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

[Mucka]

That's actually a very good question and not one that is easy to answer given that GFS12z eventually goes on to deliver a nice set up while UKMO of course only goes out to 144h. The point being we can only compare like to like and talk in general terms rather than extrapolating what is likely show at day 10+.

So with that in mind I would always prefer the more amplified pattern and slowing down/disrupting the flow from the Atlantic as that offers more opportunity in general terms if we think in terms of buckling and splitting the jet to get low pressure to undercut giving us the prospect of some decent MLB or HLB setting up later.

 

Really, when we are generalising, it is a case of trying to get low pressure to our South and high pressure to our North as you know so we are looking for a pattern that we think will best aid that process. For me that is UKMO over the GFS 12z output to 144h

 

Please excuse the quoting of my own post but the GEM has now updated and is an example of what I was ham-fistedly trying to explain/

 

144h nice Scandi ridge

 

 

Followed by undercut

 

 

and some nice HLB is the end result

 

Edited December 27, 2013 by Mucka

[mountain shadow]

Decent height extension towards Svalbard on the UK Met run, almost within reliable too.

Whenever their are heights in that local, The Murr will be posting soon, I hope.

[tight isobar]

12z ecm from +144/240, will be of major intrest.gfs 12z cold outlier???!! We,ll see....

[nick sussex]

Happy to bow to your far superior knowledge nick, would you just mind explaining why, I actually thought things were an improvement on the 12z and just looking at the 186 chart it looks like there is energy heading south to our west..

 

As you can see from the differences between the GFS and UKMO its hard to have too much faith in the detail past 120hrs, even if you have the same process of the PV pushing east in the UKMO more energy will likely go se because its forced to do so by the ridge over Scandi., add to that  tonights GEM looks very much like last nights ECM run.

 

The GFS 12hrs does eventually get to some interest but again its on a weaker foundation because it makes less of high pressure to the ne, I would be very surprised given tonights UKMO if the ECM backed the GFS.

 

It's for this reason that I mentioned earlier the likely model divergence, high pressure to the ne can be a real curveball for the models to deal with.

[TSNWK]

That's actually a very good question and not one that is easy to answer given that GFS12z eventually goes on to deliver a nice set up while UKMO of course only goes out to 144h. The point being we can only compare like to like and talk in general terms rather than extrapolating what is likely show at day 10+.So with that in mind I would always prefer the more amplified pattern and slowing down/disrupting the flow from the Atlantic as that offers more opportunity in general terms if we think in terms of buckling and splitting the jet to get low pressure to undercut giving us the prospect of some decent MLB or HLB setting up later. Really, when we are generalising, it is a case of trying to get low pressure to our South and high pressure to our North as you know so we are looking for a pattern that we think will best aid that process. For me that is UKMO over the GFS 12z output to 144h

Many thanks for taking the time to explain, learning all the time. This winter is the 1st time I have posted with any confidence that I knew what I was talking about and I have been a lurker since bbc snowwatch hehe... And the reason I can now post is because of the good folk on here. Cheers.

[The Giant Daddy Jackpot]

Just a hint that heights will build towards Scandinavia as we head into the new year. The solutions have been showing some positive signs in the past three to four days and all eyes on the next 72 hours to confirm a real trend towards some real winter. Mid Atlantic blocking ridge and heights over Greenland looking good too. All in all very positive but all to play for.

 

 

 

Edited December 27, 2013 by Sussexwalker

[lassie23]

it'll be spring by the time all those steps fall into place.Typical!

[Cheshire Freeze]

Get ready....it's coming.

[TSNWK]

As you can see from the differences between the GFS and UKMO its hard to have too much faith in the detail past 120hrs, even if you have the same process of the PV pushing east in the UKMO more energy will likely go se because its forced to do so by the ridge over Scandi., add to that  tonights GEM looks very much like last nights ECM run. The GFS 12hrs does eventually get to some interest but again its on a weaker foundation because it makes less of high pressure to the ne, I would be very surprised given tonights UKMO if the ECM backed the GFS. It's for this reason that I mentioned earlier the likely model divergence, high pressure to the ne can be a real curveball for the models to deal with.

See this is why this place is cool, another member taking the time to answer a question for the benefit of all. Many thanks

[Ali1977]

How did all this happen after such a negative meto outlook...defo helped moral on here!!!

[tight isobar]

Get ready....it's coming.

well didn't like to pop up with that quote myself....but I think it may well be.

[IDO]

As you can see from the differences between the GFS and UKMO its hard to have too much faith in the detail past 120hrs, even if you have the same process of the PV pushing east in the UKMO more energy will likely go se because its forced to do so by the ridge over Scandi., add to that  tonights GEM looks very much like last nights ECM run.

 

The GFS 12hrs does eventually get to some interest but again its on a weaker foundation because it makes less of high pressure to the ne, I would be very surprised given tonights UKMO if the ECM backed the GFS.

 

It's for this reason that I mentioned earlier the likely model divergence, high pressure to the ne can be a real curveball for the models to deal with.

 

 

The problem is that we only have the UKMO op run so we do not know where that stands in its ensembles. We know from the GFS ens that there are many members closer to the UKMO op:

 

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=144

 

The mean at T144: 

 

A very similar profile and would not take a lot to equalise, either way. The trend is there, attempted ridging to our NE; and when it failed on the GFS op, it still got us to cold, a good sign I think.

[Polar Maritime]

Get ready....it's coming.

 

GP Once said that...

[Cecil Hogmanay Melchett]

Get ready....it's coming.

LOL Stop it Crewe,

You'll still be saying that in mid March!!

[Tamara]

How did all this happen after such a negative meto outlook...defo helped moral on here!!!

It hasn't happened yet - there are simply members looking at possibilities from latest model output

 

As one of the biggest snow and cold fans there is, and following on from an earlier post, I remain very cautious indeed about the progress of this trough disruption pattern - albeit the UKMO this evening is very interesting at face value.

[Jason M]

The opp isn't without support from GEFS in FI. It's by no means an overwhelming signal but it's there nonetheless.

[Fozfoster]

LOL Stop it Crewe,You'll still be saying that in mid March!!

Now your starting to sound like a Loud-mouthed,childish,unintelligent,incompetent British army General.LOL

[nick sussex]

The problem is that we only have the UKMO op run so we do not know where that stands in its ensembles. We know from the GFS ens that there are many members closer to the UKMO op:

 

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=144

 

The mean at T144: gensnh-21-1-144.png

 

A very similar profile and would not take a lot to equalise, either way. The trend is there, attempted ridging to our NE; and when it failed on the GFS op, it still got us to cold, a good sign I think.

Yes its a positive that the GFS does get there in the end, so perhaps we're not looking at a situation of an initial failure spelling disaster! However its lower resolution relies on a clearance of energy from Greenland and I'd much rather have more forcing on the pattern earlier to get more energy going se into Europe.

 

The problem for the GEFS is that if for arguments sake you used the starting condition of the UKMO at T120hrs then they would look a lot different, if the GEFS are all starting with the normal GFS bias as regards energy heading ne and have the pattern too far east initially then they really won't be giving a true picture of the outlook.

 

The curve back of those positive heights nw towards Svalbard is key and if the GEFS have got that wrong at 120hrs then they'll end up in the cat litter tray because the ships already sailed at that point.

 

The intrigue mounts as to what the ECM will do!

[Mucka]

How did all this happen after such a negative meto outlook...defo helped moral on here!!!

 

Yes it has which is always nice but I think the "discounted" term that Ian quoted was used to describe the possibility of an Easterly within 10 to 15 days which only takes us into the second week of January. The only long range output that was mentioned for January as a whole was EC32 which showed zonal throughout Jan and which I have already "discounted"  

Seriously though the MetO forecast isn't actually out of phase with the output though I have been surprised at some of the terminology they have used and the bullishness that has implied.

 

Anyway their 15 day forecast doesn't look a too much risk at the moment if we believe GFS ensembles - although despite the mean chart posted before very few actually go for the strength of ridging shown on UKMO and GEM at the mid term so probably not the best guide either. 

 

http://www.meteociel.fr/cartes_obs/gens_display.php?x=253&y=78&run=12&runpara=0&type=3&ext=1

Edited December 27, 2013 by Mucka

[Bristawl Si]

Good to see some more interesting charts, if you like it colder and maybe snowier.

They seem to be cropping up more frequently than, say, a few days ago - trend...maybe?

Going past 15 days the Meto outlook can change; each time their longer outlook updates doesnt mean to say it's set in stone for the next few weeks; same goes for the EC32.

Maybe this winter is a 'slowburn', in the UK and across Europe.

[Sky Full]

This chart could make you SCREAM!

[BLAST FROM THE PAST]

How did all this happen after such a negative meto outlook...defo helped moral on here!!!

Some of us 'alternative' method users have touted for a stormy New Year with potential quite wintry weather for the first part and certainly mid Jan.  Been away for Xmas with no internet access but I gather I haven't missed any stella runs.....lets se what models pick up on now we enter a period where a new moon and lively sun may influence the Jetstream.

12z brings me hope and the GEM is defo in my line of thinking

 

 

BFTP

Edited December 27, 2013 by BLAST FROM THE PAST

[That ECM]

http://images.meteociel.fr/im/5660/ECH1-120_jrc4.GIF

Heights ne, low heading se. Interesting.

[shaky]

Very good ecm so far!!maybe even better than the ukmo in regards to the scandi high!!low pressure going south east aswell.

[legritter]

I think there are some good signs in the models and Data in the further outlook today .if not deep cold maybe v cold zonal which we all know can deliver giving good synoptics .im not going to preach on looking too far ahead but we all know the score .the top guns [MET OFFICE ]will only put pen to paper if they see plenty of evidence in their models and Data we dont get to see ,so its a case of reading any updates and picking out certain key quotes etc .the trouble is at the say Ten /Twelve day range they might very well have good signs on a specific pattern but what is around the next corner at the 12/16 day range ,ever changing data in a Science which is not Exact .So certainly with 9 ish weeks of winter left plus March its still  GAME ON Pour yourself a DRINK ,If your weather is severe wind and floods you have Hit the jackpot this coming week or so .cheers gang  ECM on the way .