Model Output Discussion 29th December - Into mid-Winter.

[weatherguy]

216 ECM looks like another Scandy high incoming.

[karlos1983]

Just because a D8,9 or 10 chart probably won't verify, does not mean it shouldn't be up for discussion. This is the model discussion thread after all?

[snowwman]

To my thinking, ECM is going for a sustained Easterly- sort of like the 12Z GFS but which sticks around.

[Mucka]

8 minutes ago, bluearmy said:

in line with the 00z ens and now the important part re undercut way to our west. plenty of energy going over the ridge so squeaky bum time

So long as we get through to the mid term unscathed by a West based -NAO then I think Steve's, "At least it will be cold," appraisal should hold true.

ECM has actually shown great consistency in the last 3 Op runs and despite you winning the East/West lottery on this occasion I will double down on tomorrows run 

The undercut will come with a little more amplification upstream and the pattern will be backed West along with a quicker draining of those Euro heights

You'll see, oh you'll see muhahahahahaha

Edited December 29, 2016 by Mucka

[SMU]

12 minutes ago, Man With Beard said:

T216 is a nightmare chart for uncertainty!! Could get stuck in a mild pattern if the loop doesn't close at the bottom - but it could still close...

Most of the energy in atlantic going SE though means the bulge of high will continue to develop...

[radiohead]

Again...just too far eastwards. Frustrating. But it's FI and will no doubt change many times before we get there....

[mountain shadow]

Just now, Snowmaggedon said:

How can you be so certain of next week's Northerlies based on this evening's runs? Nothing is set in stone, it's still all to play for! 

Nothing is certain but the two best models arent going for it.

I think we are looking ahead now to see whether the Scandanavian High is likely at Day 10.

[Gustywind]

Pressures rising over Scandi, 264hrs would bring an easterly.

[Geordiesnow]

3 minutes ago, mountain shadow said:

Given the background teleconnections it was always more probable that the first two Northerly attempts would fail, i did caution against believing any model showing a true Greenland High.

At least it will be much colder under the UK high and light wintry showers cannot be ruled out.

 

How is the first Northerly a fail!? Potential for snow showers in Northern Scotland and down the east coast from that and temps will struggle to rise during Monday, what lets it down is that it does not last all that long but the models have been more or less bullish on this. 

As for the 2nd Northerly, there is still a lot of uncertainty regarding this so how can you be sure that is a fail at this stage? 

I am skeptical about the formations of Greenland highs though, unless I see this happening in the 96-120 hour stage then its always subject to change. 

[chionomaniac]

Great WAA north of Iceland on this run at T+240. T+264 and T+288 would make pleasant viewing.

[bradymk]

2 minutes ago, radiohead said:

Again...just too far eastwards. Frustrating. But it's FI and will no doubt change many times before we get there....

Too far eastwards for a Greenland high and northerly yes, but a few charts time after that and you'd have a good easterly. 

[Tony Beets]

The cut off low is going under in the Atlantic, feeding heights. Another variation of a possible outcome tonight 

[That ECM]

4 minutes ago, Steve Murr said:

Most of the energy in atlantic going SE though means the bulge of high will continue to develop...

I think this highlights SM point.

[snowwman]

 

Yup, Something between a Northery and and Easterly is where I think this run's headed. Most likely outcome: sustained Easterly (with undercutting latter on).

[Geordiesnow]

ECM is showing its usual 216 and 240 hours blocking charts but the main trend from last night is to lessen any height rises towards Greenland and shift things eastwards. 

Potential is there for some bitterly cold air to head our way eventually and the outlook is for a mixture of cold and mild but again, the real snowy set ups are not really there with the exception of the Northerly blast for New years day which could bring some members their first snowfall of the season. 

[weatherguy]

Lets look at the comparisons between 12z GFS and ECM then out to 240.

GFS

MAR holds, northerly incursion, HP flattens, consolidates, another northerly shot, flattens somewhat, height rises towards scandy. We know how this propogates further down the line.

ECM

MAR holds, northerly incursion, HP flattens, less potent northerly than GFS follows reamplification (to a lesser extent than the GFS), height rises up towards scandy.  

Pretty decent agreement at this range to me. The real divergence appears around 192h, with the general pattern being the same.  I'm sure the ECM solution would essentially be the same further down the line.  Makes for good watching this

Edited December 29, 2016 by weatherguy

[Richard Fisher]

12 minutes ago, ajpoolshark said:

 

A perfect example of how two members can have utterly different interpretations of the same chart.........certainly makes for 'interesting' reading does this thread at times!

Yep I tend to read the posts from more knowledgeable members rather than knee jerk reactions from others.

[Allseasons-Si]

So we have the big two at 240hrs,i know it's FL but i like both of them ,ECM has a bigger block and the Atlantic would not get through that and would be followed by an easterly.

GFS has more of a pincer against the pv,so different placements on the nh view but the trends are still the same

 

Edited December 29, 2016 by Allseasons-si

[West is Best]

Just seen the final stretches of the 12z GFS. Good LORD! Armageddon charts!!

[bluearmy]

Whilst the GEFS chop and change their orientation with each run, the eps seem pretty consistent with their op. The run pretty well as I expected it and I don't think that ridge will back much further west tomorrow mucka (though a few hundred miles feasible) 

the trough over n America at day 8/9 much sharper than the previous run and drives that Atlantic trough downstream a bit further south than might be likely. Whilst the op fits with the ens, it's good for later week 2 re the undercutting of the ridge. 

[mountain shadow]

7 minutes ago, Geordiesnow said:

How is the first Northerly a fail!? 

It is not potent and not sustained before it topples/sinks.

2nd attempt going the same way unless you believe the GFS over ECM/UKMET

Will the third amplification bring in an Easterly though? More runs needed

 

[Dominic Carey]

3 minutes ago, West is Best said:

Just seen the final stretches of the 12z GFS. Good LORD! Armageddon charts!!

In a good or bad way for cold?

[Ali1977]

I think the extended EPS will tell us which way this went on this run, the 10 day might not look that great at the 9/10 day mark, but would this be the transition to an Easterly or the Atlantic pushing in - we shall see.

[swfc]

6 minutes ago, West is Best said:

Just seen the final stretches of the 12z GFS. Good LORD! Armageddon charts!!

sorry????

do you not mean 6z

[West is Best]

Just now, swfc said:

sorry????

do you not mean 6z

Nope stunning Scandi high, bitter easterly with astonishingly low temps, followed by a classic boundary attack which can brilliant results.