The hunt for cold - Model discussion (late November)

[Methuselah]

2 minutes ago, Mike Poole said:

The trend continues it seems! Block stronger on the ICON 18z, only goes out to T120, but here it's further west than on the 12z, here 18z first then 12z at same time

Let's hope so, Mike...In the mean time, my cat is impatiently telling me it's bed time.

Full-blown blizzards, on tonight's GFS 00Z?

[SMU]

In terms of those 'stragglers' we can see why-

Theres enough energy sliding SE to scoop up the continental air & forcing it west..

[Mike Poole]

10 minutes ago, Ed Stone said:

Let's hope so, Mike...In the mean time, my cat is impatiently telling me it's bed time.

Full-blown blizzards, on tonight's GFS 00Z?

Ha, I don't do the 0z's, they are usually a downgrade and I'm asleep, yes I know, lightweight , maybe on the 12s, probably only for the north, I would suggest with the current available info.  We'll see, fascinating setup, even if it goes the way of the , that's still the form horse but by less than yesterday by some margin.  Onwards pub run 

Edited December 7, 2018 by Mike Poole

[Methuselah]

2 minutes ago, Steve Murr said:

In terms of those 'stragglers' we can see why-

Theres enough energy sliding SE to scoop up the continental air & forcing it west..

We'll see, Steve. Or should I say Mahatma?

[Nick F]

The change back towards the block over Scandi extending further west and Atlantic trough disrupting due to the jet stream positioning further south highlights how despite some success  in predicting broadscale patterns in the longer range based on MJO phases in combination with other drivers, models can often struggle with the finer mesoscale detail of the positions of low and highs beyond day 5, which is important for our small chunk of NW Europe.

12z EC indicating snow event this time next week across the north and east, as the Atlantic frontal system bumps into colder air moving over the North Sea from the southeast. However, 7 days is a long way off to forecast such detail, so subject to change and often we won't know until 36, sometimes 24 hours out where it may snow in such knife-edge marginal situations.

Given the Met Office in the their 6 days+ forecast mentioned "Through the remainder of this period there is a fine balance between colder air to the east and milder air in the west" - highlights that the battleground between milder Atlantic air and cold continental may end up closer than we previously thought. The Atlantic may eventually break through and increase mobility, but next week increasingly likely to feature slowing / stalling fronts as they head east, bringing a threat of snow in places as the rain bumps into cold air from the east.

Edited December 7, 2018 by Nick F

[Stuie]

4 minutes ago, Nick F said:

The change back towards the block over Scandi extending further west and Atlantic trough disrupting due to the jet stream positioning further south highlights how despite some success  in predicting broadscale patterns in the longer range based on MJO phases in combination with other drivers, models can often struggle with the finer mesoscale detail of the positions of low and highs beyond day 5, which is important for our small chunk of NW Europe.

12z EC indicating snow event this time next week across the north and east, as the Atlantic frontal system bumps into colder air moving over the North Sea from the southeast. However, 7 days is a long way off to forecast such detail, so subject to change and often we won't know until 36, sometimes 24 hours out where it may snow in such knife-edge marginal situations.

Given the met Office in the their 6 days+ forecast mentioned "Through the remainder of this period there is a fine balance between colder air to the east and milder air in the west" - highlights that the battleground between milder Atlantic air and cold continental may end up closer than we previously thought. The Atlantic may eventually break through and increase mobility, but next week increasingly likely to slowing / stalling fronts as they head east, bringing a threat of snow in places as the rain bumps into cold air from the east.

Quite chuffed about your post, makes my battleground posts in the last few days seem plausible.

[CanadaAl]

2 minutes ago, Stuie W said:

Quite chuffed about your post, makes my battleground posts in the last few days seem plausible.

I'm glad Walden could be in for some of the action if that chart comes off. 

[Methuselah]

Night all...May Skaði be with you!

[Ice Day]

This place has been priceless this week.  Overly dramatic posts, ups, downs and the inevitable appearance of a bit of trolling at the first sign of 'zonal'.  Pretty much standard fare for the many years I've been on here.  And long may it continue!!  

Anyway, the 18z is running and a Friday night special would be much appreciated.  

My opinion, for what it's worth, is that we'll not see too much interest this side of Christmas, but early 2019 is going to be a time of great excitement, the much vaunted SSW will see to that.  TIme as always will tell!

 

[Catacol]

1 hour ago, Ed Stone said:

A fascinating read, as always, S...But I feel I must ask a simple question: how can the models 'know' when to produce a Nino-like atmospheric pattern? Or is this a simple coincidence?

Or ought I just keep taking the s!

Personal view - NWP take snapshots of readings and then applies algorithms based climatological norms to interpret the way ahead. I would imagine by now that the best computer minds have applied machine learning to the process - so as we move forward NWP will learn.

But currently I suspect there is a reliance on normalised processes. And this is where the human ability to interpret can have an edge.

And the mountain torque charts have updated. As expected a steep climb has begun

Cue - move away from the apparent passage towards a Nina-like state in the atlantic and a return to a more Nino meridional outlook. Humans 1, NWP 0.

= Scandy fights back. (At least a bit....because expected processes would still say this phase next week is not going to produce full on goods. Need a bit more time for developments to work their way through for that....)

Edited December 7, 2018 by Catacol

[CanadaAl]

Slight west correction at T102. Fingers crossed the GFS is on a bender to remember at the pub tonight!

[shaky]

1 minute ago, CanadaAl said:

Slight west correction at T102. Fingers crossed the GFS is on a bender to remember at the pub tonight!

Brilliant am.just waiting for that first boom post of the evening from the 18z gfs!!!or am i being too positive lol!

[bluearmy]

3 minutes ago, CanadaAl said:

Slight west correction at T102. Fingers crossed the GFS is on a bender to remember at the pub tonight!

I see the opposite!

actually, I see where you’re coming from but that will make the disruption occur too far north - we want the low furthe south when it hits the blocking 

Edited December 7, 2018 by bluearmy

[Ice Day]

Just now, bluearmy said:

I see the opposite!

I'm on the fence!

[CanadaAl]

Just now, bluearmy said:

I see the opposite!

You're right, I was looking at the Atlantic low but yes there's an eastern correction on the Scandi High. Not great. 

[feb1991blizzard]

4 minutes ago, Catacol said:

 

And the mountain torque charts have updated. As expected a steep climb has begun.

Yes, we need that @DiagonalRedLine to continue into positive territory.

[feb1991blizzard]

3 minutes ago, bluearmy said:

I see the opposite!

actually, I see where you’re coming from but that will make the disruption occur too far north - we want the low furthe south when it hits the blocking 

Yes, theres not enough of a dig on this run.

[BlueHedgehog074]

2 minutes ago, feb1991blizzard said:

Yes, we need that @DiagonalRedLine to continue into positive territory.

We certainly do.

[northwestsnow]

6 minutes ago, Catacol said:

Personal view - NWP take snapshots of readings and then applies algorithms based climatological norms to interpret the way ahead. I would imagine by now that the best computer minds have applied machine learning to the process - so as we move forward NWP will learn.

But currently I suspect there is a reliance on normalised processes. And this is where the human ability to interpret can have an edge.

And the mountain torque charts have updated. As expected a steep climb has begun

Cue - move away from the apparent passage towards a Nina-like state in the atlantic and a return to a more Nino meridional outlook. Humans 1, NWP 0.

= Scandy fights back. (At least a bit....because expected processes would still say this phase next week is not going to produce full on goods. Need a bit more time for developments to work their way through for that....)

Not the fabled swedish rock band again!!

On a serious note i think are going to need all the help we can get in derailing this Atlantic steam train..

[Ice Day]

It's a messy old picture at 144.  No UKMO route for the pub run by the looks of things.

[Weathizard]

Titanic battle, quite a good watch.

[SMU]

The GFS is now in the sub 144 timeline working towards the Euro solution-

This is because its woeful at energy seperation- Which in this scenario is the defining point of difference...

NB 12z v 18z with the 18 beginning to  see more seperation..

[ALL ABOARD]

As Steve has mentioned above, the thing that is most notable for me on the 18z so far is the continued increase in heights across scandi. 

20mb higher in a 6 hour run. Substantial. 

[edinburgh_1992]

Have you seen the latest CFS run for February averages? It's nice to dream once in a while

[feb1991blizzard]

4 minutes ago, Steve Murr said:

The GFS is now in the sub 144 timeline working towards the Euro solution-

This is because its woeful at energy seperation- Which in this scenario is the defining point of difference...

NB 12z v 18z with the 18 beginning to  see more seperation..

This run has a touch of the Feb 5th 1996's about it, just shows you though, the surface pressure isobars actually look better suited to a battleground event on the 18z GFS but of course in 1996 we already had entrenched cold.

Edited December 7, 2018 by feb1991blizzard