Model Output Discussion - Colder but how cold and for how long?

[nick sussex]

Some wild differences over the north east Pacific between the GFS and UKMO at day 7.

Because of this the GFS will shunt the Canadian troughing into the Atlantic.

The UKMO has a similar pattern over the ne Pacific to this mornings ECM op .

A lot of uncertainty in the outlook towards next weekend .

 

 

Edited January 11 by nick sussex

[That ECM]

Why I love this forum.

[Penguin16]

If they ever update the bible with a modern twist that’s more harrowing than the original tale Jesus will have spent 40 days and nights trekking through this forum in search of snow instead of the desert. 

[Methuselah]

Well, I used to think that accurate weather modelling would have to wait for quantum computers. But, now, I'm not so sure: 

 

[Drifter]

9 minutes ago, Tamara said:

Two things:

The energy distribution on UKMO is much more separated upstream than GFS and hence tendency towards a more split flow/ sub tropical jet is emphasised.

Also the -ve inertia (-ve zonal wind pockets) at higher latitudes is modelled much more and the amplification inertia within the extra tropics has less low AAM bias than GFS - which piles all into the polar jet and ends up with the scribble in the extended period that it does. It sees a brick wall but models/simulates attempting to drive straight through it anyway.

‘Scribble’ - great description for what GFS churned out in FI. 

[karlos1983]

Looking through some of the gfs perturbations at +162 is eye opening. A lot of them take the low through France or across the south, many are cold!! 

 

read in to that what you will..
 

if you live in the south, P29 is worth salivating over  Before it disappears forever

Edited January 11 by karlos1983

[NewEra21]

A GFS op run in the middle of the pack would be nice for a change. Always seems to be outlier territory in the mid range!

[nick sussex]

Just now, Drifter said:

‘Scribble’ - great description for what GFS churned out in FI. 

I think I’d call it dog vomit ! 

 

[ICE COLD]

A closer look at the UKMO 12z and as feared it’s an absolute ripper . Come on ECM 12z follow that . I do like the gfs tho regarding the snow lol 17cm IMBY but I’d rather have UKMO verify and sacrifice the gfs

 

[MAF]

31 minutes ago, Penguin16 said:

If they ever update the bible with a modern twist that’s more harrowing than the original tale Jesus will have spent 40 days and nights trekking through this forum in search of snow instead of the desert. 

YES YES YES.

all I want to know is the next 3-5 days, not might be in the next month. When will people acknowledge that past 3-5 days is totally unpredictable regardless of what a computer model is saying? I treat this as a Marmite thread. only because some people wax and wane over every output instead of just looking a few days in advance where the probability chances are massively reduced. Lets face it, the science is probably more than it has ever been, but it will never be as good as what it might be....

Edited January 11 by MAF

[Ali1977]

Any snow charts for the UKMO ? 

[Met4Cast]

The GFS det whilst not technically an outlier is completely out of wack with the vast majority of the GEFS.. as per usual really.

Many of the ensembles opt for a more southerly tracking low next week & keeps the colder air on place across the south.

[ICE COLD]

Just now, Ali1977 said:

Any snow charts for the UKMO ? 

For some reason they don’t load properly on two mate . Sorry 

[nick sussex]

Just now, MAF said:

YES YES YES.

all I want to know is the next 3-5 days, not might be in the next month. When will people acknowledge that past 3-5 days is totally unpredictable regardless of what a computer model is saying? I treat this as a Marmite thread. only because some people wax and wane over every output instead of just looking a few days in advance where the probability chances are massively reduced 

It depends on the pattern . Colder synoptics tend to be more volatile because they’re  not the default winter pattern .

And if we only discussed upto 5 days it would be pretty boring .

[karlos1983]

2 minutes ago, Ali1977 said:

Any snow charts for the UKMO ? 

Trickling out on Meteociel 

WWW.METEOCIEL.FR

---

Meteociel propose de manière régulière le modèle à maille fine UKMO 0.1° du UK MetOffice (météo angaise) sur 5 zones (France, Nord-Ouest, Nord-Est, Sud-Ouest, Sud-Est...

 

[IDO]

Cold would be nice, but this is the main reason I do not want the GFS to verify; D8-16:

[Ice Day]

Pretty much identical GEFS on the 12z vs the 6z, possibly slightly less cold but nothing significant.

 

 

[karlos1983]

Not much green on there for the south coast at +192

 

 

snow piling up in Scotland by Tuesday 

Edited January 11 by karlos1983

[MAF]

10 minutes ago, nick sussex said:

It depends on the pattern . Colder synoptics tend to be more volatile because they’re  not the default winter pattern .

And if we only discussed upto 5 days it would be pretty boring .

yes but more accurate  

[Bricriu]

31 minutes ago, Duane S. said:

Yep, I really think that has played a huge part Mike, just as you’ve put it. The strat vortex hasn’t been able to strengthen unabated through November/ December as it normally would. I think the E-QBO has played (and still is playing) its part as well. 

Just to be clear, are you saying that if QBO was in a westerly phase the Troposphere  impacting  the strat  the way  it is would not be able to happen- that we would not see these splits propagating upwards?

[carinthian]

Evening all. UKMO extended has brutal cold in place over Scandinavia and possible ice day over Northern and Central British Isles. Do you think the Met Office forecasters have faith in its own model to give advance warning of a possible severe cold spell on this showing ? Probably not at the moment. However, it is showing some consistency towards a prolonged cold spell, unlike GFS. Snow forecast charts this far out not to be taken at face value. Their own advanced fine mesh model will pick this up with more certainty with-in a 48 hours of any event for location and depth. Great viewing though.

 C

Edited January 11 by carinthian

[Bricriu]

The UKMO 168 chart could be the gift that keeps on giving. 

[Stuie]

GEFS for South coast of Dorset on this run looks perfect for a battleground.

[FreezingFog]

20 minutes ago, IDO said:

Cold would be nice, but this is the main reason I do not want the GFS to verify; D8-16:

GFS verifying D8-D16 is not something that would keep me awake at night

[Scott Ingham]

52 minutes ago, Mike Poole said:

850s, nice, we can live with that!  Puts us in a great place for the chaos when the block does fail.

I think the models are sneakily extremely slowly coming full circle back to the extended long cold spell we expected in last weeks models. Looking at the ensembles it’s now stretched at a push to the 21st of January for cold