Model Output Discussion

[The PIT]

Only complaint about the GFS is that it isn't stormy enough. Looks wet average to mild and only the North West to get a good blow. I also suspect this pattern will remain for some time as well.

[snowmadchrisuk]

Plenty of Colder Options from the Ensembles .

[cyclonic happiness]

Plenty of Colder Options from the Ensembles .

And the control and operational runs are BOTH above the mean in FI.

[tollgateiow]

I'm quite pleased with this gfs run and here we see the euro high helping to change the pattern, many times we see the euro high with low heights to the north meaning it can't develop a colder pattern , the difference this time is we have building pressure to the north and ne. As i said in an earlier post IMO this is a plausible way forward because the trough to the west will eventually force a pressure rise over southern europe, its not far fetched and doesn't rely on too many factors, we need to see the other models go for this, so a glimmer of hope this evening so far, lets hope it lasts.

It demonstrates how desperate the situation is if we have to rely on pressure rises over southern europe to get our winter weather. However it would help to cool the continent down a bit. Hope the ECM gives us some hope this evening!

Edited December 3, 2009 by JACKONE
per user request

[Frosty.]

Once again the GFS shows pressure rising from the south later next week which would bring drier, brighter weather to most of the uk except the far north & west which would probably remain unsettled. This rise of pressure next week was not commented on in the meto update today but the gfs keeps showing it. I wonder if the ecm 12z will show it this evening, the gfs further on becomes very messy and there are cold possibilities but all I can see is low pressure domination, especially in northern and western areas with the cold air too far north and east of the uk to be of much interest.

[bluearmy]

it is very uncertain due to the unusual polar pressure developments - however, i think we're in danger of seeing promise where it doesnt exist. the 12z ens are not as cold as the 06z. the idea that rising heights over europe are a good thing is a very dangerous strategy. we could easily see a cold northerly not make it due to high heights over western europe diverting it to our east. there is no guarantee that a western euro high will retrogress northwest or northeast. i understand where you are coming from on this Nick, but others may start to think that a euro high is the answer to getting to cold and it isnt necessarily so. roll on the ecm and the split vortex.

[LomondSnowstorm]

I'm quite pleased with this gfs run and here we see the euro high helping to change the pattern, many times we see the euro high with low heights to the north meaning it can't develop a colder pattern , the difference this time is we have building pressure to the north and ne. As i said in an earlier post IMO this is a plausible way forward because the trough to the west will eventually force a pressure rise over southern europe, its not far fetched and doesn't rely on too many factors, we need to see the other models go for this, so a glimmer of hope this evening so far, lets hope it lasts.

[phil nw.]

The extent of the spin off energy from the Canadian vortex centre can be seen here at T96hrs.

http://charts.netweather.tv/gfsimages/gfs.20091203/12/96/npsh500.png

Lots of wind and rain still to come over the next week or so.

Plenty of PM air still in the mix though,

http://charts.netweather.tv/gfsimages/gfs.20091203/12/96/h850t850eu.png

So temps. close to average and rather cold further north at times.

[Matt12345]

Is this to be taken as gospel ? I think that all of a sudden people are too keen to use the MJO and 'GWO' as drivers, which they are not at all proven to be.

The models have turned out a little disapointing for some people, so a little cluching at straws is happening i think Ian. Lets see what happens later..

[I remember Atlantic 252]

Is this to be taken as gospel ? I think that all of a sudden people are too keen to use the MJO and 'GWO' as drivers, which they are not at all proven to be.

I think the South will be rather above average over the coming week to ten days. I think most people are sick of the rain and the best we can hope for is some ridging from the South with the mean trough a little further North and West, though this is by no means certain.

good that ecm 12Z in deep FI at least shows a high coming from south, best hope for inversion cold

[snowray]

good that ecm 12Z in deep FI at least shows a high coming from south, best hope for inversion cold

True, some foggy conditions and bit of fost around coming up to Christmas, then maybe a change to something a bit colder into January.

Of course its extraordinary that the continent does not see any real cold, even Greece misses out for a change!

Hope the Atlantic does not remain so strong too long though, hey theres always February though that might save the day.

Edited December 3, 2009 by snowray

[Frosty.]

good that ecm 12Z in deep FI at least shows a high coming from south, best hope for inversion cold

Indeed, hats off to the gfs for spotting the pressure rise from the south first! the ecm now backing towards the gfs by T+216 to 240 hours, I must say, at that range with only 12 days to christmas, I can't see how any northerly or easterly would develop in time from such a bland set up, so we might have to make do with faux cold instead, better than no cold I suppose.

[johnholmes]

latest lrf is out-link in pdf format below

issued early as I'm away most of Friday into Saturday

http://forum.netweather.tv/topic/47443-lrf-or-attempting-them/page__st__204__gopid__1626035&

[Geordiesnow]

My goodness, are people already looking as far as ahead to January for cold weather? Amazing but that normally happens when you see rather poor charts but as ever, one or two surprises do pop up so December should not be written off whatsoever at the moment.

I suppose in one way, it's good that the charts are poor as if they are showing cold spells in FI then people will get over excited and if they downgrade, the wrist slashing starts. You never know, we might see a cold shot appearing in the models soon but at the moment, the Atlantic seems to be taking control but blocking in Scandinavia is never too far away.

Frosty - how is it hats off to the GFS even though the set up has not even happened yet and it still over 200 hours away! For all we know, the next GFS run could and probably will bin that scenario.

Edited December 3, 2009 by Geordiesnow

[January Snowstorm]

Tis funny really to stand back and read the posts.

2 days ago we were reading that the models were totally different to previous starts to Winter. Now we are reading that the charts are woeful for early December.

Me, Ive learnt that our Climate aint much fun 90% of the time and that one cold blast delivering snow is the most we get, usually in early Spring.

A bit of a bore I would call it

[kold weather]

I think Ian is quite right with what he suggests. The models are starting to really suggest a high pressure building over the UK and its set-up we've seen quite a lot in recent Decembers to one degree or another. Intially any such set-up will come from a mild/very mild set-up but if it does hold for a little while it could quickly become fairly cold, as people say faux cold!

Blocking to the north is only useful if the Atlantic plays ball with us, and it'll be a hard thing to do with the global teleconnections supporting a strong jet and the upper trough/low holding close to the UK, so I don't think I'm buying the total works some models have (Ala the cold easterly evolution) just yet, but can certainly see a cold inversion high eventually forming, could have some very mild temps before then though.

[Frosty.]

Frosty - how is it hats off to the GFS even though the set up has not even happened yet and it still over 200 hours away! For all we know, the next GFS run could and probably will bin that scenario.

Because in my view it seems a logical progression that the very unsettled weather will eventually become restricted to the north & west as high pressure builds up from france and buckles the jet as the gfs has shown on all 3 runs today so far, and now the ecm has picked up on it, I realise it's well into FI but the chances of it happening are much higher than anything cold from the east or north IMO. The only alternative is the ecm 00z solution which remained unsettled everywhere with no hp influence.

[kold weather]

Also remember there actuall isn't any real heights being progged by the models over the north poles, any -ve AO is being induced by the fact that surface pressure are high thanks to split vortex on both sides of the region, its like any ridge inbetween two lows, expect its obviously more stable...if you like, its a faux -ve AO, not the true blooded northern blocking.

[JCP]

Also remember there actuall isn't any real heights being progged by the models over the north poles, any -ve AO is being induced by the fact that surface pressure are high thanks to split vortex on both sides of the region, its like any ridge inbetween two lows, expect its obviously more stable...if you like, its a faux -ve AO, not the true blooded northern blocking.

Faux -ve AO? I've heard it all now!

[Frosty.]

Also remember there actuall isn't any real heights being progged by the models over the north poles, any -ve AO is being induced by the fact that surface pressure are high thanks to split vortex on both sides of the region, its like any ridge inbetween two lows, expect its obviously more stable...if you like, its a faux -ve AO, not the true blooded northern blocking.

I seem to remember we had similar faux cold last christmas as high pressure built north from france, maybe a repeat of that is likely to occur, the models have dramatically downgraded any prospect of true wintry synoptics this side of christmas but maybe something surprising will happen hopefully, the usual british winter pastime of chasing phantom cold snaps has now commenced.

[Bristawl Si]

Reminder folks!

It's only December 3rd

[ThunderStorms]

I need rain in South of Portugal !!

I had 30 mm in the last 3 months :lol:

I completely lost confidence in the models.

The seasonal say it will be extremely rainy, but the medium-term models say it's bullonions and that the drought is to continue!

Here everything is completely dry ... nor is green herbs, just dry ...

I lost confidence in the people of the forums, models of short and medium term, seasonal forecasts

If you want visit Algarve, it´s beuatiful and you have sun all time !!

[James M]

I seem to remember we had similar faux cold last christmas as high pressure built north from france, maybe a repeat of that is likely to occur, the models have dramatically downgraded any prospect of true wintry synoptics this side of christmas but maybe something surprising will happen hopefully, the usual british winter pastime of chasing phantom cold snaps has now commenced.

Hasn't it just :lol:, it's on these occasions where I take a break from model watching and see what they are showing in a few weeks time.

[kold weather]

Maybe JCB but there is very little heights actually present over the north Poles, there are ridges obviously inbetween the polar vortex but its more surface based. As steve.M said you know its the real deal when you see the yellow colours come up in the charts, thats when you tend to have 552 heights which at the north pole tends to suggest a real blocking event. What the models are showing isn't anything close to that, and thus the highs we see over the north are simply reflections of the low pressure cells around it, remember for every trough/low there will be a ridge in there, may be all relative but there will still be one, and the blue highs (low heights) are not going to cut the mustard at all with a strong jet...because they are caused in effect by the jet and the PVs themselves...thats why you may see 1050-1060mbs high pressure cells which have low heights in topplers, then along comes a small weak lp and the whole lot will be destroyed because its not a strong high in the sense of whats needed.

[Frosty.]

it's on these occasions where I take a break from model watching and see what they are showing in a few weeks time.

Good idea, the models look pretty desperate for the next week at least and maybe much longer.