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

[Hammy79]

Number 19 please! 

[Puppazo di Neve]

Hopefully there will be precipitation, as it seems generally dry. A bit oxymoron how difficult is a combination of cold air with precipitation, considering we live on an island

[Blizzard_of_Oz]

Surely the Met office will  likely issue yellow warnings of snow and ice from Monday morning, upgrading to amber and possibly red if reading from the present charts.

[minus10]

Wow...i think...

[Mcconnor8]

1 minute ago, minus10 said:

Wow...i think...

Control run bringing the -15c Isotherm through the North of the UK is mental and it remaining cold after!

Edited January 10 by Mcconnor8

[Met4Cast]

2 minutes ago, Blizzard_of_Oz said:

Surely the Met office will  likely issue yellow warnings of snow and ice from Monday morning, upgrading to amber and possibly red if reading from the present charts.

Can’t say I’m seeing anything worthy of a red being modelled for next week.. 

[winterof79]

1 minute ago, Blizzard_of_Oz said:

Surely the Met office will  likely issue yellow warnings of snow and ice from Monday morning, upgrading to amber and possibly red if reading from the present charts.

Whoaaa there horsey lets get the cold in over the weekend but yes they will be watching very closely.

[Mike Poole]

For those unsure of whether today is a net downgrade or upgrade, the GFS 6z and the GEFS tilt it firmly in the direction of an upgrade.

GEFS ensemble mean at T162:

 

I’ve chosen this time to see the signal before it gets dissolved in uncertainty, but if we can nail this, then things should evolve well after because the NH is split with a good balance between the PV on the eastern side and a remaining lobe for ballast on the western side.  On a mean chart, this is very interesting.  As an aside, I wonder what this looks like in the lower strat.

[TSNWK]

5 minutes ago, Blizzard_of_Oz said:

Surely the Met office will  likely issue yellow warnings of snow and ice from Monday morning, upgrading to amber and possibly red if reading from the present charts.

Steady on Old bean! maybe a cheeky yellow for ice risk and I expect the public notice cold alert issued for this week, due to expire Friday will be extended..

 

[ITSY]

I'm not the first to say or think this but worth noting that in these potential battleground scenarios, usually if the cold wins out it means the initial low has moved south towards the Channel Islands and France - not always, but usually. That would remove the risk of disruptive snowfall for most but would conversely deepen and prolong the cold therefore hightening the risk of further snowfalls occurring down the track. So long as you're not the bill payer the latter option is the safer bet for the vast, vast majority. That's where the GEFS and GFS have taken us this morning - and it tallies much more closely with what Exeter has been saying...(who have to mention the risk of disruptive snowfall since, well, it is by its definition disruptive and requires some warning). 

Edited January 10 by ITSY

[Bogman]

9 minutes ago, minus10 said:

Wow...i think...

Blimey.

[Hammy79]

Well nice and positive OP run and ensembles for the GFS/GEFS

Also good to see the signal for scandi heights in a few members..

Fully expecting a few wobbles over the next few days  from ops and ensembles as they toy with the new signal and work out how they get there! 

Best chart viewing in what seems like ages! 

P.s thanks to the experienced posters in here, your info and explanations are help me learn loads 

Edited January 10 by Hammy79
Grammar

[winterof79]

Control bring the Scandi high build quicker than the Op by 3 days but all variations of a developing new trend @scott Ingham 

Edited January 10 by winterof79

[northwestsnow]

Well im out for the day but I'll be sure to keep an eye on Exeter !!

As Mike posted above,GEFS 6Z have upgraded the signal up to 168 and that is vital - that timeframe 120- 168 is really important,so while it's certainly  NOT game set and match ,any upgrade in that day 4 to 6 timeframe gets the thumbs  

Really important 12z runs in the context of 120 to 168...

[AO-]

Good afternoon 

Interesting things next week certainly. Imo the models improve run by run with the could initially more South and the shortwaves moving into the European continent advecting cold air. Besides, for my location the EPS of GFS had definitely improved with some slammers. In the end the uncertainty is great but the mid term has improved a lot since yesterday. 

 

 

[festivalking]

22 minutes ago, Mcconnor8 said:

No way Exeter would downgrade surely with output like that!

Well they are not the biggest fans of GFS - yes they look at all modules but they rarely get a mention on their broadcasts

[ICE COLD]

7 minutes ago, Mike Poole said:

For those unsure of whether today is a net downgrade or upgrade, the GFS 6z and the GEFS tilt it firmly in the direction of an upgrade.

GEFS ensemble mean at T162:

 

I’ve chosen this time to see the signal before it gets dissolved in uncertainty, but if we can nail this, then things should evolve well after because the NH is split with a good balance between the PV on the eastern side and a remaining lobe for ballast on the western side.  On a mean chart, this is very interesting.  As an aside, I wonder what this looks like in the lower strat.

The strat looks obliterated on the 6z run Mike . Can only mean great things going forward.

[tight isobar]

12 minutes ago, Mcconnor8 said:

Control run bringing the -15c Isotherm through the North of the UK is mental and it remaining cold after!

They are the 00z tags..

[Mcconnor8]

6 minutes ago, tight isobar said:

They are the 00z tags..

Meteociel - Cartes Ensemble GFS (ENS/GEFS)

WWW.METEOCIEL.FR

---

meteociel propose des rubriques météo temps réel, forums, modeles...

Take a look, truly stunning control run in honesty.

Edited January 10 by Mcconnor8

[Ali1977]

21 minutes ago, Hammy79 said:

Number 19 please! 

That’s a historic run that one - I’ll find some snow chart JFF

Edited January 10 by Ali1977

[northwestsnow]

6 minutes ago, Hammy79 said:

Well nice and positive OP run and ensembles for the GFS/GEFS

Also good to see the signal for scandi heights in a few members..

Fully expecting a few wobbles over the next few days  from ops and ensembles as they toy with the new signal and work out how they get there! 

Best chart viewing in what seems like ages! 

P.s thanks to the experience posters in here, your info and explanations are help me learn loads 

I'm experienced and I have more wobbles than a bowl of jelly !!

We are edging into the reliable timeframe now we just got to hope ..

[winterof79]

Its been a while GFS

[Derecho]

8 minutes ago, Bogman said:

Blimey.

The control run really is quite something, <-10C 850s a regular visit across the UK and then a cold high falling on top in the later stages. There would be some seriously cold minimums if that came off.

[Ali1977]

Just now, winterof79 said:

Its been a while GFS

That’s is the biggest and best upgrade I’ve seen this week - all in very unstable conditions. I expect a METO upgrade today

[Nick2373]

8 minutes ago, northwestsnow said:

Well im out for the day but I'll be sure to keep an eye on Exeter !!

As Mike posted above,GEFS 6Z have upgraded the signal up to 168 and that is vital - that timeframe 120- 168 is really important,so while it's certainly  NOT game set and match ,any upgrade in that day 4 to 6 timeframe gets the thumbs  

Really important 12z runs in the context of 120 to 168...

Through this period, the greatest likelihood is that high pressure will remain the more dominant influence on the weather, most likely centred somewhere to the northwest of the UK, with winds from the north or north-east perhaps more frequent than usual, with generally reduced amounts of precipitation. There is an increased chance, compared to normal of cold conditions along with the associated impacts from low temperatures. Even within a predominantly more settled pattern there is a still a chance that frontal systems could move in from the west or southwest at times, which while they would likely bring an interlude of slightly milder, more unsettled weather, for a time, this would also introduce a risk of snow and ice where it meets the colder air in place across the UK.

Updated: 15:00 (UTC) on Wed 10 Jan 2024