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

[Joe Levy]

As I say I’ve seen the BBC forecast which is in effect the METO and they don’t seem to be going for snow at lower levels, that will be a human call I suspect. I think the point stands, a few days ago we were being predicted cold uppers for several hours Sunday into Monday and now it’s over very quickly. Obviously in a winter like this has been, any kind of white stuff will be welcome by some, personally unless it’s going to snow and stay I can’t see the point.

The BBC forecast is not the METO, it is the public representation of the METO, a very different thing altogether. IF quite clearly said yesterday that the Met is holding fire on being too specific to the public about these matters as there is still too much uncertainty and snow showers are hardly the priority given the current flooding situation. In particular, the region most affected by the flooding is also the region most likely to see wintry showers from the wraparound effect, so you can imagine which issue they are going to focus on! With regards to the 'snow and stay' comment, well in the South West that is rare in itself, so seeing any snow is going to be pleasing for many. The short range models (EURO4) still indicate the possibility of wintry precipitation over the region and into Central Southern England, and that is good enough for me!

Edited January 25, 2014 by Joe Levy

[J10]

Suit yourself, but coming from a long term snow starved region, I call that a success in computer modelling! The signal for unusually cold uppers from a westerly was shown some days ago now, and has been maintained to a degree ever since. You will generally only be disappointed by model output more than a couple of days away if you focus on specifics. Trends are more important and the trend is still being fulfilled.

 

This is what was forecast a few days ago [Wednesday]

 

 

The pattern for cold uppers form the east, has been maintained, one change though is that they are now arriving earlier, Sunday evening and leaving earlier on Monday morning.

 

This is what is being forecast now.

 

 

The trend is pretty much the same, not quite as enticing as a few days ago, but not a bad theme IMO.

Edited January 25, 2014 by J10

[weather eater]

 Trends are more important and the trend is still being fulfilled.

We do hope so, but this thread is mainly about conjecture a lot of the time and on that basis, if the UKMO projection fails and we get something more akin to the GFS, then I suspect that the cold uppers projected for next Saturday into Sunday will get mixed out, it seems to be something the models do in NW projections, big them up and then knock them down as we approach zero hour, so let’s hope the UKMO is on the boil this time. Meanwhile we now have a storm overhead, rain, hail, the wind has got up and we have thunder and lightning like a couple of giants are having a barny up in the hills, its gone a bit mental here.

Edited January 25, 2014 by weather eater

[Ali1977]

Those maps Karlos put on look like Wiltshire could be in the firing line for some snow tomorrow evening night, due points and moisture look good for it.

[The Eagle]

I have a feeling given the key time frame is around 96 hrs for this evolution we might start seeing more agreement cross model this evening. What's frustrating to most of us IMO is not what the models show but differences between them at a short time frame even more so because those differences make a very big difference come 120 or 144 hrs.

 

UKMO 96 

 

 

ECM 96 

 

 

GFS 96 

 

 

The orientation, placement and center of the LP here is make or break (as is the strength of the jet out of Newfoundland - GFS progressive). ECM is that bit closer to the GFS than UKMO but not so much so that the game is up. Proper chance of surprises later on and if nothing else plenty of interest. There is no "bad" outcome this morning for coldies just different expectations from each model.

 

Roll on the 12z's.

Edited January 25, 2014 by The Eagle

[Tim Bland]

Meto long range forecast reads like a half way house between UKMO and ECM

[weather eater]

The BBC forecast is not the METO, it is the public representation of the METO, a very different thing altogether. IF quite clearly said yesterday that the Met is holding fire on being too specific to the public about these matters as there is still too much uncertainty and snow showers are hardly the priority given the current flooding situation. In particular, the region most affected by the flooding is also the region most likely to see wintry showers from the wraparound effect, so you can imagine which issue they are going to focus on! With regards to the 'snow and stay' comment, well in the South West that is rare in itself, so seeing any snow is going to be pleasing for many. The short range models (EURO4) still indicate the possibility of wintry precipitation over the region and into Central Southern England, and that is good enough for me!

I think you are splitting hairs I did not say the BBC is the METO, the BBC present a forecast created by the METO it’s a simple as that. As I say I've seen today’s forecast and it features no snow over anything but northern hills, even here looks very marginal and I'm only a few miles from kinder scout, yes it could be wrong but I doubt its far off the mark. I guess we will have to agree to disagree and see what happens.

 

It’s a shame for the SW, historically it has a reputation for some of the heaviest falls but it doesn’t seem to get so much these days.

Edited January 25, 2014 by weather eater

[J10]

Meto long range forecast reads like a half way house between UKMO and ECM

 

Which to be honest isn't that bad.

 

Given we are in a bit of a lull between model runs, if a new model came out that was 100% accurate out to T+168, (never will happen just saying this for discussion), it would make all model discussion irrelevant, but at least we would know exactly what would happen, would this be welcome.

[winterof79]

So a brief colder phase looks on the cards with perhaps some snow for parts of the uK mainly north & north east. Perhaps some sleet or wet snow for a while in other parts but lying snow pretty unlikely IMO.

ENS show colder then rising to average

Fairly unsettled but nothing spectaular. At least a change of sorts from the deluges of the last 8 weeks but no 'real' cold spell to inspire much enthusiasm.

Do we take it from your post that you are ruling out the UKMO output from 12z and 00z as you only quote GFS stats.Up North the story is different to your broad sweeping statement. Edited January 25, 2014 by winterof79

[cooling climate]

Just got in from work and the looked at the 06run which was very uninspiring

but then I looked at the 10hpa strat charts and WOW just WOW. If they were to

verify then I would say December 2010,February 91,Jan 87 etc synoptics would be

possible.

We have been here before though when a similar strength warming appeared in the

charts on new years day dated for the 17.01.14 only for it to reduce in strengh considerably.What it is showing now though is somewhat different in that this

warming starts at a much closer time frame although the warming it is showing at

10mb is at an altogether different level to what it has been showing the last few days.

If this were to verify though we could have all that we coldies have been craving for the last 2months roled into one from the middle of February to middle of March.

Edited January 25, 2014 by cooling climate

[A.J]

So a brief colder phase looks on the cards with perhaps some snow for parts of the uK mainly north & north east. Perhaps some sleet or wet snow for a while in other parts but lying snow pretty unlikely IMO.

ENS show colder then rising to average

 

Fairly unsettled but nothing spectaular. At least a change of sorts from the deluges of the last 8 weeks but no 'real' cold spell to inspire much enthusiasm.

Hi Purga, I must admit that I find your post slightly odd in certain aspects, first of all as already reported, your post is quoting the London ensembles which given it's geographical location is hardly indicative of your rather sweeping initial sentence, secondly the ensembles show a broad scatter early on in the piste with a large disparity at T120 (A 14 degree scatter in T850's illustrate this IMHO) and thirdly, this scatter sums up the model outputs quite well to date in as much as nothing is nailed down with a huge amount of 'model speculation' for want of a better phrase. In summary, whilst everyone is entitled to air their views on the model output, your sweeping statements based on one location ensemble does rather leave you rather wide open to be shot down....

[sparky1972]

before the afternoon and evening fun and games begin, i have just seen the headline on my aol homepage and it say temps of minus 5 to hit uk and snow, guess its bbq time then as they always jinx any potential cold and snow, lol.  i look forward to reading everyones views on todays model output and fingers crossed its good news for us cold lovers.

[Paul White.]

Do we take it from your post that you are ruling out the UKMO output from 12z and 00z as you only quote GFS stats.Up North the story is different to your broad sweeping statement.

Of course he is putting up an assemble from the urban heat island of London helps his windup/trolling cause no end for balance Shetland looks differentAnd West Yorkshire Also it's great that I now know how to post charts with my iphone #happydays Edited January 25, 2014 by Paul White.

[Gaz1985]

A high chance of snow for this area later tomorrow, 80% chance if it manages to stick but it will have to be heavy on wet surfaces, and then an increasing chance again as we get to the new month.

 

 

Wet tomorrow lunchtime, some snow for Scottish mountains

 

 

As mentioned rain turns to snow here, but it will have to be heavy to stick to soaking wet surfaces.

 

By Monday morning it's back to heavy rain here, still some snow elsewhere. Overall very mixed with the chance of everything thrown in!

 

Edited January 25, 2014 by Gaz1985

[IDO]

Of course he is putting up an assemble from the urban heat island of London helps his windup/trolling cause no end for balance Shetland looks differentimage.jpg

And West Yorkshire image.jpg

Also it's great that I now know how to post charts with my iphone #happydays

 

 

I think those graphs you have just posted confirm what Purga said. I will post Aberdeenshire (possibly one of the further north locations):

 

 

It highlights the 30 year mean (red) and comparing to the GFS mean (white) there is a degree or two below average 850 temps before the mean goes above the long term average. I also see no long term cold on that graph. To be honest, location makes little difference if you compare with the long term mean. its just average UK weather for the end of January for any area. Of course other models are different and with strat events looming this will probably all change. However Purga was referring to current charts from the GFS.

[SW Saltire]

I think those graphs you have just posted confirm what Purga said. I will post Aberdeenshire (possibly one of the further north locations):

MT8_Aberdeen_ens.png

It highlights the 30 year mean (red) and comparing to the GFS mean (white) there is a degree or two below average 850 temps before the mean goes above the long term average. I also see no long term cold on that graph. To be honest, location makes little difference if you compare with the long term mean. its just average UK weather for the end of January for any area. Of course other models are different and with strat events looming this will probably all change.However Purga was referring to current charts from the GFS

The next ice age has not been predicted though really. A snowfest is more likely. The charts Purga has posted are marginal for lowland snow but it wouldn't need much to change this. If we can get lower dew points ahead of a system moving in then we would see a better result than the upper temperatures suggest.

I'd also like to highlight these are ensembles from the GFS 06z. The UKMO this morning showed a much more potent easterly. Even if that does not appear on the 12z, the ECM was better than the GFS for snowfall.

The placement of this block is of paramount importance with regard to the depth of cold air we can get into the UK and hopefully the Azores high can back off to allow the lows to be forced further south. These two factors are both up in the air at the moment, although we should have a better idea after the 12z but it may still not be anywhere near decided.

Edited January 25, 2014 by SW Saltire

[Ali1977]

if the UKMO is correct then that is several models wrong at day 5/6. Be very interesting to see these 12z's.ajor back track on one or two of theodels surely , surely at this range 1 is going to be very nearly correct.

[shaky]

Well if ukmo is showing the same thing tonight then I personally feel the others will follow suit if not tonight then tomorrow!!on the other hand if it backs down then things are looking quite bleak especially if the ecm comes out in a grumpy mood this evening!anyway 12zs on on their way out!!!!!!!

Edited January 25, 2014 by shaky

[Purga]

Do we take it from your post that you are ruling out the UKMO output from 12z and 00z as you only quote GFS stats.Up North the story is different to your broad sweeping statement.

Not ruliing out anything and if you read my post I did say up north there is a chance of snow, also ENS for the north follow pretty much a similar pattern

[fergieweather]

if the UKMO is correct then that is several models wrong at day 5/6. Be very interesting to see these 12z's.ajor back track on one or two of theodels surely , surely at this range 1 is going to be very nearly correct.

If only Ops Centre was so convinced...! We shall see. Need better inter-model consensus before worth getting too excited.

[Bobby]

I feel that situations like this will show why the ECM is King, expecting the UKMO to back off on the 12z, although prepared to be wrong... it could hang on for a little longer before backing down or end up being right which will be a real trophy in the cabinet for the model. But I don't think so, anyway here we go.

Edited January 25, 2014 by Bobby

[beatpete]

A high chance of snow for this area later tomorrow, 80% chance if it manages to stick but it will have to be heavy on wet surfaces, and then an increasing chance again as we get to the new month.

 

 

Wet tomorrow lunchtime, some snow for Scottish mountains

 

 

As mentioned rain turns to snow here, but it will have to be heavy to stick to soaking wet surfaces.

 

By Monday morning it's back to heavy rain here, still some snow elsewhere. Overall very mixed with the chance of everything thrown in!

 

hello, first post in here, sorry if wrong thread.....but while its quite, can someone explain what the triangles mean...thanks

[Ali1977]

Has this any potential to become a more prolonged cold spell Ian? I know that no model is particularly saying it is, however latest SSW or at least SW looks quite strong . Not sure if that has potential to change medium FI quite quickly!!!

[stratty]

hello, first post in here, sorry if wrong thread.....but while its quite, can someone explain what the triangles mean...thanks

SHOWERS

[The Northern Ramper]

Sadly you would have to make a UKMO backtrack favourite, you never know though.