Model Output Discussion - Colder spell ending, what's to follow?

[Tim Bland]

4 minutes ago, Johnp said:

ECM 216 could be a cracker if the two lows don't merge. 

Will be a ‘quacker’ for the ducks with these temps

[Skullzrulerz]

6 minutes ago, Johnp said:

ECM 216 could be a cracker if the two lows don't merge. 

Sounds Like Dragon Ball Z

[swfc]

2 minutes ago, Tim Bland said:

Will be a ‘quacker’ for the ducks with these temps

850s aside it is a better run profile wise esp on Atlantic set up

[Daniel*]

Ending on an intriguing note. Much better than 00z.

[TSNWK]

My view is that the 12z suite of GFS and ECM took a reasonable swing back towards coldies favour around 168 198 and better heights upstream.. still wet and chilly but another similar push in that trend might just be enough to tip it.. you really feel that broader theme recently really wants to cut lose and delight for coldies despite the hurdles it keeps trying.   a different December so far.

Edited December 11, 2020 by TSNWK

[Skullzrulerz]

5 minutes ago, swfc said:

850s aside it is a better run profile wise esp on Atlantic set up

It's definitely unfortunate that sadly we still have this lack of cold problem  

[swfc]

1 minute ago, TSNWK said:

My view is that the 12z suite of GFS and ECM took a reasonable swing back towards coldies favour around 168 198 and better heights upstream.. still wet and chilly but another similar push in that trend might just be enough to tip it.. you really feel it wants to cut lose and delight.. despite the hurdles. It's a different December so far.

That's a big improvement. From that position any low pressure would only go one way. 

[swfc]

1 minute ago, Skullzrulerz said:

It's definitely unfortunate that sadly we still have this lack of cold problem  

I think the Atlantic ridging could swing things back to eventual colder outlook if ec varifies 

[Daniel*]

4 minutes ago, TSNWK said:

My view is that the 12z suite of GFS and ECM took a reasonable swing back towards coldies favour around 168 198 and better heights upstream.. still wet and chilly but another similar push in that trend might just be enough to tip it.. you really feel that broader theme recently really wants to cut lose and delight for coldies despite the hurdles it keeps trying.   a different December so far.

Before people start nagging on about day 10 the positive changes are there between day 5-7 a more positive evening as you say. 

[TSNWK]

3 minutes ago, Daniel* said:

Before people start nagging on about day 10 the positive changes are there between day 5-7 a more positive evening as you say. 

Yes the changes around 168 are interesting in the sense that they are near enough in to have some creditabilty  and  just far enough out that there is still a little wriggle room for another positive shove in coldies favour.. what is also interesting that both GFS and ECM have picked up on increasing heights upstream on the same runs and similar timelines.. nice also to see a drift east of low pressures..

im happy enough from the 12z to be drawn into the pub run.. despite me always thinking about John Holmes charts and be sensible.. but hey it’s all good fun.

 

cheers

[chionomaniac]

7 hours ago, chionomaniac said:

Hi You can always link my name in. As it happens, Thursday is my long day at work, and back early at work today so I have no time other than to mostly cursory glance at the models in the forum. Hopefully will be able to post later and happy to look to see what has changed in the last few days. I am not yet on the zonal band wagon with a lot of promise still ahead.

Sometimes we shouldn’t over analyse ‘what went wrong’ because there can be a multitude of small reasons that can cause the synoptic outlook to change. For me, we were relying on a few critical jigsaw pieces coming together at the right time. I said that the intensity, duration and angulation of the wave 2 trop based split were critical to opening the polar floodgates, and this had to coincide with a tropical push from the MJO into phases 5 to 6. This would increase the amplitude of any Atlantic waves to break through to the Arctic High and create the block which would then feedback to lock in cold. One can see how the Atlantic lows are hitting the wave 2 block, stalling and dissipating. Sadly the wave 2 is nowhere near as strong or as long lasting say, as seen in 2010. Combine this fading of wave 2 strength before the MJO kick, and we result in a redundant Arctic high, and the Atlantic slowly gathering strength as the moderate pressure height increase over Greenland loses intensity, then the block chances reduce.

 

We still have the MJO to keep an eye on, in the hope that this can reverse the situation, especially as it appears that upper strat wave 1 displacement is fading too.  It is one of those synoptic situations where we have come very close to having a notable cold spell, but the butterfly flapped it’s wing in the wrong direction for us!

[Icebox]

7 minutes ago, chionomaniac said:

 It is one of those synoptic situations where we have come very close to having a notable cold spell, but the butterfly flapped it’s wing in the wrong direction for us!

Again... 

[phil nw.]

It's a case of looking for any hope/positives for coldies with our current outlook.Although the pattern currently modeled lacks amplification the upshot of that is that now the Eastern ridge has gone deep cold is shown creeping south to N.Europe/Scandinavia.

Below is the GFS T96 jet,ECM T96 Op. and then the GEFs T192. 850s

                                                                      

So a step forward in that respect compared to the warm southerly flow that wafted north into W.Russia/Scandinavia via E and C Europe for so long.

Oh for  ridging upstream to bring some the cold south.

I think something from the north rather than east looks our best hope for anything colder around Christmas ie.week 2 in modeling terms, but it's whether upstream amplification appears in time to do the trick.

There's still time for further changes but we need to see these soon.

 

Edited December 11, 2020 by phil nw.

[Frosty.]

 

 

 

 

 

Just like the GEFS 6z..the 12z  shows some wintry potential at the perfect time..Christmas Day / Boxing Day!!...cherries included!  

 

[MATTWOLVES 3]

Any fortunes with those 12z ens?? There are some of interest, hopefully more will devolop in the coming days. 

Winter is only just beginning... Anyone that says it all over at this early stage...... In the words of the late great Babs... God rest her soul... Get owt of ma pub...

[Zak M]

@Jon Snow

So does P26...

      

And look at that stonking 1050mb Greenland High

Edited December 11, 2020 by Zak M

[Mike Poole]

1 hour ago, chionomaniac said:

Sometimes we shouldn’t over analyse ‘what went wrong’ because there can be a multitude of small reasons that can cause the synoptic outlook to change. For me, we were relying on a few critical jigsaw pieces coming together at the right time. I said that the intensity, duration and angulation of the wave 2 trop based split were critical to opening the polar floodgates, and this had to coincide with a tropical push from the MJO into phases 5 to 6. This would increase the amplitude of any Atlantic waves to break through to the Arctic High and create the block which would then feedback to lock in cold. One can see how the Atlantic lows are hitting the wave 2 block, stalling and dissipating. Sadly the wave 2 is nowhere near as strong or as long lasting say, as seen in 2010. Combine this fading of wave 2 strength before the MJO kick, and we result in a redundant Arctic high, and the Atlantic slowly gathering strength as the moderate pressure height increase over Greenland loses intensity, then the block chances reduce.

 

We still have the MJO to keep an eye on, in the hope that this can reverse the situation, especially as it appears that upper strat wave 1 displacement is fading too.  It is one of those synoptic situations where we have come very close to having a notable cold spell, but the butterfly flapped it’s wing in the wrong direction for us!

So it has all gone up in smoke then!  The invisible block is no more. This is more devastating this year than many for so many reasons, first +4C the go to average temperature for UK rubbish winter weather is the optimum for Covid-19, but more importantly if ever we needed something to take our minds off the apocalypse that will not end for months it is now, and endless wind and rain is absolutely not what was required.  The GloSea5 update the final kick in the teeth, if that can’t see a SSW, there won’t be one.  

Edited December 11, 2020 by Mike Poole

[chionomaniac]

8 minutes ago, Mike Poole said:

So it has all gone up in smoke then!  The invisible block is no more. This is more devastating this year than many for so many reasons, first +4C the go to aversive temperature for UK rubbish temperature is the optimum for Covid-19, but more importantly if ever we needed something to take our minds off the apocalypse that will not end for months it is now, and endless wind and rain is absolutely not what was required.  The GloSea5 update the final kick in the teeth, if that can’t see a SSW, there won’t be one.  

Lol mike, I wouldn’t quite say that it has gone up in smoke. After all, up to day 5/6 the output hasn’t changed and we have seen models subsequently react to a change in tropical forecasts after this timeframe

[Fourty Point Three Degrees]

Some cold hope within the cfs but i dont think these will verify. 

 

[stodge]

Evening all

Not much hope for fans of cold on yesterday evening's output. My fear was the warming from Siberia would simply push the PV back to Canada where it would re-strengthen in situ. There are other factors as well but the trend towards a more Atlantic-based scenario with positive alignment looked increasingly the form horse.

Still, another day, another set of output and as we know it can be "all change" as they say on the trains.

12Z GEM: - so to T+120 and the initial re-invigoration of the LP and the dragging of the jet back north has left the LP just to the west of Scotland. A new and vigorous LP has formed over the eastern seaboard while heights remain over Greenland for now. by T+180 that storm has filled slightly but moved ENE to be over or just to the west of Scotland so continuing unsettled and mild for most.  Some interesting changes by T+240 - the Greenland heights remain and the next Atlantic LP has developed at lower latitudes but is churning toward us. Heights are low over Scandinavia but rising over western Europe. Again, still on the mild side for most.

12Z GFS OP - this takes us into the Christmas period so FI will be more keenly observed than usual. By T+120, it's a little different to GEM. There is a narrow and elongated trough over the North Atlantic with main centres off the Canadian coast and smaller centres over western Britain and approaching from the west. Slack heights over much of Europe. By T+180 the complex trough sits to the west and north-west with another secondary LP over East Anglia and a ridge approaching as heights build into Europe. Mild but quite unsettled with rain for many. Moving on we do get a colder interlude with a N'ly or NNW'ly as the LP splits briefly with the next system taking its time in mid-Atlantic digging the trough south and forcing the HP over Iberia and threatening a new push of milder SW'ly air. That's pretty much what happens and the Christmas Day BBQ looks safe enough at T+336 with a draw of very mild SSW'ly winds and a deep LP out to the south-west. As expected, the LP pushes NE to the west of Ireland and then turns away NW back into the Atlantic keeping a mild airstream over most of the British Isles. The PV, however, is not the raging beast of recent winters and by the end of the OP run is over the Pole. 

12Z ECM - not much hope for cold fans tonight, is there? I'm not expecting anything from ECM if I'm being honest. T+120 not much different to the other models. By T=192 we see the Atlantic LP head NE and the next feature waiting in the wings to the SW.  Thr run ends on a cooler note with a PM airflow as the LP heads across Central Scotland and into the North Sea. One crumb of optimism is the PV looks disorganised at this time which you wouldn't expect.  

The 12Z Control looks pretty mild as did the 00Z Parallel. 

Conclusion - nothing for cold fans tonight. It's too early to draw stumps on a cold Christmas and GFS OP hints at a brief N'ly interlude but that's all realistically we have to hope for at this time. The PV remains weaker than you would expect but not sufficiently so to drive amplification to give us a break between Atlantic LP. The possibility of anticyclonic conditions remains though we need more to happen for that. It looks a mild and dry Christmas for parts southern and eastern and a wetter one for parts northern and western.

 

[MATTWOLVES 3]

3 minutes ago, Mike Poole said:

So it has all gone up in smoke then!  The invisible block is no more. This is more devastating this year than many for so many reasons, first +4C the go to aversive temperature for UK rubbish temperature is the optimum for Covid-19, but more importantly if ever we needed something to take our minds off the apocalypse that will not end for months it is now, and endless wind and rain is absolutely not what was required.  The GloSea5 update the final kick in the teeth, if that can’t see a SSW, there won’t be one.  

So now Mike that's EC46 and Glosea not looking favourable. I got the impression from chatting with Tamara that she was thinking that this EC take on things was how she thought it could be panning out. This was prior to her post the other day when she had only had a brief look into things, but I got the impression from her post that things could end up being pretty difficult. If we can't get a favourable outcome  with a favourable Hemisphere, what chance have we got! All of this is driving me nuts... A couple of years ago we had very positive background signals which didn't even devolop a cold snap... Last year we had the IOD that seem to be a major spanner in the works... Now so far this year favourable sypnotics seem to be going to waste.. I noticed when I checked the long range EC anomalies the other day, that large parts of Europe as well as the states are being shown to be warmer than avareage also.. So we are not alone. Its already been 10 years since we had significant and persistent cold, surely to god we are due a change of fortunes... But like you say Exeter don't seem to keen on the idea of any major SSW... Hopefully things will change... But my god things rapidly drift away once Xmas is out of the way.. 

[bluearmy]

Back end of the eps are trending cooler .....nothing frigid but then again, there won’t be at two weeks range ! At least it’s not trending milder at that range !

[northwestsnow]

9 minutes ago, chionomaniac said:

Lol mike, I wouldn’t quite say that it has gone up in smoke. After all, up to day 5/6 the output hasn’t changed and we have seen models subsequently react to a change in tropical forecasts after this timeframe

Thats the problem chino...

The pot of gold overwhelmingly  turns into a crock of crap.

If I had a pound for the number of times the extended eps looked fabulous until you count down and the cold signal is diluted to nothing id be a rich boy !!

Even someone like myself with a mere fraction of the knowledge of others on here could see the writing on the wall for Dec a week or more since...

On reflection I totally understand peeps looking for avenues to cold ,truth is they are,95% of the time in a warmingworld,a mirage...

Edited December 11, 2020 by northwestsnow

[bluearmy]

5 minutes ago, MATT said:

. Its already been 10 years since we had significant and persistent cold, surely to god we are due a change of fortunes... But like you say Exeter don't seem to keen on the idea of any major SSW... Hopefully things will change... But my god things rapidly drift away once Xmas is out of the way.. 

it’s not ten years since we had a brilliant snowy winter though ??  And dec ‘10 was a once in a hundred years month .....that’s more than persistent cold ! 

[bluearmy]

1 minute ago, northwestsnow said:

Thats the problem chino...

The pot of gold always turns into a crock of crap.

If I had a pound for the number of times the extended eps looked fabulous until you count down and the cold signal is diluted to nothing id be a rich boy !!

Even someone like myself with a mere fraction of the knowledge of others on here could see the writing on the wall for Dec a week or more since...

On reflection I totally understand peeps looking for avenues to cold ,truth is they are,95% of the time in a warmingworld,a mirage...

The extended eps mean has never looked fabulous ....even with the low euro anomolys, there wasn’t any cold around to get decent snowfall out of the pattern - we did well to get what we did last week!  The e euro ridge has persisted and prevented any low uppers getting into Europe