Model output discussion - Into 2021

[SMU]

ICON 120 does being that band of snow into England from the East...

Far to many people worrying about the end today when its not even started ... Same old story on here...

[Faronstream]

Getting quite worried with GFS being so keen on a change to much milder conditions  from 12-14th january but clearly it is still an outlier

[Nick F]

Morning

It seems the models aren't expecting a QTR from the SSW, so invariably we can assume background tropospheric drivers are dictating the upper flow patterns until mid-month, otherwise EC and GFS wouldn't be filling up the arctic with low heights in the medium range. 

A question mark over de-amplification of the ridge over the Atlantic days 8-10, GFS seems to have been keen on this for a few days now and EC seems to be trying to head that way, but still has more amplification upstream. UKMO, as far as it goes, GFS P and GEM holding on to more amplification. But IMO 50:50 we may experience a brief less cold spell towards mid-month or we stay blocked from Atlantic influence before perhaps we see the effects of the SSW on the trop pattern to bring more blocked colder pattern back.

Can't help but feel the west Russian block keeps preventing or delaying deep cold pools from dropping out of the arctic towards there - if this happens, then I feel things will start moving quickly in the trop with regards to deeper cold moving towards us from the east. Perhaps the SSW will help in this respect, as for now the Russian high is holding back deep cold from surging west from Siberia due to to extending quite far south or preventing deep cold pools dropping south.

[Scott Ingham]

4 minutes ago, Steve Murr said:

ICON 120 does being that band of snow into England from the East...

Far to many people worrying about the end today when its not even started ... Same old story on here...

Amen! 

[Ali1977]

2 minutes ago, Faronstream said:

Getting quite worried with GFS being so keen on a change to much milder conditions  from 12-14th january but clearly it is still an outlier

The breakdown is in FI, and there’s an SSW in the mix...All will change one way or another, let’s get this cold Easterly in first and see where it goes!!

[mushymanrob]

Another huge battle between the anomaly charts and the ops..... the anomaly charts simply do not support any sort of Bartlet style pressure build to our south... they are consistent with a negative pressure anomaly to our south and east, and a mean upper flow from the northwest.

Historically the anomalies are usually, but not always, much closer to the mark if not more or less bang on.

Personally, i just cannot see them being completely wrong. We may get a transient ridge from the west, but these charts do not in any way IMHO support the return of a mild atlantic, and are far more in favour of the colder conditions prevailing with a chance of something properly cold developing.

 

[Methuselah]

GFS seems slow this morning... the SSW must be confusing its resident homunculus?

[Griff]

30 minutes ago, Beanz said:

Why has everybody suddenly decided in the last few days that the GFS-P is the favourite model after it barely being talked about this winter, is it because it shows the Synoptics you want to see...?  
 

GFS-P might well be more consistent, but is it accurate I think is more the point?   

 

 

So I guess the bigger picture, is what support is there for the current output? 

2 minutes ago, mushymanrob said:

Another huge battle between the anomaly charts and the ops..... the anomaly charts simply do not support any sort of Bartlet style pressure build to our south... they are consistent with a negative pressure anomaly to our south and east, and a mean upper flow from the northwest.

Historically the anomalies are usually, but not always, much closer to the mark if not more or less bang on.

Personally, i just cannot see them being completely wrong. We may get a transient ridge from the west, but these charts do not in any way IMHO support the return of a mild atlantic, and are far more in favour of the colder conditions prevailing with a chance of something properly cold developing.

 

Which is what @Catacol and Scott and many others have been saying for a while now. 

[Anthony Burden]

Snow looks likely in many places next week away from coastal regions,both ECM and GFS look

cold all week.Temperatures in Oxford max have been around 3c not sure about Met office

idea of pick up of temperatures middle of month.Not really been picked up on charts yet 

but I suppose it is possible before SSW kicks in,we shall see.

[Scott Ingham]

2 minutes ago, mushymanrob said:

Another huge battle between the anomaly charts and the ops..... the anomaly charts simply do not support any sort of Bartlet style pressure build to our south... they are consistent with a negative pressure anomaly to our south and east, and a mean upper flow from the northwest.

Historically the anomalies are usually, but not always, much closer to the mark if not more or less bang on.

Personally, i just cannot see them being completely wrong. We may get a transient ridge from the west, but these charts do not in any way IMHO support the return of a mild atlantic, and are far more in favour of the colder conditions prevailing with a chance of something properly cold developing.

 

I categorically believe we wont see a breakdown as shown.

I am hugely confident this is all down to models not knowing how to deal with all the changes above us. 

Im with you and Steve Murr on this.

It was warned models would be up and down 2 days ago

[bluearmy]

Just now, mushymanrob said:

Another huge battle between the anomaly charts and the ops..... the anomaly charts simply do not support any sort of Bartlet style pressure build to our south... they are consistent with a negative pressure anomaly to our south and east, and a mean upper flow from the northwest.

Historically the anomalies are usually, but not always, much closer to the mark if not more or less bang on.

Personally, i just cannot see them being completely wrong. We may get a transient ridge from the west, but these charts do not in any way IMHO support the return of a mild atlantic, and are far more in favour of the colder conditions prevailing with a chance of something properly cold developing.

 

I’ve sussed out rob that the 8/14 day chart is taken from cross model output on day 11.  In a situation where the ens means are showing a quick drift to flat from amplified later week 2, the 8/14 can look wrong when compared to the mean for day 14. 

[chris55]

Hopefully we can get some snowfall from the easterly next week. Be that from showers or frontal incursions. 
  Going off UKMO we look to be averaging around -7-8C 850s which you would hope would be cold enough for many.

That snow in the north toady is falling in -6/-7C 850s, though moving in overnight.

Beyond day 5 lots of options available and UKMO looks to be setting up a slightly colder easterly feed, though this could be put under pressure from the west like ECM shows. Though anything from the west looks weak at best. 

 

Then we have the SSW to watch as the effects become apparent. 
 

Overall a decently wintery start to the year . 

[Scott Ingham]

3 minutes ago, bluearmy said:

I’ve sussed out rob that the 8/14 day chart is taken from cross model output on day 11.  In a situation where the ens means are showing a quick drift to flat from amplified later week 2, the 8/14 can look wrong when compared to the mean for day 14. 

Day 14 may be flatter but not day 8/9/10 on the ECM. 

Dont you agree its too progressive?

I also beleive the blip will coincide with a snowier battleground set up

[chris55]

8 minutes ago, mushymanrob said:

Another huge battle between the anomaly charts and the ops..... the anomaly charts simply do not support any sort of Bartlet style pressure build to our south... they are consistent with a negative pressure anomaly to our south and east, and a mean upper flow from the northwest.

Historically the anomalies are usually, but not always, much closer to the mark if not more or less bang on.

Personally, i just cannot see them being completely wrong. We may get a transient ridge from the west, but these charts do not in any way IMHO support the return of a mild atlantic, and are far more in favour of the colder conditions prevailing with a chance of something properly cold developing.

 

Agree.

A transitory ridge to the south would be feasible within the wider anomaly. But it would need to be short lived. 
 

 

[georgiedre]

Just now, Scott Ingham said:

Day 14 may be flatter but not day 8/9/10 on the ECM. 

Dont you agree its too progressive?

I also beleive the blip will coincide with a snowier battleground set up

I too think the weather will move up from the south temporarily but not fet too far north.  This would provide quite a north /south devide with temps... probably hoping more than thinking tbh

[SMU]

GFS 06z trends back towards the UKMO with a larger pool of 850s impacting the UK reducing the non snowy shower periods especially in the SE

[Scott Ingham]

2 minutes ago, georgiedre said:

I too think the weather will move up from the south temporarily but not fet too far north.  This would provide quite a north /south devide with temps... probably hoping more than thinking tbh

Thats my thinking. Think ecm 12z yesterday

That for me is where we go

[Tim Bland]

Icon takes until Thursday to break out any shower activity. ECM is also a mainly dry run. I’m not confident in the GFS ability to pick out streamers , but I’m hoping it is doing a good job on this one...

Edited January 2, 2021 by Tim Bland

[Battleground Snow]

GFS throws a little more energy southwards at 132, which brings the cold in faster from the north.

 

[Battleground Snow]

Para retains the low to the North, much different to its 00z run.

 

[chris55]

Cold 144 from 6z.
850s and Dew points look good for snowfall for most.

[Updated_Weather]

41 minutes ago, Faronstream said:

Getting quite worried with GFS being so keen on a change to much milder conditions  from 12-14th january but clearly it is still an outlier

Day 10! Ignore!

[Radiating Dendrite]

1 minute ago, Updated_Weather said:

Day 10! Ignore!

Ignore day 10 if showing mild, believe day 10 if showing cold because it is trending that way.

[Guest]

41 minutes ago, Nick F said:

Morning

It seems the models aren't expecting a QTR from the SSW, so invariably we can assume background tropospheric drivers are dictating the upper flow patterns until mid-month, otherwise EC and GFS wouldn't be filling up the arctic with low heights in the medium range. 

A question mark over de-amplification of the ridge over the Atlantic days 8-10, GFS seems to have been keen on this for a few days now and EC seems to be trying to head that way, but still has more amplification upstream. UKMO, as far as it goes, GFS P and GEM holding on to more amplification. But IMO 50:50 we may experience a brief less cold spell towards mid-month or we stay blocked from Atlantic influence before perhaps we see the effects of the SSW on the trop pattern to bring more blocked colder pattern back.

Can't help but feel the west Russian block keeps preventing or delaying deep cold pools from dropping out of the arctic towards there - if this happens, then I feel things will start moving quickly in the trop with regards to deeper cold moving towards us from the east. Perhaps the SSW will help in this respect, as for now the Russian high is holding back deep cold from surging west from Siberia due to to extending quite far south or preventing deep cold pools dropping south.

The Russian high could be here for all the whole winter period, SSW or not. In fact going on history and how resilient that feature is I would say it's more likely than not.

[swfc]

Seems a lot of teeth nashing this morning on things that arnt even within any forecast yet. Will it rain here, snow there. For your sanity stick to the shorter outlook ukmo and localised charts. Uto