Model Output Discussion - The Start Of Winter

[MR EXTREMES]

But knocker said gfs 6z should be binned and is there any reason why plz ?

[Jason H]

Think we all need to take a step back to be honest. Talk of cobra meetings taking place are well wide of the mark. Looking at the gfs 06z away from scotland we are looking at nothing much apart from a few fleeting cold snaps. Yes we may well be seeing a northern hemisphere pattern change taking place. But snowfall this side of xmas is very rare for the uk apart from dec 2010 of coarse.And until the mo come on board we should all be very sceptical of the eye candy runs in fi. So lets see what the next few days bring. And if were still seeing similar output around next monday then we maybe onto something. Until then i will watch ian fergusons updates with intrest regarding the met office musings.

We all need to take a step back, or the odd excitable poster?  I don't think anybody is expecting anything too dramatic yet. Certainly agree with you about a change in the overall pattern as shown the latest model runs. What fruit that bears, we wait to see.

[Backtrack]

But knocker said gfs 6z should be binned and is there any reason why plz ?

 

I don't think we can simply 'bin' any run just because it's not showing what we want it to show. All outputs should be taken into account, otherwise the mean output would be strictly biased.

[russell k]

I don't understand the Ens the 06 gfs showed this IMBY ?? I know I rarely post, but there seems to be lack of logic in this data?

hopefully the recent NWP verifies for as all, I just hope the devil will be in the detail

 

Temp

[karlos1983]

I don't think we can simply 'bin' any run just because it's not showing what we want it to show. All outputs should be taken into account, otherwise the mean output would be strictly biased.

 

I think the key here is about trends, so as you say, simply disregarding any run would be incorrect, and at the same time, some runs will show deeper cold than others so taking any one run as assurance is also not advisable, especially with the time-scales we are looking at. but as long as the overall trend continues, we should all be pretty happy with the output, the trend in my eyes from what I have seen from the models over the last 24 hours or so is definitely a trend to colder conditions the other side of Christmas, just how cold and how fruitful remains to be seen. All great viewing in any case.

[BlueHedgehog074]

But knocker said gfs 6z should be binned and is there any reason why plz ?

I'm not 100% sure if it's true I admit but, apparently, according to Accuweather (http://m.accuweather.com/en/weather-blogs/weathermatrix/why-are-the-models-so-inaccurate/18097), the GFS 06Z run (and also the 18Z run) supposedly doesn't include all the balloon data and, as such, affects the way it performs.

Edit: Having said that, I agree with Backtrack that no runs should necessarily be ignored, especially just incase some of these have picked out new trends that other models haven't latched on. Excluding the reliable time-frame, I imagine that there has been instances in that past where even the 06Z/18Z GFS runs have correctly modelled outcomes that other models didn't quite achieve.

Edited December 17, 2014 by DiagonalRedLine

[TonyH]

Dear Santa......

 

 

BFTP

My thats a nice one, surely the MO will publicise this cold snap/ spell soon - its looking nailed on!

Edited December 17, 2014 by TonyH

[Stormyking]

Some very interesting and eye candy runs of recently, GFS P have noticed keeps coming up with all different ideas, from Greenland highs, Strong Atlantic Highs and now a 2013 style looking Scandi High with Easterlies. Either way there does seem to be trend of something colder after Christmas. Still a while out, so am not getting excited about anything yet, either way its very encouraging.

 

ECM too showing good signs building north towards Greenland, nice too see good agreement on things from most of the Models.

[bluearmy]

The current output is evolving exactly as i was expecting it to, having seen it marked on the extended ens at the end of week 2 and counted down. a few fluctuations but they are all variations on a theme.  we now have the important timescale within the high res ops (ecm and gfsp) and higher res ens modelling re the pre cold pattern and the colder pattern istelf. the eye candy charts are just that for the time being. they need to come down below T200 and then T144 before you can go and buy your snow shovel. however, the higher res ens should now give us a better idea as to how good the fi ensembles were. the early signs are encouraging.

 

would be nice for MOGREPS to climb onboard but thats not the be all and end all just yet.

[Shunter]

The latest AO update seems indicative of potential pattern change.... moving into a negative value around 23rd Dec  ( 1st -4 ens showing also ) . 

The NAO swings from slightly positive to a neutral value around the same time.  

[IDO]

I'm not 100% sure if it's true I admit but, apparently, according to Accuweather (http://m.accuweather.com/en/weather-blogs/weathermatrix/why-are-the-models-so-inaccurate/18097), the GFS 06Z run (and also the 18Z run) supposedly doesn't include all the balloon data and, as such, affects the way it performs.

image.jpg

 

Yes 06z and 18z are just for fun.

 

 

I don't understand the Ens the 06 gfs showed this IMBY ?? I know I rarely post, but there seems to be lack of logic in this data?

hopefully the recent NWP verifies for as all, I just hope the devil will be in the detail

 

Temp

 

 

The charts on the right are for the 0z run and on the left the 06z run. As I have said the ensembles don't show much of a pattern change and although the GFS P is going cold, until it gets support from the GEFS lots of uncertainty.

 

 

I don't think we can simply 'bin' any run just because it's not showing what we want it to show. All outputs should be taken into account, otherwise the mean output would be strictly biased.

 

If you look at the Oslo pressure chart for the GFS 06z P it is in outlier territory on 28th December and afterwards:

 

 

 

Only one other ensemble member has a Scandi high at that time!

[terrier]

My thats a nice one, surely the MO will publicise this cold snap/ spell soon - its looking nailed on!

don't think it's nailed on yet to be honest. Yes possible but certainly far from nailed on.

[No Balls Like Snow Balls]

Yes 06z and 18z are just for fun.

 

 

 

The charts on the right are for the 0z run and on the left the 06z run. As I have said the ensembles don't show much of a pattern change and although the GFS P is going cold, until it gets support from the GEFS lots of uncertainty.

 

If you look at the Oslo pressure chart for the GFS 06z P it is in outlier territory on 28th December and afterwards:

 

MT2_Oslo_ens.png  gfs-0-264.png

 

Only one other ensemble member has a Scandi high at that time!

That's not really a proper high in Scandi anyway. It's only surface pressure. You need greens and yellows for it to start being a proper high pressure cell.

Edited December 17, 2014 by No Balls Like Snow Balls

[Banbury]

My thats a nice one, surely the MO will publicise this cold snap/ spell soon - its looking nailed on!

No it isn't , charts posted are too far out to labelled nailed on, been here before with this

[mushymanrob]

But knocker said gfs 6z should be binned and is there any reason why plz ?

 

well i read it as one of his witty remarks.. he really is quite funny and adds abit of humour to this frenetic thread.

[karlos1983]

My thats a nice one, surely the MO will publicise this cold snap/ spell soon - its looking nailed on!

 

I presume this was tongue in cheek TonyH? with 9519 posts, I'm convinced you will have seen enough failed attempts to know full well it's far from nailed on! 

[IDO]

That's not really a proper high in Scandi anyway. It's only surface pressure. You need greens and yellows for it to start being a proper high pressure cell.

 

Thats when it starts to build. Later in the P run: 

[russell k]

Yes 06z and 18z are just for fun.

 

 

 

The charts on the right are for the 0z run and on the left the 06z run. As I have said the ensembles don't show much of a pattern change and although the GFS P is going cold, until it gets support from the GEFS lots of uncertainty.

 

 

 

If you look at the Oslo pressure chart for the GFS 06z P it is in outlier territory on 28th December and afterwards:

 

MT2_Oslo_ens.png  gfs-0-264.png

 

Only one other ensemble member has a Scandi high at that time!

Please look again and at the 2m v 850 on the 12Z and the min v max from the op.

cheers

[weather_it_will]

My thats a nice one, surely the MO will publicise this cold snap/ spell soon - its looking nailed on!

Hardly nailed on, when it's only appeared on a couple of model runs today.

 

Tomorrow it may show something different again.

 

More consistency with cross model agreement in a more reliable time frame is required.

[bluearmy]

That's not really a proper high in Scandi anyway. It's only surface pressure. You need greens and yellows for it to start being a proper high pressure cell.

 

i'd bite your hand off for that chart to verify

[IDO]

Please look again and at the 2m v 850 on the 12Z and the min v max from the op.

cheers

 

 

Yes I see what you mean, 850s below the mean and 2m above! I was thinking it was maybe the Foehn Effect but then I realised its the 06z. The op can go silly with 2m temps in FI, and looking at the London 2m it does the same there (from the 26th):

 

 

Ignore. One of the many reasons why the 06z is not helpful after around D6. The 12z will hopefully be more useful.

[blizzard81]

Yh totally agree there were some big similarities just hope that tomorrows runs don't follow the ecm. Going to be looking at 00zs runs tomoz from behind my sofa also worries me that the met office are not so enthusiastic as well now which ties in with If comments and matt hugos tweet. But can the gfs get it so spectacularly wrong at just 8 days away. Those pesky shortwaves are the bain to all coldies they never seem to help us. So hope its gone in the morning.

Yeah, I don't feel as though we have moved any further after the outputs so far today. The best news so far is the met have gone back to mentioning the possibility of colder weather in the extended. Will be watching the 12z runs with great trepidation lol.

[knocker]

But knocker said gfs 6z should be binned and is there any reason why plz ?

 

It was tongue-in-cheek as a higher authority had previously decreed that when the tablet came down from the mount the 11th read, "the 06z is always rubbish and should be ignored".

[Roadrunner]

You can smell something is afoot when there is over 400 people viewing the model thread at 2.30pm.

Eyes down for the 12z suite soon. Netweather is awesome and thanks to all involved behind the scenes that keep this great site up and running.

PS Am I the only one who watches model runs through your fingers when things are looking promising?

[Barry12]

Things have changed a lot for Christmas day from a couple of days ago.

 

This is the chart from 3 days ago:

 

 

This is the chart today:

 

 

From +6 uppers for some to -6 uppers...

 

wasn't long ago that people were mentioning a mild Christmas day

Edited December 17, 2014 by Barry95