General Model Output Discussion

[Ian Fergusson]

Upgrades (I think) to GFS for a snow event in the central south on the 00z ad 06z. This despite my comments last night that I felt the flow would be too slack and any precip would fizzle. The GFS at least intensifies the pressure. The latest ECM also doing the same which would allow for...as I said, stronger flows across the front, more uplift and hopefully (though personally snow gives me a headache at home and work) more snow.

I do have a question however and it is related to outputs and the meto output.

Without giving the game away several government authorities rely on bespoke meto forecasts to go about their duties. The ones we get have a good deal of linguistic interpretation and a summary of many models. They then have associated confidence bands for each model as well as verification analysis (much like the ones posted on this forum). I was wondering, however, if the METO on their main forecasts also undertake this task, or if they output forecasts based entirelyon their own model run. Also...do the BBC use data solely from the METO as opposed to any other models??

Thanks in advance for any responses!

Morning John

Coincidentally I've almost answered your very question a few minutes ago on the SW thread, when posting continuity frames from the UKMO's latest runs for 12Z Wed (have a look). As you would expect (in the context of proper scientific analysis rather than a myopic approach based on a sole product), the medium range guys at Exeter - whilst obviously steering a path based largely on the GM output - are always making tweaks and seeking better consensual approach to the modified graphics we show on-air, based on what other models suggest alongside the GM solution. Their guidance briefings to BBC make frequent reference to whatever the likes of GFS, JMA, GME and lest us forget France's Arpege are suggesting. Indeed, I've often had such briefings where the GM solution is largely rejected in favour of another product, which again is what you'd expect from a robust, open-minded scientific methodology employed by the good folk in Exeter, as opposed to one wishing to favour a sole solution....

Thus although our graphics effectively reflect the NAE or longer-term GM solutions, it's not necessarily a slavish acceptance of the UKMO products but a more complex approach where a slightly hybrid version is often the result you see on-air.

Best

Ian

[Snow storm]

Why is no one commenting on the channel low?

http://www.wetterzentrale.de/pics/Rtavn781.png

http://www.wetterzentrale.de/pics/Rtavn782.png

http://www2.wetter3.de/Animation_06_UTC/78_30.gif

Surely it will give the south a pasting?

[weather eater]

i see the mood has gone downbeat from 1 run this morning still looks very exciting and if anyone thinks its time to throw in the towel then think again.

might be worth taking a look at gp post this morning,

i have had no snow but some really nice cold frosty mornings,

i know the snows will come in any great snowy winter cold sets in first this is whats happening.

the models are suggesting this and id say forget this mornings run until all models come into agreement im sure things will be brighter laster today they always are

I don't think anybody's downbeat, just a healthy dose of realism, plenty to be upbeat about in fact, I think its a good thing to have an acceptance that fantasy scenarios are not set in stone, doesn't mean they wont come off.

[kold weather]

although the ecm looked less cold, under a col with snow cover, look at the temps for london

http://www.meteogrou...e_forecast.html

Without a doubt outside of a beast from the east thats just about the coldest solution possible for London, however saying that the ECM would have the cold spell over by the 14th I'd imagine. I'd imagine the easterly progged would probably also give sub zero maxes in the London region.

Anyway the GFS ensembles suggest the 06z was too far west in where it centers the upper high sets itself up. Also some increasing agreement on a strengthening jet stream which could well spell trouble for this cold spell...saying that we've seen time and time again the models rather under-estimate the strength of the blocking in the longer term.

[BARRY]

Why is no one commenting on the channel low?

http://www.wetterzen...cs/Rtavn781.png

http://www.wetterzen...cs/Rtavn782.png

http://www2.wetter3....6_UTC/78_30.gif

Surely it will give the south a pasting?

We have been trying to get some answers about that on the SW thread

[Neilsouth]

We have good agreement on a north east wind , good one at that with the UKMO/GFS but GEM/ECM say no just a slack flow. Any reason behind the difference between the models?

[weather eater]

Why is no one commenting on the channel low?

http://www.wetterzentrale.de/pics/Rtavn781.png

http://www.wetterzentrale.de/pics/Rtavn782.png

http://www2.wetter3.de/Animation_06_UTC/78_30.gif

Surely it will give the south a pasting?

I think you will find that its been well commented on, especially on the threads for down south. Strictly speaking its not really a channel low as its not moving west to east up the channel, its running down the north sea and then into the channel East to West, it is an interesting feature never the less.

[Bristawl Si]

We have been trying to get some answers about that on the SW thread

Prob because it's currently predicting this main snow action for Central s.england and into the S.W.

[West is Best]

nothing's been delivered yet in the West [...]It's not even that cold here in the West. Ok, colder than recent years, but defo not as cold as some of the winters experienced many many years ago [...] here in the West.

As someone who lives properly in the west, can you do me and us all a favour and take off your parochial spectacles? Thanks! You don't speak for 'the West' thanks. We've had a covering of snow here in my part of north Devon, some remarkable ice conditions, and some very cold nights. If -5.4C near me in Exeter doesn't constitute a cold night by west country standards then you may be comparing this with western Canada rather than western England. There have been a succession of very cold nights in this part. -6.3C in Yeolviton the previous night

I'm just back from a 9m run and it's bitterly, bitterly, cold with a stinging wind. It's 0C. Even with a slight rise over the next hour or so this will be an ice day in this part of north Devon (mean below freezing). That's properly cold and anyone suggestion otherwise is talking arrant nonsense.

I repeat: patience. The synoptics on the model outputs are fabulous, and some of those who are still complaining are going to have fallen as silent as the snow by the end of the week.

Edited January 3, 2010 by West is Best

[Bristawl Si]

As someone who lives properly in the west, can you do me and us all a favour and take off your parochial spectacles? Thanks! You don't speak for 'the West' thanks. We've had a covering of snow here in my part of north Devon, some remarkable ice conditions, and some very cold nights. If -5.4C near me in Exeter doesn't constitute a cold night by west country standards then you may be comparing this with western Canada rather than western England. There have been a succession of very cold nights in this part. -6.3C in Yeolviton the previous night

I'm just back from a 9m run and it's bitterly, bitterly, cold with a stinging wind. It's 0C. Even with a slight rise over the next hour or so this will be an ice day in this part of north Devon (mean below freezing). That's properly cold and anyone suggestion otherwise is talking arrant nonsense.

I repeat: patience. The synoptics on the model outputs are fabulous, and some of those who are still complaining are going to have fallen as silent as the snow by the end of the week.

Easy Tiger! It's not that cold in the city that is the gateway to the West.

My expectations are v.high after trudging thru' exceptional blizzards in 79, 81, 87, 91, plus a few other years. Cold and dry doesn't float my boat - all that cold for nothing. Synoptics alone will not deliver what many on here want - decent snowfall. Enjoy your Sunday in the West. Grab a pint of the cloudy stuff and chill

[Duane S.]

Why is no one commenting on the channel low?

http://www.wetterzentrale.de/pics/Rtavn781.png

http://www.wetterzentrale.de/pics/Rtavn782.png

http://www2.wetter3.de/Animation_06_UTC/78_30.gif

Surely it will give the south a pasting?

I've been harping on about it since it starting showing up on the GFS. Unfortunately it doesn't have cross-model agreement.

To be fair, it is the GFS progging it so I think it may well not happen. My rationale was that I do think a small closed circulation is going to form off the back of the cold front going south into France, so why not as the GFS has it?

[noggin]

As someone who lives properly in the west, can you do me and us all a favour and take off your parochial spectacles? Thanks! You don't speak for 'the West' thanks.

....and you do? In that brief quotation above, you have presumed to do that very thing which you accuse Bristle Boy of doing!

Personally, having lived in Devon and/or Bristol for over 53 years, I would class Devon as Southwest and Bristol as Westcountry.

[johnholmes]

I do have a question however and it is related to outputs and the meto output.

Without giving the game away several government authorities rely on bespoke meto forecasts to go about their duties. The ones we get have a good deal of linguistic interpretation and a summary of many models. They then have associated confidence bands for each model as well as verification analysis (much like the ones posted on this forum). I was wondering, however, if the METO on their main forecasts also undertake this task, or if they output forecasts based entirelyon their own model run. Also...do the BBC use data solely from the METO as opposed to any other models??

Thanks in advance for any responses!

The Met O have access to and use every computer centre output we see and more-more from ECMWF, more from a variety of different models they run themselves from global scale down to 15km across, maybe less, for the UK.

Re the ensembles, yes they use them, both as basic forecasting tools (see my query over them) and also to enable them to do the other part I mentioned, giving probabilities in forecasts to clients.

The BBC use output solely from UK Met and UK Met staff.

This begs another question of mine, no argument with their presentations nor of those met trained media people (certainly no disrespect intended to our NW fan Ian in that), but why their CEEFAX output is so abysmal at times nor their own BBC web site on the weather forecasts can be so often so different to what someone has just said on TV.

hope that gives some explanations.

[kold weather]

I've been harping on about it since it starting showing up on the GFS. Unfortunately it doesn't have cross-model agreement.

To be fair, it is the GFS progging it so I think it may well not happen. My rationale was that I do think a small closed circulation is going to form off the back of the cold front going south into France, so why not as the GFS has it?

Its something worth watching IMO, its the sort of short term feature that the GFS does sometimes do very well with picking up on. Whilst it may not create its own little low it seems quite probable that it will help to pep up the frontal system for the southern part of the country so its well worth watching IMO...

[West is Best]

....and you do? In that brief quotation above, you have presumed to do that very thing which you accuse Bristle Boy of doing!

Not at all: that's why I only went on to speak of 'this part of north Devon'. Read more carefully in future.

But frankly, there are some misery guts out there who wouldn't realise what they'd gone through until it was May 1947.

I strongly suggest the whingers take careful note of what John Holmes has been posting.

Now for the 12z's ...

[johnholmes]

Morning John

Coincidentally I've almost answered your very question a few minutes ago on the SW thread, when posting continuity frames from the UKMO's latest runs for 12Z Wed (have a look). As you would expect (in the context of proper scientific analysis rather than a myopic approach based on a sole product), the medium range guys at Exeter - whilst obviously steering a path based largely on the GM output - are always making tweaks and seeking better consensual approach to the modified graphics we show on-air, based on what other models suggest alongside the GM solution. Their guidance briefings to BBC make frequent reference to whatever the likes of GFS, JMA, GME and lest us forget France's Arpege are suggesting. Indeed, I've often had such briefings where the GM solution is largely rejected in favour of another product, which again is what you'd expect from a robust, open-minded scientific methodology employed by the good folk in Exeter, as opposed to one wishing to favour a sole solution....

Thus although our graphics effectively reflect the NAE or longer-term GM solutions, it's not necessarily a slavish acceptance of the UKMO products but a more complex approach where a slightly hybrid version is often the result you see on-air.

Best

Ian

thanks for your up to date input Ian-appreciated

mine just posted is from a long time ago although with the links I still have at Exeter I know pretty much how things are-thanks again Ian

[Snowyowl9]

We have good agreement on a north east wind , good one at that with the UKMO/GFS but GEM/ECM say no just a slack flow. Any reason behind the difference between the models?

This is what I don`t like about ECM from this,a very slack NE-ly

http://91.121.93.17/pics/Recm1681.gif

To this HP but a NW-ly

http://91.121.93.17/pics/Recm1921.gif

No doubt it would be very cold indeed colder than the coldest night in december 2005 but dry only.

[kold weather]

Yep snowy owl, the ECM ensembles for London show it would probably give maxes around -2/3C, thats clearly exceptionally cold and mins would likely be quite severe as well...

What is helping the weak high to hold on right to the bitter end is the fact that the upper low over Europe is actually rather strong which means we keep a relative region of high pressure over the UK.

Hopefully the 12z GFS shows more of an undercut attempt rather then a flabby high pressure set-up which would much less cold then the ECM solution...maybe an 0z GFS solution would be good.

[Neilsouth]

What time is the ECM coming out?

Would like to see an increase in this flow for mid-end of week

[yamkin]

What time is the ECM coming out?

Would like to see an increase in this flow for mid-end of week

Here's the link regarding your query

Availability Time Issuer Time Base

03:30 - 04:45 GFS 00z

06:00 ECM 00z

06:30 NOGAPS 00z

06:30 UKMO 00z

09:30 - 10:45 GFS 06z

10:30 FAX 00z

15:30 - 16:45 GFS 12z

17:30 UKMO 12z

18:00 ECM 12z

18:30 NOGAPS 12z

19:00 JMA 12z

21:30 - 22:45 GFS 18z

22:30 FAX 12z

Edited January 3, 2010 by yamkin

[SteveB]

What time is the ECM coming out?

Would like to see an increase in this flow for mid-end of week

About 6-6.30pm

[Neilsouth]

Here's the link regarding your query

Availability Time Issuer Time Base

03:30 - 04:45 GFS 00z

06:00 ECM 00z

06:30 NOGAPS 00z

06:30 UKMO 00z

09:30 - 10:45 GFS 06z

10:30 FAX 00z

15:30 - 16:45 GFS 12z

17:30 UKMO 12z

18:00 ECM 12z

18:30 NOGAPS 12z

19:00 JMA 12z

21:30 - 22:45 GFS 18z

22:30 FAX 12z

Thanks! + Steve :unsure:

[Nick F]

While it's quiet, if anyone wants to know what the coming week may have in store without having to trawl through this thread, based on this morning's model output, I have created a new blog for the cold weather in this New Year, both current and outlook:

http://forum.netweather.tv/topic/59644-new-year-cold-spell/

[SMU]

Thanks! + Steve

03:30 - 04:45 GFS 00z

06:00 ECM 00z

06:30 NOGAPS 00z

06:30 UKMO 00z 03:50-04:15

09:30 - 10:45 GFS 06z

10:30 FAX 00z

15:30 - 16:45 GFS 12z

17:30 UKMO 12z 15:50-16-15

18:00 ECM 12z 18:10- 18:45

18:30 NOGAPS 12z

19:00 JMA 12z

21:30 - 22:45 GFS 18z

22:30 FAX 12z

UPDATED in BOLD

[Ben_Cambs]

GFS 12z run starting to come out. Interesting to see their position on what happens later in the week. Hopefully the weak high over the UK will be shunted west