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

[Iceberg]

Ecm finishes with an amazingly snowy chart and bloody cold. 

[Ali1977]

What a run from the ECM with fridges air flooding in at 240, history had me thinking this cold spell second week of Jan would get watered down , starting to think otherwise. Great start to the day, the GFS was also good with an excellent set of ENS, and the control was outstanding.

Beyond 240 would be a notable and newsworthy event if it became reality with -20 uppers already into southern Norway on route to the UK (albeit warmed slightly over the North Sea) , hopefully backed up by some great ENS later.  What is also available is a much larger chunk of frigid European air, helped by the WAA being further North before pivoting to create the Easterly, PV also getting hit from the Alaskan side too.

Edited December 30, 2016 by Ali1977

[booferking]

Boom.

[Lampostwatcher]

Fantastic gfs 0z and ECM 0z

[That ECM]

Apart from great charts to view, this period of model watching is good for improving knowledge as little differences have big impacts . 

Ecm has been solid and consistent with is output and long may it continue

[Connor Bailey Degnan]

Amazing GFS and ECM. When we get the UKMO on board at 12z, we can start to get very excited.

BOOM BOOM BOOM BEASTERLY ECM 240 !

[Man With Beard]

9 minutes ago, Man With Beard said:

ECM T216 - heights in position to the north, expect fusion of low heights to the south and the holy grail easterly at T240...?

BANG BANG BANG BANG BANG BANG!!

Good morning Netweather, I present you the holy grail easterly, courtesy of ECM T240.

I also recommend http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 for many more easterlies.

Enjoy your morning

Edited December 30, 2016 by Man With Beard

[mountain shadow]

1 minute ago, booferking said:

Boom.

Notice the pivot of the high is much further North than yesterday. It is Iceland today, yesterday was central UK.

 

[Timbo]

looks like all the snow from the last few years will be arriving all at once,if this mornings ECM is to be believed.

Looks like East Anglia could be digging ourselves out next weekend 

[Severe Siberian icy blast]

What a fantastic start to the day. It's been 4 years (Jan 13) since we saw European deep cold like this And GENUINE northerly blocking,  especially March 13 which was a once in 50 year event, but this January really has a different look about it and after the expectations before December ruined it all its nice to see winter crawling back into game, be great to see at least one widespread snow event for us all!

[cheshire snow]

Great charts this morning my only concern is UKMO not been on Board,wont let that dampen my spirits at the moment.

ECM and GFS Excellent

C.S

[Duane S.]

Wifi sped up a bit but decided to see it through on here first before having a quick look at the charts on Meteociel.

Thanks for the updates guys, GREAT looking ECM, was much better than I had dared hope for. It looks like it's coming...

Edited December 30, 2016 by s4lancia

[knocker]

The ecm also playing with some complex little secondary lows around the North Sea. Of course none of this will verify.

Edited December 30, 2016 by knocker

[Man With Beard]

1 minute ago, knocker said:

The ecm also playing with some complex little secondary lows around the North Sea. Of course none of this will verify.

Let me clarify - Knocker means that the finite details of the secondary lows, the exact positioning of the pattern (E.g. will it snow over London at 3pm rather than 4pm), this kind of detail will not verify. He is not saying that the easterly itself won't verify. Is that right, Knocker?

[NO LONGER POSTING]

Good set of models this morning BUT we need to get through a lot before we get there.  Things need to fall in line etc etc.  It's very good that most of the UK this week away from the west and north have barley thawed out these last few days helping being down ground temperatures. With a lot of snow cover out east too aiding anything that may come from that direction. 

RE front moving south weekend, I don't think snow will be an issue some may see some flakes mixed in, what will be a problem I think is ice and lots of it

[sorepaw1]

Looking at the cracking set of charts from ECM and GFS. 

any deep lying snow that falls and settles on exposed hills and lower regions and the end of next week is that if the wind picks up above 28mph we will start to see fantastic drifting snow and blizzards. 

Looking forward to the 06z .

And stocking up on logs for my log burner.

Happy model watching. 

Edited December 30, 2016 by sorepaw1
To add timing

[knocker]

 

31 minutes ago, Man With Beard said:

Let me clarify - Knocker means that the finite details of the secondary lows, the exact positioning of the pattern (E.g. will it snow over London at 3pm rather than 4pm), this kind of detail will not verify. He is not saying that the easterly itself won't verify. Is that right, Knocker?

I'm quite intrigued  that you know what I'm thinking MWB, incorrectly as it happens. But just to clarify I think the wind veering from NW to N is a pretty fair bet as the depressions track SE but at the moment the easterly only appears right at the end of the run and is very dependent on the handling of the renewed amplification of the upper ridge. Any sensible person would treat that with caution at that range which I accept rules out most on here. There is also the added problem of when the upper trough continues to slip SE (or does it?) where does the ridge go even if one accepts the evolution is correct?

Edited December 30, 2016 by knocker

[jvenge]

Not sure if anyone mentioned it since the 15 pages I last visited yesterday (heh), but the EPS Weekly is showing the UK under colder than average uppers on the mean for the next month or so. Not showing frigid, but one imagines for it to be showing cold and over such a large area, there would need to be some candy in there. Perhaps someone with access to the individual members can update later.

As a FYI, that's the first time since the phantom front loaded winter disappeared that a EPS Weekly has shown the UK under cold weather, for such a prolonged period, on the mean.

[Iceberg]

To be objective about the models this morning a moe detailed look shows no support for the meto variation even as early as t96 it seems to play a pattern off the eastern seaboard and in the Atlantic which disagrees with its fellows. Given that it must be a slim chance. 

The differences between the gfs and ecm are really quite tiny at the t96-144 time range. A slightly different angle of jet had an enourmous effect. Given that we cannot see this level of detail in the ecm ens, but that the Ctrl and ens favour the ecm. I would lean a little more in that direction. However I would not be fully confident until I see that critical energy transfer at the t72-96 range. Currently it's at t144 so Sunday should be the tell the family day. Unless of course it's already gone pear shaped by then !

Edited December 30, 2016 by Iceberg

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=6

 

now  snow  by jan 2  nice way to bring the  new year  in 

[IDO]

So a positive start to the day with the "Potential" still remaining for those that want a wintry setup. Looking at the GEFS clusters, as per the trend, the second trough/ridge combo from around D8 has a strengthening signal and it now looks nailed according to the GEFS. The clusters are here

A northerly flow from the low as it moves through now around 70%, and its how far west the pattern is , which will dictate the potential for wintry disturbances. The ECM is more progressive with that trough and it remains too far east initially for much of the UK, snow wise.

GFSGEM: 

As you can see there are big differences going forward from there with the WAA on the GFS coming from the SW and from the SE ECM. From a synoptic POV the op has only small cluster support for that direction, and there are as many going the ECM route and similar directly from the south,There are a few that support the GEM with energy splitting the Azores trough.

As you would expect at this range still uncertainty and clearly that wave of energy significant as to the extent of the second shot of cold and how the pattern develops from there.

Looking upstream and it is apparent the Pacific wave is declining by D10 and any amplification will be dampened with the knock on effect for our region. The window remains that we need to get a cold pattern in by around D10 as it will get harder for Northern Blocking afterwards; D10 &  D12 GEFS mean:

We can see the mean flattening of the NH pattern. Looks like the trend of draining the lower heights to a NE Canadian vortex remains the majority signal, hence the potential for a ridge to build NE from the wedge of heights that build from the wave around D8. The control is a great solution but it relies on the perfect setup where two wedges of HP form from the Pacific and Atlantic heights move into high latitude, with a near perfect pincer attack, ripping the PV to pieces. About a 16% chance according to the GEFS.

The WRF model suggesting the cold front on NYD will not be significant and a rain event for all but mountains and favoured hills:

Wintry showers to coasts following. Feeling cold as -10c uppers march in from the north by the end of the day. But again the white stuff remains elusive and the first shot a fail for that for most. Then dry for next week, but cold, London:

  2m temps

From then the uncertainty and potential is apparent.

 

Edited December 30, 2016 by IDO

[Johnp]

Over the past few years, my perception is that whenever UKMO has played party pooper, it has always proved correct.

I simply cannot get excited until it is on board!

[Scandinavian High.]

heavy snow showers pushing south.

[Ben Lewis]

16 minutes ago, Johnp said:

Over the past few years, my perception is that whenever UKMO has played party pooper, it has always proved correct.

I simply cannot get excited until it is on board!

Couldn't agree more. Until the UKMO plays the game you are doing damage to your health and sanity getting excited. 

To view as eye candy? Absolutely, but make sure it is only that. 

[Iceberg]

Re the meto model. It really is a sub par model now and gets nowhere near the money or power of the ecm. It does still have its uses primarily as a short term model feeding more data into the shorter term models such as Ukv. 

As a hemispheric model at t96 you will be hard pushed to find many that would place it over gfs and ecm unless it was maybe a Icelandic or north sea meso low.