Model output discussion - Into 2021

[Penrith Snow]

Bloody hell, looking at ECM and GFS FI we go from Beast to Bartlett in 48hours! Only the timescale is different.

However, I don't believe neither of them for a second.

Andy

[Mike Poole]

4 minutes ago, bluearmy said:

Is it going anywhere before mid month ? And will it ever effectively get out of the COD ?  not seen anything convincing that it’s going to be relevant for a while yet .....

But does that matter, with nothing forcing the upstream of UK jet, I’m not sure we need help from the MJO for this to work out for UK cold scenario.  

[Tim Bland]

37 minutes ago, SLEETY said:

 But ecm op mild outlier at end AGAIN,just like gfs as well,seems to be every run at the moment,all models are struggling with the current set-up,so dont rule much colder runs soon...

GFS op at colder end...

[bluearmy]

4 minutes ago, Mike Poole said:

But does that matter, with nothing forcing the upstream of UK jet, I’m not sure we need help from the MJO for this to work out for UK cold scenario.  

It doesn’t matter if it doesn’t get any amplitude....I haven’t felt the MJO has had much to do with global patterns for some time. Posters on here were referencing MJO phases and downstream ridges but I have always been of the opinion that an MJO in the COD plays no part in global patterns. (And one in low amp is questionable) 

and if the ssw does split and imprint onto the trop with a greeny ridge and Asian vortex into sceurope  then it may take an MJO getting into a ‘high amp warm phase’ for the Atlantic sector to break our cold period .....

 

Edited January 2, 2021 by bluearmy

[Mark1664]

13 minutes ago, snowbob said:

As a rule any model that produces snow south of the m4 is barking up the wrong tree

if a model is showing cold and snow less than 48 hrs in the middle of the British isles, then that is to be taken with a ton of salt

further north a pinch of salt 

hope that helps

GFS snow for Somerset this evening was spot on

[Bricriu]

3 minutes ago, Penrith Snow said:

Bloody hell, looking at ECM and GFS FI we go from Beast to Bartlett in 48hours! Only the timescale is different.

However, I don't believe neither of them for a second.

Andy

Unfortunately, i do, coupled with what the UK Met Office have said lately, a relaxation of the cold looks likely now. Hopefully, it is just a  temporary thing before the -12  uppers are over all of us.  It will be a real kick in the teeth if this SSW does not deliver later on in January/ early February.

[chionomaniac]

19 minutes ago, bluearmy said:

It doesn’t matter if it doesn’t get any amplitude....

and if the ssw does split and imprint onto the trop with a greeny ridge and Asian vortex into sceurope  then it may take an MJO getting into a ‘high amp warm phase’ for the Atlantic sector to break our cold period .....

 

Yep this is critical. With the SSW showing signs of a quick response, the MJO will be struggling to override these signals as suggested by @Catacol earlier.

And continuing on that note-

What I don’t think Ian Pennell understood earlier is that you can’t put traditional tropical and QBO responses into times where we have not seen the La Nina expected atmospheric early winter responses ( more Nino-ish), and strat has been a dead duck.  The train is on a completely different track, and you cannot carry on predicting as if it was on the original track as it will only lead to derailment. Big time.

Edited January 2, 2021 by chionomaniac

[TSNWK]

52 minutes ago, Jeremy Shockey said:

ECM 12 z ensemble mean

If we cant get some snow between the 4th and the 8th then God help our tiny island.

Very decent mean until 10th and then who knows ?

That plot is a kick in the nuts big time.  The whole suite heading upwards from day 8. Ops flip and flop at that range but to see a whole set of 50 members  heading up is telling...

[Mike Poole]

1 minute ago, TSNWK said:

That plot is a kick in the nuts big time.  The whole suite heading upwards from day 8. Ops flip and flop at that range but to see a whole set of 50 members  heading up is telling...

Probably not, just the models flailing around pre SSW.  The only ru n I’ve looked at properly for the last two days is the ECM 12z mean and spread.  

[Djdazzle]

13 minutes ago, TSNWK said:

That plot is a kick in the nuts big time.  The whole suite heading upwards from day 8. Ops flip and flop at that range but to see a whole set of 50 members  heading up is telling...

We’ve seen entire ensembles flip at T96.

[bluearmy]

5 minutes ago, Mike Poole said:

Probably not, just the models flailing around pre SSW.  The only ru n I’ve looked at properly for the last two days is the ECM 12z mean and spread.  

Mike, the U wind at 1hpa is already -27 m/s 

Above 50N it’s reversed down to 3hpa and at the pole it’s reversed down to 9 hpa. 
 

I’m still unsure how you think this might not happen at 10hpa/60N when it’s already happening ??

The models aren’t flailing pre SSW - they may be struggling to resolve the early hemispheric response as the flow reverses - is that what you’re getting at ??

 

[chionomaniac]

1 minute ago, bluearmy said:

Mike, the U wind at 1hpa is already -27 m/s 

Above 50N it’s reversed down to 3hpa and at the pole it’s reversed down to 9 hpa. 
 

I’m still unsure how you think this might not happen at 10hpa/60N when it’s already happening ??

The models aren’t flailing pre SSW - they may be struggling to resolve the early hemispheric response as the flow reverses - is that what you’re getting at ??

 

Yep. In short  

The SSW is effectively a done deal.

The early tropospheric response is almost a done deal.

How the troposphere responds is up for grabs and certainly not a done deal.

[northwestsnow]

A flattening of the pattern looks pretty likely as we head through next weekend,however....

I'm feeling hopeful I'm not going to be spending the last third of Jan chasing cold charts at 384 ! ( As i have done many many times during the last 16 years).

 

[chris55]

18 minutes ago, TSNWK said:

That plot is a kick in the nuts big time.  The whole suite heading upwards from day 8. Ops flip and flop at that range but to see a whole set of 50 members  heading up is telling...

That plot is slightly devious lol...it looks like we are going mild....but with such a low starting point the mean only actually recovers to around -4C! (Still 2-3degrees below average).

No doubt a clear signal for an uptick in 850s towards day 10 but far from mild.

Hopefully some kind of battleground scenario will set up, high risk with boundary frontal snowfalls. I like them  

[Klippieboo10]

Im only an amateur here but some really need to wake up and remember years gone by.

BBC, met office and other cant even get the next 24 hours right so why the drama.

potential is there which is more than previous years so lets asses the charts overall daily rather than by the run/hour.

 

todays snow certainly proves this point! 

[I remember Atlantic 252]

1 minute ago, chris55 said:

That plot is slightly devious lol...it looks like we are going mild....but with such a low starting point the mean only actually recovers to around -4C! (Still 2-3degrees below average).

No doubt a clear signal for an uptick in 850s towards day 10 but far from mild.

Hopefully some kind of battleground scenario will set up, high risk with boundary frontal snowfalls. I like them  

chris agree, not boring going out with a whimper

[Battleground Snow]

Icon at 120, ridge not as good into Greenland, cold uppers heading down from the north.

 

[Big Dave]

1 hour ago, Chasbrown said:

Which is the most reliable model please? 

Window

[Don]

2 minutes ago, Big Dave said:

Window

Window model during the day and lamp post model at night!

[Snowman.]

4 minutes ago, Battleground Snow said:

Icon at 120, ridge not as good into Greenland, cold uppers heading down from the north.

 

Ridge in Scandi more prevalent and further west. Trough is barely dropping down now wouldnt be surprised if we end up into a similar position we are now with a ridge toppling NE.

[Man With Beard]

ECM individual ensembles: 

At D10, I would describe 22 out of 51 members as a return to average or above average temperatures. Lots of very cold runs still present.

At D15, I would describe 34 out of 51 as above average temperatures. 20-25 members show a long draw SWly.

If I had to make a forecast, I'd say the cold will stay probably at least 10 more days (and therefore the op run too quick), but mild air likely to win out between D10-D15

Let's see how the SSW affects the models in the next few days, and even more so, what upcoming cold spell will bring - I still believe chances of snow at some point(s) is very good for all.

[northwestsnow]

Hard to imagine the pattern is going to flatten out in around 5 to 6 days  from this chart.

Beauty of a chart that!!

[Sweatyman]

1 minute ago, northwestsnow said:

Hard to imagine the pattern is going to flatten out in around 5 to 6 days  from this chart.

Beauty of a chart that!!

Yes but you know it might not dont you!? PS Had a lovely hour of heavy snow here

[Severe Siberian icy blast]

3 minutes ago, northwestsnow said:

Hard to imagine the pattern is going to flatten out in around 5 to 6 days  from this chart.

Beauty of a chart that!!

I didn't realise the charts from this evening had a crystal ball 

[Battleground Snow]

9 minutes ago, northwestsnow said:

Hard to imagine the pattern is going to flatten out in around 5 to 6 days  from this chart.

Beauty of a chart that!!

If anything it's a tad better at 84 hours

Let's see where it goes