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

[ghoneym]

11 minutes ago, swfc said:

think it says europe on the said tweet

My assumption based on his usual dialog being bias towards the USA (obviously as he is a yank) is that the "coldest temperatures over Europe" are at 10 hpa, and the downward propagation to the trop "suggests" favourable cold pattern for the USA. Thats how I read it anyway.

[bluearmy]

9 minutes ago, ghoneym said:

My assumption based on his usual dialog being bias towards the USA (obviously as he is a yank) is that the "coldest temperatures over Europe" are at 10 hpa, and the downward propagation to the trop "suggests" favourable cold pattern for the USA. Thats how I read it anyway.

Agreed 

[Gowon]

The GFS looking more amplified to our NE..

 

[NorthernRab]

The GFS 12hz continues the recent trend of backing away from any swift return to zonality. Quite a bit more in the way of heights around Greenland  too. 

 

 

[frosty ground]

The trend that has been noted by a few is really apparent now. (Undercut almost)

Edited January 18, 2017 by frosty ground

[Seasonality]

39 minutes ago, swfc said:

think it says europe on the said tweet

I thought it referred to coldest strat temps over Europe, not the surface. And if you read his other recent tweets he refers to increasing surface cold over the USA. It is that kind of ambiguity that means posting such tweets in this thread without any context can be confusing. In the 12z, sharper ridging pushing warm uppers past iceland and colder uppers making better inroads into central Europe compared to the 12z, good signs.

[Seasonality]

Spot the difference, this could be a good one.

[Gowon]

No zonal there.. We're back to cold continental air.

 

[frosty ground]

UKM is miles away from the GFS,

Edited January 18, 2017 by frosty ground

[MR EXTREMES]

10 minutes ago, D.V.R said:

No zonal there.. We're back to cold continental air.

 

7 days away do u trust it lol.

I think we're going to have to wait for the long awaited ssw event.

Does the ukmo show anything remotely interesting ecm this morning was only showing hints of something colder into end of January.

 

Although I don't see any real zonal onslaught so chilly at times not really so cold in the north.

Well my answer is above awful ukmo.

So pretty mild for a bit.

 

Edited January 18, 2017 by MR EXTREMES

[winterof79]

36 minutes ago, bluearmy said:

Agreed 

Not much point in getting any hopes up over here really then? SSW or no SSW If that is how it transpires.

Why am I not surprised.

Although no one of any standing has predicted anything correct thus far.

Edited January 18, 2017 by winterof79

[Gowon]

Just now, MR EXTREMES said:

7 days away do u trust it lol.

I think we're going to have to wait for the long awaited ssw event.

Does the ukmo show anything remotely interesting ecm this morning was only showing hints of something colder into end of January.

 

Although I don't see any real zonal onslaught so chilly at times not really so cold in the north.

Not really just looking for trends

[sebastiaan1973]

1 hour ago, nick sussex said:

Looking at todays Velocity Potential 200 signal, for those not following the thread last night this over the last few weeks has been better at discerning the correct MJO signal. That shows the MJO now in phase 1:

Although this has now come into more agreement with the normal Wheeler Hendon index it could be because of the lag effect that the models are still trying to incorporate too much of the phase 8.

We really need to lose that phase 8 effect!

In terms of the trend, this has been in recent days to have the high near the UK hanging on for longer. The ECM in particular although now given some support from the GFS 06hrs run tries admittedly without vain to bring high pressure to the ne into the equation but too much energy spills over that and we see as we have done for much of the winter the deep cold heading towards the eastern Med.

Trying to resolve whether this green shoot can turn into a plant depends greatly on the behaviour of troughing in the eastern USA. Last nights ECM had more amplification at a key timeframe which means theres less easterly push to low pressure to the nw, todays has less amplitude and that's the reason that the ECM 00hrs doesn't have the same interest towards days 9 and 10.

Overall the ECM ensembles and GEFS aren't really interested in another easterly drama, whether that changes over the next few runs we'll have to wait and see but we do need a favour from that upstream troughing if the trend is to gather any pace.

 

Why is MJO phase 1 so important to you? 

[bluearmy]

8 minutes ago, winterof79 said:

Not much point in getting any hopes up over here really then? SSW or no SSW If that is how it transpires.

Why am I not surprised.

Although no one of any standing has predicted anything correct thus far.

Propagation of reversal patterns from the strat down to the trop are generally at least  2 weeks - that's if we get a downwelling 

add to that there is a chance of a quick trop response within a  few days

however, neither are guaranteed to deliver deep cold to nw europe

n America is likely to go cold based on the current modelling of Alaskan ridge anyway - they prob won't need any strat forcing 

Edited January 18, 2017 by bluearmy

[winterof79]

Story of this winter

One model shows promise GFS

the other busts it UKMO

I know Nick will be able to give me the upstream differences and their subsequent consequences for us

 

Edited January 18, 2017 by winterof79

[Seasonality]

Full on zonal has taken even longer to arrive on this run. A slow change in the modelling to me feels more reliable than any sudden flip. I'm not sure there is any scientific basis to that though I admit.

[Day 10]

Not getting sucked in again! UKMO (flat) not buying the GFS (amplified) idea at the mo.

Anyway the GFS has this spot on, the UKMO is way out! HONEST!!!

[winterof79]

9 minutes ago, bluearmy said:

Propagation of reversal patterns from the strat down to the trop are generally at least  2 weeks - that's if we get a downwelling 

add to that there is a chance of a quick trop response within a  few days

however, neither are guaranteed to deliver deep cold to nw europe

n America is likely to go cold based on the current modelling of Alaskan ridge anyway - they prob won't need any strat forcing 

It could be me but following downwelling in the past seems to allow colder continental air to retrogress toward us rather than an arctic plunge. This year the cold air seems to have been embedded over Europe for a while so you never know.

Edited January 18, 2017 by winterof79

[joggs]

5 minutes ago, Day 10 said:

Not getting sucked in again! UKMO (flat) not buying the GFS (amplified) idea at the mo.

Anyway the GFS has this spot on, the UKMO is way out! HONEST!!!

Yes.Let's see what ecm brings.

[IDO]

Slight variations within the theme for the next ten days but GFS shows no sign of building a HLB, just the the default 2017 Winter ML UK/Euro high. It is painfully slow to push east and yes we hang onto a more settled regime till around D8-9 but the profile has IMO zero  potential for anything wintry. The high's resistance just prolongs the agony of waiting for a pattern change, though TBH even with that pushing through quicker, its not inconceivable that we will just repeat the pattern again.

The zonal flush does happen as expected and that takes us past D16, so the slowing down of the pattern (GFS usual Atlantic bias) doesn't appear to do us any favours, just delay the inevitable and wipe another sixth of the winter with it! Of course that is just based on what the GFS op is currently showing and although I feel that D9 is the limit to the Euro high's stubborn holding off of the Atlantic, subsequent events may trigger a pattern change within the following westerly regime. The D16 GFS suggests a Pacific wave is possible:

  GEM D10 same: 

I would have thought some trop forcing to disrupt the trop PV would be an interesting starting point combined with the subsequent downwelling of the strat forcing?

So a decidedly uninteresting period upcoming, more HP for those that haven't had enough of that yet, followed by the pressure release of the Atlantic as we lose the Euro high to Russia. Then maybe some background signals, hopefully of more impact than the mediocre efforts of the winter so far.

Edited January 18, 2017 by IDO

[MONKEYJAM]

This time yesterday it was -0.3c here at 5.43pm today same time it's -1.2c !! Is it going to be colder tonight??

Edited January 18, 2017 by MONKEYJAM
Wrong thread

[MONKEYJAM]

Sorry wrong room

[nick sussex]

1 hour ago, sebastiaan1973 said:

Why is MJO phase 1 so important to you?

Its really more about moving away from phase 8 as that's less favourable for western Europe in terms of cold. Phase 1 is more favourable but still depends on other factors.

[blizzard81]

Ecm rolling out now.  Should be interesting

[nick sussex]

The ECM says no to the UKMO at T96hrs. Much better over Arctic Canada with the high set up.