General Model Output Discussion:

[Lewis]

Has anyone noticed since the parallel has become live, things have gone very different on the whole GFS outputs, especially with low pressures? Before 10 people bite my head off, I'm asking the question, not telling.

Lewis

[swfc]

Yes it does indeed look like getting colder.I think sometimes the speculative talk of record low temps ete does tend to over excite the younger folk who havnt prob exp severe cold ete.The extreme cold may well arrive but it is still subject to change like most things regarding synoptic set ups.All looks well tho.

Edited December 30, 2009 by swfc

[snowking]

I fully understand embedded cold scenarios thank you. What I was stating though is that the 06z operational run at T120 brings about a return of what we currently have in the South. The run shows the Trough moving N/ NE bringing in turn warmer dew points and a snow to rain event as it progresses. Yes it is only one run from one model but that is what it shows.

I'm sorry but the 6z operational run does not bring milder dew points in around the time you quoted to the extent of a 'snow to rain' event. That is factually incorrect unless you are in the very far SW - the difference we have this time around is that the colder air is embedded across us and the continent, so as we start to see a SEly fetch the whole circulation across to the UK is colder

I didnt mean to come across nastily, I was pointing out that there was some factually incorrect information being passed around and that's not helpful for anybody i apologise if thats how it came across

As for:

I thought this was a model discussion thread ?. Not a cold ramping thread ?

A mild outlier was spotted and commented on , no need to be nasty about such comments just because you dont want to see/ hear about mild outliers. How many times do we see post of GFS charts of blizzards at T240 or T384.

Post a mild chart at T240 and you would be jump upon as it being 'unreal'

Again ditto above. I'll make no secret of my love for cold snowy weather and i completely agree too much cold ramping does go on, however I have at no point here done anything other than comment on what the 6z is showing (of course from there we go into the argument about it only being 1 run etc etc.)

As for your last comment if you look back over this winter's threads im sure you'll find that I have not once commented on any mild charts as being 'unreal' - if others choose to do so thats their business but accusations of that sort towards me are unfounded

Anyway, back to the main discussion and a pretty impressive set of 6z ensembles

http://www.wetterzentrale.de/pics/MT8_London_ens.png

Quite a lot of scatter citing the uncertainty but a majority of members dropping below the magic -5c line for much of the run, with the operational not a mild outlier for me with a little support but certainly one of the milder scenario's. Once more its a channel LP that causes all the fuss

SK

[cooling climate]

Snow showers seem to be alot more widespread according to the 06z run for the eastern half of the

country on new years day.

I do agree that the 06z GFS run seems to throw more wobbles than the other 3 runs and I am sure

someone has in the past posted data to prove this although I do not have access to it.

As far as I can see its a win, win situation with regards to the low down to the southwest for if the

06z verifies then we will see widespread snowfall but if the low takes a more southerly track ( which I

believe it will ) then we will see a colder wintry northeasterly airflow across the country with max

daytime temperatures even in the southwest only likely to reach freezing at best.

[rbw]

06z - major snow event (away from the South Coast) followed by a prolonged freeze retaining snow cover.

Other ensembles = colder as the LP does not get as far north, less snowy as the LP does not get as far north.

Be careful what you wish for.

I am not sure I can see a major snow event - when are you referring to , please?. I see showers in the east and a marginal event in the west

R

[Frosty.]

The 6z run is brilliant for the north, not so good for the south in the longer range but it's only 1 run and probably a mild outlier in FI so i'm not concerned at all. A very wintry outlook and especially in the north and east with frequent snow showers, some heavy, even a polar low close to northeast scotland around new years day into saturday and that could dump a foot of snow. Winds between N'ly and NE'ly for much of next week with sub-zero temps in places and more snow showers more likely in the north and east whereas more central areas could be sunny but still v.cold...nice meto update today

Edited December 30, 2009 by Frosty039

[Archie_Lewis]

A couple of points before I shoot off.

First of all the LP system than many are talking about. I said a few days ago that when you have model disagreement the answers often lies inbetween. This proved to be correct because the LP wasn't as far N as some GFS runs indicated but was further N than the ECM suggested. Now don't make the mistake that the GFS was right because of the lack of snow. The lack of snow was due to the marginal temps. In some respetcs I blame the Met O because alongside their warnings they should of said 50% risk of disruption on lower ground. They should add percentages along side their warnings on how possible disruption could be.

Back to the models and I find looking for a severe cold spell in the UK is the same as baking a cake. You need all the ingredients for the perfect outcome but sometimes you can get away with one.

Here are the ingredients we currently have.

1. Negative AO which is off the scale!

2. S,ly tracking jetstream.

3. Block of HP over Greenland.

4. Pool of cold air over the UK (will have from Friday onwards).

Now if like the 06Z a LP manages to get far enough N then we will experience heavy snow due to No4 ingredient. However if the LP is further S i.e ECM then as it tracks E this will pull in even colder NE,ly bringing more snow. However if the block moves further W this exposes us to a risk of the LP moving much further N bringing snow and then milder weather. At the moment this scenario isn't suggested by the models.

I don't need to ramp the potential because around lunchtime the Met O 6-15 day forecast will do that for me!

Just add that the ECM from +168 would not be dry. I can tell plenty of snow showers would develop just by looking at some of those charts. This is why the Met O forecast suggested more widespread snow middle of next week.

Hi TEITS,

I think you better go check the update from Met Office.

Nothing to ramp about - If you like it dry - Then sure.

Looks like turning very cold though

[Snowly does it]

I am not sure I can see a major snow event - when are you referring to , please?. I see showers in the east and a marginal event in the west

R

Around 4-6 Jan as ther LP tries to move North would provide a dumping of snow across the Midlands, SW and later the East if it occured as shown on the 06Z

[Bristawl Si]

Around 4-6 Jan as ther LP tries to move North would provide a dumping of snow across the Midlands, SW and later the East if it occured as shown on the 06Z

Ian Fergusson, on the SW thread posted 10 minutes+ ago that the part of the UKMO model only the met office see, is predicting only Cornwall and parts of Devon being hit by this system. He stresses that this is what current modelling is predicting. Things could change....as we all know!

EDIT: From Ian - "Note the limited frontal progression into the SW peninsula, albeit this could of course change and suggest more advancement inland in subsequent runs. The NE bounds of PPN remain very uncertain. Will keep you informed how it stacks up against the other models."

Edited December 30, 2009 by Bristle boy

[SMU]

Around 4-6 Jan as ther LP tries to move North would provide a dumping of snow across the Midlands, SW and later the East if it occured as shown on the 06Z

I Doubt very much we will be waiting that long...

S

[Snowly does it]

Ian Fergusson, on the SW thread posted 10 minutes+ ago that the part of the UKMO model only the met office see, is predicting only Cornwall and parts of Devon being hit by this system. He stresses that this is what current modelling is predicting. Things could change....as we all know!

I am just saying what the 06z shows. It will not likely get that far North.

I Doubt very much we will be waiting that long...

S

Hoepfully not.

[Lewis]

I Doubt very much we will be waiting that long...

S

Hi steve,

What do you hope to see, and (or) expect with the 12z? At least some agreement with the ECM?

Lewis

Edited December 30, 2009 by Storm Force Lewis

[Dingwantssnow]

Thing is its going to remain cold and dry for everyone north of the midlands unless your on the east coast according to the models. This in my view wouldnt constitute anything special. Sure its going to be COLDER then normal big deal but apart from that theres nothing really to be getting excited about IMBY.

Theres still loads of posts on this thread that are misleading in regards to potential snow events etc ect. Especially in regards to where these events are likely to happen. I know its not done on purpose but when posts are made stating major snow events or extreme cold new people like me that are trying to learn from this get confused as to where exactly your refering to...which in 95% of the time is southern regions.

Like the next LP system comming from the SW, if it turns into a channel low whats areas would be effected by that?? If it gets further north where would you expect the effected areas would be??

Please dont take this as a dig im just trying to make heads and tails of where this will happen(IF they Happen)

[Solar Cycles]

Thing is its going to remain cold and dry for everyone north of the midlands unless your on the east coast according to the models. This in my view wouldnt constitute anything special. Sure its going to be COLDER then normal big deal but apart from that theres nothing really to be getting excited about IMBY.

Theres still loads of posts on this thread that are misleading in regards to potential snow events etc ect. Especially in regards to where these events are likely to happen. I know its not done on purpose but when posts are made stating major snow events or extreme cold new people like me that are trying to learn from this get confused as to where exactly your refering to...which in 95% of the time is southern regions.

Like the next LP system comming from the SW, if it turns into a channel low whats areas would be effected by that?? If it gets further north where would you expect the effected areas would be??

Please dont take this as a dig im just trying to make heads and tails of where this will happen(IF they Happen)

As it stands your right, but at this far out it's impossible to say if other areas won't be affected. I must say 2 weeks of cold dry weather isn't my idea of heaven!!

[Archie_Lewis]

Thing is its going to remain cold and dry for everyone north of the midlands unless your on the east coast according to the models. This in my view wouldnt constitute anything special. Sure its going to be COLDER then normal big deal but apart from that theres nothing really to be getting excited about IMBY.

Theres still loads of posts on this thread that are misleading in regards to potential snow events etc ect. Especially in regards to where these events are likely to happen. I know its not done on purpose but when posts are made stating major snow events or extreme cold new people like me that are trying to learn from this get confused as to where exactly your refering to...which in 95% of the time is southern regions.

Like the next LP system comming from the SW, if it turns into a channel low whats areas would be effected by that?? If it gets further north where would you expect the effected areas would be??

Please dont take this as a dig im just trying to make heads and tails of where this will happen(IF they Happen)

I do agree with you to a point, people will post or pay more attention to their area because they live there. Thats just how it goes.

As I am trying to learn the models, members ramping snow potential can be a little confusing especially as the met office says none of the sort.

All eyes on the 12z... Will it upgrade PPN? I hope so.

[SMU]

Hi steve,

What do you hope to see, and (or) expect with the 12z? At least some agreement with the ECM?

Lewis

Ive started missing the 06z, it hs been utterly useless over the last cold spell & so on...

Its garbage-

12z will be back behind the ECM- all thats to be really resolved is the track of th low-

S

[Radiating Dendrite]

I am tiring of reading posts complaining about the southern bias in terms of the discussions on this thread. I think some people are being a bit paranoid in regards to this and should also remember that there are plenty of other threads with discussions in terms of different geographical locations (many of which include model discussion and analysis).

I can understand some newbies getting slightly confused, but there are plenty of guides provided by netweather and personally I think some people need to use some common sense. Sometimes there is some ramping, but people should be able to see this for waht it is.........a bit of over enthusiasm and nothing more, not the gospel truth. Once the cold is established (which is going to happen) then we should start looking for snow and not before. Compalining that the ECM has next Wednesday as dry or the GFS has Monday as only dry and cold etc is a waste of time, snow is hard to predict and should only be looked for a few hours ahead in my opinion and not stressed about when it is not shown at +114.

Anyway.........my first netweather rant over and back to the models. As has been discussed the 06z was a little enthusiastic in bringing the low north and I would expect this to be resolved by the 12z. What needs to be understood though is that even the 06z had lots of good things and would have been a run that some people would have been rejoicing over a few winters ago. I suppose when you have seen nirvana in a sensible time frame then some disappointment should be expected when a run does not show these synoptics but a slightly different version (albeit a a good one).

[tesaro]

I see the METO have decided to go with the flow with their updated winter forcast. Their long range views on things have changed quite starkly!

With regards to percipitation on the upcoming cold spell, dont look too far ahead. Things do tend to pop up out of nowhere. The faxes are your best friend for these.

[Weather-history]

Thing is its going to remain cold and dry for everyone north of the midlands unless your on the east coast according to the models. This in my view wouldnt constitute anything special. Sure its going to be COLDER then normal big deal but apart from that theres nothing really to be getting excited about IMBY.

Well, it could be interesting in some respects, photo opportunities of frozen canals, rime covered trees etc.

I think the point is really cold spells during the winters of the last 20 years have not been that common. A fair few of the great cold spells of the past were not snowfests. Winter 1962-63 wasn't day after day of snow, the great frost of February 1895 wasn't a snowfeast, the coldest temps accompanied an anitcyclonic spell. Its the chance to experience it, a lot of the younger members have never had that opportunity and have only read about it.

Edited December 30, 2009 by Mr_Data

[Frosty.]

I think it's good that the utterly useless and garbage 6z (as steve murr puts it) can still deliver bucket loads of snow to many areas yet still be called garbage..I do agree that the 12z gfs will probably look better for the south as well as the north because I think we are entering one of the most severe wintry spells for many years.

Edited December 30, 2009 by Frosty039

[snow drift]

The METO 6-15 day outlook suggests a cold but mainly dry period.

This is what I think the Models are showing. The noteable exceptions may well be the East coasts of the UK and the South west as the LP tries to push in. Dry and cold is better than Mild and wet.

Interestingly for any new peolple viewing the thread. If peolple are bickering then the models will have shown a downgrade or someone who expected to get snow didn't. Look for themes and not detail until t24 then you will lessen your chance of disapointment.

The models do show that theme moving forward is cold and once this is inplace we can then look for ppn.

[snowray]

Very disapointing todays event, rain all the way to the Scottish borders apart from the highest ground, where has the snow for the Midlands, Wales, etc etc all gone? It is always a worry to see rain even in the North East of England, by now it should be turning very wintry up there at least! Hopefully by this evening we may see more general snowfall North of Birmingham ish.

By late tomorrow the showers of rain, sleet and snow should be right down the East coast, will it remain as rain on the coasts though I wonder?

Still a lot of uncertainty around T120 I feel, big question has to be, how far North will that shortwave get?

Edited December 30, 2009 by snowray

[Methuselah]

Can we please stop all the anti-IMBY nonsense??

Before anyone-else fancies a rant, think about numbers; think about where most people live. We ALL make posts/see things according to our respective locations. Isn't that perfectly natural? It ain't a SE thing...

Give each other some leeway, please? We're not all perfect...

We're not all in our senior years, either!!! :wacko:

[kent]

The METO 6-15 day outlook suggests a cold but mainly dry period.

This is what I think the Models are showing. The noteable exceptions may well be the East coasts of the UK and the South west as the LP tries to push in. Dry and cold is better than Mild and wet.

Interestingly for any new peolple viewing the thread. If peolple are bickering then the models will have shown a downgrade or someone who expected to get snow didn't. Look for themes and not detail until t24 then you will lessen your chance of disapointment.

The models do show that theme moving forward is cold and once this is inplace we can then look for ppn.

Exactly, what the models are showing at present is a period of cold weather we need as the building blocks for possible snow as TEITS is always stressing. As for this talk of southern bias thats laughable but understandable that some people whatever area would love to see something dramatic happen. Perhaps I for one may be guilty in trying to learn and concentrate on the possibility of snow for my own area,which is more southern than most in Poole Dorset. Having seen only 1cm in probably 10 years there are kids here who have never had a snowball fight let alone sledging and building a snowman. So for all those who wish for snow may it come and happy snowy year hopefully for all.

[weather eater]

Several points here, firstly its no good getting hung up on individual model runs, of course model runs are there to be commented on, but some members insist on taking each one as literal, they are all subject to change. If I have to read another post complaining about the lack of snow for their area I might just scream, comment by all means but stop the moaning. Secondly in regards people getting mislead by other members posts, I have to say mainly this is the fault of the reader. I can recall several posts regarding the degree of cold we might expect if some model runs were to come to fruition, I don't remember many members claming to see masses of snow potential, that again is down to members interpreting very cold as very snowy, if you don’t understand what is meant, ask. Comments claiming, if this had happened in the 60s, 70s, 80s we would have had masses of snow, are just plain wrong, I can recall a fair few cold winters that were not snowy and plenty with spells like this one, very marginal with a real wintry mix. Last point, be careful who you listen to, there are some good posters on this thread and there are a couple whose reputation is IMO not deserved. Just because a poster predicts cold and sounds like they know what they are talking about, does not mean they do or that they are being completely objective.

My list of members, who I pay special attention to, goes like this

John Holmes

Steve Murr

Glacier point

Nick Sussex

T W S

Kold Weather

Others include

NSC (Tamara)

TEITS

Ian Ferguson

Pyrotech

Ian Brown

And a few others

Edited December 30, 2009 by weather eater