work wise but I get a sneaky feeling the cold is not finished with us yet.

[shotski]

3 minutes ago, Summer Sun said:

Amazing how quickly the pattern is changing from what was looking like a cold month we could even end up above average yet the way ECM and GEM are going!

Wasn’t this coming week meant to be mild when viewed last week ? 

I’ll have to look back at the archive’s ?

Edited December 11, 2017 by shotski

[Frosty.]

3 minutes ago, Summer Sun said:

Amazing how quickly the pattern is changing from what was looking like a cold month we could even end up above average yet the way ECM and GEM are going!

Yes it's amazingly awful Gavin, let me just cling onto what the Gfs 12z shows later this week / early next week before the 18z probably snatches it away.

[Troubleatmill]

5 minutes ago, nick sussex said:

The ECM is most progressive of the big 3. It does actually manage to eject the shortwave from Scotland to ne Spain between T144 and T168hrs. This would become the trigger if we had something that could lead to but too much energy upstream so no chance of developing any ridging to the ne.

There are differences between the big 3 upstream with views of the trough and how far east it gets. I still wouldn't rule out a GFS type outcome because its not really outlandish given the overall set up but its hard to see this as anything other than the dam holding a few more days before the Atlantic flood moves in.

It would need some bigger changes to develop a stronger ridge to the ne and sufficient trough disruption upstream.

 

One thing ive seen on the GEFS ensmbles tonight is that at 240hrs every member has the azores high tilted SW to NE which is never a good position unless all the stars align and energy somehow get beneath it or splits it. At 384hrs every memeber has the azores at a NW to SE tilt. In my mind a far better position and ready to pounce on any let up from the atlantic. Not pointing to what GP and others have said but id take anyway to cold!

[Summer Sun]

4 minutes ago, shotski said:

Wasn’t this coming week meant to be mild when viewed last week ? 

I’ll have to look back at the archive’s ?

Today 1 week ago

Actual

Both charts ECM

[phil nw.]

21 minutes ago, Frosty. said:

All I will say about the Ecm 12z is I hope the Gfs is right!!!!

Yes Frosty the focus is on day 6 with ECM much more progressive with pushing the Atlantic through.

The 3 at T144hrs

We can see GFS holding back the ejection of energy into the northern arm of the jet(see the extra purples across S.Greenland on the others).More pressure therefore on Atlantic ridging seen by the forward positive tilting especially on the ECM.

This is the key time if we get that delay and trough disruption just to our west with some energy heading se then this could change the outlook from milder in week 2.UKMO seems the middle ground but would need to step back even more than GFS to rescue the situation from flattening later.

The expected week 2 pattern is still for westerlies but with these differences and a split jet this is not a given just yet.

ECM clusters will be useful later to see if they are at least considering a different path to the day 6 Op.Certainly some of 06/12z gefs have this slower option where the cold air shows some resistance to the Atlantic push next week end.

Edited December 11, 2017 by phil nw.

[andymusic]

4 minutes ago, shotski said:

Wasn’t this coming week meant to be mild when viewed last week ? 

I’ll have to look back at the archive’s ?

yes ukmo was toying with idea of blowtorch south westerlies come the end of this week but it's looking mighty cold again

[andymusic]

45 minutes ago, Frosty. said:

Well, according to the Gfs 12z the less cold midweek blip shows snow spreading from the west later on wednesday and there is another very cold spell towards the end of this week with further snow showers and severe frosts continuing into early next week..I would call that an upgrade..hope it continues!

yep - the mild keeps getting thrown out

[nick sussex]

1 minute ago, booferking said:

One thing iv notice about GFS this winter it has been more amplified this Winter than the EC which is strange usually the other way around, but sadly when the GFS has shown more amplification it slowly loses it run by run to be more inline with EC this has happened a few times during are Northerly outbreaks.

Yes its been strange because its normally the GFS which is often flatter upstream. Don't discount the GFS trend though , its really how much dig we can see upstream in that troughing to force some ridging more ne ahead of it and a shortwave heading se through the UK.

Energy distribution in these scenarios is poorly handled by the models. Theres I would say enough time to extend the cold given the timeframes but its going to be a struggle to hold on to that , perhaps a few days but the Atlantic looks in no mood to be denied at the moment.

[tight isobar]

2 hours ago, Lynxus said:

Good olde La Nina,

Its funny how this place changes from WESTERLIES EVERYWHERE! to cold in a matter of hours.

One thing ive noticed year on year is that the models hate having to deal with any form of blocking or long term cold.
Anything further out than a few days and they always seem to point to a warmer west and the Atlantic taking control.

The models just cant cope with any other setup. hence the tendency to constantly push back towards it.

Granted, there are signs of extremely brief milder days but they seem to keep getting push 

[Frosty.]

1 minute ago, andymusic said:

yep - the mild keeps getting thrown out

The Gfs 12z really sparked my enthusiasm for an upgraded cold shot, especially in terms of longevity..hope its right..

Ps..great post Phil nw

[JBMWeatherForever]

Seems that at the moment in order to see temperatures anything above the long term average you have to look out into fantasy land. The opposite of our norm. And there is still no certainty that this long foretold milder spell will last very long, if indeed it happens at all!  Also the northerly at the end of the week seems to be getting more pronounced too. It seems to be generally considered here fait accompli that a mild spell will commence after this weekend, but I am still not fully convinced of this and still think we may yet see some interesting developments in the models as the cold air holds on longer than currently suggested, and perhaps even fights back.   

Edited December 11, 2017 by JBMWeatherForever

[Frosty.]

13 minutes ago, phil nw. said:

 

We can see GFS holding back the ejection of energy into the northern arm of the jet

This is what I'm clinging to this evening as I'm sure are all the coldies.

[stodge]

Evening all

Well, I'm sure this evening's ECM has got some of the more over-anxious contributors rushing for the door.

Never mind.

It was always likely if not inevitable there would be a resumption of the "normal" winter pattern after the amplification of current times and of course the worst runs always seem to be at the end of the cold spell.

So where do we go from here ?

As is often the case in life, probably nowhere slowly. A 10-14 day Atlantic dominated period starting from early next week wouldn't surprise and we'd still have two thirds of winter to play with. There are plenty of options knockering (sorry) around in the Ensembles and the idea of rising heights to the NE is far from dead albeit some of the more hopeful charts suggesting a rapid transition may have been overdone.

The teleconnections offer plenty of optimism in the longer term but if I've seen my snow for the winter so be it.

[MR EXTREMES]

Safely say gefs ECM and gem all lean towards long fetch SW flow.

[The Enforcer]

5 hours ago, Timmytour said:

So much I agree with about this.  The "signs" that are there are signs that are nearly always there.  They are the same signs that are seen when it looks like the zonal norm is set to return to ruin a cold snowy period and we are told we can safely ignore them.

The key for me is whether the signals are current or whether they are projected. If the former, then, as set out in the NW winter forecast, there can be reasonable confidence in conditions supporting wintry weather emerging at some point.

However, if it is a forecast for favourable background signals then it is just that - a forecast - and as such needs to be weighted accordingly. Hypothetically, a forecast today for a SSW on 1st Jan 2018 is not really any more reliable than GFS charts showing snow on xmas day at T+384. I have lost track of how many times the charts show MJO is expected to move into 'this' phase and a few days later they instead say that it is expected to move into 'that' phase.

 

[LRD]

The latter stages of the ECM are a bit of a horror show for those who want to see cold

BUT

...there are signs that pressure is building to the NE in FI and the seemingly inevitable mild spell is getting pushed back even if it is only by a matter of hours

I don't mind a spell of Atlantic weather as long as it's lively and interesting. The later frames from ECM will be both mild and dry for the south. Or, to put it another way it will be BORING for the south

[northwestsnow]

If EC is correct then i think we are going to have to have a little patience over the coming week(s).

One positive i can see by day 10 is some very cold dense air building over the Baltics- if we see some amplification in the western Atlantic thereafter then there will be some cold air to tap into -

Worth watching IMHO and although it does look a +NAO i honestly don't think it will be one that lasts for weeks on end.

Just a case of riding out the coming 10 -14 days