Model Output Discussion 19th January 2014-18z onwards.

[Captain Shortwave]

I will take the NAVGEM

 

There is your decent energy clearance, low will sink south east and in comes the easterly.

Edited January 21, 2014 by Captain shortwave

[karlos1983]

If only we were seeing the mouth drawling, jaw dropping 10hpa charts that have been consistently chucked out by the GFS, the 18z no exception, back in December.

 

Take a look, its quite a finish

 

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=384&mode=10&carte=1 

[Purga]

These are the sort of daft posts that ruin this thread. 'pity it won't happen' ? Why not then? Perhaps you'd care to explain or are you just trying to dampen the mood because it's a pretty good run and spirits are high. Sorry Purga but you do have form in this respect...

Do you seriously expect a low resolution GFS run to verify exactly as shown at +264h when it's been pointed out by professionals the extreme uncertainty (Shannon Entropy) present even at a relatively short range? It's a fun run to look at as I said but c'mon get real!

[Bobby]

The pub run sure has been on the whisky tonight, I'd be buried under 2 feet of snow if those FI charts came off.

 

 

Shame the odds of that happening like that are a quintillion to one or something, ah well a bit of fun

Edited January 21, 2014 by Bobby

[Duane S.]

BANK!!! GFS 18z is clearly bang on the money and all other models and the metoffice are wrong. Every other model will look like this tommorow and the Meto will be warning of impending blizzards....what could possibly go wrong!?

 

The 18z is stepping up to the plate, seizing its opportunity to shine! Fed up of the continual ridicule and booze related quips, it has sensed that now is the time to step into the limelight and whilst all others around it dither and dally, the 18z has boldly set the trend leaving others to follow, shamefully, in its wake!!

 

Either that or it's just miles off like normal...

[karlos1983]

 

The pub run sure has been on the whisky tonight, I'd be buried under 2 feet of snow if those FI charts came off.

 

 

Shame the odds of that happening like that are like 1 quintillion to one or something, ah well a bit of fun

 

happened last March? I'll have a nugget on that if your offering those odds though

Edited January 21, 2014 by karlos1983

[Blizzardof82]

Does make me laugh on here when snowfests are showing people saying no chance of verifying yet when wind, rain and zonal dross are showing winter is over and its a nailed on pattern for next 6 weeks

[Joe Levy]

The pub run sure has been on the whisky tonight, I'd be buried under 2 feet of snow if those FI charts came off.

 

 

Shame the odds of that happening like that are like 1 quintillion to one or something, ah well a bit of fun

You do know reverse psychology doesn't work with models right? also, no point using probability on something which we don't know the precise chances of happening, even if it is a ridiculous number like quintillion there are so many variables we cannot account for. I reckon that the chances of it happening exactly this way are extremely slim, but then we don't need it to happen precisely like this to get snow! Actually, the chances of colder weather are relatively high, just not the most likely. In any case, dabbling with probability is dangerous as it can lead to false hope and false pessimism! A 90% chance of snow leaves a 10% chance of no snow! The same works in reverse!

[nick sussex]

BANK!!! GFS 18z is clearly bang on the money and all other models and the metoffice are wrong. Every other model will look like this tommorow and the Meto will be warning of impending blizzards....what could possibly go wrong!?

This was in my list of two possible scenarios, not the deep cold but lots of snow if troughing disrupts to the west of the UK, I don't think the deep easterly is on as it looks like troughing will always be very close to the west.

 

It would be nice to be in this model thread discussing which areas are likeliest to see snow rather than theres a chance of snow at T200hrs! I would be very frustrated if this Arctic high can't deliver something to the UK, its the best chance all winter but some luck will be needed with the upstream pattern.

 

At least theres some cold air to tap into over mainland Europe so lets hope that something finally goes right, and lets hope the BBC don't force their forecasters to look miserable if by some chance the snow finally arrives, I want one to pull rank and say great, we've had enough crapola rain and flooding, enjoy the snow folks!

Edited January 21, 2014 by nick sussex

[bluearmy]

Do you seriously expect a low resolution GFS run to verify exactly as shown at +264h when it's been pointed out by professionals the extreme uncertainty (Shannon Entropy) present even at a relatively short range? It's a fun run to look at as I said but c'mon get real!

the thing is, there is nothing wrong with the run.,its broadly in line with the mean anomolys and shows that a fairly small westward correction brings a whole different ball game for our little island, this was my point earlier in response to the mean 11/15 day ECM chart.

That run could easily be chucked out by ECM in a day or so. Tbh, it isn't Shannon entropy, those runs which follow the mean anomolys are the antithesis of that. as Martin posted earlier, the consistency of the ens (thats ecm/gefs/gem) runs around this general solution is noteworthy out to around T300 when the American models go a bit more normal zonal.

[ukpaul]

What is useful, though, is that the change that allows for this run happens very early, a change in the relative positions of the lows allowing heights to build up to Greenland. Of course there could be the usual shortwave drama popping up later but, as we stand now, that first step makes the result a greater possibility.

[Tamara]

Don't post them across to get credits StuieW but just try to offer a balanced perspective from a thread that can become over burdened with posts looking for that elusive snowflake in what has been one of the most fascinating winter seasons that I have followed model wise for years. I know that will go down like a lead balloon for many on here but there really has been some fascinating model output over recent months and there still is plenty on offer on tonight's output.

 

On a separate issue I have noticed that there is a lot of talk about wild swings between models and runs of length which I don't wholeheartedly agree with. Yes there has been the occasional divergence into a more wintry outlook but always in FI and only when viewed from an operational run's viewpoint. The Ensembles which I much prefer to gauge my end summary upon within my reports have maintained a lot of stability in their prediction of a maintained trough near or just to the East of the UK for what seems ages now, particularly ECM. I think people would get a better idea of the most likely outcome in 7-14 days time if they viewed these ensembles rather than get hung up on each individual operational run which shows something mouthwatering and probably off kilter from the rest of the member output..

 

This is not a criticism of anybody and the debate and constructive arguments at times from those more knowledgeable on here make for very interesting reading at the end of a long day and long may it continue. I just sometimes feel that the less knowledgeable can become disorientated by the skewed obsession from a wealth of posters on the one factor of weather which is the most rare in the UK. I agree with Ian Ferguson's earlier post which reflected the more important issues of impending further flooding issues that are likely as long as this current pattern persists rather than searching for snow which is far less likely currently.

 

Finally from me tonight a note of optimism for coldies. Although the evidence for cold is not great at the moment going by tonight's output the building blocks are there to the NE and for those who can think back to my Winter Forecast I suggested then that February offered the best hope for cold and snow this Winter in the UK and that still stands as of now.  

I think your model summaries are always very well presented, balanced, methodical and very impartial and I say that as one who has a very well known personal bias to cold weather but always *tries* to do the same albeit usually on a longer timescale, and this winter I know that I have also played down any fleeting colder weather suggestions up till this time 

 

Its very much harder though to try and take a longer term view than you do and try and read between the lines of the ensembles and other safer perimeter guidance markers that protect a shorter term overview such as a daily summary provides for up to 10 days ahead. It goes without saying that shorter term belt and braces adherence to face value model and ensemble output provides a network where error is more often (but by no means always) reduced

 

I know there is a lot of sense in suggesting that shorter term guidance reduces confusion amongst members, and especially newer members, such as all of us are or have been at some stage or other. Therefore such guidance is to be welcomed wholeheartedly in that respect

 

However, the nature of threads on this forum, very much obviously including the model thread, also provide a more progressive platform for longer term guidance and a huge amount of ground breaking knowledge has been unearthed in this process which has inspired some real expertise on here from such members who I know I have learned a lot from, and I know many others have too

 

Those of us who try to read between the lines, and there are very many, often make large mistakes on the basis that distance in time clearly leads itself prone to error (if taken at simplest logic)

 

I disagree with what you say in that I think there is a very real basis to argue that the recent and upcoming (still ongoing!) pattern has been very hard and uncertain to second guess - there have been enough welcomed updates from a professional capacity to confirm the uncertainties in this respect with a block to the NE, an incalcuably slow degenerating Canadian vortex and much more besides, and hence why there will be posters such as yourself who restrict their guidance to a time period where such divergence is reduced and mitigated as much as possible.

 

The shorter term problems that we face again in terms of flooding from the much advertised next pulse of energy from the Canadian vortex are very real again as you say, and I know that I have referred to the same in my posts through the winter so far, as have many other posters of perhaps a similar colder disposition, shall we say

 

So finally I would say that I think it is both possible to be a 'coldie' but at the same time be objective about the way ahead..always on the basis that plotting a further time ahead is much more fraught with error margins that people infinitely more qualified would also have to think carefully about and be aware of such margins

[J10]

lol, it  looks like the pub run is actually  living up to it's name for once

 

It is so good, this is the brewery run.

 

I am enjoying it for what it is, very unlikely to come off but that's another matter.

[Duane S.]

Do you seriously expect a low resolution GFS run to verify exactly as shown at +264h when it's been pointed out by professionals the extreme uncertainty (Shannon Entropy) present even at a relatively short range? It's a fun run to look at as I said but c'mon get real!

 

 Of course not but would you have posted the same comment had it shown mild? Surely it is as likely as most other GFS 'default progressive' low res output of late?

[Cheshire Freeze]

It's so frustrating watching the PV get distorted and split and all the cold air spilling to low latitudes around the northern hemisphere.....everywhere except the UK! It really is bad luck. Look at the 850 uppers around the northern hemisphere next week! The USA is about to get "polar vortex part 2" as the media are calling it. At least Russia is getting the cold and snow for the winter games. We might all need to tune in and get our snow fix that way!

 

As I've repeatedly said, it was clear days ago that it would be a lottery as to where in the mid latitudes the cold ended up engulfing. There was just too many variables against getting a favourable location for the blocking to take hold- bar one or two suites neither the GEFS or ECM ensembles went for a well positioned block and there was never a point (that I saw) where both ensemble suites brought favourable blocking to our locale at the same time. That PV around Greenland/Canada won't allow blocking to gain a proper foothold in a location that will benefit us as it just acts to keep spitting energy into the Atlantic. Until it's 'warmed out' or pushed from its residence, I can't see a way to get cold into the UK.

[Bobby]

You do know reverse psychology doesn't work with models right? also, no point using probability on something which we don't know the precise chances of happening, even if it is a ridiculous number like quintillion there are so many variables we cannot account for. I reckon that the chances of it happening exactly this way are extremely slim, but then we don't need it to happen precisely like this to get snow! Actually, the chances of colder weather are relatively high, just not the most likely. In any case, dabbling with probability is dangerous as it can lead to false hope and false pessimism! A 90% chance of snow leaves a 10% chance of no snow! The same works in reverse!

 

It's hard to predict that at 24hrs let alone 252. At that range it's looking across the models and the ensembles over a period of time for trends and building blocks. What an individual run shows at that range is virtually meaningless. So it's just a bit of fun, meanwhile keep looking for those building blocks across the ensembles etc.

Edited January 21, 2014 by Bobby

[Cloud 10]

This was in my list of two possible scenarios, not the deep cold but lots of snow if troughing disrupts to the west of the UK, I don't think the deep easterly is on as it looks like troughing will always be very close to the west.

 

It would be nice to be in this model thread discussing which areas are likeliest to see snow rather than theres a chance of snow at T200hrs! I would be very frustrated if this Arctic high can't deliver something to the UK, its the best chance all winter but some luck will be needed with the upstream pattern.

 

At least theres some cold air to tap into over mainland Europe so lets hope that something finally goes right, and lets hope the BBC don't force their forecasters to look miserable if by some chance the snow finally arrives, I want one to pull rank and say great, we've had enough crapola rain and flooding, enjoy the snow folks!

 

There can be only one!

 

https://encrypted-tbn3.gstatic.com/images?q=tbn:ANd9GcQybCL-azym-tVq207Nr_8DaUfsmJxrUPnCym_xxI5p6nVdSw333Q

[The Post-modern Winter]

If you think that way then why do you constantly post GFS FI charts when they are showing mild outcomes? Come on purga, give it a rest now please! Your wind ups are getting very tiresome!

 

This is very true. Whenever zonal outcomes are shown way in to FI Purga posts them and makes a statement about how "the westerly onslaught looks set to continue" or other such nonsense in a definitive manner. Never any statement of "It won't happen" then. 

Edited January 21, 2014 by The Post-modern Winter

[bluearmy]

As I've repeatedly said, it was clear days ago that it would be a lottery as to where in the mid latitudes the cold ended up engulfing. There was just too many variables against getting a favourable location for the blocking to take hold- bar one or two suites neither the GEFS or ECM ensembles went for a well positioned block and there was never a point (that I saw) where both ensemble suites brought favourable blocking to our locale at the same time. That PV around Greenland/Canada won't allow blocking to gain a proper foothold in a location that will benefit us as it just acts to keep spitting energy into the Atlantic. Until it's 'warmed out' or pushed from its residence, I can't see a way to get cold into the UK.

Not quite true Crewe. It's tough but an adjustment sw of about 300/500 miles would do the trick. Is that impossible?

[Jason M]

For the benefit of lurkers on here, don't take the GFS precipitation charts literally after 192 hours. The resolution decreases and therefore the grid sizes also increase which makes it look like there will be far more rain / snow than us actually going to be the case. Obviously even before this they are not useful really at long range anyway. In essence they can be amusing to look at but even if the Synoptics were bang on there would be much less snow than these charts tend to show.

[weather eater]

Does make me laugh on here when snowfests are showing people saying no chance of verifying yet when wind, rain and zonal dross are showing winter is over and its a nailed on pattern for next 6 weeks

Let’s put it this way, over the last 7/8 years I’ve seen the models forecast zonal, wind, rain, dross, hundreds of times and be right, this winter a case in point, I’ve also seen dozens of occasions during that time where the models have forecasted cold and snow, the majority of which have failed to happen. The cold hard fact of living in the UK is that most of our weather comes off the Atlantic, so when the models run with the idea of zonal, wind, rain, dross, it’s perfectly believable, cold and snow projections on the other hand should always be viewed with hope rather than expectation, personally I want to see the whites of the eyes before putting faith in cold synoptics, 96hrs or less.

Edited January 21, 2014 by weather eater

[Purga]

the thing is, there is nothing wrong with the run.,its broadly in line with the mean anomolys and shows that a fairly small westward correction brings a whole different ball game for our little island, this was my point earlier in response to the mean 11/15 day ECM chart.That run could easily be chucked out by ECM in a day or so. Tbh, it isn't Shannon entropy, those runs which follow the mean anomolys are the antithesis of that. as Martin posted earlier, the consistency of the ens (thats ecm/gefs/gem) runs around this general solution is noteworthy out to around T300 when the American models go a bit more normal zonal.

BA if we get some consistency starting to manifest over the coming days and cross model agreement etc then sure I'll start to get interested. In fact I am interested in how things are developing but we should all be aware of how notoriously difficult it is to get cold into these Isles and how the usual 'form horse' is indeed zonal dross which always seems to have much more chance of verifying.

I would dearly love it if the cold charts materialise and yes it's great fun to ramp it all up on a wing and a prayer . Ramp on folks!

[draztik]

Not quite true Crewe. It's tough but an adjustment sw of about 300/500 miles would do the trick. Is that impossible?

given the 'winter' so far, it may be a stretch lolfor what its worth, i do hope the seemingly impossible, works out for us! Even tragic draztik would like some snow. If for the sake and sanity of this forum alone

[Captain Shortwave]

As I've repeatedly said, it was clear days ago that it would be a lottery as to where in the mid latitudes the cold ended up engulfing. There was just too many variables against getting a favourable location for the blocking to take hold- bar one or two suites neither the GEFS or ECM ensembles went for a well positioned block and there was never a point (that I saw) where both ensemble suites brought favourable blocking to our locale at the same time. That PV around Greenland/Canada won't allow blocking to gain a proper foothold in a location that will benefit us as it just acts to keep spitting energy into the Atlantic. Until it's 'warmed out' or pushed from its residence, I can't see a way to get cold into the UK.

Not quite true, even with a raging PV over Canada/Greenland you can still get heights close enough to the UK to bring cold weather. Just in this case we are literally just a couple of hundred miles away from very cold surface conditions and potential battleground events.

Not to say that won't change. The Arctic high looks set to reinforce that high to the north east, could it push west? Could we get a link (even briefly) between the Atlantic and arctic ridges. Both of those could push things in our favour. 

Oh well with the block to the north east continuing to exist, my sanity levels will continue to drop to new depths (currently sub zero by my last check).... standard 

Edited January 21, 2014 by Captain shortwave

[Mucka]

GFS 18z ensembles.

 

Looking through the ensembles out to 120h it seems they have finally caught on to Arctic high and are modelling it more accurately.

The general result of this a Westward correction the pattern. 

They are also showing a little more amplification upstream in the main which is also what we want to see but no way to know if these changes are particular to this set or a trend we can look forward tomorrow.

Either way it will be interesting to see how many manage to develop colder runs.