Model output discussion 25th Jan - The final third of winter beckons..

[frosty ground]

I don't see any retrogression on this run. A bit messy now with an Atlantic is sleep mode 

[MidnightSnow]

Why am I getting the impression that this run is a downgrade when chances of snow this weekend just increased? 

[Johnp]

3 minutes ago, MidnightSnow said:

Why am I getting the impression that this run is a downgrade when chances of snow this weekend just increased? 

Because people don't realise that FI is about 72 hours at the moment! 

The tiny cold pool West of Ireland is slowing down the retrogression. Chances are that'll be totally different on the next run.

The general trend is still there and that's all I'm happy about.

Edited February 6, 2017 by Johnp

[Mucka]

1 minute ago, MattTarrant said:

The positioning of high by 162 wasn't far different to the 6z albeit perhaps 100 miles further south. 

Also note by 168 there is massive surge of WAA into northern Scandinavia, Mucka what could this do? 

It is the warmth from the Azores being forced NE by a sharpening of the Atlantic pattern.

The more vertical we can get that orange wedge the better off we will be as it will allow for the pattern to back West (retrograde) while at the same time reinforcing high pressure to our NE.

[northwestsnow]

5 minutes ago, MidnightSnow said:

Why am I getting the impression that this run is a downgrade when chances of snow this weekend just increased? 

Well gfs12z has temps at night above zero by sat night for many so compared to the 6z ? If thats not a pretty big downgrade i dont know what is..added to that temps of 4 and 5 widely through saturday..

Edited February 6, 2017 by northwestsnow

[Ali1977]

6 minutes ago, MidnightSnow said:

Why am I getting the impression that this run is a downgrade when chances of snow this weekend just increased? 

Longer term and compared to the last run it is a downgrade for sure, I have a feeling this will be way off reality though and wouldn't look to far beyond the weekend which looks fairly good for some snow flurries in places.  I imagine the GEFS will have numerous options beyond the weekend, some good and some not so good like the Op.  

You watch, the ECM will flip to the better runs in the longer term now.

Edited February 6, 2017 by Ali1977

[Summer Sun]

Ian F

12z UKMO-GM less bullish on weekend cold pool aloft anyway, so moving towards other solutions. But wintry showers for some.

[northwestsnow]

2 minutes ago, Summer Sun said:

Ian F

12z UKMO-GM less bullish on weekend cold pool aloft anyway, so moving towards other solutions. But wintry showers for some.

Yup, both 12zs have backtracked, and thats coming from a pro!the bit about ukmo at any rate.

Edited February 6, 2017 by northwestsnow

[Ali1977]

1 minute ago, Summer Sun said:

Ian F

12z UKMO-GM less bullish on weekend cold pool aloft anyway, so moving towards other solutions. But wintry showers for some.

MMMM, maybe the GFS is looking quite accurate.

[Johnp]

I'm increasingly confident of a proper old school big freeze in the next couple of weeks.

It's almost as if the atmosphere is trying to shuffle it's pieces into place but we just have to be patient.

GEM also good tonight.

[Seasonality]

3 minutes ago, northwestsnow said:

Well gfs12z has temps at night above zero by sat night for many so compared to the 6z ? If thats not a pretty big downgrade i dont know what is..

Go over @Bring Back1962-63's excellent nowcast posts. The models aren't even handling the progression of the cold at 24h and less very well, let alone the weekend.

[Ice Day]

4 minutes ago, Summer Sun said:

Ian F

12z UKMO-GM less bullish on weekend cold pool aloft anyway, so moving towards other solutions. But wintry showers for some.

Interesting and slightly disappointing update.  I thought the UKMO looked pretty good!

[Frosty.]

5 minutes ago, northwestsnow said:

Well gfs12z has temps at night above zero by sat night for many so compared to the 6z ? If thats not a pretty big downgrade i dont know what is..added to that temps of 4 and 5 widely through saturday..

Plenty of snow around though!

[Methuselah]

Just now, Ali1977 said:

MMMM, maybe the GFS is looking quite accurate.

How can you say that, Ali? It hasn't even happened yet! But, at the end of the day, does it really matter: the weather will do what it does, irrespective of any model-output?

[Weathizard]

3 minutes ago, Johnp said:

I'm increasingly confident of a proper old school big freeze in the next couple of weeks.

It's almost as if the atmosphere is trying to shuffle it's pieces into place but we just have to be patient.

GEM also good tonight.

The 12z GEM isn't good, far from it IMO! 

[Methuselah]

Just now, Frosty. said:

Plenty of snow around though!

Bugger! Rain for the Triangle of Doom!

[Ali1977]

Just now, Ed Stone said:

How can you say that, Ali? It hasn't even happened yet! But, at the end of the day, does it really matter: the weather will do what it does, irrespective of any model-output?

GFS looks less bullish on the weekend cold pool, like Ian mentioned....simple really!!  

[frosty ground]

2 minutes ago, Seasonality said:

Go over @Bring Back1962-63's excellent nowcast posts. The models aren't even handling the progression of the cold at 24h and less very well, let alone the weekend.

To be fair to NNN his assessment of the 12z GFS is pretty much spot on, not sure he is saying it's going to be correct.

[northwestsnow]

1 minute ago, Seasonality said:

Go over @Bring Back1962-63's excellent nowcast posts. The models aren't even handling the progression of the cold at 24h and less very well, let alone the weekend.

Not saying the 12zs are correct, just saying they are a downgrade, esp the ukmo run from this morning, as ian fergie says, its removed the cold pool.Anyway, lets see what ecm says..

[Methuselah]

Just now, Ali1977 said:

GFS looks less bullish on the weekend cold pool, like Ian mentioned....simple really!!  

But nothing that you or I, or pros or models say can have any effect on the weather...

[nick sussex]

1 minute ago, Ice Day said:

Interesting and slightly disappointing update.  I thought the UKMO looked pretty good!

It looks like around -5 towards the north and close to -9 towards the se in terms of 850's at T144hrs so not sure that's a downgrade or not. This cold pool seems to be causing a lot of drama with the models.

[Seasonality]

Look at the size of this bugger on GEM at 240. Now that is a cold pool.

[Johnp]

Just now, Seasonality said:

Look at the size of this bugger on GEM at 240. Now that is a cold pool.

Awful chart according to Weathizard!

[Ali1977]

3 minutes ago, Weathizard said:

The 12z GEM isn't good, far from it IMO! 

The GEM isn't bad with the cold pool hanging around to the East most of the run and in FI the high orientates itself well enough to bring in another large cold pool from Siberia - all way way out in FI of course.

[Seasonality]

7 minutes ago, northwestsnow said:

Yup, both 12zs have backtracked, and thats coming from a pro!the bit about ukmo at any rate.

The op runs have, yes. But #justonerun 

Could go either way yet. Just trying to get folk to rewrap the razor blades but by the same token, don't ice the champagne yet.