Model Output Discussion

[cooling climate]

Just viewed the Parallel run and to be honest making a summary of the models is relatively simple.

A brief E,ly early next week with upper temps possibly as low as -8C in the SE. We then see a brief less cold N,ly (surface temp similiar though) followed by an even colder E,ly. At the moment the favoured locations for the E,ly from midweek onwards is definately SE/E Anglia for the simple reasons being coldest upper temps, duration. This E,ly could be followed by a N,ly as we see the HP retrogress NW.

Again subject to change!

This is a fairly well rounded summary of what to expect, and during the entire period snow is a definite

possibility. For all winter weather lovers you can't help but be totally dumbfounded by anyone that

moans at this outlook.

Even in the 60s,70s,and 80s this would be an excellent spell of winter weather especially for December.

Hell there is even a threat(thats all it is at the moment)from the ECM model that over the Christmas

period it could become bitterly cold if the vortex locks in over Europe instead of lifting out like the

GFS shows.

[Matty M]

obviously abit disappointed with the model runs since the other day.

Still lots of potential there and also huge uncertainty even in the very short term.

Expect lots of changes ahead with regard to those pesky shortwaves i think.

12z tonight will be key and tomorrows 0z.

I am beginning to bear less and less relevence to the 6z and 18z runs.

[Shiny_Bottom_1]

I think there has been a downgrade relative to earlier GFS outputs (not so sure about the UKMO- perhaps its earlier high-potential outputs would've led to the scenario the models are now showing? It's certainly been the most consistent of the three models out to T+144). But certainly not the downgrade that many of us were fearing - at least not yet, anyway.

Hi Ian.

I would agree with that analogy.

GEFS Air Pressure Ensembles for Derbyshire:

Shows really the scope of differences just from this model in the short term, and also the mid to long term.

There are still some favourable GEFS members. I would say that the average is quite a plausable compromise at the moment.

[Big Innes Madori]

Well said that man!

I still hope that this cold shot delivers for all , even if i do favour my own area who wouldn't?

High Neil,

It's not so much about you or any of the more south based members favouring your own area

I think that it's more to do with us more north based members looking for the more knowledgable on the forum giving their opinions on what the models are showing regarding the whole of the UK

Big Innes.

[Shiny_Bottom_1]

Well...forgot to save to the desktop, then couldnt use the full editor.

Anyway...

[smhouston]

Hi Ian.

I would agree with that analogy.

GEFS Air Pressure Ensembles for Derbyshire:

Shows really the scope of differences just from this model in the short term, and also the mid to long term.

There are still some favourable GEFS members. I would say that the average is quite a plausable compromise at the moment.

Exactly, look at the 850s below...there's divergence from as early as T48!!

It shows how hard the models are finding it to deal with these synoptics, which I think is a good thing as it shows anything is possible, and atm it might seem unlikely for the North to get much, but that could so easily change. Saying that, if it does come off then I think hats off to GFS as it has been remarkably consistent, and even when it has "downgraded" it hasn't been by much, and you don't expect the exact charts to come off anyway. Time will tell I guess which is correct though.

[kold weather]

The ECM ensembles are interesting in that they show that the ECM op is a cold outlier by 192hrs, this is important to the UK because it strongly suggests to me the ECM op places the low too far east, the other ensemble members are warmer as they get a modified SW airflow on the eastern side of the low.

So I'd assume many of theECM ensemble members would look rather like the 06z op run I'd imagine.

[Lewis]

Exactly, look at the 850s below...there's divergence from as early as T48!!

It shows how hard the models are finding it to deal with these synoptics, which I think is a good thing as it shows anything is possible, and atm it might seem unlikely for the North to get much, but that could so easily change. Saying that, if it does come off then I think hats off to GFS as it has been remarkably consistent, and even when it has "downgraded" it hasn't been by much, and you don't expect the exact charts to come off anyway. Time will tell I guess which is correct though.

Huge downgrade on the ensembles, just been looking at the metoffice website, a lot of people don't take notice of there 6-14 day forecasts but they have changed there tune, and now go for wintry showers with snow confined to the Hills.

So it's certainly going to get colder and dry, but how cold could it really be . I suppose we will find out today on the next GFS and ECM.

Lewis

Edited December 11, 2009 by Storm Force Lewis

[Iceni]

Well rather than complaining and adding nothing why not step up to the plate and provide your opinion on SE wales?

I think he was being ironic in response to Frosty's charge that the forum was IMBY/SE biased.

Silly how the usual toys get thrown from prams the minute snow (for anyone) is forecast. We are a small island on the edge of a warm (at this time of year) ocean and there are always going to be 'winners' and 'losers'… I'm just grateful we seem to be going to have a ground frost next week — the first of the year for my locality.

[Methuselah]

Some of the GFS runs have been so 'out-of-this-world,' it's hard to see how they could possibly 'upgrade'?

[D KARLSON]

I still think it's too early to claim victory for one model or another- the pattern could still change, given how uncertain the models have been until recently, and bearing in mind how poorly the models traditionally handle easterly incursions. My hunch is that they might actually be toned up slightly, rather than down, as we get nearer the time- my mind goes back to late December 2005 for example when the models were too keen to send high pressure south too quickly.

!!!!!!!!!!!!!!!!!

Its strange to say it ,but as last year the models are more likely to upgrade rather than down these are genune cold synoptics in prevous years you could always rely on a downgrade

but further back in the 80s upgrades were common place.

As for now its one cold outbreak followed by a second colder outbreak next weekend which should deliver the goods for many eastern counties , with penetrating hard frosts to follow on the back of a northerly.

After this it gets very interesting because it does not seem to me that any milder incursions will occur perhaps more less cold at best and by this time europe and russia will be in a deep freeze and that type of cold will prove stubborn to even budge

Moscow latest forecast temp for next week is -19 dayime max thats 14degrees below average thats record breaking cold almost and some of the models project a large circulation of lows around the south and east of Europe which would bring this frigid air directly to us

1947 synoptics ??????

Edited December 11, 2009 by D KARLSON

[Hammer]

Huge downgrade on the ensembles, just been looking at the metoffice website, a lot of people don't take notice of there 6-14 day forecasts but they have changed there tune, and now go for wintry showers with snow confined to the Hills.

So it's certainly going to get colder and dry, but how cold could it really be . I suppose we will find out today on the next GFS and ECM.

Lewis

Lewis and yesterday they said snow. Tomorrow it could say snow again, discount this. The key now is seeing which model is correctly trending the current spell, i.e from a few days ago, to today and perhaps taking a look just a few days ahead. The mention of downgrades and upgrades is of no use, if every few hours people change their view.

[Lewis]

I still think it's too early to claim victory for one model or another- the pattern could still change, given how uncertain the models have been until recently, and bearing in mind how poorly the models traditionally handle easterly incursions. My hunch is that they might actually be toned up slightly, rather than down, as we get nearer the time- my mind goes back to late December 2005 for example when the models were too keen to send high pressure south too quickly.

Its strange to say it ,but as last year the models are more likely to upgrade rather than down these are genune cold synoptics in prevous years you could always rely on a downgrade

but further back in the 80s upgrades were common place.

As for now its one cold outbreak followed by a second colder outbreak next weekend which should deliver the goods for many eastern counties , with penetrating hard frosts to follow on the back of a northerly.

After this it gets very interesting because it does not seem to me that any milder incursions will occur perhaps more less cold at best and by this time europe and russia will be in a deep freeze and that type of cold will prove stubborn to even budget

Moscow latest forecast temp for next week is -19 dayime max thats 14degrees below average thats record breaking cold almost and some of the models project a large circulation of lows around the south and east of Europe which would bring this frigid air directly to us

1947 synoptics ??????

It's ok saying that, but the ECM had a wobble, now the GFS which has been the so called " most conistent " has backed up the ECM and so has the UKMO, so how can we not claim a victory if now all 3 models are showing more or less the same? I grant you it's only happened on this one run, but it's the first time all the models have come to an agreement over the past week, and it's not just a coincidence its occurred in reliable time frame.

[MR EXTREMES]

Huge downgrade on the ensembles, just been looking at the metoffice website, a lot of people don't take notice of there 6-14 day forecasts but they have changed there tune, and now go for wintry showers with snow confined to the Hills.

So it's certainly going to get colder and dry, but how cold could it really be . I suppose we will find out today on the next GFS and ECM.

Lewis

i expect,

not as cold as you i and everyone else on here was expecting,

but it looks like its easy to get sucked in by model watching.

but what we do have is dry colder air and europe is freezing with a strong greenland block weak jet.

what more could we ask for early in december.

SFL infact they all agreed a couple of days ago.

Edited December 11, 2009 by badboy657

[Lewis]

i expect,

not as cold as you i and everyone else on here was expecting,

but it looks like its easy to get sucked in by model watching.

but what we do have is dry colder air and europe is freezing with a strong greenland block weak jet.

what more could we ask for early in december.

Yep,

Snow does not bother me, i can wait for that. I just want us to be organized and ready, and a cooling period/trend is what we need, and i'm very happy with the models at the moment.

Yes the models did agree, but they all didnt agree shifting the colder feed S and further E of us

lewis

Edited December 11, 2009 by Storm Force Lewis

[karyo]

The good thing today, is that the ECM has abandoned it's unfavourable 12z outlook!

However, overall the easterly late next week has been downgraded somewhat, as the flow gets cut off relatively quickly and we don't manage to pull the coldest air across the country.

If things stand as they are now, eastern areas should more certainly see some snow but predominantly dry elsewhere. Certainly not as good as last February when the strong easterly brought bands of snows showers across the country. Even Manchester, which is somewhat sheltered by the Pennines had several cms.

I hope the northerly that the models show comes off as then many other areas can benefit.

As long as the cold weather continues, the lucky areas that see the snow next week are likely to keep it with minimal thaw! The advantage of getting snow when the sun is at its weakest and the day at its shortest! Snow in February happens more frequently but the sun tends to melt it easily (apart from where there are shadows).

Karyo

[pyrotech]

To put an end to the south east bickering can i just clarify the position.

Most of the knowledgeable members seem to be from that area and it would be more helpful to the users from other areas if you expand your thoughts for the Uk in general as well as areas local to you.

I value members thoughts and its frustrating when we only talk about one small area, when your thoughts would be welcomed about other areas even if its not what we want to hear weather wise.

I realise that its your local area which most interests you all but like i said your knowledge would be very welcome and more interesting for information for people to read where ever they live.

I hope that i have not offended anyone and that you can understand what i mean.

Sorry mods just want to clarify and put end to this and get back to models talk

[kold weather]

The good thing today, is that the ECM has abandoned it's unfavourable 12z outlook!

However, overall the easterly late next week has been downgraded somewhat, as the flow gets cut off relatively quickly and we don't manage to pull the coldest air across the country.

Karyo

Yep its the same here, at least the 12z ECM solution is gone from the models for now, still plenty of uncertainty mind you down the line but we shall see. As for not pulling down the coldest air, this is also true butn with any luck we will replace it with some sort of northerly flow, depending on whether the low doesn't get too far west...

[bluearmy]

The ECM ensembles are interesting in that they show that the ECM op is a cold outlier by 192hrs, this is important to the UK because it strongly suggests to me the ECM op places the low too far east, the other ensemble members are warmer as they get a modified SW airflow on the eastern side of the low.

So I'd assume many of theECM ensemble members would look rather like the 06z op run I'd imagine.

beware the onshore flow off the north sea KW - could skew your assumptions a bit. sebastian posted a link to a site last evening which gave the ens for different part of holland which would help to remove any modification near the german border.

[NorthNorfolkWeather]

i would not even bother looking that far out lots will change by then.

cold is apon us and will deepen how cold how snowy is not set in stone,

as gp has said great start to winter with maybe things falling futher inplace for january,

ofcoarse milder air will be about but europe is looking good,

look back 2 weeks ago not much going on in europe except mush look now and mid nextweek it will be very cold.

and its true let the cold settle in and let the party begin expect to see the models flap about because thats what there going to do 100% cert on that.

but what will happen will happen.

Hi BB,

I agree totally. These are fantastic charts and are, considering it's ONLY December more than what most of us could have dared to hope for. I think GP and the other 'teleconnections' experts need a big pat on the back for giving us a heads up, and a continuous commentary on this evolution. We are still very much on the 'warm side' of winter which is why some of the cold being advected towards us isn't as potent as it might have been, but these charts, especially the GFS Parallel has been consistent with it's runs. And basically that means this cold isn't going anywhere fast.

Finally, the 1060 high in Greenland, incredible to see one so early

[karyo]

Yep its the same here, at least the 12z ECM solution is gone from the models for now, still plenty of uncertainty mind you down the line but we shall see. As for not pulling down the coldest air, this is also true butn with any luck we will replace it with some sort of northerly flow, depending on whether the low doesn't get too far west...

That's certainly a danger!

GP sounded quite positive about staying on the north side of the polar front but he also mentioned the high pressure cell gradually transferring westwards - destination Canadian Artic.

Let's hope if this happens, the transition will be slow so that we can benefit from a northerly in the process!

Karyo

[SLEETY]

looks like we are going to get sub-zero maxima,latest bbc forecast going for sub-zero air heading over slowly from Europe next week

Well done to gfs and meto office models for excellent consistency this week,apart from one blip from the meto model,the least said about the ECM the better,at least it saved its credibility-just mind-with it last run.

Edited December 11, 2009 by SLEETY

[stewfox]

To put an end to the south east bickering can i just clarify the position.

Most of the knowledgeable members seem to be from that area and it would be more helpful to the users from other areas if you expand your thoughts for the Uk in general as well as areas local to you.

I value members thoughts and its frustrating when we only talk about one small area, when your thoughts would be welcomed about other areas even if its not what we want to hear weather wise.

I realise that its your local area which most interests you all but like i said your knowledge would be very welcome and more interesting for information for people to read where ever they live.

I hope that i have not offended anyone and that you can understand what i mean.

Sorry mods just want to clarify and put end to this and get back to models talk

No offence

ps where is 'Cardiff'

Is Arctic oscillation (AO) still predicted to be in very –ve terrorty.

I did ask in the previous thread.

I suppose we don't have data re AO and 1947,1963 etc

I'm looking at the wider trends, rather then all this 'will it snow in my back yard' or why is he/she interested in his/her local weather. Most of the 'Pros' on here publish world wide data

Edited December 11, 2009 by stewfox

[Thundery wintry showers]

It's ok saying that, but the ECM had a wobble, now the GFS which has been the so called " most conistent " has backed up the ECM and so has the UKMO, so how can we not claim a victory if now all 3 models are showing more or less the same? I grant you it's only happened on this one run, but it's the first time all the models have come to an agreement over the past week, and it's not just a coincidence its occurred in reliable time frame.

I would agree with you if the ensembles were in good agreement. However there is still considerable scatter, with a few GEFS ensembles supporting a milder scenario like yesterday's ECMWF 12Z, and a few going for much colder solutions- 850hPa values for Yorkshire as low as -8 from the Monday/Tuesday easterly and in order of -10 to -15 for Thursday.

I think the general pattern is pretty much decided but the potency of these two easterly outbreaks in the coming week is still open to considerable change. There is an outside chance that neither of them come off, and also an outside chance that eastern and south-eastern areas could pick up significant snowfalls from both of them, especially the second one.

[Snow Queen one]

To put an end to the south east bickering can i just clarify the position.

Most of the knowledgeable members seem to be from that area and it would be more helpful to the users from other areas if you expand your thoughts for the Uk in general as well as areas local to you.

I value members thoughts and its frustrating when we only talk about one small area, when your thoughts would be welcomed about other areas even if its not what we want to hear weather wise.

I realise that its your local area which most interests you all but like i said your knowledge would be very welcome and more interesting for information for people to read where ever they live.

I hope that i have not offended anyone and that you can understand what i mean.

Sorry mods just want to clarify and put end to this and get back to models talk

TEITS, Nick F, Paul Sherman, John Holmes, JACK ONE and TWS all do not live in the SE so to say what you just did is wrong. We do not have snow forcast for us by the models like this very often so there will of course be a lot of posts about us but this is going to be a very localised SE event if it happens at all.

Edited December 11, 2009 by Snow Queen one