Model Output Discussion 17th Dec.2013-12z onwards.

[lorenzo]

Still don't get why the ECM weeklies are subject to bad press ? It's just model output and the best we have that science can offer at present?

[IDO]

GFS FI was hinting at something cooler/colder for the UK in its pre-Christmas runs, although apart from one or two runs there was no clear trend. Now the latest GFS are suggesting we lose the Arctic High by D8 (0z and 06z), so we have to rely on other factors getting us amplification of the pattern. Mean at T216 (06z):  

 

The end of FI mean is a Long Wave carbon copy of the 0z mean:

 

There are still about five members showing a UK trough at the end of FI, but we are currently losing support for this after each run, and zonality is now the main cluster: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=384

 

There has been a flip by GFS to downplay any blocking in the last few runs and we can only hope they are picking up the wrong signal and will revert closer back to the ECM mean in future runs. Looking at the latest GFS it is not surprising that the UKMO is downplaying any "cold"; a zonal reset is not what we need as we enter January (usual caveats for the north and higher ground).

 

 

[Newberryone]

I think most would agree when I say how uninspiring these last two frames from the Ecm 00z appear for anything really cold and added to that while the Met Office are calling for a continuation of this turbulent spell up to mid-January, I wouldn't be surprised to see heights building from the south, which is clearly evident here, reverting things back to conditions very similar to that of late Nov and early Dec.

Ever changing I know as models tend to be but ever since the weather broke down we've seen constant ridging from the south between lows only now I get the distinct feeling we could be facing a bartlett type setup again very early January.

I hope I'm totally wrong of course 

[draztik]

Hmm, fear it may be a case of low res gfs leading folk down the garden path.

If we look for balance, and use naefs at t324, we see our problem. Mean trough to our NW, with a poor profile forecast for Greenland. I appreciate these synoptics are slightly better than what we have at present, with the trough showing signs of wanting to sink into Europe somewhat into Jan, but signs of blocking? Not present..

The prospects of a cold start to Jan appear remote this morning. And crewecold's statement of a Dec 10 cold spell taking hold in Jan seems bizarre at this juncture.

[Purga]

Well well. After reading about that update from Susan Powell, it kinda makes me wonder if there is any point viewing the models for a while. We might get a bit of eye candy every so often like yesterday, but it's like watching your team on match of day when they have lost, even if they score first you can't really get excited as you know the final outcome.

But we don't know the final outcome do we, unless Santa gave you a time machine? So the analogy is flawed.

Furthermore the METO will admit that forecasting anything beyond 10 days at best is very tenuous (have a read of some of Ian Fergusons' excellent posts). They will look at possible trends and give some 'probability' forecasts for the longer term but this is far different to them issuing a deterministic long term forecast.

It's wise to listen very carefully to what Susan or any other forecaster actually says rather than what they appear to have said or what they are reported to have said - Chinese whispers and all that!

There does appear to be a trend in the models later stages and anomaly ENS to suggest mean pressure to be lowering over Europe and this is certainly a nudge in the right direction if it's correct. No time to be writing off winter yet.

Edited December 26, 2013 by Purga

[Rollo]

I certainly would not write this winter off yet but let's be realists and admit that certainly the first half of January is not looking good at this stage. Thought I would refer folks to Roger Smiths long range forecast which so far(to my regret) has been very good.

[stratty]

Just to stop the Chinese whispers:

UK Outlook for Friday 10 Jan 2014 to Friday 24 Jan 2014:

Current indications suggest the unsettled start to January is more likely than not to persist through the middle to latter part of the month. Spells of dull, wet and windy weather would then alternate with brighter but colder and showery periods, including some wintry showers. Some signs are also emerging suggesting temperatures being less mild in general terms than the last couple of weeks and perhaps even slightly below average.

Updated: 1142 on Thu 26 Dec 2013

 

.......there is the hope!

Edited December 26, 2013 by stratty

[MR EXTREMES]

Wow hold on but the models are showing signs of change and this change will take time, but after the November near Miss for cold I'd be a little cautious of the ecm and gfs the ukmo is the model to follow but things are set to change but possibly could end up with a near Miss or half way situation.

No offence but the current vortex situation has led me to believe this entire winter will be a right of.

But forecasters at the met are always a little reluctant to use the wintry outlook because of the failures of other winter long range forecast but have become more cautious about there approach and what Susan Powell and others have suggested about the continuation of the resent pattern we have been experiencing is indeed correct but even against my ideas of this winter change can indeed come! And so far I've been right as has the met office and netweather long range.

But it's very likely the change could end up half way house or my idea would be another mlb around or over the UK.

[ukpaul]

Hi All,

 

Hope you all had a good Christmas. The large amounts of wine I drank yesterday is lingering a bit this morning.

 

I'm still trying to learn things here and I don't want to start criticising, but it is actually hard to figure out what you lot been by "mild" or "cold". For example, today in my neck of the woods it will struggle to get above 2 degrees today. However, I get the impression you lot don't think this is cold. The weather forecast tells me it will get a little warmer for the weekend, with temps around 7 degrees. So, when you say no signs of cold, are you basically saying no signs of days where it doesn't get above freezing? No sign of prolonged cold (3-4 days or more)? 

 

It seems a lot of people spend time discussing the model outputs but don't actually translate what it would actually equate to in real terms. Again, I'm not going to tell you what you should and shouldn't discuss, but it would be helpful for a little more detail.

Four main reasons and it would be useful for newbies to keep these in mind as none should have a place here. Firstly IMBYism, looking at charts from Aberdeen will get a different response from someone in Penzance. Secondly, overreaction to a single run. Thirdly, the differing definition of individuals as to what is cold, there are meterological definitions but these are widely ignored. Finally, and most unforgiveably, trolling.

 

To take this morning, I get the impression that most didn't look at yesterday's runs and so couldn't see the context which the ensembles later made clear, i.e. that they were on the milder edge.

[A.J]

Well well. After reading about that update from Susan Powell, it kinda makes me wonder if there is any point viewing the models for a while. We might get a bit of eye candy every so often like yesterday, but it's like watching your team on match of day when they have lost, even if they score first you can't really get excited as you know the final outcome.

Of course, how stupid we've all been, as we've all forgotten that in our fruitless search for cold the the model output dictates the weather!  

[cooling climate]

 

Well well. After reading about that update from Susan Powell, it kinda makes me wonder if there is any point viewing the models for a while. We might get a bit of eye candy every so often like yesterday, but it's like watching your team on match of day when they have lost, even if they score first you can't really get excited as you know the final outcome.

I can remember at least two occasions early December last year and December 2011when the BBC weather had stated that the December weather was likely to becolder than normal with a greater risk of snow and ice. They then went on to showvideo clips of the snow in 2009 and 2010.No sooner had these these forecasts beenaired it was as if someone had flicked a switch and the NWP models etc changed toa much milder pattern which as we know verified.The point of course is that although a colder more wintry pattern during Januaryis certainly not set in stone nor is one of mider regardless of what the BBC orMet office say. Edited December 26, 2013 by cooling climate

[Frosty.]

Just to stop the Chinese whispers:

UK Outlook for Friday 10 Jan 2014 to Friday 24 Jan 2014:

Current indications suggest the unsettled start to January is more likely than not to persist through the middle to latter part of the month. Spells of dull, wet and windy weather would then alternate with brighter but colder and showery periods, including some wintry showers. Some signs are also emerging suggesting temperatures being less mild in general terms than the last couple of weeks and perhaps even slightly below average.

Updated: 1142 on Thu 26 Dec 2013

 

.......there is the hope!

Yes it's the same as yesterday..no downgrade

[Duane S.]

There seems to be a trend to drop heights into Europe around about the 5th, it has been showing for quite a while. Whist in itself it will not be enough to allow decent blocking to develop, it will help stave off any anomalous high pressure building to the south at least.

Edited December 26, 2013 by s4lancia

[Due South]

Fergie has twitted. further ahead growing signs of somewhat colder/less milder conditions into early Jan.

[Catacol]

Morning all

 

Strat forecasts continue to show zonal winds on the slide as we head into Janurary: from this today

 

 

to this on Jan 4

 

 

 

Quite a contrast after a December of constantly high values.

 

The effect is going to be a less compact and powerful vortex. Take your pick of any strat level on this really... but here is the 50hPa for today:

 

 

and then once again for Jan 4

 

 

 

 

The models are now going to start playing around with all kinds of scenarios I suspect.

 

The issue, however, is whether we are really going to see westerlies in this part of the NH lose their grip. Wave 1 warming set to take over from Jan 4 onwards with Siberian warming forcing the vortex over towards our part of the world. I mentioned in my last post that I think this might cause vortex energy to split enough to see atlantic influence wane and the possibility of winds shifting to a more northerly vector. Pattern change.  However... what happens if wave 1 activity is insufficient to force an energy split?

 

The answer would be a continuation of the westerly pattern - a very wet pattern I would think.

 

The 100hPa charts show exactly this for Jan 4 this morning:

 

 

You can clearly see signs of the energy split, with a modest signal for height rises over Greenland as a result, but the troughing heading into Europe is not particularly far south and most of the energy is flowing straight over the UK.

 

Into Mid Jan? Very much up in the air in terms of how great a forcing this warming might have on the trop - but to be optimistic as per my last post week beginning Jan 13 might/ought/could see a pattern change to something with a bit more "east" in it. Still looking for further warming in the back end of January and the chance of proper cold in the final third of winter.

[bluearmy]

i think the issue re ecm/naefs is more to do with the gem ens.  a comparison of ecm 00z ens and gefs 06z  at t288/t360 shows very similar in our vicinity and elsewhere with the caveats already expressed on here earlier.

 

 

 

                           

 

 

 

 

                            

 

 

 

[Cecil Hogmanay Melchett]

Pretty volatile output at the moment.

No clear sign of where we are headed as we move through January yet although the signal for relentless high pressure across Southern Europe has diminished somewhat in recent days that may well spell good news for northern elevated areas as Atlantic systems take a more southerly track.

Still nothing for those down south cool/cold zonal isn't the best of patterns if you live in Kent but it isn;t to be sniffed at manchester northwards and as mentioned elevated.

Edited December 26, 2013 by Cecil Hogmanay Melchett

[Biggin]

Hmm, fear it may be a case of low res gfs leading folk down the garden path.

If we look for balance, and use naefs at t324, we see our problem. Mean trough to our NW, with a poor profile forecast for Greenland. I appreciate these synoptics are slightly better than what we have at present, with the trough showing signs of wanting to sink into Europe somewhat into Jan, but signs of blocking? Not present..

The prospects of a cold start to Jan appear remote this morning. And crewecold's statement of a Dec 10 cold spell taking hold in Jan seems bizarre at this juncture.

As does your reliance on a T324 ??

[John Badrick]

I certainly would not write this winter off yet but let's be realists and admit that certainly the first half of January is not looking good at this stage. Thought I would refer folks to Roger Smiths long range forecast which so far(to my regret) has been very good.

Really? I thought he was forecasting record mild temperatures in December. He said it would be 15 c on Christmas Day. Well it ain't be mild here (Cornwall). It's been cold with wintry showers colder. than the last couple of years. So he was way off the mark

[Cloud 10]

i think the issue re ecm/naefs is more to do with the gem ens.  a comparison of ecm 00z ens and gefs 06z  at t288/t360 shows very similar in our vicinity and elsewhere with the caveats already expressed on here earlier.

 

 

 

eps_z500a_exatl_49.png                            gefs_z500a_exatl_49.png

 

 

 

 

eps_z500a_exatl_61.png                            gefs_z500a_exatl_61.png

 

The GEM ensemble mean at day 10 is certainly the coldies choice,although it

does look a tad suspect. 

 

[bluearmy]

The GEM ensemble mean at day 10 is certainly the coldies choice,although it

does look a tad suspect. 

 

gensnh-21-1-240.png

 

its wrong - i emailed sylvain about it a while ago. only the atlantic view is valid

[UV-RAY]

Fergie has twitted. further ahead growing signs of somewhat colder/less milder conditions into early Jan.

But it's not mild to start with, so any further decrease in temps would make it well below average. Edited December 26, 2013 by Sceptical Inquirer

[bluearmy]

But it's not mild to start with, so any further decrease in temps would make it well below average.

Ian is the forecaster for the sw. I expect his tweets reflect that. At the moment, cool and mild is interspersed. Looks like a few mild days around new year in the south. once the trough drops to our south, i doubt there will be any noticeable mild spells.

[Snowman.]

hehe!
 

 

CFS showing an easterly certainly means its impossible to get one.

[The Northern Ramper]

Just to stop the Chinese whispers:UK Outlook for Friday 10 Jan 2014 to Friday 24 Jan 2014:Current indications suggest the unsettled start to January is more likely than not to persist through the middle to latter part of the month. Spells of dull, wet and windy weather would then alternate with brighter but colder and showery periods, including some wintry showers. Some signs are also emerging suggesting temperatures being less mild in general terms than the last couple of weeks and perhaps even slightly below average.Updated: 1142 on Thu 26 Dec 2013 .......there is the hope!

Yep, anything below the average in January should give us hope.