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

[mountain shadow]

1 hour ago, chicken soup said:

Mmmmm...here we go again...i read earlier not to believe any wonder charts unless they are backed up by teleconnections and background signals... and i have heard nothing about those changing as of yet....unless I have missed something.

Nope, you haven't missed anything. Remember it is the GFS showing the outlandish cold, it is a poorer model, stick with the UKMO and ECM, they handle the teleconnections much better.

 

[snowice]

 EC 240hrs the high is back again, All we can hope for is a shift in the models in the next 72hrs.You would like to think with all that cold around its only a matter of time before we hit the bullseye. UKmo Gfs and ecm have great potential we just need a bit of luck. 

[tight isobar]

Fi and all that.

However taking ecm 240 v's gfs 240..12z suites' its not hard to see the issues  both azores high and placement/position of heights cutting into the pole on the Russian side ' are modeled very differently. ..

With a complete reversal of outcomes suite against suite...

However not because its the favored outcome but simply the  the gfs found track and form' of the final outcome for cold' I atm find more appropriate via modeling. ..the ecm had far more impactual complexity. ..

When dealing with positions of for mentioned forcing and heights accomplishments! !!!

Take that how you will?

Look forward to gfs next run -ie 18z.....

Edited January 4, 2017 by tight isobar

[nick sussex]

The Euro slug high although edging west never really leaves the scene in the ECM and the pattern is too far east with a lack of amplitude upstream. Barring some PM incursions its really not upto much.

With high pressure over Russia this does lock in the troughing so its a battle between that and the PV, the latter wants to send the jet pummelling eastwards the high wants to divert this se'wards.

The only route to something interesting and not a few hours of slush and BBC reporter stuck on a hill somewhere bigging up a pants cold snap is for the PV to relocate nw as in the GFS FI.

Otherwise theres really not that much to get excited about and after 5 weeks of crud I won't spinning a few brief PM incursions into anything other than average winter fare which normally wouldn't get a look in but because our bar has been set so low we're supposed to welcome this and say thanks!

Thanks but no thanks!

 

[Mucka]

Pretty decent snow signal in GFS ensembles for  overnight 12th/13th, more especially North and West.

 

Edited January 4, 2017 by Mucka

[Mucka]

2 minutes ago, nick sussex said:

The Euro slug high although edging west never really leaves the scene in the ECM and the pattern is too far east with a lack of amplitude upstream. Barring some PM incursions its really not upto much.

With high pressure over Russia this does lock in the troughing so its a battle between that and the PV, the latter wants to send the jet pummelling eastwards the high wants to divert this se'wards.

The only route to something interesting and not a few hours of slush and BBC reporter stuck on a hill somewhere bigging up a pants cold snap is for the PV to relocate nw as in the GFS FI.

Otherwise theres really not that much to get excited about and after 5 weeks of crud I won't spinning a few brief PM incursions into anything other than average winter fare which normally wouldn't get a look in but because our bar has been set so low we're supposed to welcome this and say thanks!

Thanks but no thanks!

 

Day 10+ would likely bring in a cold pattern, all you need do is believe ECM day 10 is correct

[bluearmy]

4 minutes ago, Mucka said:

Day 10+ would likely bring in a cold pattern, all you need do is believe ECM day 10 is correct

ECM at day 10 is rarely correct but similarly rarely completely wrong. 

i think the pattern to day 7 is decently set and thereafter, the ens show the trough dropping south. imo, that is going to happen unless the ops pick up on something to scupper it. So we should be looking at developments on the op output days 6, 7 and 8 which may mean the trough doesn't drop south far enough west. 

last time, it was the ukmo at day 6 which sang the wrong song but if you had bothered to look closely enough, there were enough hints on ECM op earlier that this solution was more than possible. 

 

[nick sussex]

1 minute ago, Mucka said:

Day 10+ would likely bring in a cold pattern, all you need do is believe ECM day 10 is correct

In what Universe? lol The pattern is already too far east at that stage and we're not going to see any meaningful cold from the nw, with zero chance of Greenland blocking we need something like the GFS solution. Rather than me become the NW misery at least the Euro slug does shift westwards even though not far enough so my glass is a quarter full.

[bobbydog]

6 minutes ago, nick sussex said:

The Euro slug high although edging west never really leaves the scene in the ECM and the pattern is too far east with a lack of amplitude upstream. Barring some PM incursions its really not upto much.

With high pressure over Russia this does lock in the troughing so its a battle between that and the PV, the latter wants to send the jet pummelling eastwards the high wants to divert this se'wards.

The only route to something interesting and not a few hours of slush and BBC reporter stuck on a hill somewhere bigging up a pants cold snap is for the PV to relocate nw as in the GFS FI.

Otherwise theres really not that much to get excited about and after 5 weeks of crud I won't spinning a few brief PM incursions into anything other than average winter fare which normally wouldn't get a look in but because our bar has been set so low we're supposed to welcome this and say thanks!

Thanks but no thanks!

 

Not so sure Nick...

Now of course a day 10 chart is unlikely to verify, however, I've had the electronic crayons out.

In the 240 chart we see the Azores ridge as usual. But we also see a strong ridge building over NE Canada. The low in the Atlantic (circled) hangs about and stops the two HP's linking. The Azores high gets flattened and the Canadian high pushes into Greenland. A couple of days later and the UK population of snowmen explodes....

Well, maybe not but hey... Johnholmes mentioned such a ridge having significance a couple of days ago.

Cold weather sneaking in the back door?

 

[tight isobar]

Exactly nick Sussex. 

That being the gfs 12z takes the Azores hp and sits its placement mid-Atlantic. .while its Russian (partial) ridge punch into the pole holding the develop cold pattern. .then devolving things further' with a meet of heights. .then the penultimate. .ie easterly/north easterly inflow. 

The ecm on the other hand as in my former post- wants both azores high and Russian high to shut up and stay quiet. ...leading to another bore fest of polar maritime incursion. ..at best...

And even that looks an eye blink scenario! !!

Stick with gfs on this...well iam for the sack of sanity! !!

Edited January 4, 2017 by tight isobar

[phil nw.]

There is decent support for some form of Northerly around days 8/9 in the gefs as the Atlantic pattern sharpens enough with the high ridging a little nw and a downstream Scandi.trough digs quite well south into C.Europe in the following couple of days.

and a link to the clusterings

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cslp&HH=204&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

The positioning of these 2 features vital to how deep any cold will be for the UK which at this stage is of course for interest only.Looking further on there's no support for any easterly evolution in fact later clusters favour the return of the Azores high.

Until we see that Greenland chunk of pv undermined or shifted we are really struggling to see anything other than transient cold from the north west-that does appear to be the favoured outlook this evening.

[tight isobar]

Bobbydog..

A great illustration and a possibility. .

However 'again' I'd latch on to the gfs ...far less complexity. 

As-per all will be revealed' preety soon with a probable outcome! ?

Edited January 4, 2017 by tight isobar

[Gustywind]

I'm struggling to see much in the way of joy for cold fans tonight, other than for those on higher ground in the north or northwest.

PM north westerlies rarely deliver for everyone else, just sleet or transient snow which quickly melts. On top of that you tend to get mild sectors and higher dew points with the flow off the Atlantic.

[bluearmy]

Assuming the eps don't jump ship in half an hour we approach a period of wintry potential we haven't seen on the modelling thus far  this winter with all three ens suites in agreement that the low anomolies drop to our south. 

And yet the misery on here from coldies is palpable.

cheer up - it could look zonal with a big euro hig! 

[nick sussex]

3 minutes ago, bobbydog said:

Not so sure Nick...

Now of course a day 10 chart is unlikely to verify, however, I've had the electronic crayons out.

In the 240 chart we see the Azores ridge as usual. But we also see a strong ridge building over NE Canada. The low in the Atlantic (circled) hangs about and stops the two HP's linking. The Azores high gets flattened and the Canadian high pushes into Greenland. A couple of days later and the UK population of snowmen explodes....

Well, maybe not but hey... Johnholmes mentioned such a ridge having significance a couple of days ago.

Cold weather sneaking in the back door?

 

I see you have a cunning master plan! lol Unfortunately you won't get that Canadian high into Greenland with that upstream pattern and theres no signal for proper blocking over that region  then if we want snow and deeper cold it has to come from the east/ne. The issue with even -6 to -8 uppers even if they verified in a PM flow is the modification so it might be okay for higher ground but can't be sustained anyway. Milder sectors will come over the top of the high.

I'm not saying that a PM flow won't deliver something to favoured areas although likely to be brief but at this point I'm looking for something that could deliver more widely and with deep enough cold to sustain that for a few days.

[karlos1983]

2 minutes ago, bluearmy said:

Assuming the eps don't jump ship in half an hour we approach a period of wintry potential we haven't seen on the modelling thus far  this winter with all three ens suites in agreement that the low anomolies drop to our south. 

And yet the misery on here from coldies is palpable.

cheer up - it could look zonal with a big euro hig! 

That's a bit like telling the family a cold spell is coming.. Que eps shift 

that would keep the consistency of our winter going 

[chris55]

 

15 minutes ago, Gustywind said:

I'm struggling to see much in the way of joy for cold fans tonight, other than for those on higher ground in the north or northwest.

PM north westerlies rarely deliver for everyone else, just sleet or transient snow which quickly melts. On top of that you tend to get mild sectors and higher dew points with the flow off the Atlantic.

Your right, a PM flow from the north west rarely delivers for many away from the sweet spots, however on this occasion I think ECM could deliver snow showers even down to lower levels for many in the west, even in England and wales, not the "big freeze easterly" but a covering overnight is more than possible.

Xmas 2004 is a decent comparison, a nice xmas day shower gave a covering even here at low levels in Gloucestershire. 

Edited January 4, 2017 by chris55

[Severe Siberian icy blast]

4 minutes ago, bluearmy said:

Assuming the eps don't jump ship in half an hour we approach a period of wintry potential we haven't seen on the modelling thus far  this winter with all three ens suites in agreement that the low anomolies drop to our south. 

And yet the misery on here from coldies is palpable.

cheer up - it could look zonal with a big euro hig! 

But this is it mate, how many eps/ens complete suites do we see promoting cold only to water the pattern down considerably as we move nearer the time? 

I understand that the fact that all suits are singing the same song at last but I just don't share your optimism at the min, maybe that's because I'm covered in scars from the last failed 1000 attempts but then I guess you are aswel?!

[Singularity]

How many steps - that is the question, as each new one edges the overall pattern west a bit. ECM adds in another step on the 12z compared to that of GFS, with the upstream ridge really to pull the one to our southwest out more to the west for day 11+

How quickly the tropical forcing gathers strength in the Pacific may well be what decides whether we need that extra step or not.

[nick sussex]

5 minutes ago, bluearmy said:

Assuming the eps don't jump ship in half an hour we approach a period of wintry potential we haven't seen on the modelling thus far  this winter with all three ens suites in agreement that the low anomolies drop to our south.

And yet the misery on here from coldies is palpable.

cheer up - it could look zonal with a big euro hig!

You're banned you used the P word! lol Didn't you get the memo? I take it misery and coldies could describe my mood this evening but I think it depends where our expectations lie. Are we supposed to book the mariachi band and get out the bunting for a PM flow? Yes its better than nothing but still isn't really what most members want to see.

[Mucka]

26 minutes ago, bluearmy said:

ECM at day 10 is rarely correct but similarly rarely completely wrong. 

i think the pattern to day 7 is decently set and thereafter, the ens show the trough dropping south. imo, that is going to happen unless the ops pick up on something to scupper it. So we should be looking at developments on the op output days 6, 7 and 8 which may mean the trough doesn't drop south far enough west. 

last time, it was the ukmo at day 6 which sang the wrong song but if you had bothered to look closely enough, there were enough hints on ECM op earlier that this solution was more than possible. 

 

I refer the RH gentleman to my post of Jan 2nd

I think the route forward is very clear if we want cold from 168+ (we need the burgeoning heights to our N/NE to help us out with any deeper prolonged cold though)

We want the trough to dig into the heart of Europe (the further SW it can get the better)

That could bring a cold NW/N flow at least and sharpen up the upstream Atlantic pattern. How much the trough disrupts against any heights to our NE will help determine how much amplification we can get behind and how far West we can bring any ridge to our NE.

In a perfect world we would have locked in low pressure over the continent with an Atlantic ridge and Scandi ridge connecting between day 10/12.

Only trouble is, the output doesn't show that but I did just manage to find 1 ensemble member that at least helps draw a picture.

There certainly isn't enough evidence to talk up that solution yet except in optimistic terms but I still hold out hope that suggested increases in heights to our NE in FI will come into play if we can just get that trough to dig far enough South and West, That will be the first and most important part of the puzzle because it will potentially squeeze the spoiler Azores high West and lower heights to our South, not to mention actually bring us some cold air in the process!

So far the pattern has always found a way to scupper any cold prospects by rebuilding pressure to our S/SW, so flattening and forcing the pattern East so I'm not going to get too taken in by anything that shows a nice Northerly and then Easterly transition( even if it is actually modeled) though it is the pattern I will looking for in our next search for snow.

 

[Cleeve Hill]

To my eyes we are about to see a significant change in Synoptics so far seen this winter. The blocking highs of December are moving and for the first time we can look north west for our weather and with this originating from Greenland directions it will be a very raw and seasonal mix of all sorts, which has to include snow. 

Both GFS and ECM are now showing this change for next week and I wouldn't look beyond 192 as that rarely varifies. 

So a long awaited change on its way and it's a wintry one ! 

[Man With Beard]

22 minutes ago, bobbydog said:

Not so sure Nick...

Now of course a day 10 chart is unlikely to verify, however, I've had the electronic crayons out.

In the 240 chart we see the Azores ridge as usual. But we also see a strong ridge building over NE Canada. The low in the Atlantic (circled) hangs about and stops the two HP's linking. The Azores high gets flattened and the Canadian high pushes into Greenland. A couple of days later and the UK population of snowmen explodes....

Well, maybe not but hey... Johnholmes mentioned such a ridge having significance a couple of days ago.

Cold weather sneaking in the back door?

 

We do have one GEFS member that has that Canadian high at T240

ok not exactly the same over Europe but the theory is that the Atlantic high would be drawn towards the Canadian high as they link up - did it happen on GEFS P7 - yes, a little:

a northerly coming up and potential for a cut-through to the Siberian High round the top of the low.

The set up of the ECM would lead to a far better Atlantic/Canadian high link-up too.

Far too far out to take seriously, of course!

[ANYWEATHER]

11 minutes ago, Gustywind said:

I'm struggling to see much in the way of joy for cold fans tonight, other than for those on higher ground in the north or northwest.

PM north westerlies rarely deliver for everyone else, just sleet or transient snow which quickly melts. On top of that you tend to get mild sectors and higher dew points with the flow off the Atlantic.

Hello Mate. Generally that would be a fair assumption of PM air, but occasionally like it did back in late 2000 an extremely active cold front from Greenland called the " The Snow Plough" delivered snow to all parts of the UK ,   

[phil nw.]

13 minutes ago, nick sussex said:

You're banned you used the P word! lol Didn't you get the memo? I take it misery and coldies could describe my mood this evening but I think it depends where our expectations lie. Are we supposed to book the mariachi band and get out the bunting for a PM flow? Yes its better than nothing but still isn't really what most members want to see.

Yes tend to agree Nick.I think we all getting a bit jaded looking for some deep cold and the outlook of transient polar maritime shots is a poor consolation prize.

Too add to the frustration that Azores high keeps turning up like a bad penny,briefly moving away a little then coming back.