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

[johnholmes]

Well a lot of posts in here which is good to see, various opinions again good to see, also very good not personal digs of any real import.

So where are we?

This from T probably best sums up where we are and what we can expect in my view

sustained upper cold pattern in the UK 

I appear to have chopped off a bit of that quote so my apologies it suggests quite rightly there has not been any real sign this winter nor does there currently appear to be any sustaned cold pattern for the UK.

Please correct this if it not what you posted or meant T?

There has never been nor does there currently look like being the above. Perhaps hard for some to accept but it is true from the vagaries of the synoptic models be they 2x or 4x daily, or any other output. We are going to get a colder shot within the next 6-14 days. I would anticipate it being from 1-5 days in duration, best estimate/guess is for 2-4 days. Why, search me folks, I only deal in 6-14 days possibly 20 days at most from my knowledge. The detail is being finalised in the synoptic models, not without hiccups but the trend is there. Finer details, will it snow and where, how cold? As ever much closer to the event occurring.

Anomaly charts tomorrow morning but the NOAA has been posted by knocker already. The main change is the dropping of the fairly intense ridge and +ve heights west of Alaska. I am not too sure just what this may mean 6-14 days down the line but it may be as k has suggested. 

Edited January 5, 2017 by johnholmes

[StretfordEnd1996]

Yeah ... whatever GFS18z ... you just do what you want, much to all our dismay! 

Hopefully after a good telling off from all us lot the early morning GFS run will behave itself and give us a bit more passion than that 

 

Still very cold uppers for a time on Friday and Saturday next week but after the ECM and GFS12z I was hoping for a bit more of an effort to produce and maintain a decent Northerly 

 

Will go to sleep not too overly concerned at this stage - every single 'build up' to a cold snap in the UK always includes some poor charts like this one - we all know that. 

 

Hopefully ECM has latched onto the right idea

Here's hoping for a good FI too - for what it's worth

Ensembles were looking good too earlier - 

It's so incredibly annoying to end on a chart like this after today but whatever stilll plently to play for tomorrow I think, upgrades and downgrades from here. 

 

Goodnight

Edited January 5, 2017 by StretfordEnd1996

[Zakos]

ECM and GFS at 192.

both have a very large anomaly in the atlantic - encouraging.

However, when comparing these two charts, it looks as though the siberian high may act as our friend rather than our foe this month.

A much stronger Siberian high on the ECM, looks to me that this forces the core of low heights over europe to be much further west.

It also appears to increase heights around Scandi/Svalbard, which would be key in order for us to see an easterly flow.

An even better comparison is the GFS 18Z vs 12Z

The 12z shows a stronger Russian high, which the altantic ridge is trying to link up with. If the highs do link up, game on for a bitter easterly flow

18z is pants- no link up of the highs.

Can't see a Greenland High anytime soon... definitely potential for an easterly IMO. Not saying it will happen, but patience is required. As long as both blocks remain in place, it is certainly a possibility, all we need is a bit of luck.

Edited January 5, 2017 by Zakos

[radiohead]

18Z GFS is a shorter cold shot and not as snowy but we'll probably get another variation again on the 0Z. This is still over 160 hours away....there are going to be changes at this range on every run.

North/northwest still gets some nice snow on this run.

[snowice]

7 minutes ago, January Snowstorm said:

Poor 18z with everything shunted east.

Still cold but less ppn as the high moves in. As nick mentioned yesterday it sums up the winter to date to be getting excited about this.

Let's hope for an improvement over night 

EC handles the PV over the US different than Gfs therefore if ec is right the high should push futher West in the 00z

Edited January 5, 2017 by snowice

[chris pawsey]

Can't post charts from my phone unfortunately but the GFS at 216hrs shows -8 850 uppers from a NW/N direction, if precipitation was associated with this would it produce snow to lower levels? Forgive my inept knowledge... still learning... after 9 years of model watching... eeekkk! Straw clutching!

[Banbury]

I do like the way we bin a run because the OP is rubbish , se what the ENS say if 18 show a strong bitterly cold Easterly then the 18z will be a beauty eh? lol

ENS always help with the story

[radiohead]

3 minutes ago, chris pawsey said:

Can't post charts from my phone unfortunately but the GFS at 216hrs shows -8 850 uppers from a NW/N direction, if precipitation was associated with this would it produce snow to lower levels? Forgive my inept knowledge... still learning... after 9 years of model watching... eeekkk! Straw clutching!

Here is T210. DP temp below zero pretty much everywhere so that would be snow.

[blizzard81]

I must admit, reading some of the posts tonight, we might as well call it a day and come back in November. If some of the very learned members on here are correct with their thoughts tonight then this will be another epic fail by the ecm ens and not for the first time this season. No offence intended but I do hope the ecm trumps those particular members tonight. If not, kudos to them. Wouldn't particularly want the 18z on my side though

[StretfordEnd1996]

Just now, Banbury said:

I do like the way we bin a run because the OP is rubbish , se what the ENS say if 18 show a strong bitterly cold Easterly then the 18z will be a beauty eh? lol

ENS always help with the story

You are right mate - although I don't think we should really 'bin' the run - yes I will show huge dislike towards it but for the purposes of the fact that our weather is so unpredictable and cold spells are so hard to come by in our shores of the world - we certainly have to take into account what it is showing. 

But hey - it's not a complete breakdown by any means - there is still some very cold uppers in place on Friday and Saturday of next week before that high pressure tumbles in;

 

 

Usually by now we'd be in dismay having seen the NW/N completely disappear but it is still there 

-8 uppers down to Northern England 

 

Will have to wait and see what the ENS are like you called it right - but the op has put me in the mood to sleep rather than stay awake for those!

 

Not the best ends to the day but every chance this will lead to a better rise tomorrow when my alarm goes off at 05:30 for the GFS00z (Yeah - the obsession is that severe)

Goodnight 

 

[Jason M]

This run seems very much in keeping with the GEFS earlier. There has been a gentle uptick in the number of ptrbs raising pressure to our south in the last few days and I suspect that's going to be the story of this winter. From experience my instincts are that the northerly will get further modified over the next couple of days. I think we will end up with a NW with slightly higher uppers than currently shown. Still some snow for some in that scenario but just a bog standard winter cold snap.

Looking through the 12Z GEFS any signal for HLB had pretty much disappeared. Others hold a contrary view from reading the posts this evening but I felt they were rather uninspiring tbh. The 18Z suite rolling out now will be interesting.

[nick sussex]

The issue with the GFS 18hrs run is the failure to lock in the Euro troughing which then allows too much eastwards progression of the high.

Putting that aside the trend in terms of flattening the pattern upstream past day 8 is backed by the ECM, the issue is whether we get one or two amplified shortwaves  working east across the USA before that happens. The ECM has two, the GFS only has one before that flattening.

We need the second one to help get the PV further to the nw and help split that from low heights to the ne. Its likely that the PV will elongate and edge south in the Atlantic towards day ten , both the GFS and ECM agree with this. The uncertainty is where the high is as that happens and how far west and north that is.

Edited January 5, 2017 by nick sussex

[TEITS]

Im sitting on the fence this evening and this is purely based on following the ECM & GFS over many years.

The ECM whilst regarded as the best model does have a tendancy of over amplifying whereas the GFS tends to do the opposite and flatten too quickly. So yes to the colder NW,ly outbreaks but on the fence with regards to a prolonged, colder N/NE,ly.

I will add despite the various forecasting methods on this thread i.e teleconnections. Nobody can really say how this will develop. Look at tonights 18Z compared to last nights and in F.I we see a very cold E,ly being replaced by a very mild.SW,ly. If a supercomputer shows such a massive difference in 24hrs for 14 days out, is it any wonder why long range forecasts especially seasonal forecasts often fail.

[bluearmy]

4 minutes ago, blizzard81 said:

I'm beginning to wonder if the ecm is going to look like a right plonker again in the morning lol.

Compared to which GFS op from today?

all ops are only ens members post day 7/8. 

Look at them this way and life will be on so much easier! 

[Mucka]

Don't rate the 18z Op much even though there would be a chance of snow, but ECM ensembles not bad.

[blizzard81]

6 minutes ago, bluearmy said:

Compared to which GFS op from today?

all ops are only ens members post day 7/8. 

Look at them this way and life will be on so much easier! 

I know but whole ecm suites have been way off many times this season and don't get me started on the ec46 lol.

Edited January 5, 2017 by blizzard81

[karlos1983]

4 minutes ago, Mucka said:

Don't rate the 18z Op much even though there would be a chance of snow, but ECM ensembles not bad.

Not bad Mucka!! They are pretty tasty compared to the past 3 or 4, nicely grouped on the cold side at the end also. I'll happily hit the hay on them! 

[Mucka]

3 minutes ago, karlos1983 said:

Not bad Mucka!! They are pretty tasty compared to the past 3 or 4, nicely grouped on the cold side at the end also. I'll happily hit the hay on them! 

Yeah considering it is off a PM flow and those are London temps and though the mean can be a little misleading at least it is on the cold side.

Talking of means, here is the GFS mean 180 - not bad at all, especially the further N/W you are or extra elevation you have

Edited January 5, 2017 by Mucka

[radiohead]

Quite a variety of outputs in the GEFS at T168

About 8/20 develop a strong low near Scotland on the 12th. Perhaps a new trend that might pop up on the next Op run?

[Man With Beard]

EC 46

D11-D18: Hint ridging towards Greenland 

D18-D25: Shock horror - no positive northern heights anomaly!

 

 

[nick sussex]

As everyone knows I've hardly been enthused by recent outputs! I did seem in a rather grumpy mood yesterday but I really wouldn't lose any sleep over the GFS 18hrs run.

You have to look at it in the context of what its been doing for the last few days.

Heres the list of fails.

Low se USA too flat and shallow in depth had to backtrack. Flatter shortwave US plains which effected the high exiting Canada and downstream lead to a messy Atlantic picture with shortwave complications, another backtrack.

NCEP ditched both the GFS 00hrs and 06hrs runs beyond Tuesday and didn't use them in their forecast. NCEP stated in their extended discussion the last 3 GFS ops all had different solutions for some key synoptics.

That's not to say the ECM is correct because as Dave just mentioned and we have seen this in recent winters the ECM can over amplify especially in FI however the GFS is often too flat, even if we end up with a middle ground solution it will still be better than the GFS's original view.

We'll see in the morning.

 

 

[karlos1983]

3 minutes ago, Man With Beard said:

EC 46

D11-D18: Hint ridging towards Greenland 

D18-D25: Shock horror - no positive northern heights anomaly!

 

 

Greeny high inbound then 

Edited January 5, 2017 by karlos1983

[pyrotech]

14 minutes ago, Mucka said:

Don't rate the 18z Op much even though there would be a chance of snow, but ECM ensembles not bad.

Yes and even where the op's sky high later in fi, the mean is steady with a good majority at very low temps. ECM here is very much a colder outlook, but i think we need to keep our feet firmly on the ground with such difference. Tamara has shown tonight that its quite feasible for what GFS is showing to come true. In my opinion the teleconnections will effect us differently if the Siberian heights become stronger and blocking to our North help to hold the Azores high further West. The same factors could cause the Northerly flow to last longer and sent a Shortwave South over the UK. Unfortunately The Azores high ridging towards Uk and into Europe is more feasible. All options do remain on the table thou. ECM particularly the better option.

I would suggest polar maritime incursions with temps rolling from 2-4c then 11c in a rolling basis with wintry showers in the South during the cold spells, but the ECM still offers a pleasant alternative.

 

Edited January 5, 2017 by pyrotech
auto spell changed ops to oppose

[shuggee]

Interesting watching the Azores High bobbing around the Atlantic - flattening on occasion, such as the next seven days, then popping up north and west, to allow that precious incursion of PM air into NW UK - days seven onward are that cold(er) shot..

I am however reminded, not sure who said it many years ago on here - the Azores High migrating (retrogressing even) north rarely delivers little more than fleeting glimpses of cold. What nearly always needs to happen is that a Greenland High extends south, blocking the Atlantic. Wise words....?

[bobbydog]

Just a gentle reminder for us all. The models cannot 'smell coffee'. They do not have tails, or legs to put them between if they are wrong. The 18z doesn't drink, therefore does not go to the pub. Computers don't have feelings so are unlikely to feel like a "plonker". They can't "fail" at something they don't guarantee. Importantly, they are not constantly trying their best to give netweather members the weather we want. They are a computer algorithm churning out endless possible evolutions of a chaotic force known as "the weather", designed to help professional forecasters to make reasoned decisions when trying to make sense of the aforementioned chaos...

Watch them, analyse them, enjoy them. But don't blame them if it doesn't snow...