Model output discussion - here comes the beast!

[Paul]

Ooh yes, it's busy and with good reason - it's a rare beast to see the sort of charts we're seeing right now. It would appear the UK and much of Europe is headed into the freezer, but how cold, and for how long?

As always, please keep to just discussing the model output in this thread.

We have a thread open to discuss the cold spell - so if you're wanting to chat more generally about it, or talk about forecasts from the BBC, Met Office, Netweather etc, please head over there:
https://www.netweather.tv/forum/topic/89358-ssw-related-cold-spell-will-it-wont-it/

It's also worth keeping an eye on is the blogs from our team including @Jo Farrow & @Nick Finnis, there's some great info about the SSW, the cold spell etc, and new articles will be posted regularly:
https://www.netweather.tv/weather-forecasts/blogs

Want to view the model outputs?
You can get all the major ones here on Netweather:

GFS
GEFS Ensembles
ECMWF
ECMWF EPS
NetWx-SR
NetWx-MR
Met-Office
Fax
GEM
GFS Hourly

Snow forecast and precip type
Model Comparison
Global Jet Stream
Stratosphere

[Scandinavian High.]

The beast from east will the 12z upgrade even more ..

[Polar Maritime]

That's first 2 post gone directly under Paul's opening post..They will just go missing so don't wast your time and spoil the thread for the rest of the commuity. Members repeatedly posting off topic will be added to the ever growing restricted list. Not a good place to be what with the upcoming interest...

On we go.

[Frosty.]

All the models are pointing to siberian winds around a large scandi anticyclone next week with sub-zero maxima and penetrating frosts due to the strength of the Easterly airflow..it's definitely going to happen!..will it snow?..well I think so because it looks an unstable easterly on the Gfs  / Gefs  / Ecm  and Gem which means snow showers piling inland from the North sea ❄❄❄❄❄❄❄❄

[frosty ground]

From the last thread we had a few poster rightly asking for caution, What I personally did not understand was which way the Cold could get shunted. NW or SW 

Also the appearance of a small surface feature could alter the upper air pattern and deflect the jet that will be flowing east to west around the base of the high. It will also stop the retrogression of the high north and west.
 

[Quicksilver1989]

5 minutes ago, Frosty. said:

All the models are pointing to siberian winds around a large scandi anticyclone next week with sub-zero maxima and penetrating frosts due to the strength of the Easterly airflow..it's definitely going to happen!..will it snow?..well I think so because it looks an unstable easterly which means snow showers piling inland from the North sea ❄❄❄❄❄❄❄❄

Be wary about saying 'definitely' like I mentioned in the end of the past thread the Scandi low over Finland at T72 needs to be kept a close eye on given cluster 2 of the ECM ensembles.



It could well just end up being cold and dry for many with those in the north wondering what the fuss is about whilst France and the Channel Islands get all the deep cold uppers

If its gone by today's 12z ECM then I'm ready to start ramping. Lets be cautious until then.

[metaltron]

This thread title is really going to rub it in for the next few weeks if it all implodes later! I sense that the Met Office believe the real cold air going south is a real possibility and Cluster 2 from the ECM ensembles shows that this is still on the table. Also a backtrack from the GFS 6z towards the ECM solution (would have been more comforting if the GFS stuck more closely to its morning output!). Nevertheless, I do think a classic easterly, like Feb 1991, is the most likely option, based on the data we have freely available. Fingers and toes crossed for tonight's runs!

[Frosty.]

6 minutes ago, Quicksilver1989 said:

Be wary about saying 'definitely' like I mentioned in the end of the past thread the Scandi low over Finland at T72 needs to be kept a close eye on given cluster 2 of the ECM ensembles.



It could well just end up being cold and dry for many with those in the north wondering what the fuss is about whilst France and the Channel Islands get all the deep cold uppers

If its gone by today's 12z ECM then I'm ready to start ramping. Lets be cautious until then.

I take your cautionary point but I'm just basing my post on solid cross model support and emphatic support from exeter..the models are reaching dizzyingly new heights and I expect it to continue..

[kev238]

Well I must be missing something with all this talk of backtracks .

From what I can see the GFS 6z was one of coldest and snowiest I have ever seen . Yes the deep cold lands on our shores about 12-18 hrs later but that is hardly a backtrack

 

 

[ScottishSnowStorm]

Does anyone have the ECM clusters to post again that are causing so much cause for concern because if it is the same ones i am thinking of then they still show heights over greenland and a cold solution anyway 

[seb]

What backtrack? Where? Unless someone has access to more recent model runs than the ones publicly available and they show a backtrack, there is no backtrack. I can't remember the last time there was such x-model consensus.

[Banbury]

4 minutes ago, metaltron said:

This thread title is really going to rub it in for the next few weeks if it all implodes later! I sense that the Met Office believe the real cold air going south is a real possibility and Cluster 2 from the ECM ensembles shows that this is still on the table. Also a backtrack from the GFS 6z towards the ECM solution (would have been more comforting if the GFS stuck more closely to its morning output!). Nevertheless, I do think a classic easterly, like Feb 1991, is the most likely option, based on the data we have freely available. Fingers and toes crossed for tonight's runs!

Why do you say that ? Every model output I have seen doesn't indicate this . The ENS are excellent

[FENDER.]

Bound to be some wobbles  given  all the different models and runs.     Overall output still looks almost perfect to me 

[Djdazzle]

1 minute ago, metaltron said:

This thread title is really going to rub it in for the next few weeks if it all implodes later! I sense that the Met Office believe the real cold air going south is a real possibility and Cluster 2 from the ECM ensembles shows that this is still on the table. Also a backtrack from the GFS 6z towards the ECM solution (would have been more comforting if the GFS stuck more closely to its morning output!). Nevertheless, I do think a classic easterly, like Feb 1991, is the most likely option, based on the data we have freely available. Fingers and toes crossed for tonight's runs!

Agreed. This is far from a done deal in terms of deep cold. If we start to see more ensembles showing differing evolutions then we need to take note. I’d say 50% chance of deep cold next week. The other issue is that the transition to deep cold is creeping into the reliable frame now, and that’s when things often get watered down. I’m not saying it will, but it can’t be discounted.

[Catacol]

3 minutes ago, Quicksilver1989 said:

Be wary about saying 'definitely' like I mentioned in the end of the past thread the Scandi low over Finland at T72 needs to be kept a close eye on given cluster 2 of the ECM ensembles.



It could well just end up being cold and dry for many with those in the north wondering what the fuss is about whilst France and the Channel Islands get all the deep cold uppers

If its gone by today's 12z ECM then I'm ready to start ramping. Lets be cautious until then.

I think I'm with @frosty ground on this one. A surface feature like this is unlikely to overrun a pattern that is being driven by much larger forces. I was a bit concerned a few days ago by thoughts that the warming might actually drive the whole storm track too far south - but such suggestions have moderated. Frictional input from layers above is holding the cold to a trajectory that works for us - ECM strat 150hpa here for 192h

and nothing here to suggest that the track is going to drag down towards Spain. We'll wait and see if that ECM cluster for a mid atlantic high returns - but frankly it feels somewhat counter intuitive to the current setup.

[The Weather Watcher]

1 minute ago, Djdazzle said:

Agreed. This is far from a done deal in terms of deep cold. If we start to see more ensembles showing differing evolutions then we need to take note. I’d say 50% chance of deep cold next week. The other issue is that the transition to deep cold is creeping into the reliable frame now, and that’s when things often get watered down. I’m not saying it will, but it can’t be discounted.

It's clearly more than a 50% chance. That is literally a coin toss, which in forecasting terms is a pointless forecast. The ensembles show clearly what the chances are and with 70% or more clustered for deep cold, shouldn't the chances be thus?

[Catacol]

8 minutes ago, metaltron said:

This thread title is really going to rub it in for the next few weeks if it all implodes later! I sense that the Met Office believe the real cold air going south is a real possibility and Cluster 2 from the ECM ensembles shows that this is still on the table. Also a backtrack from the GFS 6z towards the ECM solution (would have been more comforting if the GFS stuck more closely to its morning output!). Nevertheless, I do think a classic easterly, like Feb 1991, is the most likely option, based on the data we have freely available. Fingers and toes crossed for tonight's runs!

I know this is the model thread - but have to challenge you on this: where in the MetO forecast does it suggest a move south? I cant see it. They have tweaked the text at lunchtime today to be a bit more region specific (the SW gets a mention!!) but nothing else.

In terms of model support for a move south - also don't really see it. This excellent chart for 100hpa winds from Hannah Attard shows very clearly the latitude of the block and the trough slamming through the UK.

 

All good.

[Djdazzle]

2 minutes ago, The Weather Watcher said:

It's clearly more than a 50% chance. That is literally a coin toss, which in forecasting terms is a pointless forecast. The ensembles show clearly what the chances are and with 70% or more clustered for deep cold, shouldn't the chances be thus?

Mathematically yes! But I’m adding in an extra bit of caution due to many past let downs. . .

[Tog]

10 minutes ago, Quicksilver1989 said:

Be wary about saying 'definitely' like I mentioned in the end of the past thread the Scandi low over Finland at T72 needs to be kept a close eye on given cluster 2 of the ECM ensembles.



It could well just end up being cold and dry for many with those in the north wondering what the fuss is about whilst France and the Channel Islands get all the deep cold uppers

If its gone by today's 12z ECM then I'm ready to start ramping. Lets be cautious until then.

The excitement that would cause if it does go down to CI’s is beyond words. We rarely get any snow, just mention snow the place grinds to a halt. Every time someone’s groans and says South I go Yes, Yes please. Been watching and learning for the last ten days, quite an education. Just getting to grips with this model stuff so excuse my lack of knowledge. 

[FetchCB]

10 minutes ago, metaltron said:

This thread title is really going to rub it in for the next few weeks if it all implodes later! I sense that the Met Office believe the real cold air going south is a real possibility and Cluster 2 from the ECM ensembles shows that this is still on the table. Also a backtrack from the GFS 6z towards the ECM solution (would have been more comforting if the GFS stuck more closely to its morning output!). Nevertheless, I do think a classic easterly, like Feb 1991, is the most likely option, based on the data we have freely available. Fingers and toes crossed for tonight's runs!

Where is that sense coming from? 

How is that backed up in the models? 

Whilst the Met may be cautious in their wording that is because they have very serious responsibilities. 

I have watched many a fabled easterly come and go , seen many scuppered by shortwaves but have never seen such agreement between ensemble members and intra models on such a cold outlook.

[Quicksilver1989]

3 minutes ago, Catacol said:

I think I'm with @frosty ground on this one. A surface feature like this is unlikely to overrun a pattern that is being driven by much larger forces. I was a bit concerned a few days ago by thoughts that the warming might actually drive the whole storm track too far south - but such suggestions have moderated. Frictional input from layers above is holding the cold to a trajectory that works for us - ECM strat 150hpa here for 192h

and nothing here to suggest that the track is going to drag down towards Spain. We'll wait and see if that ECM cluster for a mid atlantic high returns - but frankly it feels somewhat counter intuitive to the current setup.

Yup I agree Iberia is unquestionably too far south but its something to be wary of. For reference here is the ECM clusters



The northerly cluster 2 resembles this evolution. Remember the 00z yesterday. Aside from that the cold pool could still just be focused on the SE, one or two members show this.

Personally I think we would be really unlucky if things didn't materialise, especially given the size of the cold pool. The ensemble swing of February 2009 still lingers on my mind though.

[metaltron]

3 minutes ago, Banbury said:

Why do you say that ? Every model output I have seen doesn't indicate this . The ENS are excellent

Just the tone of some of the messages we are getting from the professionals (say through Twitter). I like to think it's just them being professional and not being drawn into making a forecast too early, but it could be that one of the Met Office's homegrown models is showing the cold travelling a more NE-SW trajectory. Comparing the 6z to 0z we can see some differences to our southwest with the 6z being slightly less amplified; so that's why I called the 6z a backtrack. Luckily the 00z ECM was a great run, but it is a lot closer to deflecting the cold too far south than the GFS 00z was!

 

 

I am still very optimistic though, even though I may not sound it! 

[markw2680]

From what I can see pretty much all of the models (at this stage) are looking like we may get a feb 91 type thing or similar, really don’t think we would mind that. I’d be very surprised if it all goes to the south of the uk looking at the current situation. That’s just my opinion though....

get them sledges out and say goodbye to cars and public transport ?

[Rayth]

1 minute ago, FetchCB said:

I have watched many a fabled easterly come and go

Has there been a comparable pattern like this current one where the output has just evaporated in the past ? Was ‘that ecm’ after a SSW ? 

[The Eagle]

NMM 1km resi