Model output discussion - another cold spell on the horizon?

[O'Maille80]

23 minutes ago, LoisE said:

Could you please explain what "upgrade" means on the 18z GEFZ weather model compared to the earlier version? Is it using new technology or something? Thank you. 

Same model. He is just referring to fact that the amplification up to Greenland looks better in the  18z gefs run than it did in the 12z run.(hence upgrade). 

[Stu_London]

My take on it is that the flip flopping will continue and models will firm up a bit by around 14th January. 

Probabilities as I see them for the final third of the month

15% - SSW continues to disrupt patterns but the whole thing has a bit too much mobility and we miss out. Further disruption of the vortex might lead to better luck in February as mobility tends to drop away then.

25% - A cold spell of sorts will occur but rather like the new year one, it will not deliver for everyone and will frustrate many. Likely to break to milder set for first part of Feb.

20% - Frequent transient events with conditions alternating between cold and mild with some epic localised battleground set ups. - could progress to something more special in February. 

30% - A solid but unspectacular cold spell with some snow events but a lot of dry weather as the high eventually topples over the UK. High pressure likely to stick around but could retrogress to Scandi in Feb. 

10% - Epic cold spell going down in the history books comparable 2009, 2010 (twice), 2013 (March, not January) and 2018 that continues to deliver well into Feb. 

 

 

[northwestsnow]

ICON 156 ...

Upgrade ...

Good start to the day !

180..

Not perfect but its an improvement ...

And we need upgrades today.. 

Edited January 11, 2021 by northwestsnow

[icykev]

4 minutes ago, northwestsnow said:

ICON 156 ...

Upgrade ...

Good start to the day !

Artic high 1050! Looks good NWS.

[Battleground Snow]

8 minutes ago, northwestsnow said:

ICON 156 ...

Upgrade ...

Good start to the day !

180..

Not perfect but its an improvement ...

And we need upgrades today.. 

I know I keep banging on about the cut off low, but it really is critical... You can see on this run its so much more intense compared to the ECM and fires waa north to help create a better ridge

[northwestsnow]

6 minutes ago, Battleground Snow said:

I know I keep banging on about the cut off low, but it really is critical... You can see on this run its so much more intense compared to the ECM and fires waa north to help create a better ridge

Yup.

If I were being picky I'd want the pattern a few hundred miles east ..

But 00z is an improvement on its 18z so that's a trend I want continued.

I was subdued yesterday as personally i did not like the Euro models in particular.

Edited January 11, 2021 by northwestsnow

[O'Maille80]

Would have liked to see a few hours more on that icon run. Looked like it was evolving with some promise.

[Battleground Snow]

Interestingly there were a few similar ensembles from last nights 18z GFS. 

Lets see what today's run bring

 

Edited January 11, 2021 by Battleground Snow

[Stu_London]

I like the ICON solution - lets see how the other models handle this evolution - until the cut off low situation is resolved everything afterwards should be binned. 

[icykev]

3 minutes ago, Battleground Snow said:

I know I keep banging on about the cut off low, but it really is critical... You can see on this run its so much more intense compared to the ECM and fires waa north to help create a better ridge

Very true BS looks key to GH possibilities at only 7-8 days. I think marine cold air outbreaks could become a distinct probability in these circumstances.  Causing so much uncertainty along with the ssw repercussions its a dream.

 

[Stu_London]

With the exceptional of high elevations in Scotland, GFS not interested in making much of the front on Wednesday / Thursday - pushes the cold air away to the east

[Battleground Snow]

Ukmo not amazing, but it also has a more intense feature at 144, the ridge heading up further west though.. I'll take that for a starting point.

Nice Arctic high placement

Edited January 11, 2021 by Battleground Snow

[northwestsnow]

UKMO looks a big improvement to me !!

Edited January 11, 2021 by northwestsnow

[Mucka]

6 minutes ago, Battleground Snow said:

Ukmo not amazing, but it also has a more intense feature at 144, the ridge heading up further west though.. I'll take that for a starting point.

Nice Arctic high placement

Looks pretty good to me. Was going to post it saying as much.

Low out in the Atlantic is going to become cut off and strong ridge build behind it into Greenland.

the two lows to the NW and North would phase with the upper trough over Scandi.

Only worry would be Iberian heights if the trough didn't dig far enough SW but I would expect us to be in NE flow around day 10 from there.

[Stu_London]

Cut off low present on the GFS - huge downstream changes again from 18z at 144hrs

Edited January 11, 2021 by Stu_London

[Battleground Snow]

1 minute ago, Mucka said:

Looks pretty good to me. Was going to post it saying as much.

Low out in the Atlantic is going to become cut off and strong ridge build behind it into Greenland.

the two lows to the NW and North would phase with the upper trough over Scandi.

Only worry would be Iberian heights if the trough didn't dig far enough SW but I would expect us to be in NE flow around day 10 from there.

I was trying to remain cautious, but I'm happy to go with that assessment! Sounds good

[Stu_London]

1 minute ago, Stu_London said:

Cut off low present on the GFS - huge downstream changes again from 18z at 144hrs

Although there is another low spawned of SE Greenland on this run - gone from no lows to 2 lows. Doesn't look all that viable to me

[Mucka]

Just now, Battleground Snow said:

I was trying to remain cautious, but I'm happy to go with that assessment! Sounds good

Yes sensible because we are only projecting from there but it is in abetter place than GFS 00z with a similar synoptic for both the trough to develop to our NE and ridge to our W so if GFS is decent you can give UKMO a gold star 

[Battleground Snow]

2 minutes ago, Stu_London said:

Cut off low present on the GFS - huge downstream changes again from 18z at 144hrs

If that low near Iceland shifts off would be good, but better for sure.. it's almost as if the models have shifted back to the previous way of thinking. We have seen this happen in the past... A little wobble then revert.. great model watching!

[Battleground Snow]

I'd like to welcome the para back onboard too! All quite a bit different around 144, so best to remain cautious

 

[Kasim Awan]

Gfs op is a poor attempt, failed retrogression, the result is stagnant westerlies and the UK quite mild despite the on face-value mammoth blocking 

[Howie]

1 minute ago, Kasim Awan said:

Gfs op is a poor attempt, failed retrogression, the result is stagnant westerlies and the UK quite mild despite the on face-value mammoth blocking 

The Iberian high is being a real pain in the neck on most runs. What are the chances that will downgrade on future runs?

[Daniel]

Much better models this morning. Let's hope ECM joins in 

[Battleground Snow]

Lov

3 minutes ago, Kasim Awan said:

Gfs op is a poor attempt, failed retrogression, the result is stagnant westerlies and the UK quite mild despite the on face-value mammoth blocking 

Could work out later on?

[Mucka]

2 minutes ago, Battleground Snow said:

I'd like to welcome the para back onboard too! All quite a bit different around 144, so best to remain cautious

 

It seems pretty inconsistent run to run to me, like a broken watch it will be right some of the time as a happy accident.

UKMO and GFS aren't so far apart

4 minutes ago, Kasim Awan said:

Gfs op is a poor attempt, failed retrogression, the result is stagnant westerlies and the UK quite mild despite the on face-value mammoth blocking 

Are you looking at the right charts?