General Model Output Discussion

[KTtom]

Very dissapointing outputs today if you were still hoping for an easterly. GFS shows the Atlantic trying to push through the UK, which, may not be a bad thing in the longer term as it will increase the chances of what has been a very rare northerly.

The GFS also backs the Mets thoughts (BBC monthly) which indicates the high slowly sinking towards southern europe.

[yamkin]

when I look at the models I always try and learn from them especially with regards to how they handle certain patterns. Now I agree todays operationals have backed away from an E,ly but can we honestly believe 100% that what they are showing at +144 is exactly what will happen. The answer is no and many years of following these models have taught me this. This is why im very surprised at some of the comments today. You will find Mr D has posted many example of where the GFS has been wildly inaccurate.

For starters the ECM +240 ensembles do not agree with the GEFS ensembles because i've already looked at the DeBilt GEFS mean. Look at the ECM at +168.

http://www.wetterzentrale.de/pics/Recm1681.gif

Are we seriously suggesting the chance of an E,ly is gone based on the ECM OP/ECM ensembles. Sorry but im afraid we need to keep a more open mind.

TEITS, The following is from the 'TWO' forum courtesy of 'pthomps'. This is very interesting:

But ECM is still going for very cold from the 22nd (see below - the red line). Why is ECM being ignored, when it is generally regarded as being the better model? http://www.meteogroup.co.uk/meteo/eps/ensemble-tt6-london.gif

[igloo]

after looking at last nights euro runs i was not surprised to see the GFS this morning fall in line with them more times than not it takes 1-2 days to do so.the problem now looks as if all the lows will be sucked up the side of the high and will leave us in mild wet and windy conditions the only place i can see escaping from this setup will be the SE with possible frost and fog

[Polar Continental]

Quiet in here for a change this afternoon.

Well will the next big easterly arrive? That is the big question.

The amazing northern blocking felt this year and synoptics still being projected are something that has been so elusive for so long. Could we be entering another cold era, or is this just a cold blip in a warm period? Last January and especially the first half of February seemed to be the start of a possible long-term change in my opinion.

Have been looking at the 06z northern hemisphere charts this morning, what strikes me the most is the massive westwards ridge of the Siberian high at T114 to the eastern edge of the UK. Something else to note is the central pressure of 1070mb.

Obviously this is a very powerful force driving the weather westward, something not seen for many years and certainly not since there has been public access to the models.

The models are going to struggle with this scenario, as we have already seen. We don’t know how modern computer models will handle this, as it is not a regular occurrence with the types of pressure anomalies around this location. A couple of hundred miles ether way is going to make all the difference for us here in the UK.

In my opinion, we haven’t seen the last of this yet.

Expect more model drama.

[TEITS]

TEITS, The following is from the 'TWO' forum courtesy of 'pthomps'. This is very interesting:

But ECM is still going for very cold from the 22nd (see below - the red line). Why is ECM being ignored, when it is generally regarded as being the better model? http://www.meteogroup.co.uk/meteo/eps/ensemble-tt6-london.gif

I agree with the poster and I can't understand why some are ignoring the ECM ensembles. What I find ironic is despite the GFS backtracking the Met O latest forecast is much more wintry than yesterday and even mentions snow showers in the E. The reason for this is simply due to the ECM mean which is what the Met O use for their long range forecasts.

[Thundery wintry showers]

ECM's ensembles show about as much potential for a cold easterly as the last 5-6 runs- quite limited potential with most runs going for a milder solution, but it's still certainly there.

[mushymanrob]

Yes sorry there, I must admit perhaps you didn't also relish wind and rain and preferred some benign conditions instead

well i guess im even more alone with my liking for benign gloom in winter then what i am for prefering mostly mild! but either im happy with. and tws... id LOVE another feb 80!

Mildies on here think their mild pattern is set in stone just as much a coldie when the models show cold.

This is winter. Winter should be cold in my book, thats why I look for cold. I presume the mildies look for hot hot hot in the summer, its just the same. Nothing worse than non-seasonal weather, if you like that move to tenerife.

with respect, thats nonsense. im the 'mildy' on here and im fully aware that theres a return to cold next week ... winter should be mixed, in fact an ideal season should be mixed . yes i look for heat in summer, why not? is it any more unacceptable then looking for excessive cold in winter? isnt excessive cold un-seasonal even in winter? if you want that why not move to siberia?

Tomaz S on the Radio 4 said that a return to colder conditions next week and he sounded pretty resolute in his manner, thats after a very mixed weekend ...Oh well!

i like tomaz, indeed he has said we are returning to cold next week .... but for how long?

the second half of this month looks distinctly 'normal' with a nice variety of weather types ... suits me!

[bluearmy]

TEITS, The following is from the 'TWO' forum courtesy of 'pthomps'. This is very interesting:

But ECM is still going for very cold from the 22nd (see below - the red line). Why is ECM being ignored, when it is generally regarded as being the better model? http://www.meteogroup.co.uk/meteo/eps/ensemble-tt6-london.gif

Yamkin, no one is disputing that the ecm 12z isnt a cold run re surface temps into the se but it doesnt look like it would evolve into a decent easterly. the op run is very much on the cold side of those ens with only a few runs colder. if the ens showed greater support, then i think more would be made of the run. it does indeed look as though we will advect surface continental cold across us next week so the meto call of cold returning is a pretty safe bet. it doesnt mean very low uppers and snow though as we have recently seen. we could end up with messy battleground scenarios as per the 06z GFS op which may well give some snow on its eastern and northern edges as a shallow shortwave cuts through next week. mild it isnt, but a return of the cold in the same way we've just had it - its not that either.

[Thundery wintry showers]

Mildies on here think their mild pattern is set in stone just as much a coldie when the models show cold.

This is winter. Winter should be cold in my book, thats why I look for cold. I presume the mildies look for hot hot hot in the summer, its just the same. Nothing worse than non-seasonal weather, if you like that move to tenerife.

I think in a model output discussion thread it's best to look at the models for what they are showing, be it mild or cold, and regardless of whether one's preference is for mild or cold. I don't think categorisation of "mildies" or "coldies" helps the situation. There are plenty of other threads available in which we can focus on our own preferences. A modest amount of commenting on personal preferences is fine, it just becomes problematic when it starts interfering with people's judgements of what the models are showing, or results in a cascade of one-liners like "ECM is good" and "GFS is dreadful in Formula One FI".

After all, the "newbies" often come into the MOD to help improve their understanding of how the models work, and to get an idea of what the models are showing- they aren't going to get much help if they see a load of posts that are only looking for cold solutions!

[La Bise]

Following the musings of various people, would the following scenario be possible: cold interlude from mid-week followed by a euro high setting stall for a chunk of february?

[Eugene]

GFS and ECM have it drying up after saturday with pressure rising and with temps dropping again, can't see what is bad about that, i suppose the unrealists expect sub zero by day all winter long, zzzzz.

[Bobby]

Following the musings of various people, would the following scenario be possible: cold interlude from mid-week followed by a euro high setting stall for a chunk of february?

I think there's a good chance of that according to the teleconnection forecasts. All too often you see a sustained spell of one kind of weather only to see a complete flip to the opposite kind of weather. Things have a way of balancing out I've found. Just look at this autumn for example with a very dry September/October only to get the wettest November ever recorded.

Edited January 14, 2010 by Barb-

[Thundery wintry showers]

Glacier Point's latest teleconnections update did show a large Euro high dominating proceedings during February. This wouldn't rule out the possibility of further cold incursions from the east (if we got a ridge northwards) but his chart also had a lot in common with February 1998, which as many of us will remember was a very mild month, sunny in the SE, dull in the NW.

However there are some blocking forecasts suggesting a retrogression of the Siberian/Scandinavian High to Greenland over the next fortnight which could give us a wintry end to January.

[sandstorm2]

Have just had a quick look at the models and I am still going to go with cold returning from the East next week. The Siberian HP is very intense again 1070mb which (must be close to the record) cannot be discounted. I don't know much about the physics of the atmosphere, it is just a gut feeling I have that we will be under the influence of continental air next week, I am still thinking of GP's advice that the models would dip in performance. This is what is happening now one day showing cold the next less cold. All of a sudden the severe cold will be on our doorstep at 24hrs notice thats the way of these easterly outbreaks.

SS2

[Sawel]

Except for yesterday, when I suggested odds were 70-30 in favour, I always thought that easterly looked an outside bet, despite frequent support from the ECMWF operational runs. I quoted 30-70 against back then- now maybe it's out to 20-80, as the support for it is quite low. However both GFS (06Z) and ECMWF, while they don't go for a full-on easterly, they go for enough of an input of continental air to give potential for snow events as the Atlantic systems push against the cold air. Bear in mind that in this setup you don't necessarily need a full-on easterly for it to get cold.

I do think that, in countering the "cold ramping" tendency to see only what people want to see, you're sometimes going towards the other extreme in focusing heavily on the mild possibilities. Level-headedness implies staying away from both extremes.

Excellent post.

It is very frustrating reading through this thread sometimes. It would be better if the model discussion thread was an "invite only" thread with yourself and a few other informative posters giving an accurate reflection of what exactly the output is showing.

[Just Below Zero]

Having looked at some archives I have found a similar set of charts to the ones at present.

These are from Jan 1940.

Having had a prevous cold spell with undercutting LPs and SWs the UK is now left in no mans land on the 7th

http://www.wetterzentrale.de/archive/slp/1940/Rslp19400107.gif

Large siberian high is evident.

HP manages to exert an influence by the 9th just as current ECM predicts.

Could go either way...

By the 10th Full Easterly is starting to develop.

http://www.wetterzentrale.de/archive/slp/1940/Rslp19400110.gif

Later the HP slips SE as some say today might happen although in this case heights develop over Greenland to keep the cold weather going.

http://www.wetterzentrale.de/archive/slp/1940/Rslp19400115.gif

[snowlight robbery]

I think in a model output discussion thread it's best to look at the models for what they are showing, be it mild or cold, and regardless of whether one's preference is for mild or cold. I don't think categorisation of "mildies" or "coldies" helps the situation. There are plenty of other threads available in which we can focus on our own preferences. A modest amount of commenting on personal preferences is fine, it just becomes problematic when it starts interfering with people's judgements of what the models are showing, or results in a cascade of one-liners like "ECM is good" and "GFS is dreadful in Formula One FI".

After all, the "newbies" often come into the MOD to help improve their understanding of how the models work, and to get an idea of what the models are showing- they aren't going to get much help if they see a load of posts that are only looking for cold solutions!

Very good point,I am new to all of this and due to the recent snow have become interested in GFS model output etc.Last week whilst trying to understand the GFS model outputs I asked a very sensible question as to reading the GFS on this site and just wanted reassurance that I was on the right lines.Unfortunately didn't get one reply back just countless comments such as "can't see where this next cold spell is coming from" or "possible re-load from 24th Jan" etc.I would imagine in extreme weather condition times as of recent, forums like this pull in huge amounts of people that then like myself become interested in other aspects of the weather so it would just be nice to involve all people,even 'newbies' that need a little help with model readings etc on this forum after all it is titled "General" model output discussion. Otherwise now regularly enjoying this forum and the many excellent posts that have been written.

[Eugene]

Atlantic really struggling on this run in the reliable timframe, looks a pretty chilly start to the week now with a continental influence.

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=144&mode=0

[nick sussex]

Looks like the gfs after being the earlier model which wanted to develop the easterly continues to implode and has gone from one extreme to the other. This is why its not to be trusted with any sort of easterly, as i wasn't convinced by its earlier easterly runs neither am i convinced of its latest 12hrs output.

[Thundery wintry showers]

The Atlantic, to me, looks a little stronger on this run. The continental air holds the Atlantic at bay for a time, possibly resulting in frontal snowfalls around 18/19 January, then the mild south-westerlies slowly push across all parts for the 20th. This is a run that shows the Atlantic ultimately winning the battle, at least for a time.

We will have to see, though, if UKMO and ECM agree. Can't read too much into one run of one model at this stage with all the chopping and changing.

[Sawel]

The Atlantic, to me, looks a little stronger on this run. The continental air holds the Atlantic at bay for a time, possibly resulting in frontal snowfalls around 18/19 January, then the mild south-westerlies slowly push across all parts for the 20th. This is a run that shows the Atlantic ultimately winning the battle, at least for a time.

We will have to see, though, if UKMO and ECM agree. Can't read too much into one run of one model at this stage with all the chopping and changing.

The UKMO 12z has the Atlantic in control.

http://www.meteociel.fr/modeles/ukmo2.php?nh=&ech=120&carte=1021

[igloo]

looking at this run and todays previous runs i think a reset of things is required that block to our east does not look like having any real effect on us bar help the lows slide up the side of us bringing us wet and windy conditions if that block would get blasted away it might help in the longer term

[MR EXTREMES]

The UKMO 12z has the Atlantic in control.

http://www.meteociel...=120&carte=1021

http://www.meteociel...44-21.GIF?14-17

well theres good to come out of the alantic domination and thats arctic north flows although they only last 24 hours but still intresting weather lol.

if teleconnections work out i go end of jan for cold return but i think it be better for us coldies to be realistic there is no sign now of a cold returning for awhile so ive excepted this and its good to see some milder air back to be honest.:unsure:

and i agree igloo this is what i want to happen blast all the rubbish away and start again see what happens,

it is possible feb could be blowtourch oh well not a big deal we done well this winter.

although i do like the cold it also gives the uk the chance to get to grips with another cold attack :unsure:

Edited January 14, 2010 by badboy657

[Optimus Prime]

If you're after cold the last thing you want is for the cold block to be 'blasted away'. That would leave us with the jet across us and a potential SW dominated high as a result.

What we need is for the high to stay where it is and for the atlantic to drive slightly further south, re intensifying the cold westward momentum which should hopefully get the heights to rise over Greenland as the high spreads over the far northern latitude.

Looking at the way past events panned out I think we'll start seeing the models trend towards an easterly scenario for next week.

[snowingtequila]

well theres good to come out of the alantic domination and thats arctic north flows although they only last 24 hours but still intresting weather lol.

if teleconnections work out i go end of jan for cold return but i think it be better for us coldies to be realistic there is no sign now of a cold returning for awhile so ive excepted this and its good to see some milder air back to be honest.:unsure:

and i agree igloo this is what i want to happen blast all the rubbish away and start again see what happens,

it is possible feb could be blowtourch oh well not a big deal we done well this winter.

although i do like the cold it also gives the uk the chance to get to grips with another cold attack :unsure:

the only hope for cold weather is that block, once blasted away that will be it for a long time. I am never convinced when people want to see everything blasted away and a clean sheet to start again, it never happens.

Edited January 14, 2010 by snowingtequila