Model Output Discussion - 12th December Onward

[Cheshire Freeze]

To be fair the high pressure has been fairly consistent over the past 2-3 runs, but even then, that means absolutely nothing, as we saw with the storm earlier this week! Can't really see anything develop; re: an easterly this side of Christmas though, the jet may be a little strong for it. That's not to say it won't develop into January though - which is a possibility as we go into the month.

Yes I'd wager nothing this side of Christmas. Early-mid Jan transitional IMO.

[ChartViewer]

Yes I'd wager nothing this side of Christmas. Early-mid Jan transitional IMO.

This I agree with...it fits in with with the NW forecast, GP summaries and the In Depth posts....However it seems in this thread that doesnt relay to here............

This isnt a southerly tracking jet...A good guide to what our weather is doing!!!!

[phil nw.]

http://www.meteociel...44-21.GIF?15-17

noone want to comment on the UKMO tonight

Chart of the day that

S

yes ,i commented on it above Steve.

May help to build the AH further north -for surface cold-but i can`t see anything more than that.

[chionomaniac]

It really depends on other factors. If you've read the Strat thread it is looking likely that any warming will have a quicker effect than the average strat warming.

That doesn't make sense and certainly not what I have said, CC!

[karyo]

This isnt a southerly tracking jet...A good guide to what our weather is doing!!!!

Why are you posting a chart for the 31st Dec?

Karyo

[Weather-history]

Just a reminder what could have happened tonight. It could have be one of the biggest weather events for some years.

[Cheshire Freeze]

That doesn't make sense and certainly not what I have said, CC!

I'm not an expert on the stratosphere but understand the basics.

Summer Blizzard quoted this: ''Different winters see the effects of a SSW impact on differing time scales.

In winter 2009, the atmosphere responded almost immediately however in winter 2010 we saw that the delay was about a month.''

''It looks as if this year could be a quicker year''

I never mentioned your name Chiono?

[ChartViewer]

Why are you posting a chart for the 31st Dec?

Karyo

Why not it is the Model thread and it ties in with GP, NW and In Depth posts where it says we will have to wait until Jan until change in this cooler/milder weather pattern...What is wrong with posting a jet model image that ties in with the current models....If you feel it maybe diff plse feel free to oppose my opinion...

Regards

[chionomaniac]

I'm not an expert on the stratosphere but understand the basics.

Summer Blizzard quoted this: ''Different winters see the effects of a SSW impact on differing time scales.

In winter 2009, the atmosphere responded almost immediately however in winter 2010 we saw that the delay was about a month.''

''It looks as if this year could be a quicker year''

I never mentioned your name Chiono?

Phew sorry. I don't necessarily go with that, but that is not for this thread.

[Barometric]

Just a reminder what could have happened tonight. It could have be one of the biggest weather events for some years.

It still could be with the first significant winter snow event for S Wales and the E Midlands

James

[karyo]

Why not it is the Model thread and it ties in with GP, NW and In Depth posts where it says we will have to wait until Jan until change in this cooler/milder weather pattern...What is wrong with posting a jet model image that ties in with the current models....If you feel it maybe diff plse feel free to oppose my opinion...

Regards

You said this is not a southerly jet and posted the link as if to prove it! The jet has been quite southerly despite the low hights to the north and continues to do so.

[ChartViewer]

You said this is not a southerly jet and posted the link as if to prove it! The jet has been quite southerly despite the low hights to the north and continues to do so.

That isnt a Southerly tracking jet....as per the Models which change into a milder theme towards Xmas day and dont change until that date....Im just sayin the jet doesnt continue to go South unfortunately for coldies....Unless you can demonstrate it does after Xmas on the Models?

[snow drift]

You said this is not a southerly jet and posted the link as if to prove it! The jet has been quite southerly despite the low hights to the north and continues to do so.

I wonder if the pressure outside is negativity correlated with the pressure in the thread. i.e. one drops the other rises.

What is apparent from the models at this time is from Monday the temps will warm up and this looks like the lead into Christmas. Not as warm as some would suggest but not as cold as most of us would like. Average would be a good description.

[phil nw.]

That isnt a Southerly tracking jet....as per the Models which change into a milder theme towards Xmas day and dont change until that date....Im just sayin the jet doesnt continue to go South unfortunately for coldies....Unless you can demonstrate it does after Xmas on the Models?

Let`s not get too intense.

It may be wise to keep some balance in your posts and view the other models too--they don`t all show the same picture.

[ChartViewer]

Let`s not get too intense.

It may be wise to keep some balance in your posts and view the other models too--they don`t all show the same picture.

I agree Phil and agree that we are going into a cooler short period then milder....But you say this when someone called a possible Easterly for a period beyond Xmas and you didnt ask them to post alternative charts?....Come on certain members have posted why we feel it will be milder and have been shot down.....Im happy to display a range of charts...

Regards

[Pixel]

Just a reminder what could have happened tonight. It could have be one of the biggest weather events for some years.

spot the difference ?

an interesting observation on what was predicted some time ago Mr Data

[nick sussex]

Anyone for a white Xmas?

http://www.meteociel...?ech=192&mode=1

Thats for the 23rd December but projected forward even with it toppling the ridge that would have a chance!

Of course its the JMA! but thought I'd highlight it to lighten the mood in here!

Although it only has 26 versus 30 days verification its ahead of the GFS 12hrs run at day 6 and day 8.

Edited December 15, 2011 by nick sussex

[Geordiesnow]

As others have said, it does look a matter of if rather than when the proper mild weather will arrive but until at least Monday the outlook still looks cool/cold with nighttime frosts and snow showers for exposed coasts in Scotland especially.

UKMO may offer something different down the line but on this evening runs its on it own regarding any potential height rises to our North. If this mild spell comes off, no doubt you will see some forecasters claming this to be good news despite most areas will probably see no sunshine from this set up unlike you get in PM spells generally.

[Cheshire Freeze]

Anyone for a white Xmas?

http://www.meteociel...?ech=192&mode=1

Thats for the 23rd December but projected forward even with it toppling the ridge that would have a chance!

Of course its the JMA! but thought I'd highlight it to lighten the mood in here!

Oooooh I'd bank that. Has 2004 written all over it, which provided a very snowy Xmas day with a very similar set up.

[phil nw.]

I agree Phil and agree that we are going into a cooler short period then milder....But you say this when someone called a possible Easterly for a period beyond Xmas and you didnt ask them to post alternative charts?....Come on certain members have posted why we feel it will be milder and have been shot down.....Im happy to display a range of charts...

Regards

I just thought you were getting a little hung up on that GFS chart and wasn`t considering other output,for example UKMO 144 which shows a different flow to GFS.

Anyway let`s move on.

[ChartViewer]

I just thought you were getting a little hung up on that GFS chart and wasn`t considering other output,for example UKMO 144 which shows a different flow to GFS.

Anyway let`s move on.

No prob accept your comment and will display other charts in future...thanks...Nice to see your not as harsh as OON:-)

Edited December 15, 2011 by ChartViewer

[Robbie Garrett]

I probably wont get a reply from this but I might aswell try. As my views and ability on model's and how they are setup is extremely limited, but can the GFS/ECMW/UKMO be prone to hide things in the future until last minute? I.e this storm with a undercutting of cold air overnight to provide snow? Which was not forecasted until at least 2 days ago. Could let's say 1st January be widespread -10*C with record breaking snowfalls but the Models wont show it as it doesn't have the data for what could happen in let's say 7 day's very accurately.

Sorry if it's a stupid question, because I know models change every run from what ever gets fed into them (Data or some kind of world wide conditions and trends or something)

But I am no meteorologist and don't claim to be, but surely these models may be wrong in some sense and all this hinting is of something just around the corner? January 2009 - December 2010 (cold periods) where only really well know a few weeks/days before they happened. All this talk about Barlett highs from every poxy high pressure that forms is starting to annoy me now, but anyways can someone give me a detailed explanation as to how the models work?? All I do is look at them, just like 99% of most members and shout what we see, not what we can't see.

Edited December 15, 2011 by Robbie Garrett

[I remember Atlantic 252]

Oooooh I'd bank that. Has 2004 written all over it, which provided a very snowy Xmas day with a very similar set up.

yeah, and here, GFS flirting with northerly Xmas eve, FI anyway but ensembles seem to dip between Xmas eve and boxing day, hopefully another weekend northerly toppler

[nick sussex]

I probably wont get a reply from this but I might aswell try. As my views and ability on model's and how they are setup is extremely limited, but can the GFS/ECMW/UKMO be prone to hide things in the future until last minute? I.e this storm with a undercutting of cold air overnight to provide snow? Which was not forecasted until at least 2 days ago. Could let's say 1st January be widespread -10*C with record breaking snowfalls but the Models wont show it as it doesn't have the data for what could happen in let's say 7 day's very accurately.

Sorry if it's a stupid question, because I know models change every run from what ever gets fed into them (Data or some kind of world wide conditions and trends or something)

But I am no meteorologist and don't claim to be, but surely these models may be wrong in some sense and all this hinting is of something just around the corner? January 2009 - December 2010 (cold periods) where only really well know a few weeks/days before they happened. All this talk about Barlett highs from every poxy high pressure that forms is starting to annoy me now, but anyways can someone give me a detailed explanation as to how the models work?? All I do is look at them, just like 99% of most members and shout what we see, not what we can't see.

The models all start with errors ie they can't map every part of the atmosphere, to overcome this ensembles are run, these tweak the starting conditions for each member, if these still end up in roughly the same place as the operational run then forecast confidence increases.

In terms of later outputs, sometimes models maybe slow to pick up on a change in the overall teleconnections so for example the GFS may continue to churn out zonal runs in its outer reaches, then it will suddenly switch.

It is best to not take models at face value especially when dealing with more complicated set ups, there are certain set ups that often cause models most problems and where they're liable to go off the rails, unfortunately these are often the ones that deliver cold and snow to the UK!

[phil nw.]

ECM goes a similar route to GFS early next week bringing in the milder SWesterly flow as the Azores High situates around Biscay.

http://www.wetterzen...cs/Recm1441.gif

The pattern keeps pretty flat further on with the south continuing in milder uppers- nearer average further north but more unsettled.

Edited December 15, 2011 by phil n.warks.