Model output discussion - cold proper on the way?

[kold weather]

Well the GFS ensembles have really shifted BACK towards high pressure dominating Scandi/Europe. It doesn't mean we will get an easterly but the ensembles are surprisingly strong with the signal considering what they have done thus far.

Just when you think its all done...a small breadcrump thrown back at us, HA!

The main thing though is to watch the blocking forming in the upper latitude later in FI. If we have blocking nearby, all the better clearly.

Edited January 19, 2019 by kold weather

[edinburgh_1992]

15 minutes ago, Mr Frost said:

Mate I am based in Scotland and I think you live in a Scotland that is based in outer space!

I am on the West coast and have a high of 5 degrees for next Friday going by the Metoffice - Aviemore a high of 2 degrees ect ect...

John is spot on with his post.

 

 

Fom Thursday temps on GFS are showing to be  around 6C and then up to 9 in the next days along the east coast. Even showing 6 degrees on Thursday and Friday night around Edinburgh. Not exactly what I would call cold

[MattStoke]

GFSP gives more snowfall from Tuesday’s front.

Usual caveats apply about GFS snow charts, but I thought I’d try and lift peoples’ mood somehow.

[bradymk]

Straw clutching perhaps but still a respected model!

JMA by far the best at +84 tonight. 

Will the ECM be as amplified..

[Stuie]

2 minutes ago, edinburgh_1992 said:

Fom Thursday temps on GFS are showing to be  around 6C and then up to 9 in the next days along the east coast. Even showing 6 degrees on Thursday and Friday night around Edinburgh. Not exactly what I would call cold

You have quoted Thurs/Monday/Friday

[bluearmy]

1 minute ago, kold weather said:

Well the GFS ensembles have really shifted BACK towards high pressure dominating Scandi/Europe. It doesn't mean we will get an easterly but the ensembles are surprisingly strong with the signal considering what they have done thus far.

Just when you think its all done...a small breadcrump thrown back at us, HA!

They have certainly pricked my interest - if we do have the downwelling wave interacting with the trop then we can expect the modelling to be unreliable - even at short timescales (as we have seen over the past 36 hours). 

[kold weather]

Mattstoke, quite an impressive looking event if the GFS was to be right, probably widespread couple of cms...but no real support from any other models thus far so it maybe too cold in the fronts wake. That is a common GFS flaw in such a set-up.

[Rocheydub]

2 minutes ago, bradythemole said:

Straw clutching perhaps but still a respected model!

JMA by far the best at +84 tonight. 

Will the ECM be as amplified..

And what I like about it, is less pressure in the Griceland area meaning arctic high link up is more possible.... Nice spot!

[Pembroke Dangler]

Just now, abbie123 said:

I don’t believe the ship as sailed gem could have picked up an signal meto are still shouting cold let’s see what the ecm does hasn’t this happened before modles to drop then pick up a day or so later.???

They have but it’s now under 120 hours until it unfolds so time is of the essence here and I just think barring a monumental back track in the next 36 hours max then it’s a done deal and the Euro trough will sink to far south east allowing the Azores high to topple in over us rather than to the north of us.

[Met4Cast]

GFS Day 6 mean isn't exactly awful

Still a fair amount of support for high pressure to the N/NE so I suppose in theory there's still a chance of models reverting back to the Easterly, though I'd personally put that at about 20% currently. 

Not expecting a whole lot of change from the ECM, interested to see what the clusters show later this evening

[danm]

2 minutes ago, Borei said:

The next potential has been at 300 hours for over a month.

Personally I believe neither the models beyond 144 nor those who tell us about tele-connected led macro events.

The truth seems to be that our understanding of atmospheric science is still a long way from being able to predict very much into the future.

Thus isn't a plague on 'experts' it's just a reality check. The MO thread is a testament to exaggerated claims and eventual frustration.

Model output have evolved over the last 24 hours to a much less favorable outlook for U.K. cold. It may change again ........ and that's the point. It constantly illustrates the limitations of human understanding. We all need to re-connect with this reality in our attitude towards what is shown in MO.

 

Sorry, but I’ve got to pull you up on this. 

Anyone’s disappointment with the potential collapse of this cold spell vs what the teleconnective signals were predicting is flawed. No one guaranteed the UK would see anything. The point was ALWAYS that a SSW, plus other favourable background signals, increased the probability of a UK cold spell, not guaranteed it. 

Those same experts you refer to have also stated that micro scale features and spoilers can/could always result in the UK just missing out. If you temper your expectations then you wouldn’t feel the need to criticise those experts on here who have been largely bang on with the broad scale pattern changes we’ve seen. 

[SLEETY]

What's the betting ECM throws out a stellar run in a liitle while

[JBMWeatherForever]

Still to early to say "This ship has sailed", there is still time for an easterly for next week. Still much uncertainty, the models have still not settled on the final outcome just yet ! There also seems to be a perpetual theme by the GFS to bring us a north easterly eventually ! But maybe still later next week.   

[Mucka]

GFSp at 174 is a repeat of the pattern coming up that promised us the Easterly

174h V 54h

[Dean E]

I don't think anyone of us expected such a turn around at this stage, but this is the beauty of meteorology, we still only understand so little!

I think the issue here is with the Low moving down eastern side of the UK on the 23/24th. Both the EC and GFS appear to stall it over Eastern Scotland. Allowing the Azores high to ridge in the gap as the lower heights sink over the med.

GFS +96                                                                +126hrs

 

What is interesting to me is there is nothing stopping the low sinking south (I believe someone else mentioned this?) but eventually it gets moving and promotes lower heights over the med. But even then, this is too late as the pattern completely flatten out.

One thing is for certain, we've got positive outlooks (AO, NAO, MJO to name a few) all on our side. It's just getting the pieces in the right place. I would not be surprised if the EC tonight promotes a new trend for next weekend...

 

 

Edited January 19, 2019 by Dean E
Grammar correction

[MattStoke]

2 minutes ago, kold weather said:

Mattstoke, quite an impressive looking event if the GFS was to be right, probably widespread couple of cms...but no real support from any other models thus far so it maybe too cold in the fronts wake. That is a common GFS flaw in such a set-up.

Indeed. It’s the showers following that have my interest for here and other northern and western areas, but north westerlies are generally rubbish for south, including my home city of London.

[Dancerwithwings]

3 minutes ago, MattStoke said:

GFSP gives more snowfall from Tuesday’s front.

Usual caveats apply about GFS snow charts, but I thought I’d try and lift peoples’ mood somehow.

LOL! the 'ICON hi res' has it coming in as rain to snow and back to rain again....never was a fan of that model

[kold weather]

1 minute ago, bluearmy said:

They have certainly pricked my interest - if we do have the downwelling wave interacting with the trop then we can expect the modelling to be unreliable - even at short timescales (as we have seen over the past 36 hours). 

Regardless of whether it actually were to go back to an easterly, the fact that the block holds would be no bad thing, if only to keep cold near our shores so any -ve NAO set-up with undercutting lows has a cracking cold pool to tap into.

Quite a large number of runs have that high pressure at least making some effort at resistance, really does seem as you say there is huge uncertainty even at real close range.

[Singularity]

 

So putting the Tue-Wed slider fail debacle aside... what do we now have at 6 day's range?

IMO - a pattern very sensitive to changes in the zonal flow. Small adjustments can make the difference between the Atlantic troughs disrupting against the Scandi High and riding up over it. Currently modelling is a lot more keen to do this with the next trough in the chain, but I'd not be surprised to see the one on D6 have more of a go first.

The UKMO D6 is a highly unusual chart, so not the easiest to interpret from, but the 'dangling' trough down through the Azores suggests a weaker jet than GFS has for that time so the odds of disruption and slider developments for D7-D8 are higher. 

Arguably I'm looking a day too late given that GFS is extremely close on D5 to a trough angle sufficient to build an Azores-Scandi high link.

UKMO a very different matter of course. For what it's worth I don't think I've ever seen a real example of the 'flabby banana-trough' that it's gone with.

[Mucka]

GFS ensembles, still a handful dreaming of -10 uppers last week of Jan

[Nick F]

I’m still not sure we can be confident that any of the models will be more likely than others to have the right way forward with the synoptic evolution mid-late next week week by the end of today.

There seems to be a great deal of uncertainty still over the track and depth of the winter storm over the eastern USA this weekend as it moves NE out of NE USA toward Greenland, combine this with uncertainty of the degree of speed and spatial extent of trough disruption over NE Atlantic / UK / North Sea mid-week (something models often struggle with at close range) and also how the arctic high moving off eastern Greenland interacts with the amplifying Azores high.

I’m not saying that in all this uncertainty that the models will flip back to a bitterly cold easterly or northeasterly later next week, but by no means is the resurgence of the Atlantic westerlies a done deal either. Maybe wait until tomorrow’s runs to see if the Fat Lady has sung.

We await the 12z EC with angst though.

[Rocheydub]

2 minutes ago, Dean E said:

I don't think anyone of us expected such a turn around at this stage, but this is the beauty of meteorology, we still only understand so little!

I think the issue here is with the Low moving down eastern side of the UK on the 23/24th. Both the EC and GFS appear to stall it over Eastern Scotland. Allowing the Azores high to ridge in the gap as the lower heights sink over the med.

GFS +96                                                                +126hrs

 

What is interesting to me is there is nothing stopping the low sinking south (I believe someone else mentioned this?) but eventually it gets moving and promotes lower heights over the med. But even then, this is too late as the pattern completely flatten out.

One thing is for certain, we've got positive drivers (AO, NAO, MJO to name a few) all on our side. It's just getting the pieces in the right place. I would not be surprised if the EC tonight promotes a new trend for next weekend...

 

 

AO and NAO are not drivers.

[Stuie]

1 minute ago, Mucka said:

GFS ensembles, still a handful dreaming of -10 uppers last week of Jan

Also Mucka, hardly any deviation for 5 days, like that.

[snowfish1]

1 minute ago, Nick F said:

I’m still not sure we can be confident that any of the models will be more likely than others to have the right way forward with the synoptic evolution mid-late next week week by the end of today.

There seems to be a great deal of uncertainty still over the track and depth of the winter storm over the eastern USA this weekend as it moves NE out of NE USA toward Greenland, combine this with uncertainty of the degree of speed and spatial extent of trough disruption over NE Atlantic / UK / North Sea mid-week (something models often struggle with at close range) and also how the arctic high moving off eastern Greenland interacts with the amplifying Azores high.

I’m not saying that in all this uncertainty that the models will flip back to a bitterly cold easterly or northeasterly later next week, but by no means is the resurgence of the Atlantic westerlies a done deal either. Maybe wait until tomorrow’s runs to see if the Fat Lady has sung.

We await the 12z EC with angst though.

When is the ECM run due out please I hope. It takes up the easterly baton again 

[MattStoke]

1 minute ago, snowfish1 said:

When is the ECM run due out please I hope. It takes up the easterly baton again 

Starts to come out at 6pm.