Model output discussion - 1st December onwards

[Allseasons-Si]

3 minutes ago, Mucka said:

http://www.meteo24.fr/fr/home/meteo-france-et-europe/passion-meteo/ensemble-de-previsions.html?eps=london

 

Or you get it from the Metociel site by clicking on ECM and then London (Londres) link under the pressure charts

Thanks Mucka and saved,look at berlin lol

[Jason M]

By day 10 most GEFS are 'near misses'

Still, if you had offered me the charts as they stand tonight a couple of days okay i'd have banked them every time.

 

[Allseasons-Si]

10 minutes ago, Jason M said:

By day 10 most GEFS are 'near misses'

Still, if you had offered me the charts as they stand tonight a couple of days okay i'd have banked them every time.

 

Yes they are,rubbing large salt into the wound,but in la la salt

just for fun,that trough isn't getting past the BI on the gefs control.

2 wave

Edited December 25, 2015 by Allseasons-si

[nick sussex]

Wow just caught up with the ECM. Must be that weird lack of data over Christmas! lol

Looking at the ensembles its clear that the trough disruption is the key, in Scandi high set ups its often a problem for the ensembles whose lower resolution have an even harder time deciding where the energy goes.

I still find it bizarre how the UKMO have completely ruled out anything colder from the east/ne. It's also strange that one of the strongest MJO's for 6 months isn't even raising eye brows there.

[Jason M]

1 minute ago, nick sussex said:

Wow just caught up with the ECM. Must be that weird lack of data over Christmas! lol

Looking at the ensembles its clear that the trough disruption is the key, in Scandi high set ups its often a problem for the ensembles whose lower resolution have an even harder time deciding where the energy goes.

I still find it bizarre how the UKMO have completely ruled out anything colder from the east/ne. It's also strange that one of the strongest MJO's for 6 months isn't even raising eye brows there.

I think deep down many of us who have been on here for a few years probably suspect they will be right. To me, this has 'close, but no cigar' written all over it. Its great to have some interest at long last though, and maybe we might just get lucky for once. My worry is that we end up with a big block stretching from the Balkans up into Western Russia with the whole of NW Europe sitting in a deep fetch SE flow sourced from the eastern med!

 

 

[swilliam]

15 minutes ago, Jason M said:

By day 10 most GEFS are 'near misses'

Still, if you had offered me the charts as they stand tonight a couple of days okay i'd have banked them every time.

 

 2 and 17 appear to be the best but all are interesting if not delivering cold for us.

 

Edited December 25, 2015 by swilliam

[Aaki Khan]

Wasnt It The GEM Which Picked Out This Trend Few Days Back?

GEM at 192

Edited December 26, 2015 by Aaki Khan

[Allseasons-Si]

7 minutes ago, Jason M said:

I think deep down many of us who have been on here for a few years probably suspect they will be right. To me, this has 'close, but no cigar' written all over it. Its great to have some interest at long last though, and maybe we might just get lucky for once. My worry is that we end up with a big block stretching from the Balkans up into Western Russia with the whole of NW Europe sitting in a deep fetch SE flow sourced from the eastern med!

 

 

Quiet right JM,

how many times have we been here before looking at fi charts and go up to 96 hrs and the pattern shifted west with europe in a deep freeze,so let's get to that timeframe and see were we end up,still fantastic model watching though as will be in the next week.

Edited December 25, 2015 by Allseasons-si

[Eskimo]

I know there a lot of factors to consider before saying, "COLD IS COMING". But agreed, I did also wonder why the MetO haven't sniffed at least something from this. 

[nick sussex]

Just now, Jason M said:

I think deep down many of us who have been on here for a few years probably suspect they will be right. To me, this has 'close, but no cigar' written all over it. Its great to have some interest at long last though, and maybe we might just get lucky for once. My worry is that we end up with a big block stretching from the Balkans up into Western Russia with the whole of NW Europe sitting in a deep fetch SE flow sourced from the eastern med!

 

 

Given that most Scandi highs aren't forecast well into the future and normally pop up within the ten day timeframe then their forecast looks to have ignored not just the Scandi high but the jet being on a more nw/se jet axis with high further  to the ne. Their forecast reads as if theres no MJO signal and that theres no possibility of any cold. I'm not saying that cold is definitely on the way but their own output this morning could go that way and I've never seen a Scandi high have good ensemble support from way out because the ensembles are always slow to come on board compared to say a northerly toppler which is easier for them to handle. I'm keeping an open mind but if theres favourable trough disruption between T144 and T168hrs then the UKMO outlook is going to look a bit silly.

[Allseasons-Si]

Banana (vortex) split

[swilliam]

10 minutes ago, Aaki Khan said:

Wasnt It The GEM Which Picked Out This Trend Few Days Back?

Well it was shown by several GEFS members for several runs before that in F1 (adn derided on here by some). Then the ECM showed it once and then went away from it, then the GEM showed it for a couple of runs (and it was derided for that as being cannon fodder). Now the ECM is showing it but not really in the ensemble and the UKMO is showing the correct set up for it. Meanwhile the GFS is showing the same general pattern but not the cold outcome for us. Currently GEFS are all showing roughly the same pattern but with a wide range of outcomes most of which do not lead to cold here. (some do though).  So no model was right or wrong. This is due to the volatility of the this kind of set up and small changes have large effects. What it shows is that no runs should be ignored or binned as we were told to do so several days ago. Each run should be given the same credibility and assessed in terms of the overall developments. As I said yesterday following means for this kind of development is pretty useless until it is almost certain.

 

Just to add re the post from Jason M the most likely outcome is that we will miss out but what the current outputs show us is that it is possible. Likely we will not know whether we hit the jackpot until about +96 Hrs but even then it can go wrong as we have seen previously. This is because a lot of (small) things have to fall in place. The most likely outcome I would say is that we do not get the trough disruption  and trigger low which would lead to the cold lifting out into Scandinavia (as if they need it). This will not be known until much nearer the time.

Edited December 26, 2015 by swilliam

[Jason M]

1 minute ago, nick sussex said:

Given that most Scandi highs aren't forecast well into the future and normally pop up within the ten day timeframe then their forecast looks to have ignored not just the Scandi high but the jet being on a more nw/se jet axis with high further  to the ne. Their forecast reads as if theres no MJO signal and that theres no possibility of any cold. I'm not saying that cold is definitely on the way but their own output this morning could go that way and I've never seen a Scandi high have good ensemble support from way out because the ensembles are always slow to come on board compared to say a northerly toppler which is easier for them to handle. I'm keeping an open mind but if theres favourable trough disruption between T144 and T168hrs then the UKMO outlook is going to look a bit silly.

Yep, completely get where your coming from. I suspect one way or the other we will have a good idea in the morning. It feels to me like we have reached that point where upgrades will start coming thick and fast, or the trend will go into sharp reverse. If its the former the METO will presumably need to start at least acknowledging this. I guess its not a big issue at the moment in METO HQ as its too far away at present to warrant much comment with Joe Public.

[london and south east kent]

Hi it's nice to see  charts like this with a  sign of rise in  pressure  to the north east gem went for it then gfs  ukmeto model and Ecm it's got to be a trend now so why is the met office not singing from the same sheet I love for a big change in weather  patterns  But not getting my winter coat out just yet.

Edited December 26, 2015 by abbie123456

[nick sussex]

10 minutes ago, Jason M said:

Yep, completely get where your coming from. I suspect one way or the other we will have a good idea in the morning. It feels to me like we have reached that point where upgrades will start coming thick and fast, or the trend will go into sharp reverse. If its the former the METO will presumably need to start at least acknowledging this. I guess its not a big issue at the moment in METO HQ as its too far away at present to warrant much comment with Joe Public.

Yes this type of set up normally either continues to gather pace or implodes quickly. Given the timeframes involved we hopefully shouldn't have to wait long. Even if theres no clean easterly trough disruption near the UK could pull a very cold se in from the Continent. You wouldn't need very cold 850's for that to bring frontal snow and low temps, low dew points would do the trick.

Edited December 26, 2015 by nick sussex

[Allseasons-Si]

Re the ensembles

just like to ask because when viewing them they always seem to scatter after days 5-6(uncertainty) when a cold spell is shown on the models,when i looked at them a week ago they was showing a straight line through them with no cold outliers(consistency)

 

[swilliam]

1 minute ago, Allseasons-si said:

Re the ensembles

just like to ask because when viewing them they always seem to scatter after days 5-6(uncertainty) when a cold spell is shown on the models,when i looked at them a week ago they was showing a straight line through them with no cold outliers(consistency)

 

Mainly because when they are showing mild mush we do not scrutinise them  - we just look and say no cold. When cold is showing they are examined to death and large spread is apparent. When it mild we do not care much if is slightly mild, quite mild or very mild.

[NoTraction]

12 minutes ago, swilliam said:

Mainly because when they are showing mild mush we do not scrutinise them  - we just look and say no cold. When cold is showing they are examined to death and large spread is apparent. When it mild we do not care much if is slightly mild, quite mild or very mild.

Also to add, When High Pressure is at more northern latitudes such as Scandinavia, the volatility of the weather up there with the trop pv and the jet etc, there are bound to be more possible outcomes than if the High Pressure cell was over the Azores!

Or should i say the possible outcomes will have more divergence in temp profile over the uk with a scandi high hence more scatter,

Edited December 26, 2015 by NoTraction

[Rollo]

35 minutes ago, Allseasons-si said:

Quiet right JM,

how many times have we been here before looking at fi charts and go up to 96 hrs and the pattern shifted west with europe in a deep freeze,so let's get to that timeframe and see were we end up,still fantastic model watching though as will be in the next week.

Easterlies have always difficult to predict and this time is no different,I have followed the weather for many years and sometimes it can be 24 hours before the event before one can say it is going to happen. As a number of posters have said it is nice at least to see the eye candy so enjoy watching the developments over the next few days and a merry Christmas to all(belatedly).

[Allseasons-Si]

6 minutes ago, Rollo said:

Easterlies have always difficult to predict and this time is no different,I have followed the weather for many years and sometimes it can be 24 hours before the event before one can say it is going to happen. As a number of posters have said it is nice at least to see the eye candy so enjoy watching the developments over the next few days and a merry Christmas to all(belatedly).

Merry Boxing day

my ass firmly on the fence rollo

[Mucka]

2 hours ago, swilliam said:

Mainly because when they are showing mild mush we do not scrutinise them  - we just look and say no cold. When cold is showing they are examined to death and large spread is apparent. When it mild we do not care much if is slightly mild, quite mild or very mild.

 

The signal for height rises to our East existed way back on the 14th Dec and I posted about it then and again on the 16th.

Some of it just gets lost in the noise and others will only look for cold as you say rather than a route to cold but there will usually be some sign even out to day 15 of a possible significant change in weather patterns for the UK.

I have said and shown often enough that you can pick signals out of FI within GFS ensembles long before they show on any anomaly charts by filtering out what you believe to be noise but it comes with some risk because there is no way to know whether the signal will gain strength or simply disappear again.

For a keen amateur like me posting here it is not really issue, you win some you lose some, but for someone who wants to issue longer range forecasts professionally - well that is where they earn their money.

 

[Mucka]

So now Christmas is behind us (if not the turkey sandwiches) we can look toward the New Year and the potential change of fortunes for cold weather fans.

First order of business is UKMO which you will remember looked good last night.

Another decent run this morning I'm pleased to say with nicely oriented high though it would be better if the pattern were further NW

 

GFS not quite so good for the same period though (144h) with the block further East

 

 

Into FI and we can see GFS is more Russian  high than a Scandi high with the cold air stalled over Central Europe

 

It has a second bite of the cherry with some good trough disruption further on which is encouraging but the Atlantic roars in. At least the vortex looks under duress though.

 

GEM gets the job done again though. (Please let ECM look like this this morning)

Edited December 26, 2015 by Mucka

[Liam J]

6 hours ago, PerfectStorm said:

I know there a lot of factors to consider before saying, "COLD IS COMING". But agreed, I did also wonder why the MetO haven't sniffed at least something from this. 

Sounds like they have 'sniffed' the possibility, Ian F said this yesterday evening. ECM rolling out, what's it's gonna do?!

Quote

But it's clearly plausible, because the potential is so obviously there out east (albeit *right now* it's there as a minority solution...but that doesn't wholly discount it).

 

[January Snowstorm]

You couldn't really say we have moved closer to an easterly this morning. Stuck in a no man's land for a while.

Looking certain now we will need a 2nd bite of the cherry

[Liam J]

ECM T168 not as good this morning with the high quite a bit further SE, cold pool not advancing westwards.