Winter Model Discussion 18Z 12/2/13 onwards.

[SMU]

Ok, so to offer the rationale:

UKMO-GM is rather an outlier versus other deterministic models: i.e. it is much quicker with the cold advection by mid-week. MOGREPS continues to show wide spread of the sub-528DAM air as per yesterday's output and given such limited support for this extent and rapidity of CAA, the 12z GM was modified (as per yesterday) to slow this process and keep the whole pattern further NE. One net result is to hold higher WBFL's over the UK for longer and albeit tephigrams suggest light showers by Weds in easternmost areas, their wintry component is greatly reduced versus the more widespread signal progged in the raw output.

Hope this explains! In summary: little change in thoughts from Exeter out to t+144 but a greater imponderable is actually proximity of the frontal zone near the SW by Monday, which is a more problematic part of the MRF.

Hi Ian - Good to see the rationale-

My comment would be- Is it a level playing field-?

Is the MOGREPS resolution & handling of the baroclinic zone slightly weaker than the ECM OP-

I also heard you mention their default setting- which of course is west east-

It would be my assessment that all ensembles should be modified west towards the Raw as opposed to the other way round- as the ensembles- rather like the GFS are not resolving the track very well & are losing the signal for a westerly curving track as the model 'blueprint' takes over...

only my take--- & obviously UKMO will go with consensus- however if a pity you are a little restricted with your comments as I would hazard a guess given the choice you may sway towards the RAW as opposed to the MOGREPS ensemble suite....

S

Edited February 14, 2013 by Steve Murr

[randomwalk]

Hi Ian - Good to see the rationale-

My comment would be- Is it a level playing field-?

Is the MOGREPS resolution & handling of the baroclinic zone slightly weaker than the ECM OP-

I also heard you mention their default setting- which of course is west east-

It would be my assessment that all ensembles should be modified west towards the Raw as opposed to the other way round- as the ensembles- rather like the GFS are not resolving the track very well & are losing the signal for a westerly curving track as the model 'blueprint' takes over...

only my take--- & obviously UKMO will go with consensus- however if a pity you are a little restricted with your comments as I would hazard a guess given the choice you may sway towards the RAW as opposed to the MOGREPS ensemble suite....

S

i.e ian if you were given a free hand you would side with with Steve Murr rather than the Met Office with their flawed models and in built biases towards what they see as the most likely outcomes?!?

[Panayiotis]

i.e ian if you were given a free hand you would side with with Steve Murr rather than the Met Office with their flawed models and in built biases towards what they see as the most likely outcomes?!?

Sorry but we shouldnt be discussing the Met and what Ian thinks, Steve has his doubts and he has reasoning behind them but they are not called the Meteorological Office for no reason, they do know what they are on about! Edited February 15, 2013 by Panayiotis

[The Eagle]

I will be up for the 00z but not quite as confident on timing of cold arrival as I was earlier. Looking more like the 144 - 168hrs timeframe and that's assuming synoptically it holds together.

[ZONE 51]

Image below GFS/ECM compare 20/2

Edited February 15, 2013 by ElectricSnowStorm

[swfc]

Sorry but we shouldnt be discussing the Met and what Ian thinks, Steve may have his doubts and he has reasoning behind his doubts but they are not called the Meteorological Office for no reason, they do know what they are on about!

why should or woudnt you be discussing it?This is a model output forum so anyone posting be it a meto guy or whatever is to be questioned?If not why post on here?The weather is or never has been cast in stone so given its volatility is open for debate and question who ever the contributor may be. Edited February 15, 2013 by swfc

[Dave Kightley]

Great runs again today... Everything been said so bring on the 00z

[Panayiotis]

why should or woudnt you be discussing it?This is a model output forum so anyone posting be it a meto guy or whatever is to be questioned?If not why post on here?The weather is or never has been cast in stone so given its volatility is open for debate and question who ever the contributor may be.

Thing is though people are discussing models which they have no access to eg the MOGREPS and they are putting them down? How does that work?

[The Eagle]

00z GFS much closer to ECM at 78hrs.

[Zenarcher]

A big change on the GFS 00z more heights building up over the North

Compared with 18z

Edit - UKMO and GFS at 96h look very similar.

Edited February 15, 2013 by weathermaster

[Ali1977]

Epic GFS

[The Eagle]

NOGAPS pretty awesome synoptically.

UKMO is near miss stuff.

[dallas]

Well well well the GFS is coming on board, 528 air over eastern UK by T126, hope its still there at T24

[Beaufort12]

so tired or should i say snow tired

hope we all get one last long long blast next week

good night fellow snow freaks

Edited February 15, 2013 by Beaufort12

[Zenarcher]

A good set of runs so far pretty much all of them looking good and similar to each other, GFS, GEM, UKMO, NOGAPS, NAVGEM.

[chionomaniac]

Epic GFS

Yes.

Finally the GFS joins the party. We are seeing the op play out one of the 18Z cold ensemble runs - and with the trend I suspect the op will be with an ensemble cluster later.

Here at T+144 we have a cold pool being unleashed on the UK

Rather typically the UKMO not orientated quite as favourably for the majority of the UK - but still not bad!

Would bank the GFS today - it's a pity that it will change as it moves closer!

[The Eagle]

GFS ensemble mean @ 144 is around 5c lower than 18z set.

[rory o gorman]

Gfs is just what the doctor ordered 100% prefect synoptic pattern for snow in southeastern Ireland .

[AWD]

GEFS have finally come around to the easterly outbreak next week now;

The Op and control follow each other pretty much all the way, both colder than the mean in the mid term;

However, like the EC ens;

they then go on to show an uptick into week 2, so uncertain on the longetivity of the cold outbreak. For joe however, an easterly wind shall prevail next week.

[Ice Day]

ECM looking stacked with potential at 144. Cold uppers flooding in across the county; 168 should be good

Edited February 15, 2013 by Ice Day

[Ian Brown]

Yes, GFS as usual finally wakes up the situation as it comes closer.

ECM is looking similar to last night at day 7, not looking for retrogression of the High as fronts approach the SW and cold SErlies over the UK.

http://www.meteociel.fr/modeles/ecmwf/runs/2013021500/ECM1-168.GIF

[Ian Brown]

What happens next ? The High is well positioned to fight off an Atlantic attack, will the system to the SW undercut ? It should do.

[winterof79]

Classic 70/80 style set up

http://www.meteociel...1-168.GIF?15-12

Battle at some point or undercut.Sorry Ian just seen your post.

Edited February 15, 2013 by winterof79

[winterof79]

Long way off but that would be fun

http://www.meteociel...1-192.GIF?15-12

After another look uppers are not great but its miles away.Happy with the charts for a colder outlook.

Edited February 15, 2013 by winterof79

[london-snow]

Excellent charts all around this morning.

GFS looks to finally woken up and had a sniff of the ukmo & ecm smelling salts.

Yet to see latter part of ecm to see if the retrogress happens but not concerned if it don't as time is on our side.

Brilliant 00z.