Model Output Discussion 23/11/2012 18Z onwards

[Iceaxecrampon]

Well well - its all going **** up - that's the 12Z and the 06Z GFS runs both in agreement of sorts.

I have serious money on this cold spell with the missus and my lad has just waxed his sledge.

Best day for ppn for Cumbria is now the 2nd December

[MKN]

Tbh you have to look at the trends. Over the last 24hours northern blocking is shown to be weaker than Outputs suggested previously. Not a good trend. Hopefully 12zs show more promise

[AWD]

I know its not model related but it may ease some souls in here, this from Ian Fergusson;

W COUNTRY: Looking further ahead, turning colder next week with UKMO describing start of December as "significantly colder than average".

Meanwhile, for my area, I'm more concerned about the rainfall expected over the next couple of days;

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=nae&MODELLTYP=1&BASE=-&VAR=rsum&HH=48&ARCHIV=0&PANEL=0&ZOOM=0&PERIOD=

Widely 30mm across the country, locally more in the south & west.

The Midlands & Wales look like getting a drenching too;

http://www.wetterzentrale.de/pics/Rmgfs9014.gif

Whilst the SE look like getting some pretty severe wind gusts;

http://www.metoffice.gov.uk/weather/uk/se/brighton_forecast_wind.html

http://www2.wetter3.de/Fax/bracknell+24.gif

[IDO]

As we near the reliable the usual December westerly Atlantic flow is not going to let the block favour the UK, without a fight. The model trend is for the Atlantic HP to push towards the UK. It is unlikely to win outright, but could delay the N'Easterly, and will no doubt keep trying. The models, including the ECMW seem to be adding more weight to the Atlantic in their recent output than they have over the previous five days. In my opinion all signs still point to a cold snap, so this upstart looks like bringing a cool/cold settled period (up to T200), before the snow potential increases, and the battleground scenario near the UK looks like the headline on the 06z.

It looks to me like the op runs are suggesting waves of cold rather than a sustained flow at the moment, suggesting the block is not as strong as some believe, but of course this could all change and probably will.

[Methuselah]

As I said, after yesterday's 12Z: it's one run from one model...It still shows bucket-loads of cold air in the vicinity of the UK, for much of the time...Unfortunately, what it doesn't show is bucket-loads of snow...

It's almost certainly going to turn substantially colder over the coming week or so; but, how can anyone expect to pin-down individual events, 10-days' hence? They can't. Nobody can!

So, why not take some of JH's advice and concentrate on the 500mb anomaly forecasts instead? it could certainly save a hell of a lot of wrist-slitting!

[Timmytour]

The 06z is desperately poor by comparison to any earlier runs for us cold and snow lovers (especially downs south).

But it were to be the run that verifies, that's a hell of a storn heading our way on thursday week!

[ICETAB]

What - you mean both runs - the 12Z as well hopefully not a trend.

What - you mean both runs - the 12Z as well hopefully not a trend.

I'm talking about the 06z. The 00z was better for cold but developments didn't look right to me after T96. I think the ECM and UKMO models have got a better grip of the situation, as per previous similar blocking setups.

Expect to see upgrades for cold middle of next week...

[SMU]

Another woeful preforming 06z- It really should be discontinued.

Once & for ALL

Top performing model-

ECM

http://www.emc.ncep..../html/acz6.html

However in the CURRENT NH PATTERN- UKMO AT THE TOP-

The GFS is third which is the 00Z run

Now the individual runs- THESE STATS SHOW ALL THE GFS BIAS

http://www.emc.ncep....region.168.html

Now look at the regionals & see how far the 06z is behind the 00z- Probably on a par with the NOGAPS-

Look at the varification stats for the atlantic Its probably as bad as TEITS crayon model.

So we now have

ECM/ UKMO trumps the GFS 00z, the 00z GFS trumps the 06z & the 06z is of a better resolution than the 06z GFS ensembles.

RESULT.

Set fire to the GFS 06z & use its 06z ensembles as firelighters.

S

[Robbie Garrett]

Is it not quite rare to get a north easterly in December? I remember 2010 being high pressure stuck over us?

Any good examples of past December Northerly/ Easter ly?

Edited November 24, 2012 by Robbie Garrett

[kate1]

comment!

Why don't ALL of you comment about how the charts look to you, give the chart, date/time?

Comment on the interpretation but is it not possible to do it without arguing with one another?

I will post my latest ideas using the anomaly charts in the technical thread shortly, my ideas from last evening are there if anyone wants a read of an ATTEMPT at an unbiased summary of how events look 6-15 days ahead.

Why some of you get so hung up on ONE run and almost always in its less reliable time scale has always puzzled me, new and old members alike.

I'm a newbie trying to interpret the situation and I would thoroughly recommend popping over to the calmer atmosphere of the technical thread and reading what John has to say (don't worry, it isn't technical - even I understood it!). Much more thoughtful and balanced a viewpoint than some of the rather hysterical and hand-wringing one-liners that crop up here on occasion.

[Weathizard]

When people say 'just ignore the gfs individual runs' what does this actually mean? Only look at the ens? + I don't think we can ignore the GFS to be honest, I'm going against more experienced people on here, but its shown a breakdown of heights on its last few runs (with them appearing agan at end of FI sometimes). I'm not a negative nelly I just think we need to seriously consider the outputs of the ECM/GFS rather than just ignore it

[mountain shadow]

Steve, you must feel like a broken record on here sometimes.

What is clear is that it is going to turn much colder, we will no by tomorrow whether it will be the snowy variety or not.

[bluearmy]

Another woeful preforming 06z- It really should be discontinued.

Once & for ALL

Top performing model-

ECM

http://www.emc.ncep..../html/acz6.html

However in the CURRENT NH PATTERN- UKMO AT THE TOP-

The GFS is third which is the 00Z run

Now the individual runs- THESE STATS SHOW ALL THE GFS BIAS

http://www.emc.ncep....region.168.html

Now look at the regionals & see how far the 06z is behind the 00z- Probably on a par with the NOGAPS-

Look at the varification stats for the atlantic Its probably as bad as TEITS crayon model.

So we now have

ECM/ UKMO trumps the GFS 00z, the 00z GFS trumps the 06z & the 06z is of a better resolution than the 06z GFS ensembles.

RESULT.

Set fire to the GFS 06z & use its 06z ensembles as firelighters.

S

unless it shows good continuity with the general consensus. tbh steve, if it shows a solution which seems reasonable, given all the model output, i'd take it seriously. however, today's op run is odd quite early so unless the 06z has some data that all the other models have been missing it is indeed for the fire.

[Frosty.]

Careful! I got shot down for saying as much earlier on!

It does certainly show possibly colder surface conditions, but Thurs/Fri/Sat/Sun are much less wintry than the 00z, as we are in a much slacker flow. It may come later on (no doubt!), but this evolution does still mean that the potential wintry weather is put back from the formlerly more rock-solid "start" date of Friday 30. THat's all I'm saying.

At least ICETAB waited for the run to finish first

And the GEFS mean is still solidly supporting a colder and colder outlook which added to the ukmo 00z, it still looks promising, model wobbles aside.

[Iceaxecrampon]

I'm talking about the 06z. The 00z was better for cold but developments didn't look right to me after T96. I think the ECM and UKMO models have got a better grip of the situation, as per previous similar blocking setups.

Expect to see upgrades for cold middle of next week...

Apologies - meant the 00Z and 06Z runs are both trending a similar downgrade.

Members on here yesterday were betting their mortgages of armageddon on the 30th - I hope you are right.

Cumbrian GEFS mean ensembles are nice and flat - yes there is cold but we were all spoilt by last weeks runs - here's hoping.

Ian

Edited November 24, 2012 by Iceaxecrampon

[Tim Bland]

When people say 'just ignore the gfs individual runs' what does this actually mean? Only look at the ens? + I don't think we can ignore the GFS to be honest, I'm going against more experienced people on here, but its shown a breakdown of heights on its last few runs (with them appearing agan at end of FI sometimes). I'm not a negative nelly I just think we need to seriously consider the outputs of the ECM/GFS rather than just ignore it

The intelligent thing to do I's shook at all the output available including the ensembles and then spot when a run is out of kilter with the others. As Steve says, give less credence to runs such as the GFS 06z which is worth the same as the NOGAPS. It is also clear if a model has a handle on the pattern by whether or not it is consistent. If you look at the 300hrs NH profile from the last few GFS runs they are completely different and the differences start v early on.

IMO the Reason the GFS gets so much attention and comment year in year out is because we have all the data from it and it is then interpreted into snow depth charts and precip type. It also goes out further than the top model -ECM so it's fun to look at for FI

I used to get sucked into every run from GFS, now I don't bother looking at it beyond 200hrs and just view the ensembles to see if there is a trend, and on the last few GFS ensemble sets the clear trend is for lower temps

[bluearmy]

looking through the updated ecm extended graphs for berlin and warsaw, shows the milder runs generally dropped out as the over amplification of the euro trough is dropped by the model suite. if we get a proper easterly within a fortnight, it wont be a warm one. i'd say the clustering for london through week two remains just below the mean. these charts will not show a mean max of zero for somewhere like london in week 2. they didnt in 2010 either. consistent evidence from the model that temps for the first week of december will be maxing in the upper thirties F at best.

[Iceaxecrampon]

looking through the updated ecm extended graphs for berlin and warsaw, shows the milder runs generally dropped out as the over amplification of the euro trough is dropped by the model suite. if we get a proper easterly within a fortnight, it wont be a warm one. i'd say the clustering for london through week two remains just below the mean. these charts will not show a mean max of zero for somewhere like london in week 2. they didnt in 2010 either. consistent evidence from the model that temps for the first week of december will be maxing in the upper thirties F at best.

Adding to the confusion even more bringing Warsaw and Berlin into the equation! - let alone a possible easterly in 2 weeks time - I am more concerned about what will or won't happen in Cumbria on Thursday

Ian

[Frosty.]

Steve can';t you read? all of us stop digging at other folk-we all end up with egg on our face at times, you Steve and me!

I don't think any of us, even the most meteorologically minded, can second guess what the models will do next or which model can be trusted in the current situation, of course whichever model shows the coldest solution will be flavour of the month.

[January Snowstorm]

I have to say Steve I don't agree that the 06z is the worst performing model but rather than arguing can we put it to the test today.

Right, it has developed the shortwave to our West further and delayed any potential cold and is miles away from what the UKMO is showing.

So let's all hold fire until the 12's come out and (ignoring ECM for the moment) let's see which model backsdown the UKMO or the gfs?

I'm sure if the UKMO proves correct we will all be delighted and jump on the bandwagon that the 06z run is useless!

This afternoon at this time range one will have to backdown

Of course if the gfs does prove to be correct, let's be honest then too and say rather than being useless it actually spotted a trend.

My heart says ukmo will win this, my head knows it wont

Edited November 24, 2012 by January Snowstorm

[MKN]

Steve would you not agree with those who are saying things aren't looking as good based on the fact the strength of high pressure to the north is now looking like it could be weaker than was forecast 36hours ago? ive not seen many in here say the 06zs bad it looks all over, most people seem to have noticed the trend has been for weaker heights hence the chance of something more prolongued looks less likely. However at this range does not mean its not possible.

[Bobby]

People should be able to give their humble opinion of what they think the weather will do without being attacked and labeled 'doomsaysers' or 'rampers' or whatever. If you think someone's forecast is wrong then explain why you think so, if someone is just trying to wind people up then ignore it. It'll be much calmer and saner here then.

The 06z GEFS ensemble mean vs the 00z has less cold air over us with it pushed further East.

06z

00z

At +192

[ISAAC]

Guys guys, easy!

Remember November 2010, there was alot of chopping and changing all the way till the start of the cold spell. We had eye candy -15c uppers showing at one stage even in T140 with the gfs and then back to -5c in between runs with attempts of the Atlantic pushign back in FI. This was just bound to happen, we see great charts and expect them to keep showing up, but it just doesnt happen like that

I wouldn't totally undermine the GFS, but take 4 daily runs and see the overall pattern day by day.

If by tomorrow 18z GFS continues this tread and IF backed up by the UKMO and ECM then i'd be worried.

[legritter]

Morning all ,noticed many times GFS in its later charts can be the difference between 1030 MB and 1000MB ,in just 6 hrs . when i started modell watching about 3 yrs ago on this forum my mood would change with the GFS run . i had to say to myself GET A LIFE .As for todays runs so far ,plenty of mouth watering charts and data on offer .and i would say later next week plenty of surprises could pop up . its going to be hard for the modells to get a grip especially IF high pressure to the north is the eventuall winner ,because if it does get a grip Dense air as got a lot of muscle in it .and we could get reloads .catch up later .

[Paul]

Done some tidying, can we keep things polite & model related please