Model Output Discussion - January 11th.

[Frosty.]

The 12z's have seriously reduced the chances of a very cold spell within the next few weeks but that actually means nothing because of how much the models are chopping and changing every run. I don't think the ecm tonight looks as promising in it's evolution towards day 10 and the gfs 12z was a mild rerun of this week, i'm sure most on here are alarmed with how mild this winter is turning out compared to those autumn predictions but at least james madden still believes we will have tons of snow and icy weather soon.

[Isolated Frost]

Very encouraging suite from the ECM 12z at 500mb. Polar vortex firmly over nunavut/nw territories. It would have been nice to see the Aleutian Ridge with more influence.

[phil nw.]

Still we are deleting too many posts that are not directly related to Model discussion.

Please think before posting and make everyones life easier.

The clue is in the thread title.

Thanks again.

Edited January 11, 2012 by phil n.warks.

[Zenarcher]

Review on the weather models this evening,

GFS

Good model agreement up to 96 hours after this it does show high pressure over the UK with a rather weak low in the Atlantic which heads over Northern Scotland on Tuesday bringing a spell of wet and windy weather for the North of the UK. Some uncertainty over its position with no other models agreeing on this. Looking ahead into FI the GFS does still bring a change with mainly high pressure over the UK making it mild but as we go further on it makes things more interesting with colder air coming down from the North and high pressure building to the North as well it could bring some snow. To learners this is deep FI aka long range and will change.

JMA

Good model agreement up to 96 hours and after this for early next week it brings a weak low in the Atlantic just over the far North of Scotland probably bringing some wet and windy conditions with it. Further into the long range it has good model agreement with the ECM at 144 hours with low pressure sitting in the Atlantic and as it makes it way forward it heads North bringing more unsettled wet and windy for the North of the UK. After this it also wants to bring in high pressure from the Atlantic and probably leads to mild weather later.

ECM

This seems to have a bit more support with the other models up to 120 hours and still has some support after this. For early next week it brings the low in the Atlantic a bit more North and would probably only bring the unsettled weather for the far North Scottish Isles. From 144 hours to 168 hours it basically supports the JMA's idea of things with a another Atlantic low moving across but yet again the ECM has things further North. For the fourth run in the row the ECM is showing a change around the 19th to 20th of January in about 8 or 9 days time. It also supports the high pressure building in the Atlantic idea meanwhile the UK would see colder weather set in from the North.

GEM

Agrees with the ECM up to 120 hours bringing that low in the Atlantic further North at the start of next week. Around 144 hours it does want to make some changes and a mild weather fan would like this it has the low in the Atlantic weaker and much more North with high pressure over the UK bringing mild conditions however a bit unsettled in the far North of Scotland.

NOGAPS

It does back up the GFS over the low for the start of next week but more with its position rather than how deep it gets the NOGAPS shows something even weaker and probably just brings a strong breeze and some wet weather. Looking ahead it doesn't support the idea of low pressure at 144 hours and moves over to GEM's idea bringing mild weather to the UK instead.

UKMO

It just really wants to have mild and settled weather for the start of next week and probably a bit wet and windy only for the far Northern Isles of Scotland. However at 144 hours it doesn't support the ECM's idea of the low in the Atlantic and agrees with NOGAPS and the GFS as they show something weaker that leads to mild weather later.

Today to Sunday Summary: Tonight some windy weather for the North of the UK and we have warnings issued for Southern Scotland and Northern England gusts between 60 to 70mph can be expected tonight and on Thursday morning. From Thursday afternoon to Saturday the UK will see settled weather but it will get colder. For Sunday again mostly settled and cold at times but a bit windy over Western parts.

Monday to Wednesday Summary: Mainly settled and cold again on Monday with this continuing into Tuesday and Wednesday however only for Southern parts meanwhile for Northern parts on Tuesday and Wednesday it could get wet and windy.

Ahead of Wednesday: All models do show a change I feel the Atlantic lows will play a big part in our future outlook we need to see them head North I believe to boost our cold weather chances because the models show if they don't appear at all we could be left with mild weather and be left waiting a bit longer for colder weather to come along.

REMINDER: Just a shout out to everyone please keep your feelings to the model mood thread found HERE and only post in here if its actual model output discussion

[Frosty.]

The Ecm 12z op run is still heading in the right direction for a colder spell but not a patch on the 00z equivelant run.

Edited January 11, 2012 by Osbourne One-Nil

[swilliam]

Short ECM ensembles out and op is near the mean.

Interesting change in the ECM mean profiles between 192 and 216 hrs. You can see the PV East of Greenland disappear at 216 and a commensurate several degree drop in the mean 850 temp over the UK. I guess it proves NS is right to keep going on and on and on and on and on and on about this!

[winterof79]

The 12z's have seriously reduced the chances of a very cold spell within the next few weeks but that actually means nothing because of how much the models are chopping and changing every run. I don't think the ecm tonight looks as promising in it's evolution towards day 10 and the gfs 12z was a mild rerun of this week, i'm sure most on here are alarmed with how mild this winter is turning out compared to those autumn predictions but at least james madden still believes we will have tons of snow and icy weather soon.

http://www.wetterzentrale.de/pics/Rtavn3841.png and http://www.wetterzentrale.de/pics/Recm2401.gif although in FI do not seriously reduce any chances of very cold weather hitting these shores.

This chart http://www.wetterzentrale.de/pics/archive/ra/1947/Rrea00119470117.gif ,had we had weather forums,would have brought on the same reaction about there being no cold prospects.

17th through to 20th our high ridged north http://www.wetterzentrale.de/pics/archive/ra/1947/Rrea00119470120.gif and Boom.Never say never i have learned.

[Cloud 10]

Very encouraging suite from the ECM 12z at 500mb. Polar vortex firmly over nunavut/nw territories. It would have been nice to see the Aleutian Ridge with more influence.

The +240hrs ECM 12z ensemble mean chart shows very good support for the op run,looks like some

sort of northerly attack in the 7-10 day timeframe.

Fits in well with the NAEFS at the same timeframe,with high pressure anomalies

over the arctic and north atlantic with the jet running NW to SE between them.

[nick sussex]

Again NOAA move the PV away from the heart of Greenland, someone tell the operationals especially the GFS to stop this PV love in!

http://www.cpc.ncep....y/610day.03.gif

http://www.cpc.ncep....y/814day.03.gif

And this is all you need to read from their discussions:

WHILE A POLAR VORTEX IS PREDICTED

NORTH OF HUDSON BAY.

We wait to see if this will indeed be the case, believe it when its within 144hrs!

If you look at those maps the PV is edged even further west in the second one, the further it goes the better if you're looking for cold, I'd actually be happy to see it blasted into orbit!

Edited January 11, 2012 by nick sussex

[BLAST FROM THE PAST]

Again NOAA move the PV away from the heart of Greenland, someone tell the operationals especially the GFS to stop this PV love in!

http://www.cpc.ncep....y/610day.03.gif

http://www.cpc.ncep....y/814day.03.gif

And this is all you need to read from their discussions:

WHILE A POLAR VORTEX IS PREDICTED

NORTH OF HUDSON BAY.

We wait to see if this will indeed be the case, believe it when its within 144hrs!

Nick

Will be nice to see the UKMO T144 show this, then we'll be really onto something methinks. Big positive for me is the ECM today, mind you the chopping and changing of models in a backhanded way is a positive as this IMO suggests that a big pattern change is on the cusp.

BFTP

[Paul]

Just trying a new thread this evening - the models: summed up.

It's a bit different and could be quite fun/interesting so it would be great to have as many of you taking part as possible:

http://forum.netweat...dels-summed-up/

[nick sussex]

Nick

Will be nice to see the UKMO T144 show this, then we'll be really onto something methinks. Big positive for me is the ECM today, mind you the chopping and changing of models in a backhanded way is a positive as this IMO suggests that a big pattern change is on the cusp.

BFTP

Good advice given that the PV seems to want to cling on for dear life!

Show me that PV away from Greenland within 144hrs and I might actually believe it's really going to happen, until then we can just sit and enjoy/suffer! the constant model changes!

[phil nw.]

For what it`s worth both mean hts. for days 8-10 and CPC days 6-10 outlook mean anomols.at 500hPa look in broad agreement.

They both Indicate a Scandi trough with Atlantic and Siberian Heights either side.

Interestingly the core of the vortex is modelled towards Canada by then but the GFS keeps some lower hts.towards Greenland.

This seems to be the area of greatest model uncertainty and the main reason we get switching run to run of where the energy goes-- north or south.In simple terms north =cold,south=milder.

Good cross polar heights endorsing a negative AO.

You would think all that cold air leaking south has to affect us eventually.

[sebastiaan1973]

Long ECM ensemble out. Op and control look good - mean is the same as this morning.

That's the old one. Here you can find the fresh one. http://www.weerplaza.nl/15daagseverwachting/default.asp?r=midden&type=eps_pluim

[bluearmy]

I'm sure Stewart is interested to see ECM retrogressing the trough. The spreads may well show that it might come even further west. What is clear is that the ECM ens are trending with the op in dropping the trough just to our east.

The cpc mean heights are better than yesterday in that the upper trough associated with the vortex no longer cuts energy across the pole. If you can bring yourself to ignore the gfs ops then it's a pretty good day.

[Frosty.]

Big positive for me is the ECM today, mind you the chopping and changing of models in a backhanded way is a positive as this IMO suggests that a big pattern change is on the cusp. BFTP

I really hope so fred, it's been another strange day but I can't help but think we are going to see something special beyond T+240 hours, we were all just talking about it in chat and beyond 10 days suggests a major pattern change won't be far away by then.

[Glacier Point]

I'm sure Stewart is interested to see ECM retrogressing the trough. The spreads may well show that it might come even further west. What is clear is that the ECM ens are trending with the op in dropping the trough just to our east.

The cpc mean heights are better than yesterday in that the upper trough associated with the vortex no longer cuts energy across the pole. If you can bring yourself to ignore the gfs ops then it's a pretty good day.

Indeed, this teleconnects extremely well with falling angular momentum. Finally we get an operational run bang down the middle of its synoptic ensemble mean. I note that the ECM mean takes -4C through -8C values across the country at day 10.

No big tropical fireworks expected in the next 2-3 weeks, so more falling angular momentum across the globe and scrubbing of westerlies. A steady retrogression of mean ridges likely which brings our ridge extending out of Russia into Svalbard nicely into play between day 10 and day 20, shifting it towards Iceland and Scandinavia. Brrrrrr.

[mountain shadow]

This the ECM 240 chart from two days ago...

http://nwstatic.co.uk/ecmimages/20120109/12/npsh500.240.png

and this is tonights ECM 192 chart.....

http://cdn.nwstatic.co.uk/ecmimages/20120111/12/npsh500.192.png

I think that's pretty good consistency towards moving the PV north west from Greenland with a possible shot at a northerly. Hopefully tomorrow we get it into the semi-reliable timeframe.

[BLAST FROM THE PAST]

I really hope so fred, it's been another strange day but I can't help but think we are going to see something special beyond T+240 hours, we were all just talking about it in chat and beyond 10 days suggests a major pattern change won't be far away by then.

It has been said in past many times and the fact the models are yo yo ing is a good sign. HOWEVER, we need to see some consistency build now especially consolidating a positve t120 mark and I would like to see some more support tomorrow, not total support but say half of the runs maintain momentum...and bring the set ups 24 hrs closer too. A stuck record at 192 to 240 isn't of use and I must admit we are seeing signs of this.

You see when/if it flips to cold ISN'T the pattern change, the pattern change IMO is the developments leading to the cold flooding in as change is over 7 + days NOT overnight.. So maybe real cold hitting shores probably looking at it is say 20th onwards with some colder influence felt before then......but it seems its a work in progress.

Mountain Shadow posts a good idea of seeing developments brought forward as we seek more consistency.

I'm thinking back to a time when I was 19......good winter that

BFTP

Edited January 11, 2012 by BLAST FROM THE PAST

[Geordiesnow]

For the timebean it looks like we will have a battle between the Atlantic and the PV over Greenland and general height rises over the Arctic and more especially Russia/Scandi and at this stage the model output and has in general suggested the PV might override any blocking so I'm struggling too see much to get excited about on a snow enthusiast POV but it will be interesting how things develop in the next few days, will the models finally hint the PV weakening or backing westwards as per that NOAA report or not.

In the shortterm it looks like we may get high pressure dominating for a little which will lead to sunny days and frosty nights although there might be more cloud over in the West. The Atlantic weather the GFS in particular has predicted has been pushed back somewhat so still quite a bit of uncertainty regarding the future outlook.

[Matty M]

18z looks more positive than the 12z suite

Angles better. and things more pronounced to the NE

Much better run to run consistency between the 12z and 18z GFS to 132hrs than in previous days, although conditions around the Arctic still subject to large changes.

[ITSY]

yeah, more energy headed south and a more distinct split in the Jet Stream IMO

http://www.wetterzen.../Rtavn10815.png

EDIT: perhaps not http://www.wetterzentrale.de/pics/Rtavn13815.png

Edited January 11, 2012 by ITSY

[bluearmy]

comparing the parallel gefs and ecm means at T240, there really isnt that much difference

where is the model disagreement ? just to our east actually. however, the parallel then goes on to drop the trough in even closer to the uk though not as deep as ecm at T240. given that its a later timescale, not a surprise. as it stands, looks like xmas is going to be approx a month late this winter !!

[Grimsby Snow Lover]

One positive so far is the PV looks to be further West by the middle of next week. Surely a good thing for those of us wanting cold weather here in the UK further down the line.

http://cdn.nwstatic.co.uk/gfsimages/gfs.20120111/12/141/h500slp.png

[swilliam]

The PV is not so far East on this run

12z

18Z

Edited January 11, 2012 by swilliam