General Model Output Discussion

[Frosty.]

maybe I am missing something but I see less of the block returning in every run. All I can see is an incresing chance of a high pressure to the south, icelandic lows and Sw winds.

I think I am missing something as well, the 6z run shows the cold block being shunted even further east next week but the latest meto update says next week will be cold with wintry showers in the north and east with frost and ice hazards everywhere with rain turning to sleet and snow inland across other areas, they must be supporting the ecm or the gfs 00z but definately not the 6z even with my limited meteorolgical knowledge.

[Thundery wintry showers]

There is less support for the easterly reload this morning than there was yesterday evening- but still more than there was yesterday morning. Remember that initially it was given little support other than via the ECMWF operational runs.

The current pattern has similarities with the dull drizzly southerlies that persisted for much of January 1996- a parallel that Mr_Data mentioned a while ago- and that month did finish with a snowy easterly episode on the 25th-27th.

[Frosty.]

There is less support for the easterly reload this morning than there was yesterday evening- but still more than there was yesterday morning. Remember that initially it was given little support other than via the ECMWF operational runs.

The current pattern has similarities with the dull drizzly southerlies that persisted for much of January 1996- a parallel that Mr_Data mentioned a while ago- and that month did finish with a snowy easterly episode on the 25th-27th.

Why has the latest meto update said it will be cold and wintry next week then? they take all the models into account before typing out their update and considering the 00z and 6z output i'm a bit surprised and bemused.

And the current pattern indicates a blizzard in the sw tonight and tomorrow with snow spreading north and more snow later in the week, especially in the north, not particularly drizzly.

Edited January 12, 2010 by Frosty039

[Weather-history]

I think I am missing something as well, the 6z run shows the cold block being shunted even further east next week but the latest meto update says next week will be cold with wintry showers in the north and east with frost and ice hazards everywhere with rain turning to sleet and snow inland across other areas, they must be supporting the ecm or the gfs 00z but definately not the 6z even with my limited meteorolgical knowledge.

You can't really write an outlook based on one set of runs and in any case look at the GFS 06z mean ensemble chart and how close the -5C is to eastern UK at 192hrs

http://www.wetterzentrale.de/pics/Rt850m8.gif

[Thundery wintry showers]

Why has the latest meto update said it will be cold and wintry next week then? they take all the models into account before typing out their update and considering the 00z and 6z output i'm a bit surprised and bemused.

And the current pattern indicates a blizzard in the sw tonight and tomorrow with snow spreading north and more snow later in the week, especially in the north, not particularly drizzly.

The current pattern is quite reminiscent of January 1996 but for now we have much colder air in the circulation than in early to mid Jan '96, and so we are indeed looking at a snow event for many tomorrow. From Friday onwards it looks set to turn milder- but it may or may not be temporary.

Regarding the MetO outlook, they must think that the models are predominantly underdoing the strength of the Scandinavian High and expect the models to fall more into line with yesterday's ECMWF outputs. This is quite a plausible scenario and just a small shift west from the GFS T+192 ensemble chart would support it.

[grab my graupel]

I like the look of these 850hpa panel maps; suggests to me that any milder spell could be short-lived

[johnholmes]

You can't really write an outlook based on one set of runs and in any case look at the GFS 06z mean ensemble chart and how close the -5C is to eastern UK at 192hrs

http://www.wetterzen...ics/Rt850m8.gif

Kevin-I have to say I'm surprised at you-I know you don't have a lot of belief in UK Met but to suggest they only use data from one run is hardly correct.

I'm not repeating what I've tried to explain many many times about just what input they have before they issue ANY forecast, be it for 12-24 hours, 3-6 days, 6-15 or further out.

Of course they may be wrong but IF any of us did a thorough check on their 6-15 day outlooks I am pretty certain that it would be a fairly high correct figure that would be shown over 3-12 months of data?

[Winter Monsoon]

Just cut and pasted this fromt he mdoel tech thread where GP has just posted this:-

Suggest a Euro High solution and this seems to be where the long range modelling is going. Whether the MJO and stratospheric warming can modify this towards month's end and force height rises to our NW and lowering heights over Iberia is a watching brief.

This also gives us some clues as to how the medium term pattern (mid January onwards) might evolve. This would tend to support the idea that the block forming over Scandnavia is going to become a dominant feature and repel the Atlantic weather fronts extending across the UK which would allow colder continental air to creep back across the UK, south-eastern parts most particularly.

Perhaps the Meto are thinking along the same lines??

[casparjack]

I like the look of these 850hpa panel maps; suggests to me that any milder spell could be short lived

I'll take 3, 4, 7 and 16 please Sir!!

I remain convinced that we will see a trend towards a colder evolution in the next 48/72 hrs, I feel that if the Atlantic was going to roar back in there would be solid model agreement and it just isn't there.

[bluearmy]

the NAEFS mean temps on yesterdays runs in far off fi were showing uppers below -4c coming into the eastern side of the uk. now i found this significant because i remember just before xmas, seeing this being shown at the same kind of timescale and thinking - 'thats a long way off for a mean of 50 runs to show this upper temp. this gave me the confidence to post that i could see a return of decent cold within a fortnight. just a note that these uppers have receded a couple of hundred miles east on the 00z run. unusual to see big movements from run ro run so would expect this to be consistent when the 12z updates around 9pm, though i hope it returns to yesterdays output.

[johnholmes]

I have a dream sometimes - only sometimes mind!

That is that we could have a section in the weather forum where only posts trying as hard as possible to give a posters views on what the models ACTUALLY appear to show NOT WHAT THEY MIGHT LIKE them to show is available. Its usually called the Technical discussion thread but why oh why can't we have a similar attempt on here.

Now I can make a fairly good case using the last 24 hours outputs from the models and their ensembles for it turning less cold-milder if you prefer that term. Equally I can I think make as good a case for showing that the ensembles or some models show the case for the cold returning.

the TRICK is to take ALL the information we have on the web, on Net Wx and elsewhere and TRY and make fair and unbiased prediction from all that data.

To be honest I am more than a touch fed up with so many TRYING to show that this or that model indicates the cold will stay/return-why cannot we have a balanced unbiased view please?

[Weather-history]

Kevin-I have to say I'm surprised at you-I know you don't have a lot of belief in UK Met but to suggest they only use data from one run is hardly correct.

I think you misunderstand my point, John. I was saying you can't really base an outlook on one set of runs, I wasn't saying they were basing their forecast on one set of runs and in anycase I was showing that GFS 06z mean chart shows how close the cold air was still to the UK and the Met Office outlook is not way off.

[mickpips]

I have a dream sometimes - only sometimes mind!

That is that we could have a section in the weather forum where only posts trying as hard as possible to give a posters views on what the models ACTUALLY appear to show NOT WHAT THEY MIGHT LIKE them to show is available. Its usually called the Technical discussion thread but why oh why can't we have a similar attempt on here.

Now I can make a fairly good case using the last 24 hours outputs from the models and their ensembles for it turning less cold-milder if you prefer that term. Equally I can I think make as good a case for showing that the ensembles or some models show the case for the cold returning.

the TRICK is to take ALL the information we have on the web, on Net Wx and elsewhere and TRY and make fair and unbiased prediction from all that data.

To be honest I am more than a touch fed up with so many TRYING to show that this or that model indicates the cold will stay/return-why cannot we have a balanced unbiased view please?

John , it does sound like you having a bit of a tantrum there

I do however find that post rather confusing , basically if individuals are looking for cold or milder weather and talking about possible evolutions then where is the problem ?

Personally i do not post often ( in fact rarely ) on here but surely this is the model discussion thread and discussing what the models are CURRENTLY showing and what the possible evolutions of said output might become is all model discussion in my eyes and quite relevant ..... Quite frankly I prefer to read posts from the likes of Steve Murr, Nick Sussex, TEITS etc etc who discuss exactly this, not just what the models/ensembles etc are showing but possible upstream evolutions , whether it be mild, cold, gale force winds etc etc

Mick

[SP1986]

I have a dream sometimes - only sometimes mind!

That is that we could have a section in the weather forum where only posts trying as hard as possible to give a posters views on what the models ACTUALLY appear to show NOT WHAT THEY MIGHT LIKE them to show is available. Its usually called the Technical discussion thread but why oh why can't we have a similar attempt on here.

Now I can make a fairly good case using the last 24 hours outputs from the models and their ensembles for it turning less cold-milder if you prefer that term. Equally I can I think make as good a case for showing that the ensembles or some models show the case for the cold returning.

the TRICK is to take ALL the information we have on the web, on Net Wx and elsewhere and TRY and make fair and unbiased prediction from all that data.

To be honest I am more than a touch fed up with so many TRYING to show that this or that model indicates the cold will stay/return-why cannot we have a balanced unbiased view please?

John which posts are you referring to?

[Thundery wintry showers]

Kevin-I have to say I'm surprised at you-I know you don't have a lot of belief in UK Met but to suggest they only use data from one run is hardly correct.

I'm not repeating what I've tried to explain many many times about just what input they have before they issue ANY forecast, be it for 12-24 hours, 3-6 days, 6-15 or further out.

Of course they may be wrong but IF any of us did a thorough check on their 6-15 day outlooks I am pretty certain that it would be a fairly high correct figure that would be shown over 3-12 months of data?

I don't think that's necessarily what Kevin was trying to say. I read his post as suggesting, conversely, that the Met Office took more than one set of runs into consideration when supporting some kind of cold return from the east in their long-range outlook, as supported by the very slim margins by which the UK is projected to stay in relatively mild air by the GFS ensembles.

I might have misinterpreted the post myself, but I think that's what he might have been trying to say.

It seems to me that the MetO think most of the models are overdoing the jet and underdoing the Scandinavian High, judging by their outlooks. Given the way the models have handled the cold spells this winter, there's quite a strong case for that argument.

I think the overall point that comes out of John's rant ain his other post is that some people could do with looking at the model outputs more objectively instead of letting personal preferences interfere with their perception of what is and isn't likely to happen. I would quite fancy a reload from the east myself following the milder interlude for the weekend- but me "fancying" it doesn't make it any more or less likely to happen, and we need to bear this kind of thing in mind when looking for objectivity.

Edited January 12, 2010 by Thundery wintry showers

[mountain shadow]

I love these situations where we enter the realm of reality against what the models predict. We are only just now entering the phase where the Atlantic engages the block and it will be interesting to see how it pans out.

Very good agreement between the GFS ppn predictions and actuals radar for 3pm.

http://69.16.133.139/c9s4a5k3/cds/gfsimages/gfs.20100112/06/09/ukprec.png?dopvhost=charts.netweather.tv&doppl=841a626ccf56e840cf06e8101ec3e35bcf06e82c&dopsig=d2a0019df7fd84bc61b9b0ce41708bd9

against

http://www.metoffice.gov.uk/weather/uk/radar/index.html

[Matt12]

I'm no weather expert, but the latest GFS ensembles seem to suggest that, in the long-term, things could go either way i.e. either very cold or slightly less cold. Although it's way out in F1 territory, I'd guess at this stage that it will get pretty cold in more than a week's time, but not as cold as it has been (although cold enough for snow again by about the 19th/20th, after a brief slightly warm-up).

[Thundery wintry showers]

It's worth noting that tomorrow's event looks like producing a fair amount of snow in the west, but it looks very marginal for eastern areas- a surprise that it's that way around when the Atlantic air is out west, but presumably the warming effects of the North Sea are affecting things in the east.

East Anglia, the SE, and NE England could end up with sleet or rain from this while western parts see snow.

[i luv snow]

It's worth noting that tomorrow's event looks like producing a fair amount of snow in the west, but it looks very marginal for eastern areas- a surprise that it's that way around when the Atlantic air is out west, but presumably the warming effects of the North Sea are affecting things in the east.

East Anglia, the SE, and NE England could end up with sleet or rain from this while western parts see snow.

The dew point has decreased today though, which I thought was a positive sign! hmm, damn marginality...

[BLAST FROM THE PAST]

It's worth noting that tomorrow's event looks like producing a fair amount of snow in the west, but it looks very marginal for eastern areas- a surprise that it's that way around when the Atlantic air is out west, but presumably the warming effects of the North Sea are affecting things in the east.

East Anglia, the SE, and NE England could end up with sleet or rain from this while western parts see snow.

TWS

One would think that south of London would not be affected by the north sea in this setup? The flow would be SE so off the very near continent? Funny day in Redhill, it certainly seems to have got colder compared to early this morning.

BFTP

BFTP

[PB22]

Wow, this will feel very different across Ireland and south-western Britain on Friday if the 12Z GFS is to be believed:

http://www.wzkarten....s/Rtavn781.html

http://www.wzkarten....s/Rtavn782.html

http://www.wzkarten..../Rtavn7817.html

Edited January 12, 2010 by Paul B

[cj114]

I don't think that's necessarily what Kevin was trying to say. I read his post as suggesting, conversely, that the Met Office took more than one set of runs into consideration when supporting some kind of cold return from the east in their long-range outlook, as supported by the very slim margins by which the UK is projected to stay in relatively mild air by the GFS ensembles.

I might have misinterpreted the post myself, but I think that's what he might have been trying to say.

It seems to me that the MetO think most of the models are overdoing the jet and underdoing the Scandinavian High, judging by their outlooks. Given the way the models have handled the cold spells this winter, there's quite a strong case for that argument.

I think the overall point that comes out of John's rant ain his other post is that some people could do with looking at the model outputs more objectively instead of letting personal preferences interfere with their perception of what is and isn't likely to happen. I would quite fancy a reload from the east myself following the milder interlude for the weekend- but me "fancying" it doesn't make it any more or less likely to happen, and we need to bear this kind of thing in mind when looking for objectivity.

Must admit I "Fancy" 25c and lot's of sunshine.

However, I do remember from years past, 80's etc quite often the Met office would predict weather coming back in from the Atlantic and milder temps, we would get all excited and it wouldn't happen due to the cold being so entrenched.

Personally I hope it does not happen this time. But their latest forecasts don't look mild at all.

Seeing what we want to see is all very well and we are all guilty of it to some extent. But I have pretty much given up on a warmish spell arriving anytime soon. :unsure:

An LRF from John or Nick or TWS would be helpful. [pretty please?]

[PB22]

Saturday is mild in the west, and back to near normal values in the north and east:

http://www.wzkarten.de/pics/Rtavn1021.html

http://www.wzkarten.de/pics/Rtavn1022.html

http://www.wzkarten.de/pics/Rtavn10217.html

[R.P. McMurphy]

Saturday is mild in the west, and back to near normal values in the north and east:

http://www.wzkarten.de/pics/Rtavn1021.html

http://www.wzkarten.de/pics/Rtavn1022.html

http://www.wzkarten.de/pics/Rtavn10217.html

hmmm mild or not as harsh cold as it currently is?

[snowingtequila]

hmmm mild or not as harsh cold as it currently is?

no that is near normal temps or mild, never convinced by these temperature projections from GFS but I don't think they will be that far off if those synoptics happen