Model Output Discussion - Staying cold into the new year

[bluearmy]

6 minutes ago, Allseasons-si said:

The ECM day ten mean,...it doesn't drop the trough south enough.

lets hope it improves in the morning.

Despite the spread showing that there are runs further south, the fact remains that this is the mean and you’re right, it isn’t far enough south with the lowest heights although better it heads se than sw! 

[Skullzrulerz]

9 minutes ago, bluearmy said:

 

expect a decent size cluster to be further south .....

So if the low was further south would it also bring colder air into the UK? Just trying to understand the meaning here 

[The Eagle]

1 minute ago, Skullzrulerz said:

So if the low was further south would it also bring colder air into the UK? Just trying to understand the meaning here 

At that point it would be bringing the beast. Something much more potent if we get there.

[warrenb]

Means are pointless when confusion reigns. You could half with +10 uppers and half with -10 uppers, guess what the mean is. Yes pointless

[Weathizard]

Looks like we could potentially have the classic LP moving S (SW or SE) into cold air, a notoriously tough pattern for the models to predict, wouldn’t even worry about that at day 8 to be honest, not worth getting knickers in a twist every 6/12 hours over at this point.
 

All this without potential stratospheric effects coming up at a perfect mid winter time, that’s the equivalent of a 10000 strong army riding in horseback when the enemy is already depleted and on the ropes.

 

[bluearmy]

8 minutes ago, Skullzrulerz said:

So if the low was further south would it also bring colder air into the UK? Just trying to understand the meaning here 

The further south the trough the colder the U.K. becomes 

4 minutes ago, warrenb said:

Means are pointless when confusion reigns. You could half with +10 uppers and half with -10 uppers, guess what the mean is. Yes pointless

to a degree,  yes but when the mean corrects further north with the upper trough, you aren’t getting to a better place whatever way you look at the data ! 

[earsnow]

Happy New Year everyone! Things can change rapidly during this SSW evolution! keep the faith!

[chionomaniac]

I’m still concentrating on trends with the NH profile after day 5 and all is still good. Even before the expected cold shot I was always convinced an SSW would occur despite some reservations from a number of people.

So where are we heading for January. Well that is a difficult one.  We have seen some wonderful Synoptics without the matching 850’s so far.  I am sure that if they had been a couple of degrees lower we would already be talking about an historic spell.  The lower strat is still completely broken and that is likely to remain for at least a couple of weeks. So expect a continuation of the Atlantic blocking profile for a while - with this we can never be guaranteed of snowmaggedon, but this year we have so many tickets to the lottery that if one big payout doesn’t occur then we will be considered very unlucky.

my main concern has always been whether or not the SSW will knock the current pattern out and we are left with a displacement SSW only. Indications are still strong that the displacement will be followed by a split as the following chart is pretty indicative of recent runs.

If this type of situation occurs then we will be surely entering a nirvana of cold winter Synoptics, the likes of which we have not seen since the last withdrawal of solar minimum. Coincidence you wonder? I suspect not. But that can be left for another time.

Just enjoy the Synoptics and any cold and snow that results from this wonderful pattern. I suspect that we won’t have to wait too much longer for the Boom charts to enter the reliable timeframe. It’s nice to see that so far this winter that the expected cold pattern has occurred and looks like there is no sign of it abating.

Happy new year to all.

[Allseasons-Si]

The latest day ten EPS...

are we starting to close that warm gap between Siberia and Europe?

EPS clusters at day ten look OK to me but don't look at the ext'd,...oh go on then,the ext'd show a SW'ly come mid Jan in cluster 1 but i nae am worried about it that far out when we can't resolve d 6>

latest zonal mean winds at 10hpa bottoming out between -10>-15.

P.S,i like the Happy New Year emoji 

 

Edited December 31, 2020 by Allseasons-si
Added more info

[bluearmy]

As shown above, too many clusters to get worked up over ...... just need patience until the output settles down .....we have a broad evolution but the envelope way too wide 

the extended period continues to show a relaxation of the cold but I’m way off being convinced that the onset of a reversal is a time for putting much analysis into output two weeks away .......

[Man With Beard]

Keeping my eye on a possible pulse of heights running from Azores to Iberia between D7 and D11. Could temporarily throw up a SWly depending on the interaction with what's happening further north. 

[Cheshire Freeze]

7 minutes ago, bluearmy said:

As shown above, too many clusters to get worked up over ...... just need patience until the output settles down .....we have a broad evolution but the envelope way too wide 

the extended period continues to show a relaxation of the cold but I’m way off being convinced that the onset of a reversal is a time for putting much analysis into output two weeks away .......

I'm trying to think of what dominant pattern could lead to SW'lys for an extended period of time with the strat reversed? The ensembles must be seeing something though as it's a consistent theme.

[georgiedre]

Sorry mods This was posted on twitter and I think it relevant for the model thread but unsure if it has any credibility 

[feb1991blizzard]

4 minutes ago, bluearmy said:

As shown above, too many clusters to get worked up over ...... just need patience until the output settles down .....we have a broad evolution but the envelope way too wide 

the extended period continues to show a relaxation of the cold but I’m way off being convinced that the onset of a reversal is a time for putting much analysis into output two weeks away .......

Once the trend starts though on the extended ensembles, its very hard to reverse, history tells us that, Feb 2012 a classic example, and that was an SSW as well or 'near enough' SSW, we went from runs that were bringing nearly the -20c isotherm into Kent, to a battleground, then after the battleground, the Met Office switched their 30 dayer from bitterly cold month to blowtorch within 2 days worth of updates. it blew up in the space of a few days, if i had gone with my own instinct with reading GEFS suites rather than MO updates, i would have seen it coming quicker and save myself some devastating disappointment.

[Snowman.]

2 minutes ago, georgiedre said:

Sorry mods This was posted on twitter and I think it relevant for the model thread but unsure if it has any credibility 

The orignal image is a gif, it basically inverts the signal with prominent blocking across the northern regions with strong troughing south of us.

Good news.

[chris55]

40 minutes ago, bluearmy said:

 

expect a decent size cluster to be further south .....

What’s the date stamp for this Blue? Would be helpful  

[Mike Poole]

Well 2020 is drawing do a close... maybe time to leave you with the JMA at T192:

What’s possible when there’s no vortex!  

My last post of the year.  

I would like to thank everyone who posts in here, and everyone who reads the stuff we write.  It has been a horrible year, and for me, this is one of the few hobbies that I have been able to carry on doing, so whilst we may not agree about every shortwave, I think we might agree about the long wave picture, which is that we need each other.   

Best regards for a happier 2021!

Mike

[chris55]

5 minutes ago, georgiedre said:

Sorry mods This was posted on twitter and I think it relevant for the model thread but unsure if it has any credibility 

I think they missed a ‘C’

[Weathizard]

Being really fussy, a little bit west based but can’t complain at that for the next month or so, looks like for once the vortex might be staying well away from that eastern Canada/ESB locale for mid winter

[danm]

Am I missing something here?  The SSW isn’t meant to occur for about 4/5 days, and it’s impact on the trop is still to be determined. So surely the output is due to change dramatically, and hopefully for the better, over the coming 10-14 days. It’s still very much a wait and see approach from my POV for the medium term outlook. 

[supernova]

4 minutes ago, Mike Poole said:

Well 2020 is drawing do a close... maybe time to leave you with the JMA at T192:

What’s possible when there’s no vortex!  

My last post of the year.  

I would like to thank everyone who posts in here, and everyone who reads the stuff we write.  It has been a horrible year, and for me, this is one of the few hobbies that I have been able to carry on doing, so whilst we may not agree about every shortwave, I think we might agree about the long wave picture, which is that we need each other.   

Best regards for a happier 2021!

Mike

Nice post. How about a SSW to celebrate, Mike?! Thanks to all posters, in fact, on whom so many of us rely. 

[BARRY]

7 minutes ago, Mike Poole said:

Well 2020 is drawing do a close... maybe time to leave you with the JMA at T192:

What’s possible when there’s no vortex!  

My last post of the year.  

I would like to thank everyone who posts in here, and everyone who reads the stuff we write.  It has been a horrible year, and for me, this is one of the few hobbies that I have been able to carry on doing, so whilst we may not agree about every shortwave, I think we might agree about the long wave picture, which is that we need each other.   

Best regards for a happier 2021!

Mike

A happy new year to you

 

[Weathizard]

Just now, danm said:

Am I missing something here?  The SSW isn’t meant to occur for about 4/5 days, and it’s impact on the trop is still to be determined. So surely the output is due to change dramatically, and hopefully for the better, over the coming 10-14 days. It’s still very much a wait and see approach from my POV for the medium term outlook. 

Doesn’t downwelling start a while before the actual SSW event? There’s a few very good long posts on some other threads about it.

I think the point most are making is, ensemble suites are fickle at the best of times, let alone when we have such an unusual NH pattern and stratospheric warming occurring.
 

[Kentspur]

6 minutes ago, Weathizard said:

Being really fussy, a little bit west based but can’t complain at that for the next month or so, looks like for once the vortex might be staying well away from that eastern Canada/ESB locale for mid winter

Is that last image a long fetched Siberian flow from the NE? Beast?

[bluearmy]

6 minutes ago, chris55 said:

What’s the date stamp for this Blue? Would be helpful  

Day 10

1 minute ago, danm said:

Am I missing something here?  The SSW isn’t meant to occur for about 4/5 days, and it’s impact on the trop is still to be determined. So surely the output is due to change dramatically, and hopefully for the better, over the coming 10-14 days. It’s still very much a wait and see approach from my POV for the medium term outlook. 

Yes and no ..... there is only one model from top to bottom.  So it’s modelling the reversal and then goes on to model the remainder of the run.  That’s the no part. The yes part relates to the fact that models don’t deal with reversals too well as they don’t happen v often so as the run progresses, it’s likely to be even less reliable than usual. (Which isn’t great anyway)