Model Output Discussion 29th December - Into mid-Winter.

[bobbydog]

2 hours ago, karyo said:

That's a good point. For some reason the models want to speed up the return to mild. Maybe they have overeacted to a signal.

The models are not speeding up a return to anything. We've had every weather you could think of in the past few weeks and the models are showing the same buffet of weather options going forward. We could see the beast from the east or a Spanish plume showing by tomorrow. However, with an SSW on the table, we could be going from a buffet to a banquet....

[Purga]

ECM short ENS are better than this morning with the Op very much on the mild side for days 5-7

Things trend a bit less cold thereafter but there are still some cold solutions.

As ever more runs needed.

[booferking]

2 minutes ago, Summer Sun said:

Yep high pressure remains

Thanks looks like the low in the atlantic is sliding under towards spain and the high in esb and uk trying to link up slighlty over the top of the other low.

[Seasonality]

2 minutes ago, Alekos said:

But don't think was always like this ? Many more cold spells and snow here is n Greece over the last 20 years !

I won't deny that. But I was replying in the context of models showing cold for uk and people being disappointed when it doesn't appear. The UK just happens to be a fairly mild country.  I agree with your theory about the northern jet though, quite dramatic differences for Greece. 

[bluearmy]

6 minutes ago, Purga said:

ECM short ENS are better than this morning with the Op very much on the mild side for days 5-7

Things trend a bit less cold thereafter but there are still some cold solutions.

As ever more runs needed.

They are this mornings ? 

[bobbydog]

15 minutes ago, Jonathan Evans said:

After next weeks anticyclonic activity - have it on good authority that we are going zonal into following week - lasting at least two weeks. That takes us into February and the last chance saloon.

Good authority? Even the good authorities don't know. Do you know someone with a De Lorean and when it hits 88mph....

[Gael_Force]

1 hour ago, SN0WM4N said:

Maybe leave the nitpicking on models to yourself. They're forecasting tools and like a forecast they won't always be accurate. 

The seasonal models have had a bit of a mare in the last few months. Gray wolf posted an ENSO blog in the thread earlier and the OND surface anomaly map.

actual     UKMO (eg)

Either something strange going on that models can't get a handle on or just illustrating the futility of long range forecasting.

[Seasonality]

33 minutes ago, Jonathan Evans said:

After next weeks anticyclonic activity - have it on good authority that we are going zonal into following week - lasting at least two weeks. That takes us into February and the last chance saloon.

And a couple of weeks back some were touting 4-6 weeks of zonality... Ill advised certainty in your post. Especially in the unpredictable context of this winter 

[SMU]

Cant keep away-its like pandoras box

fantastic 18z from t96, max 1c for England as well-

Also 144 onwards the atlantic is going ESE not ENE- superb...

[Banbury]

41 minutes ago, Jonathan Evans said:

After next weeks anticyclonic activity - have it on good authority that we are going zonal into following week - lasting at least two weeks. That takes us into February and the last chance saloon.

Please tell more

[bradymk]

Much better from the 18z so far. Cold end of next week In the south for sure 

going to mainly just look until then (Day 7) on the models from now because we've just been let down way too much from longer term forecasts this year....both from the ops and the longer range models

one of the reasons why everyone thinks the UKMO-GM has been the best performer so far this winter is because it has been. But secondly it only goes out to +144 (for what we see) so it's prone to less fluctuation and we don't see wildly changing day 10 charts like we do from ecm and GFS. 

[Hotspur62]

2 minutes ago, Steve Murr said:

Cant keep away-its like pandoras box

fantastic 18z from t96, max 1c for England as well-

Also 144 onwards the atlantic is going ESE not ENE- superb...

Knew you wouldn"t keep away lol!!-Lets hope that this becomes a trend but we need the UKMO to follow suit and how likely do you think that is?

[nick sussex]

You have to love the GFS 18hrs run so far, just about manages to split that shortwave energy in the Atlantic and so far has boxed the high in over Greenland.

This is key we don't want a gap opening up near Canada, its looking crucial as mentioned earlier to get that split. The ECM didn't do this and then slowly went pearshaped.

[chionomaniac]

Well the GFS 18Z is not exhibiting any return to zonality. I don't think I have seen too many wetter winter charts for the North Atlantic and Europe view with so little 'purple and blue' low heights. Hmmm

[Great Plum]

Now this is more like it... let's see how the rest of the run goes - just for fun of course!

[Jonan92]

Very messy situation in the atlantic, if it verifies it will be hell to know what will happen

[festivalking]

Talk about testing the stamina of model watching.  18z onto something or leading us up the path again. All very pretty but only useful if UKMO agrees 

[SMU]

1 hour ago, Jonan92 said:

In the Spanish forum we are having some difficulties to understand what happens between t72 and t96 at ECM in relation to 850hpa temperatures

It seems to be a big change for just 24h, even more when other models don't dissipate the cold from Europeo so quicliky (GFS, GEM, Arpege, Coamps, JMA..)

My guess is that SE winds are in injected into the continent. Any idea of what could ECM be modelling here?

It will be the wind-

There are slightly warmer uppers going around the high from the North- The faster wind the higher the 'turbulence' which aids mixing - the colder uppers would mixed out..

[Alekos]

18z run very different I think but I know from as you say these charts never verify but mild ones do !

[feb1991blizzard]

GFS 18z is much more blocked than the ECM, still not clean enough but much more likely to deliver.

[Day 10]

11 minutes ago, Great Plum said:

Now this is more like it... let's see how the rest of the run goes - just for fun of course!

Not a bad chart that. Just when I was about to throw the towel in for a few days at least, the gfs says oh no you don't. Back in the morning it is then 

Edited January 14, 2017 by Day 10

[Jonan92]

What a strange map, I have never seen such a thing

[chionomaniac]

Well a cold and likely snowy set up by day 10 on the latest 18Z GFS. What could possibly go wrong in the evolution?

[nick sussex]

This is the crucial initial bit, those shortwaves circled red need to split as they do here and the ECM didn't do this, it took them as one system ne and it was game over.

The second thing to look out for is where the cross is over Canada, we don't want high pressure developing there, we want any high pressure to the north to be boxed in and not allowed to have its energy drained away by a leeching high over northern Canada.

If we could see some troughing where the x is marked elongated and joining up with troughing in the ne USA and amplified then that would help.

 

[Hotspur62]

1 minute ago, Jonan92 said:

What a strange map, I have never seen such a thing

Totally agree.If that was to verify(unlikely i know) that looks a pretty cold chart to me and the chance of snow on this map.