Model output discussion pm 13/01/2016

[TEITS]

12 minutes ago, bobbydog said:

problem is, the 'building blocks' may well be there but, bob the builder is apparently on holiday...

I Personally cannot see these so called building blocks. What I do see in the ensemble means by GFS/ECM is relatively high pressure to our S and low heights to our NW. The GEFS in F.I do suggest high pressure over Russia extending W into Scandi but the problem at the moment is the suggestion low heights will remain to our NW. The net result of this is possibly a cold SE,ly but not a cold snowy E,ly.

 

Edited January 16, 2016 by TEITS

[mickpips]

20 minutes ago, Nick L said:

This is a bit of a flawed argument to be honest. You're (rightly) talking about differences if 10s of miles. But in terms of days ahead we're talking about broad scale, general patterns rather than local features like tonight. 

True , in the grand scale of things ... I was just trying to make out , locally things can be so different to those forecast , meteorically things remain the same upstream , an onslaught from the SW seems inevitable next week 

[blizzard81]

10 minutes ago, TEITS said:

I Personally cannot see these so called building blocks. What I do see in the ensemble means by GFS/ECM is relatively high pressure to our S and low heights to our NW. The GEFS in F.I do suggest high pressure over Russia extending W into Scandi but the problem at the moment is the suggestion low heights will remain to our NW. The net result of this is possibly a cold SE,ly but not a cold snowy E,ly.

 

The output will change over the next few days and quite dramatically may I add. Pressure rise to our north west is the one to look out for

[Eskimo]

1 hour ago, Paul_1978 said:

OMG, first we have "Sceuro" and now we have "Scrussia" :-/

Well, when you have central core of the high pressure over both Scandie and Russia, what else do you call it?

Is it also possible for people to reply without sounding completely haughty? 

Edited January 17, 2016 by PerfectStorm

[Jason M]

2 minutes ago, PerfectStorm said:

Well, when you have central core of the high pressure over both Scandie and Russia, what else do you call it? 

A Bartlett!? Its just one big belt of high pressure from Iberia up into southern Scandi.

Anyway, joking aside the GEFS continue to show high pressure to our SE (as they have for days). It could change, but as a default pattern for this winter i'd want good odds before i'd put any money on it!

A few of the prbs look promising but they all fail to develop into anything interesting. Onwards to the next set of charts  (been saying that for 3 winters now).

 

 

 

 

 

[Snowman.]

43 minutes ago, TEITS said:

I Personally cannot see these so called building blocks. What I do see in the ensemble means by GFS/ECM is relatively high pressure to our S and low heights to our NW. The GEFS in F.I do suggest high pressure over Russia extending W into Scandi but the problem at the moment is the suggestion low heights will remain to our NW. The net result of this is possibly a cold SE,ly but not a cold snowy E,ly.

 

Tbf they're talking about turning point of the month and feb even the MetO updates says there's an increased chance.

I mean its 16 days away but the signs are there for height rises NW. 

[Cheshire Freeze]

4 hours ago, wishingforsnow said:

I think the Met perhaps have more information which could be making them doubt the extent, timing and occurence of the block and how it will happen like will it completely do away with the block and cold air or stall and provide some more welcome snowfall? Also I have a feeling that as cold air is difficult to shift, the Atlantic is going to have a harder time completely breaking through this block as quickly as some models suggest. As of now nothing is a done deal. The fat lady isn't singing yet. 

 

 

The Met will be more than concious of the fact that background signals and their own long range modelling has been consistently pushing for a cold Feb for months. As CS has pointed out earlier, it's no coincidence that some longer range ensemble tools are picking up a Scandinavian trough allied to N Atlantic heights-it's most probably where we're headed in the long run. It's how we get there that needs to be sorted- this is pertinent as we could find ourselves exceptionally mild again (briefly) if WAA chooses to head polewards over us.

[Swave Snow]

48 minutes ago, CreweCold said:

The Met will be more than concious of the fact that background signals and their own long range modelling has been consistently pushing for a cold Feb for months. As CS has pointed out earlier, it's no coincidence that some longer range ensemble tools are picking up a Scandinavian trough allied to N Atlantic heights-it's most probably where we're headed in the long run. It's how we get there that needs to be sorted- this is pertinent as we could find ourselves exceptionally mild again (briefly) if WAA chooses to head polewards over us.

Is the WAA not happening right now courtesy of that ex hurricane it sure looks like it on the satellite 

 

If so wouldn't that affect the pole in the Greenland direction 

Edited January 17, 2016 by Swave Snow

[Mucka]

GFS 00z keen to prolong the fight in the short term

Cold air pushing back SW out to 78h

Yet another push and milder gets a bit further east still but all a struggle with chance of more snow for some.

Edited January 17, 2016 by Mucka

[Cheshire Freeze]

Interesting, the tilt of the approach of that troughing suggests pressure will build somewhere to our E

Surface winds backed across the N of the UK suggests major snow for far N England and S Scotland

Compare this to the positive tilt of the 18z

The Atlantic may not even get in at all when all is said and done....how many times have Scandi pressure rises evaded the models before popping up at 120 hours or so?!

 

Edited January 17, 2016 by CreweCold

[Cheshire Freeze]

10 minutes ago, Mucka said:

GFS 00z keen to prolong the fight in the short term

Cold air pushing back SW out to 78h

Yet another push and milder gets a bit further east still but all a struggle with chance of more snow for some.

I'm having my doubts as to whether the Atlantic will get in fully at all....trough is being shredded S of Greenland- has all the hallmarks of an easterly setting up here Mucka

You can see the atrophy of the troughing as WAA wrap around nibbles at the Greenland plateau

Edited January 17, 2016 by CreweCold

[Mucka]

5 minutes ago, CreweCold said:

I'm having my doubts as to whether the Atlantic will get in fully at all....trough is being shredded S of Greenland- has all the hallmarks of an easterly setting up here Mucka

 

Certainly the cold air is getting shunted less far East with each run on GFS Crew and there is just a tad more energy that goes SE with each atlantic attack.

I think the building block are getting closer to set up for an Easterly but we will need to stall he Atlantic further West I reckon and get another bout WAA up there before we can think about any high pushing back West. 

UKMO has flipped the other way though and followed up last nights run with another flat effort this morning.

Just hope GFS is onto something.

Edited January 17, 2016 by Mucka

[Cheshire Freeze]

6 minutes ago, Mucka said:

Certainly the cold air is getting shunted less far East with each run on GFS Crew and there is just a tad more energy that goes SE with each atlantic attack.

I think the building block are getting closer to set up for an Easterly but we will need to stall he Atlantic further West I reckon and get another bout WAA up there before we can think about any high pushing back West. 

UKMO has flipped the other way though and followed up last nights run with another flat effort this morning.

Just hope GFS is onto something.

GFS almost makes it...

UKMO goes from hero to villain and another model drama about to unfold I'd wager!

EDIT: Nice polar profile as a bubble of warm uppers is sent northwards once again, contorting the trop vortex once more

 

Edited January 17, 2016 by CreweCold

[Mucka]

15 minutes ago, CreweCold said:

GFS almost makes it...

UKMO goes from hero to villain and another model drama about to unfold I'd wager!

LOL I'd say it has never really ended but yeah UKMO and GFS 144 look rather different again. 

 

GEM backing GFS

Edited January 17, 2016 by Mucka

[Cheshire Freeze]

9 minutes ago, Mucka said:

LOL I'd say it has never really ended but yeah UKMO and GFS 144 look rather different again. 

I'm not too fussed...there's possibilities going forward on both of those charts. That Siberian high would prompt the AO back negative with time on the UKMO, given the angle of advection. Either way the trop vortex is on borrowed time and I feel its last rites are on the way over the next couple of weeks.

Get to this stage and the vortex is pretty much banged to rights with another deep seated bout of WAA headed from the Atlantic

I'd like to see it get out of that one.....

Edited January 17, 2016 by CreweCold

[Mucka]

GEM quite amusing really. After  a week of the Atlantic trying to get in and force the cold air away East it manages to shunt it about 30 miles.

Do you think the Atlantic is doing this? 

[Cheshire Freeze]

2 minutes ago, Mucka said:

GEM quite amusing really. After  a week of the Atlantic trying to get in and force the cold air away East it manages to shunt it about 30 miles.

Do you think the Atlantic is doing this? 

It's because once the modelling stops sending the jet barrelling ENE and slows the progression of troughing it then realises that warm air is being advected further N more vertically. Once this occurs you set up a feedback in the modelling where HP is strengthened to the E or NE of the troughing. This then throws the medium range modelling into disarray as the modelling then has to work out the distribution of energy around said block. It's a perpetual problem within the NWP and is probably the reason the Metoffice have been slightly cagey RE the coming week or so.

[Mucka]

Strong warming and possible SSW being modeled by GFS but deepest FI - interesting to see if it gets dropped or picked up on future runs

[Cheshire Freeze]

By the end of the run it's pretty much goodnight Vienna for the vortex this winter with the much touted heights retrogressing to Greenland and a trough dropping into Scandi

 

I've had a look at the GEFS out of curiosity....quite a few flat-ish runs in there at day 10 (as I'd expect at this point) but also a number of Scandi high options....some showing retrogressive tendencies...

Edited January 17, 2016 by CreweCold

[IDO]

Not many changes this morning especially for the south with the move from av.-4c uppers to av.+4c uppers sometime Thursday; neither cold or mild, just average fare down here:

  

Some synoptic changes^^^, with a two wave attack from the Azores from around D4 and by D7 the above complication. As you would expect there is about 4 clusters, all handling this in a slightly different way. GEM is similar to the GFS op with a cut off low over the Azores and a temporary UK high before the heights drift east around D10 with both showing a further ridge drive up from west of the Azores around then. ECM is similar with the two waves but they are over run by the Atlantic and ECM has more subdued heights in the NE from D8-10:

ECM:   GEM for

How all this interacts has been the puzzle post-breakdown. The UKMO, as its will lately goes off in another direction:

D6:

A zonal onslaught. It seems to over react to pattern changes, so when heights are forecast is blows up Greenland blocks and when the Atlantic is incoming it gives us a zonal tsunami.

How the highs place themselves will determine surface conditions, it could be mild, average or just below from D7-13. 

The stalling front Monday looks to be a tame affair, some snizzle for some in the spine of the country as it grinds to a halt, before sinking south as it dies Tuesday. WRF take:

T28: T40:   T52: 

For the south we have had a couple of frosts, an Arctic wind one day, a dusting of snow (in south London, though some areas got a cm or so, and of course further north some were luckier) and just below average daytime temps. Normally that would not be worth mentioning in an average winter, but having been starved of anything wintry for seemingly years, then at least it is seasonal. Looking like we should get mostly dry weather over the next 7-10 days if GFS is correct, but UKMO and ECM, less so.

 

 

Edited January 17, 2016 by IDO

[nick sussex]

Last nights T96hrs fax chart, followed by todays T84hrs to the same time!

Hard to tell whether they've modified this mornings UKMO raw output as we don't have 6hr intervals but 24hr jumps at this point but last nights UKMO was the most progressive solution.

 

 

Edited January 17, 2016 by nick sussex

[bluearmy]

4 minutes ago, nick sussex said:

La

I need more than one note nick!

the ECM ens for London are rock solidly behind the warm up now. May stay blocked to our East. Upstream amplification unconvincing on ops and ens. What I do see is a general draining of heights in n America away from NE Canada though no big ridging or area of marked high heights. 

[nick sussex]

1 minute ago, bluearmy said:

I need more than one note nick!

the ECM ens for London are rock solidly behind the warm up now. May stay blocked to our East. Upstream amplification unconvincing on ops and ens. What I do see is a general draining of heights in n America away from NE Canada though no big ridging or area of marked high heights.

Lol! yes I started writing then this damn comp froze! Yes unless the GEM miracle has any legs which is the longest of longshots then its going to turn milder.

For the timebeing lets remain in the comforting embrace of the GEM! oh dear my melodrama has started already! put this down to my poor sleeping habits as I'm now close to becoming delusional with exhaustion!

[timboy666]

3 hours ago, Mucka said:

Strong warming and possible SSW being modeled by GFS but deepest FI - interesting to see if it gets dropped or picked up on future runs

What dose f1 mean? I'm new to this but want to learn

[nick sussex]

1 minute ago, timboy666 said:

What dose f1 mean? I'm new to this but want to learn

Fantasy Island. Synoptics that are well into the future and implode more often than they ever verify. Generally strat forecasts though are less subject to wild swings.