Winter Model Discussion 12Z 09/01/13> The hunt for cold ?

[Tom Quintavalle]

I would say ignore the ensembles for now. Due to the wild differences in the operationals the ensembles are pretty useless at the moment. Remember the whole purpose of the ensembles was to take into account the chaos theory to check the reliability of the model run.

Back to the weekend and here are the latest fax charts.

http://www.meteociel...fax72s.gif?09-0

Rain turning to snow on Saturday night.

http://www.meteociel...fax84s.gif?09-0

Snow showers in E areas on Sunday more particularly from around NE England southwards.

At this early stage snow moving SE during Monday although parts of Wales, SW England may only see rain.

Hi Dave,

On the Met Office site, they have updated the 5 day pressure chart at 7.12 today and for Monday still shows a low dropping into N.Scotland, with triple-point just clearing Liverpool Bay, as per last nights Fax for t120.

http://cdn.nwstatic.co.uk/fax/PPVO89.png

Regards,

Tom.

[ANYWEATHER]

The ECM is a downgrade simple as that, yesterday had -5 uppers and colder over the whole of Britain for a week, the uppers on the latest run wont be supportive of snow everywhere.

In these situation the models simply cannot deal with pattern changes such as this scenario. Wild swings are always likely , Ive seen it time and time again,and this time its no different. I think 3 days from the model outputs is at the realms of anything resembling some accuracy.

[Mr Sleet]

In terms of the pattern in the USA this from NOAA is very important:

...ADDITIONAL UPPER DYNAMICS ARRIVING IN BASE OF WRN TROUGH

FRI/EARLY SAT...

...SHEARING-OUT INTO PLAINS ON SAT...

PREFERENCE: COMPROMISE OF GFS/UKMET AND ECMWF

ALL OF THE 00Z GUIDANCE AND EARLIER 12Z MODELS SUGGEST ADDITIONAL

SHORT WAVE DYNAMICS DIVING INTO THE BASE OF THE UPPER-LEVEL TROUGH

ACROSS THE SWRN STATES LATE FRI/EARLY SAT BEFORE THE ENERGY EJECTS

OUT INTO THE SRN PLAINS AND SHEARS UP THE MID MS/OH VLY. THERE IS

A DECENT AMOUNT OF SPREAD CONCERNING THE PROGRESSION OF THE

DYNAMICS BUT AT THE SURFACE... ALL MODELS INDICATE A SURFACE WAVE

DEVELOPING NEAR THE ARKLATEX NEAR 72HRS OR 00Z/13 AND SLIDING

NEWRD INTO THE OH VLY BY 84HRS OR 12Z/13... ANYWHERE FROM SERN MI

TO WRN PA. TOUGH TO DISCERN THE SMALL SCALE DIFFERENCES THIS FAR

OUT BUT A GENERAL COMPROMISE OF THE GFS/UKMET AND EC SEEMS

SUFFICIENT. THE 00Z ECMWF IS VERY COMPARABLE TO ITS PREVIOUS RUN

AND STILL MATCHES THE ABOVE SURFACE SOLUTION... THUS STICK WITH

THE MODEL COMPROMISE.

It looks like the GFS at least made a decent call with the first shortwave not clearing east cleanly but with some shortwave energy in tow.

So it does look like we will have to deal with this. As you can see the forecaster has gone for a blended solution, as you can see he does state some uncertainty in terms of the exact detail.

How this impacts events near Greenland you can see by the differing outputs, these shortwaves aren't the only reason for this but essentially how these pieces of energy phase with troughing in the west Atlantic make a big difference.

For the timebeing I think we just have to wait till tonight, we have no idea at the moment which output has called this correctly.

Thanks Nick.Yesterday I urged caution with regard binning the GFS, simply because it got a very similar pattern right in early December,against the other models which went for a "Day after Tomorrow" event.Many years looking at these models and a bit of experience in the trade has made me very cautious!I think the GFS does better in these scenarios.

This mornings ECM is not anywhere near as good as the past few runs, it's very clear.However, all is not lost, we'll need to wait until Saturday I think, but I'm expecting the GFS type solution to be the winner with a short cold event and back to mild and damp by the end of next week. I'm not sure how significant the SSW is when pitted against what has been a strong Atlantic so far this winter.

[steelermark]

too much scatter on these 15th-16th to start congatulating gfs yet

anyone notice the kontrol run today

http://www.meteociel...&mode=0&carte=0

http://www.meteociel...&mode=1&carte=0

thought not

It's the same story every time on here unfortunately. When all the models are singing from the same hymn sheet for cold you don't see certain posters here at all. As soon as there's a wobble up they pop as if like magic. Spouting the usual "this is what I warned against" rubbish. Then they try and cover their tracks by pretending they're disappointed with the models and are coldies whilst all the time rubbing there hands at the keyboard whilst they reel everybody in.

It's plain tiresome and tbh getting to the stage where it's pointless looking in here. Why can't people post objectively on the output and say what it's showing without the cold or mild bias? Certainly without the "I told you so undertone"!!!

This mornings posts from the moment the GFS started rolling were just laughable. I can't read the models anywhere near as well as most on here so would never dream of posting about them. So many contradictory posts it's a wonder we can learn anything.

[UV-RAY]

I logged in and the first few post suggested a downgrade on the ECM,so i hurriedly viewed the charts and had to did a double take to make sure I wasn't viewing something different. All i'll say is that here are some minor differences to yesterdays chart and probably aren't as cold, but not by much, the snow seems to have been shunted North a little......... I could go on but the differences are that small it's pointless, another cracking run by the ECM IMO.

[johnholmes]

I despair of this thread be it from the mild lover or the cold lover. For the sake of sanity in here PLEASE will you all go to the link in Net Wx Extra if you have it and play the 00z charts alongside the 12z charts and then come back on here with PROOF of what you are wittering on about. It is not difficult simply look at the data available on here and show everyone and make your comments. It really is ridiculous.

[Gustywind]

Jeeez, seriously everyone, not just the above quoted poster but 90% of you. How can a model be proved right when you are talking about the future? The codswallop that is being spouted in here recently is beyond belief. At least in the Summer there are less of these 'experts' posting such drivel. Seriously if you dont really know what you are on about model wise, don't pretend that you do. There must be many more people that are not so clued up getting very confused on here. Oh and please no more talk of Shannons bloomin' Entropy. Its not big and definitely is not clever! Love youuuu.

Jason,

The ECM has taken the shortwave east initially whereas up to now it took it sse immediately, that is a downgrade in terms of snow potential for parts of the uk (the south and south west mainly) so is a downgrade and is exactly what the GFS does also. I've not said its right or wrong, however we have moved from near complete model consensus on a cold/ snowy spell to a more mixed position this morning. I've no idea how it will eventually turn out, however in my opinion the trend has swung towards the GFS this morning.

[Frosty.]

It's pretty obvious the azores high/ridge is the major spoiler, the gfs is just not having it so we have a standoff against the euros, we had this same situation last month and the gfs won, the big difference this time is we have SSW compared to a cold strat last time when the projected freeze imploded, I have a feeling the 12z runs later today will decide whether we are just going to have a cold snap followed by milder or the cold digging in with undercutting lows and blizzards, it will decide whether january is going to be memorable or as michael fish used to say on tv, nothing to write home about.

Edited January 10, 2013 by Frosty039

[mcweather]

I despair of this thread be it from the mild lover or the cold lover. For the sake of sanity in here PLEASE will you all go to the link in Net Wx Extra if you have it and play the 00z charts alongside the 12z charts and then come back on here with PROOF of what you are wittering on about. It is not difficult simply look at the data available on here and show everyone and make your comments. It really is ridiculous.

I have great respect for you so perhaps you'd be good enough to give us your learned view on the overnights John.

[Snowmad79]

Depends on where you live.

If you live anywhere N of the Midlands then the 0Z ECM is still a very snowy outlook. For those further S then yes it is a downgrade but then the colder air does move back S.

Lets not throw our toys out of the pram over the ECM because the main difference is the snowline has moved further N as I said.

The further north the better, I live in Greater Manchester lol. Definitely not throwing the toys, merely pointing out the thing that stuck me most about the early part of the run that some choose to ingore.

FWIW, I don't agree with a quick return to mild either as some have suggested. If anything it would would be cold wet and breezy should the Atlantic make its comeback

[TEITS]

I logged in and the first few post suggested a downgrade on the ECM,so i hurriedly viewed the charts and had to did a double take to make sure I wasn't viewing something different. All i'll say is that here are some minor differences to yesterdays chart and probably aren't as cold, but not by much, the snow seems to have been shunted North a little......... I could go on but the differences are that small it's pointless, another cracking run by the ECM IMO.

Yep and its also worth mentioning that with the pattern the ECM is suggesting you will always get winners and losers in these situations. If the LP is further S then those across S England would see snow with N England missing out and relying on snow showers. In these situations you always rely on some luck because you ideally need the LP far enough N to bring the precipitation to your location but you don't want it too far N because you need to remain on the cold side of the LP. Ideally the 12Z was better because with the pattern further S those further N may miss out on frontal snowfall but they would still see convective snowfall.

[nick sussex]

Thanks Nick.Yesterday I urged caution with regard binning the GFS, simply because it got a very similar pattern right in early December,against the other models which went for a "Day after Tomorrow" event.Many years looking at these models and a bit of experience in the trade has made me very cautious!I think the GFS does better in these scenarios.

This mornings ECM is not anywhere near as good as the past few runs, it's very clear.However, all is not lost, we'll need to wait until Saturday I think, but I'm expecting the GFS type solution to be the winner with a short cold event and back to mild and damp by the end of next week. I'm not sure how significant the SSW is when pitted against what has been a strong Atlantic so far this winter.

Yes there was far too much sledge polishing going on in here and whilst I can understand the excitement too many people have forgotten the first rule of winter synoptics in the UK.

The GFS cant just be binned because no one likes it, and without cross model agreement then you have to just wait. I'm all for ramping but as such time that I feel confident in the solutions offered up by the models.

The GFS for all its faults is still in the top 3 global models, it may well be completely wrong who knows but the ECM recently has hardly covered itself in glory either.

Regarding the ECM its not as good as last night and could easily go wrong past 120hrs, there is zero margin for error with its output.

We surely will know this evening which model has got at least the right trend, its understandably frustrating for everyone but we don't have much choice!

[johnholmes]

I have great respect for you so perhaps you'd be good enough to give us your learned view on the overnights John.

I will post later this morning if I have time in here and the more sedate area.

[Coast]

New thread here, please read the comments in the first post to enable the new thread to stay relevant and informative.