Model Output Discussion - 26th December - 1st January

[bluearmy]

The updated ECM ens mean at day 10 pushes the scandi trough a bit further se allowing the Atlantic ridging to edge closer int the sw of the uk. nothing too notable as the usual ebbing and flowing from run to run around a stable forecast ens mean pattern. The spreads still show a mobile ridge moving west to east as a cluster days 8 thru 10 but also the troughing digging further into western Europe like the op run. too many variables to have confidence in a specific solution within the overall long wave pattern.

I do note the vortex split into four centres around the hemisphere day 10. I also note the arctic higher heights trying to split the eastern Canadian p/v from the scandi chunk. Should the scandi trough sink a bit, we wont be too far from stewart's mjo analogue for jan over this side of the Atlantic.

[The PIT]

In the reliable time frame nothing to suggest to turn away from the zonal flow we've got. So mild mostly wet and possibly stormy in the far north. In the south mostly dry with little to interest you unless you're going for sunshine records and dryness.

Sadly for the FI cherry pickers once again you're stuck at T240 under the ECM for even a slight grain of comfort.

A few weeks to go I reckon before any real interest to kick in for the cold lovers.

[phil nw.]

The updated ECM ens mean at day 10 pushes the scandi trough a bit further se allowing the Atlantic ridging to edge closer int the sw of the uk. nothing too notable as the usual ebbing and flowing from run to run around a stable forecast ens mean pattern. The spreads still show a mobile ridge moving west to east as a cluster days 8 thru 10 but also the troughing digging further into western Europe like the op run. too many variables to have confidence in a specific solution within the overall long wave pattern.

I do note the vortex split into four centres around the hemisphere day 10. I also note the arctic higher heights trying to split the eastern Canadian p/v from the scandi chunk. Should the scandi trough sink a bit, we wont be too far from stewart's mjo analogue for jan over this side of the Atlantic.

Yes the ECM does seem to be following a trend to lose those heights over Europe and in time extend the trough into that area.

At least it shoves the High west and prevents it extending back towards europe for a while.

http://www.meteociel...H1-240.GIF?27-0

WRT to the vortex splitting,certainly signs of weakening at day 10 as reported in the Strato. thread as is the possibilty for some heights building towards the western side of NA.We would then look for E.seaboard troughing and the Atlantic heights --but will that become a block?

Putting all the background signals together would suggest this is the first step towards the pattern change that GP has alluded to for later into Jan.

The biggest hurdle imo is getting the Scandi troughing to disrupt deep enough into S.Europe later and seeing that Siberian high extending west over the top.

These are rare beasts these days and my fear is the energy to the north will remain strong enough to hold back a proper easterly.

However i am speculating on stage 2 and we are only seeing signs of stage 1 yet so i will leave it that.

Edited December 27, 2011 by phil n.warks.

[nick sussex]

In terms of the extended ECM ensembles:

http://www.weerplaza.nl/15daagseverwachting//default.asp?type=eps_pluim&r=midden

These show the main clustering suggesting a cooling trend with temps averaging around 5c for De Bilt, its mobile looking so ties in with troughing digging into Europe.

The CPC charts from NOAA suggest the high to the south edging west with the 8-14 day outlook hinting at some sinking of that trough.

http://www.cpc.ncep.noaa.gov/products/predictions/610day/fxus06.html

[bluearmy]

In terms of the extended ECM ensembles:

http://www.weerplaza.nl/15daagseverwachting//default.asp?type=eps_pluim&r=midden

These show the main clustering suggesting a cooling trend with temps averaging around 5c for De Bilt, its mobile looking so ties in with troughing digging into Europe.

The CPC charts from NOAA suggest the high to the south edging west with the 8-14 day outlook hinting at some sinking of that trough.

Clustering of temps days 9 and 10 in de bilt is below the mean and doesn't tie in with clustering on low wind speeds.

The cpc mean heights are the best we've seen so far this winter and those who continue to see nothing but 'more of the same' in the long term should maybe take their heads out of the sand and take note of the pros at NOAA who don't seem too keen on ridgidly following their own model, unlike rather too many on here.

http://www.cpc.ncep.noaa.gov/products/predictions/610day/fxus06.html

[damianslaw]

All models show a continuation in the unsettled zonal conditions we have been experiencing for quite some time now. However, the trend is towards more average temperatures, not the very mild temps of recent days so it will feel like winter once again.

Longer term - hints that we will pick up more of a pronounced cooler possible cold zonal flow much as we saw during the first half of December as we see troughing digging further east into europe. The synoptic setup on paper looks a very stubborn beast but even stubborn beasts come to an end eventually and all the signs are there for some significant changes come the middle of next month - but until then don't expect the models to start showing any change anytime soon. A winter of two halves this year.

[Frosty.]

WOW..emotions are running high and the pressure is very low, not a bad Ecm 12z tonight with a cold zonal westerly flow of arctic origins for the northern half of the uk next week and the jet appears to be a little further south and although I would prefer a nw/se tilted jet as the ecm 00z showed, we can't always get what we want but the ecm has potential. I think being realistic, the next few weeks will bring some cold zonal, cool zonal and some mild but not as mild as the last few days were.

Edited December 27, 2011 by Polar_ Low

[Grimsby Snow Lover]

All models show a continuation in the unsettled zonal conditions we have been experiencing for quite some time now. However, the trend is towards more average temperatures, not the very mild temps of recent days so it will feel like winter once again.

Longer term - hints that we will pick up more of a pronounced cooler possible cold zonal flow much as we saw during the first half of December as we see troughing digging further east into europe. The synoptic setup on paper looks a very stubborn beast but even stubborn beasts come to an end eventually and all the signs are there for some significant changes come the middle of next month - but until then don't expect the models to start showing any change anytime soon. A winter of two halves this year.

A winter of two halves sounds quite plausable to me too, after all wasn't last winter the same? I have been looking through the CFS during the last week or so and for what its worth by mid January onwards they have been consistently showing the high pressure over southern Europe getting eroded and replaced by low pressure systems and a southerly tracking Jet. Yes, I know this model is far from accurate, but a trend has been maintained pretty much each day. This is an example of what I mean, ignore the date as the charts vary quite hugely from day to day.

http://expert-images...011812_2500.gif

http://expert-images...020200_2500.gif

Edited December 27, 2011 by Grimsby Snow Lover

[SMU]

http://www.meteociel.fr/...wf/run/ECH1-240.GIF?27-0

After looking at the 240 Chart for the ECM I conclude its actually pretty good & the JMA is good as well-

The trajectory of the low at 240 will not allow it to suddenly go SE as a rule of thumb once theu get either west or east of the southern tip of greenland there always an air of inevitability about whats going to happen-

Because this system is more to the west I think we would see a sharp breakup & some trough disruption heading SE into the flow-

This may Slice across Ireland bringing Wintry conditions-

A long way out but rather similar to what occured in December-

Still not seeing large scale pressure rise anywhere exciting- but its a start heading to that day 9/10 & 11 timeframe

S

[Grimsby Snow Lover]

We have FI eye candy guys!!!

http://hw.nwstatic.co.uk/gfsimages/gfs.20111227/18/348/h500slp.png

[nick sussex]

The GFS seems in determined mood regarding the high to the south and putting aside its very late tease continues the same trend seen through all of todays runs.

Even the UKMO seems to have joined the GFS club this evening, interestingly NOAA did comment on the battle of the models this evening. So tomorrow could be interesting in seeing which model has to swallow its pride.

Either the ECM will be correct in which case it's reputation as best global model will be further enhanced or the GFS with its new friend the UKMO will land a punch.

[Craigers]

Could this be the start to the gfs picking up the trend? lets hope so!

[feb1991blizzard]

The GFS seems in determined mood regarding the high to the south and putting aside its very late tease continues the same trend seen through all of todays runs.

Even the UKMO seems to have joined the GFS club this evening, interestingly NOAA did comment on the battle of the models this evening. So tomorrow could be interesting in seeing which model has to swallow its pride.

Either the ECM will be correct in which case it's reputation as best global model will be further enhanced or the GFS with its new friend the UKMO will land a punch.

Under normal circumstances i would go with the ECM, but the fact that the UKMO is now backing the GFS with regard to a flatter pattern and the Met 15 dayer doesnt look very inspiring makes me wonder, it seems the NOAA are unsure but reading between the lines it sounds like they are non to confident in their own model, i really wouldnt like to call this one to be honest, i will sit on the fence untill its resolved.

[SMU]

http://176.31.229.228/modeles/gfs/run/gfsnh-0-288.png?18

Minus 10 850 Heavon-

Sadly thats minus 10 flowing into the Gulf of mexico!

Still a better 18z run

S

[weatherguy]

Interesting GFS 18z, moving more towards the ECM solution. The main difference however is the heights in Europe remain higher for longer, meaning a second bite of the cherry is required before the PV drops nicely down over us as shown in Craigers' post (deep in FI however). I feel that it's a massive step forward that the GFS seems to be reaching an agreement in splitting (partially or fully) the PV in the medium term (although the beginnings of this are now being modelled to start in the short term), as this then means we have a much greater chance of developing synoptics more condusive to cold. Lets hope that the agreement continues through tomorrow's runs, but for the time being I'm a very happy man

[leicsnow]

This really could be a trend, and could actually happen. On Christmas Day the GFS looked good for the 9th Jan and whilst it changed it's mind again yesterday, it's switched back to showing decent synoptics 9-11th Jan. Looks even better now the UKMO has joined forces. Maybe it will continue to switch back and forth but gradually become more consistent as we close in on the period? Could well be wrong though, but lets hope it's not.

[TEITS]

Well after finally viewing the models I have to say im not exactly overjoyed with what im seeing. For starters the SLP ensembles for Iceland, Scandinavia do not suggest any kind of blocking that we are seeking to bring a prolonged cold spell. Some members are suggesting we may see a change into the 2nd week of Jan but to be honest the best we can hope for is shortlived cold snaps via NW,lys, similiar to Dec.

http://hw.nwstatic.c...8/prmslOslo.png

Finally the forecasters over at Accu weather in the US have thrown the ECM in the bin!

http://www.accuweath...-to-lunch/59531

Edited December 28, 2011 by THE EYE IN THE SKY

[nick sussex]

Well after finally viewing the models I have to say im not exactly overjoyed with what im seeing. For starters the SLP ensembles for Iceland, Scandinavia do not suggest any kind of blocking that we are seeking to bring a prolonged cold spell. Some members are suggesting we may see a change into the 2nd week of Jan but to be honest the best we can hope for is shortlived cold snaps via NW,lys, similiar to Dec.

http://hw.nwstatic.c...8/prmslOslo.png

Finally the forecasters over at Accu weather in the US have thrown the ECM in the bin!

http://www.accuweath...-to-lunch/59531

Lol! that doesn't leave us with much to go on as earlier today NOAA binned the GFS and its ensembles in the medium term discussion, theres an outbreak of model binning going on in the USA at present!

Dave I think the accu binning is further out in relation to events past 168hrs,

http://www.meteociel.fr/modeles/ecmwf.php?ech=192&mode=1&map=1&archive=0

I think the guy at accu is talking about that storm and looking at the time of the update I wonder if thats factored in tonights output, anyway we should know by tomorrow which model meets an untimely end in the shredder!

[Brum Watcher]

had a look at GFS 00z, it has backtracked towards keeoing the cold pattern still further in fi, the ensembles for the 8th jan, why is there a 16c difference between the control and GFS op? (london)

[Uncle_Barty]

had a look at GFS 00z, it has backtracked towards keeoing the cold pattern still further in fi, the ensembles for the 8th jan, why is there a 16c difference between the control and GFS op? (london)

I refer you to my post #221 in this thread :winky:

OK, perhaps not exactly as I said in that post, having had a closer look (it's early!) but perhaps the fact that it's at not far short of T+300 might offer a clue...

Edited December 28, 2011 by Jim_AFCB

[The PIT]

ECM 00 oz just out and carries on the mobile Atlantic with plenty of active systems brushing past northern Scotland.

In the reliable time with T96 frame brief period of more normal temps before going back to mild and of course a very windy spell for northern areas again.

No sign of any proper cold and the real theme is the very strong wind that will cross the country at times.

[snow drift]

If you are new to this forum then you would be forgiven for sitting there scratching your head and thinking, well thats as clear as mud. So many varying views and what will happen.

The reason, well the models are conflicting in many ways with little being agreed past 6 or so days. Also if a Zonal outlook is being shown then the angle of "attack" can and will make a big difference to the temps. I think a change in our current pattern is coming and I think this will start to be modeled with more consistency in a few days time. Yet the weather is great at proving us wrong and I may have just put myself in the que to be proved so.

If you want to see the differences between the models then compare the big two. Start at T+24 and roll forward. It will soon become apparent where the changes start to occur.

Edited December 28, 2011 by snow drift

[Cecil Hogmanay Melchett]

Another day more of the same.

Perhaps something breif for scottish members into FI on ECM as a piece of vortex energy drops into mainland europe but the immediate chart looks to fatten the pattern out AGAIN.

We are struggling to get decent cells of High pressure to MID latitudes letalone HIGH latitudes where we need them,desperate times.

[IDO]

I thought it would be another day or so before ECM came back on board with GFS but it does now look like both are modelling zonality all the way. Very little snow, some for the heights of Scotland but all transitional. With the SSW a misnomer, stratospheric warming never looking like penetrating down to an influential level, it has always been hope rather than synoptics that have driven the sighting of cold. However this only takes us to mid-January and there are signs (AO, strat. warming again) of a better pattern, and it will not take much to favour us with cold zonality. However getting a prolonged cold spell with that raging Jetstream is not going to be easy; but there are signs we will at least get a shot.

"Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds darkness has always got there first, and is waiting for it."

Edited December 28, 2011 by i'm dreaming of...

[bluearmy]

And there was I, having looked through the models this morning thinking to myself how each day the likelihood of a cold period post mid jan increases. (caveat - not necessarily fo our part of Europe). Then o read this thread and realise it must b all a dream!

I suspect that some of your thoughts are based upon the fact that nothing tangible seems to be getting any closer. Well the models are often a bit progressive when it comes to a pattern change and the pattern we have been in is certainly well set. I really cant see where the despondency is coming from. I even see an island runner next week that could cause a lot of problems for the north of the uk. three gefs members have a cut off greeny block by the end of their runs. The mean trends colder without an obvious flip in the other direction. I keep reading mild but beyond the weekend, not sure why.