Model Output Discussion 5/12/2012 18Z onwards - the one after THAT ECM

[GoonerGregg77]

Should have towel icon option on some of these posts. People are throwing it in already, and if were not careful some the excellent posters on here who we have to credit a lot for there input may just start to stray away for some sanity!

[matty lfc]

Im a relative newbie to this forum but i clearly remember the GFS constantly trying to break down the 2010 cold spell with insane lows out in FI.The experienced posters pointed out that it desperately tries to get back to it's default setting of an Atlantic pattern.

As many have pointed out,lets get the cold first then worry about any attacks from the Atlantic.

Also,i think the mods on here are being very leniant regarding some obvious winding up posts.

[Wilxy]

Overall the pattern is looking promising lots of potential even on the 12z nothing to get down about.

ECM soon should be intresting.

[Neilsouth]

When the froth subsides a bit I will post my weekly look at what seems the probable weather pattern 6-15 days or so from now.

So you will be posting this update next week when the event is happening?

[snowking]

And for all of those questioning posts about he easterly flow:

Stick to the ensemble means where possible post 120

SK

[johnholmes]

So you will be posting this update next week when the event is happening?

eh not understand that mate?

[mulzy]

12z GEFS better than 6z GEFS with regards depth and duration of the cold - still the possibility of Atlantic breaking through by day 10 but that's way out in la-la land to be taken seriously.

http://modeles.meteociel.fr/modeles/gens/graphe_ens3.php?x=306&ext=0&y=141&run=12&ville=Londres&runpara=0

[Nick L]

And this mini-rant is targeted at those who are complaining it will be bone dry for the majority. Get the cold in and then worry about PPN. I've been guilty in the past of worrying about the snow before the cold. Troughs and other disturbances in an easterly flow won't be accurately picked up until just a couple of days out. Several times during a cold easterly, troughs have seemingly come from nowhere on the FAX charts.

And this relative positivity is from someone who's not even in the country and wants it to be snow-free next weekend so I can get bloody home!

Edited December 6, 2012 by Nick L

[SnowObsessor90]

One thing that people do often go on about is how promising synoptic's in FI never really come forward towards the reliable well some of them ARE so isn't that a positive to take from the current output if nothing else?

Edited December 6, 2012 by Anonymous21

[Frosty.]

Some rather premature posts in here, I do urge some of you to read your posts over several days. One does not need to know what the models are showing simply read some folks posts, up-down several times I won't say a day but certainly several times a week.

When the froth subsides a bit I will post my weekly look at what seems the probable weather pattern 6-15 days or so from now.

Yes John nothing has changed, we are still in for a significant cold spell from early next week. The only question is where most of the snow will be and whether we can get max temps to stay below freezing, I think we can.

As GP said this morning, follow the ensemble mean

Edited December 6, 2012 by Frosty039

[IDO]

nice to see you being positive for a change

Models look super for a very cold wintry outlook, late FI is trash, the cold spell will last for weeks!

It is what it is. The short ensembles:

http://modeles.meteo...ndres&runpara=0

Good support for cold most of next week. The GFS 12z op in the coldest 12% by Day 8.

The mean at T240 sums it up. A split Atlantic v Cold. A draw on that chart.

Edited December 6, 2012 by i'm dreaming of...

[Jayces]

I thought the big blue meant cold

You need to look at the temperature chart along with that chart.

The blue on that chart represent low pressure, yellow is high.

If the blue low pressure is on a blue (cold temperature) area on the other chart then it's good ;-)

In this case the background temperature is yellow which is bad.

[kold weather]

A look through the GFS ensembles suggests the operational run has only small level of support, most runs still have either an attacking low that is getting sheared or the HP still in charge with an EASTERLY.

Slo in other words, throw the GFS op run onto the scrapheap...maybe not quite into the bin, but close enough!!

[TAFKAP]

Last time I checked I thought it was a well known fact that the models have 'wobbles' prior to a big cold snap. Perhaps that thought will put some of the more idiotic posts in here this afternoon into perspective. Surprised the mods aren't making some good hard strikes with the old 'banhammer.'

Edited December 6, 2012 by jbuffett1980

[jessandjon]

You need to look at the temperature chart along with that chart.

The blue on that chart represent low pressure, yellow is high.

If the blue low pressure is on a blue (cold temperature) area on the other chart then it's good ;-)

In this case the background temperature is yellow which is bad.

( blush ) thanks

[Mac_SE]

I knew it, with years of watching the charts i knew last night was way too good to be true, Been used to being let down by GFS so many times, im pretty sure this will end up being a little cold for 4- 5 days at the most with dusting of light snow here and there and with the atlantic winning over. Its a good start for this time of year and hopfully a precursor of whats to come for Jan and Feb. But to be honest i think people got there hopes up way to quickly last night!

Two words guys: manage expectations. Enjoy the ride and stop being eternally disappointed at charts that are MODELLED, not NAILED ON. Amazing chart last night, but if you were seriously expecting it to deliver from that far out, just because it's stonking and what you'd love to see verify, is faintly ridiculous.

Look at the general trend instead, get excited by the potential of cold as we get much nearer the event and be realistic about the way models chop and change continually, even right up to the last minute.

[Nick L]

Last time I checked I thought it was a well known fact that the models have 'wobbles' prior to a big cold snap. Perhaps that thought will put some of the more idiotic posts into here this afternoon into perspective. Surprised the mods aren't making some good hard strikes with the old 'banhammer.'

The thing is though, I wouldn't even class it as a wobble! What the ECM threw out last night was pretty much THE best synoptics you can get for wintry weather in the UK. The only way was down from there. We're no longer on top of Everest but we're still somewhere in the Himalayas.

[Adam lufc]

Please for once can we have something spectacular models!! We never seem to achieve it and just get let dwn. Plz ecm ulmo gfs bring it to us. I Dnt believe in trends- we keep seeing them and they Dnt materialise!! Am sat on fence tonight....

[chris55]

People that compalin about the "dry" flow... I remember with great clarity how people were moaning about the Jan 2010 NE flow being "bone dry". Then at 36 hours' notice this low cropped up and dumped several inches of snow across much of the south.

http://www.wetterzen...00120100106.gif

There was no hint of it even 2 days before - the models just showed a straight and slack flow.

My point it, trying to pin down specifics more than a couple of days ahead is pointless. Look at the bigger picture.

Hallelujah Rob, I have been reading through the thread with my head in my hands at times, I guess it's just the inexperience that leads to such posts. The example you give (and many others I can remember, but this one especially) is the reason why saying a particular run "will be dry" means nothing at all unless it's at +00h. (and that Low gave up to 12 inches of snow in parts of southern England)

As for the 12 GFS, in this situation, with a large block forming, looking into FI means very little unless there is strong ensemble and cross model support, which at the moment we are struggling for in the mid term let alone FI solutions from separate operational runs!!

[kold weather]

By the way, even the pressure mean outside say 144hrs can be a little useless, you only need 2-3 runs developing a deep low (960mbs or lower) where other runs are fairly neutral or have weak pressure cells to really skew those charts.

[DanDorsetUK]

One thing i learnt over the years never trust anything over 5 days since my days with Snow4man over at the daily mail. We were let down loads lol Ill try and keep positive but i just cant see the cold holding out for as long as some of you are saying it will. i just dont see it yet

[phil nw.]

To newer members and those who have already chucked their toys out of the pram i ask you to disregard operational output beyond T120hrs.

Clearly there are differences in the way the models incl.GEM show the shape of the vortex towards Canada beyond this point and this has a bearing later on.

They all look pretty close at T120hrs.with the main upper features-heights across our north with a very cold North Easterly flow setting in.Those wanting cold-look at the uppers

Nothing to grumble about there-or the ens means at T180hrs.

Good enough i reckon.Come on folks relax and enjoy whats coming-in this setup the snow will come in time.The cold is here now and will deepen after the weekend.

[TAFKAP]

Please for once can we have something spectacular models!! We never seem to achieve it and just get let dwn. Plz ecm ulmo gfs bring it to us. I Dnt believe in trends- we keep seeing them and they Dnt materialise!! Am sat on fence tonight....

Compared to the garbage of the 90s and early 00s the current output IS spectacular.

[Severe Siberian icy blast]

Guys why look at things that's after the easterly next wk before the cold spell is even hear? Remember gp said time again recently that as the models try and work out scenarios of how where to put the vortex we should expect volatility within the models , he also said that there will be a false dawn of the Atlantic coming back , as the vortex goes from Canada to Siberia we should expect big swings, this cold spell is as good as locked now, and we will have attacks from the south and west , that's expected with northern blocking, but it also spells snowy weather, I am very excited about next wk, and I feel this time next wk we will have a lot of snow in the forecast.

[Pennine Ten Foot Drifts]

I generally stay out of here when 'dream' synoptics show up, it's just too tiring trying to separate the wheat from the chaff, but I am finding it quite astonishing that people are posting up T192+ charts then following these up with much wailing and gnashing of teeth. Lets be honest here, it's not even a given that the T96-T144 period is guaranteed to verify as it has been showing for the last few days, (we probably need to wait another 48 hrs for that yet), so to be getting over-wrought about possible solutions beyond that is ridiculous.

Too much '63 chasing goes on in here every December. As it stands everything points to next week being colder, (possibly significantly colder), than average for the UK for this time of year, due to height rises to our north and east pulling an easterly/north easterly flow, (if the various synoptic evolutions required happen as currently shown of course). And that is about as far as an accurate forecast can go at this stage.

Edited December 6, 2012 by Pennine Ten Foot Drifts