Model Output Discussion 4th Dec.2013-12z onwards.

[fergieweather]

 

But those EC32 chop and change far too frequently to have any sort of confidence in them, granted you can only post what the models show but these show something different every week.

Ah, the swings; the about-turns... the joys of NWP; and for that matter, the poisoned chalice of trying to offer even a probabilistic approach to a 4-week period!However: EC32 runs Fri and again today paint a pretty consistent story. Equally, DECIDER was already bullishly on the (broadly) SWrly bandwagon into the forseeable. The issue was degree of cyclonic v anticyclonic v unbiased re this. But we can, as I said in previous post, only "tell it as it is."PS - yellow fog warning about to be issued for tonight; areas broadly E of a line joining Wash to New Forest.

[Gael_Force]

But those EC32 chop and change far too frequently to have any sort of confidence in them, granted you can only post what the models show but these show something different every week.

 

...and the daily ones show something different every run for the low-res sections - it can only be a guide at an even longer time span - maybe more use if there is support from sources we have no access to.

[tight isobar]

Purga do you realise than an Easterly for the UK is just a distorted zonal flow to the North of the UK...? Theres next to zero chance of a Greenland block in the next 12-15 days but to rule out any cold is wrong- just look at the CFS at day 9 & 10. S

perhaps It's a fault of our own here. Many are obsessed with heights to Greenland, without knowledge or know for repercussions NE/N,. As once again although model out, is at present in stability regards semi,zonal flow,there are ample chance for switch.only variables need alignment.

[Purga]

Purga do you realise than an Easterly for the UK is just a distorted zonal flow to the North of the UK...?

 

Theres next to zero chance of a Greenland block in the next 12-15 days but to rule out any cold is wrong- just look at the CFS at day 9 & 10.

 

S

I really, really hope you're right Steve and would love to see an easterly 'spring up' as has indeed happened in the past very rarely. I just feel that what I can see and perceive from good knowledgeable contributors here and elsewhere puts the odds at such a surprise very low. I do love your analyses and insights by the way, just have a pessimistic viewpoint at the moment. Believe you me, I will ramp like crazy when I think some real cold prospects are looking more likely.

Edited December 10, 2013 by Purga

[johnholmes]

But those EC32 chop and change far too frequently to have any sort of confidence in them, granted you can only post what the models show but these show something different every week.

 

But as Ian tried to explain it is not the only output used by Exeter. Using whatever data is available at whatever time frame, adding in the professional experience of the team at Exeter and you have the best combination there is in terms of professional unbiased assessment. Unbiased is something few show  on here. The weather as I say at times can and does make all of us professional and amateur look chumps at times. Something we have to live with. As to what January and February will bring weather wise-who knows and it's no use worrying about it on the 10th December. For something to do have a look at what the charts were showing prior to some of the colder winter months or winters. Try November 2010, November 1962 or 1946 etc. The weather can and does, in spite of our huge improements in data and model prediction change and still catch us out. The ' trick' for professional forecasters is from the massive amount of data which pattern shown on which model has the most likely probability of becoming reality. it is science but it does sometimes look like a pretty inexact form of it!

Edited December 10, 2013 by johnholmes

[UV-RAY]

Ah, the swings; the about-turns... the joys of NWP; and for that matter, the poisoned chalice of trying to offer even a probabilistic approach to a 4-week period!However: EC32 runs Fri and again today paint a pretty consistent story. Equally, DECIDER was already bullishly on the (broadly) SWrly bandwagon into the forseeable. The issue was degree of cyclonic v anticyclonic v unbiased re this. But we can, as I said in previous post, only "tell it as it is."PS - yellow fog warning about to be issued for tonight; areas broadly E of a line joining Wash to New Forest.

Thanks for the reply as it isn't a dig at your good self or Matt and I did emphasise myself that you can only comment on what it's output is showing. Edited December 10, 2013 by Sceptical Inquirer

[IDO]

Despite wishful thinking the models have high confidence in the current long wave pattern.

 

Week 2 from NOAA:

 

Pretty much what all the models are showing synoptically. The experts advise "above average confidence" "4 out of 5".

 

Looking at the ECM mean, verification >40% better than the OP: at T240,  

 

Similar signal.

 

The return of the anomalous ridge in the N.Pacific/Bering (NP) area looks hopeful for the final third of December so further amplification to the US is expected (more snow & cold for them Christmas) and maybe a better downstream Atlantic ridge will give us a taste of Winter in the last week of December. Also with a strong Russian High ® and most of the PV over Greenland, there are possibilities that there will be a split flow in the NP-R regions. Not sure this is sustainable at the moment but it may bring some transient cold, if we are not again on the wrong side of the block.

 

 

[Jason T]

I really, really hope you're right Steve and would love to see an easterly 'spring up' as has indeed happened in the past very rarely. I just feel that what I can see and perceive from good knowledgeable contributors here and elsewhere puts the odds at such a surprise very low. I do love your analyses and insights by the way, just have a pessimistic viewpoint at the moment. Believe you me, I will ramp like crazy when I think some real cold prospects are looking more likely.

 

 

Cfs v2 xmas day. Beautiful.

 

 

 

 

 

 

 

 

Obviously 15 days out, So far from nailed on, But cfs has been showing some cold options starting around 17th Dec for the past couple of weeks. 

[BLAST FROM THE PAST]

Good to see you back posting Fred, I hope your father is back on the road to recovery now.

Yep out of immediate danger thank you, there's trouble ahead but his time isn't yet...but it looked like it was last Wednesday when pulled into private room by doctor.  thanks for concern and thoughts

 

regards

 

Fred

 

sorry mods off topic but wanted to say thank you to good folk on here and more than any time in my life I don't care 'that' much about a cold Christmas

Edited December 10, 2013 by BLAST FROM THE PAST

[Boro Snow]

Cfs v2 xmas day. Beautiful.

 

 

 

 

 

 

 

 

Obviously 15 days out, So far from nailed on, But cfs has been showing some cold options starting around 17th Dec for the past couple of weeks. 

 

I really cannot understand how we can get to that from where we are at the mo

[fergieweather]

I really cannot understand how we can get to that from where we are at the mo

'Tis an intriguing outcome, for sure. Very enigmatic... (!)

[SMU]

http://modeles.meteociel.fr/modeles/gfs/runs/2013121018/gfsnh-0-180.png?18

 

that's a pretty good chart- for the second wave to pull the vortex back like I mentioned to Ian earlier-  Interested in 216 & 240 etc.

 

S

[on the coast]

Looks like America is going to be very cold if FI charts keep up this trend. 

[Purga]

Blowtorch Christmas?

 

 

Probably much more likely than the CFS freeze up .

[Skyraker]

http://www.meteociel.fr/ukmo/runs/2013121012/UN144-21.GIF?10-17

 

looking at the NH plot the change is underway on the UKMO 12z.

 

Cold from day 6 on the euro tonight with high pressure ridging North/ NE this time as opposed to east last week.

 

Good call this, obvious @240 on ECM (bear in mind the ECM isn't out while the above post was made).

 

I've only read this thread to 17:10 and checked ecm, gfs... might pause for a moment and check the strat thread ... just a feeling that the game might be afoot.

Edited December 10, 2013 by Skyraker

[bluearmy]

Latest london ecm ens show no ice days in the next two weeks. Thats 700 days worth of output and not one ice day. hey ho.

[Frosty.]

I think there will be some polar maritime incursions before and during christmas so snow can't be ruled out, snow on northern hills at the very least and occasional frosts. This is the way I see the models trending today, hoping the 00z runs continue the same way.

[East_England_Stormchaser91]

Well if that ain't a mighty one I don't know what is!

And don't worry, if you read my post I did say the synoptics would be OK (meaning wintry) for the Scottish hills - have a wee dram and chill...

2011/12 took some beating. I'd say that was a proper Polar Vortex, more so than this one we have now.

[SMU]

Crucial timeframe & areas to watch tomorrow- T 126-144  -

 

ENERGY SEPERATION. -  GFS likeleyhood @ resolving this - LOW.

EUROS probability - Higher.

 

This is the GFS pushing the energy through the block-

http://modeles.meteociel.fr/modeles/gfs/runs/2013121018/gfs-0-144.png?18

 

Notice the area west of Ireland- trying to break away from the main core of the jet-

 

Remember the GFS Bias- 1 single stream of energy - not resolving split energy.

 

End result- energy / associated system moves East through the block.

http://modeles.meteociel.fr/modeles/gfs/runs/2013121018/gfs-0-168.png?18

 

 

Now pick a run where the GFS sees a split jet like the UKMO @ 144 - ( PTB2)

http://modeles.meteociel.fr/modeles/gens/run/gens-2-1-156.png?18

 

All of a sudden the split energy is providing more amplification of the jet & a cut off low

http://modeles.meteociel.fr/modeles/gens/run/gens-2-1-180.png?18

 

What you are seeing from the ENS means tonight ( GFS 12z, ECM 12z & more than likely the ECM DET32) is the poor resolution of how to model a split flow past 144 hours-

 

Where the UKMO & ECM OP are just developing it. Once the models get a grip on it they usually expand on the idea of splitting the energy away which will result in a swift move by the ENS means to a more amplified pattern.

 

The CFS presented earlier showed the end result of the split flow perfectly.

 

By what I have seens of the 18z - expect CHANGE tomorrow. especially the ECM- split flow FTW

 

 

S

Edited December 10, 2013 by Steve Murr

[swilliam]

Interesting GEFS Control in F1 in terms of developing scandi high and look at the cold pool.

 

Illustrates how we can get to this to this point as well - not sure why people saying they cannot see how it can happen when I thought SM had explained how quite eloquently. V. low chance of course but we are looking for signs.

[Panayiotis]

Interesting GEFS Control in F1 in terms of developing scandi high and look at the cold pool.

 

gensnh-0-1-384.pnggensnh-0-0-384.png

Illustrates how we can get to this to this point as well - not sure why people saying they cannot see how it can happen when I thought SM had explained how quite eloquently. V. low chance of course but we are looking for signs.

Im sure you mean Fi/FL (Fantasy island/Land) 

Edited December 11, 2013 by Panayiotis

[swilliam]

Im sure you mean Fi/FL (Fantasy island/Land) 

It's late!

[Ian Brown]

A strongly zonal GFS and UKMO this morning with the PV dominating matters.

[Long haul to mild]

Well, if rain and gales are your thing, you'll love the GFS this morning. Low after Low barrelling towards us for the entire run. Big Russian High eventually sets up in deep FI but too far away to have any influence on us.

Still hope that it's not going to be as straightforward as that though!

[terrier]

Well gfs this morning is awful heavy rain and gales for the entire run. Don't like the noises been made from the professionals at the met either at the moment. Think I'm already considering writing off this winter. Because looking at the models and long term signals it's not looking or sounding good. Anyway will come back after Xmas and see if any signs have changed. So happy Xmas to you all and happy new year. Hope everyone has a great Xmas.