Model output discussion - mid January

[Daniel*]

1 minute ago, frosty ground said:

I do hence why Im posting about it...... Is that okay?

The uppers don't look that special at 120 and if the run follows this morning the 168 chart will have a high over the UK with the coldest air to the east,

The GFs has swept the very cold air away by day 8.

 Vs 

North Westerly more likely to verify (based on GFS 12z and GEFS 06z), just hope that high can back west a little,

Everyone seemed to ignore the very cold runs on the GEFS has been removed on the 06z run!

Okay keep your wig on  

There is one only at day three did that sneak under? it isn’t especially long lasting two to three days but you should see some wintriness especially with your elevation I assume being in Oldham, NW areas favoured. 

[mountain shadow]

6 minutes ago, Daniel* said:

Difference of interpretation might be wrong but that doesn’t look clear cut to me... 

The only way to an Easterly from there is if a piece of energy from the Canadian vortex slides South East to meet the low heights over Spain, I haven't seen any indication of that in the reliable, let alone anything would somehow lead to long lasting Easterly.

Edited January 29, 2018 by mountain shadow

[Froze were the Days]

What happened to the Scandi ridge on this run?...almost non-existent, yet again models underplaying the strength of the northern arm of the jet. Trends going the wrong way in my opinion but not wholly surprising as we're chasing (the majority) an easterly which is becoming as rare as Lord Lucan sunning himself on the beach down at Newhaven.

[weirpig]

The difference between the models at the moment is stark  only have to look at the difference between the gfs 6z and 12 z run, never mind the difference between the UKMO  one thing i can say with some assurance  is that the ECM will also be different.   to many variables at play yet to make a coherant foreast.   nevermind what conditions a cold North Westerly will bring in your patch of the UK.

[Froze were the Days]

11 minutes ago, frosty ground said:

Who cares about the south East? Sorry but the air is col and its coming from the North west as shown. Your personal preference isn't the issue.

Yeah chill mate...personally had enough of cold zonality this winter, only positives it brings is fairly clear skies to this part of the world (sorry you don't want to know that) other than continuous gloom we seem to get most winters...

[igloo]

12 minutes ago, Froze were the Days said:

'very cold air' coming in from the north west?...as the majority of the UK could tell (other than northern uplands) after the last spell you don't get very cold from those situations. We had 7c for a couple of days in the south east.

1. yes it has been the theme  all season and there is nothing to suggest its going to change anytime soon many people have done well from these north westerlies  this season one thing which looks strange is you don't often see all the PV slap bang on our side of the hemisphere with nothing in Siberia and I mean nothing that's from all models for the past 3-4 days now 
2. 

[Captain Shortwave]

Significant differences in terms of the end result appear early on between the models.

The UKMO already has the trough over the UK disrupting against that weak pulse of warm air advection, this results in a weaker low moving south east through the UK with a slack easterly developing at day 6 as heights try to build over the top, not sure how wintry the result would be though as conditions for convection off the north sea look pretty poor at that stage.That said the day 7 chart might just get there for the south with high pressure probably centred over the northern half the UK stretching ENE into Scandinavia.

The GFS however is moving the trough eastwards undisrupted with a colder NW flow following behind with enough amplifiaction to pull the winds northerly and tap a modestly potent northerly albeit brief, veering the winds NE or east is possible from here but you would require a more amplified Atlantic ridge to allow cold air to dig further south and west towards Iberia to support heights building further north over the northern half of Europe.

The GEM pretty much sits between the two solutions above with low pressure disrupting further east.

You get the high but the Atlantic jet has pushed through the UK keeping the Azores high as the dominant ridge and the weather generally changeable with temperatures near normal overall. As for some of the posts above, well it is all well and good having a cold NW flow, but a fay later you will lose any lying snow as we see milder air push in.... unless we get the extra amplification to get the cold air to properly dig in over Europe and the UK.

Edited January 29, 2018 by Captain Shortwave

[Man With Beard]

There's a number of routes after this. 

If phasing happens between the front north of Norway heading east and the front near the Baltics heading west, the heights in the Atlantic, I guess, would collapse through the UK.

If phasing does not happen, the heights in the Atlantic would probably continue on their current path, with is far to our north - resulting in a monster easterly.

[offerman]

7 hours ago, Daniel* said:

If it stopped our winters would be freezing probably! Would be very significant on our climate.

http://blogs.ei.columbia.edu/2017/06/06/could-climate-change-shut-down-the-gulf-stream/

Apparently it has slowed down between 15-20% since the 1970s this is indicative below the linear trend from 1900 to 2013 North Atlantic has cooled, a slow down of the circulation is discernible; imo that’s all the ‘cooling’ can be attributed to really or indeed the fresh water melt, however it sticks out like a sore thumb compared to other cold regions which have warmed despite the melt. Which therefore makes me think it’s not the melt entirely, but I think they overlap with another, saline currents bringing warmth are being disrupted IMO by all the excessive fresh water melt. In 2014 & 2015 area south of Greenland had record coldest anomalies going back to 1880, this should not be happening really everywhere else has warmed there was a lot of discussion on here, regarding a cold North Atlantic blob which seemed to go on and on. Clearly the world warming at an unprecedented rate at least recorded there are going to be winner and losers. Where we are positioned there truly could be an impact however it will be lessened by AGW there could still be a noticeable impact but some scientist theorise we could be a while off that. 

 

Excellent Daniel 

 

Thank you so much for that informative detailed

explanation .

[mulzy]

GEFS - huge scatter at only day 5 - nothing is resolved even at such a short timeframe.

[weathermadbarnsleylad]

I really think we are in for something special at the minute, it's just not showing yet on the 12z, a couple more runs and we will back in the game, like I said earlier anything past 96hr will change about 90%of the time it's only a forecast of what might happen and not reality, it's a very interesting period coming up and still all February to go thru and maybe march, so if we don't get it now always a chance later on.

Ps it's only what I think and I could be completely wrong lol ha ha. Also already managed to take young one sledging a few weeks ago. So done lot better than last five winters roll on 12z ecm. 

[weathermadbarnsleylad]

1 minute ago, mulzy said:

GEFS - huge scatter at only day 5 - nothing is resolved even at such a short timeframe.

96hr maybe less

[Johnp]

30 minutes ago, Man With Beard said:

There's a number of routes after this. 

If phasing happens between the front north of Norway heading east and the front near the Baltics heading west, the heights in the Atlantic, I guess, would collapse through the UK.

If phasing does not happen, the heights in the Atlantic would probably continue on their current path, with is far to our north - resulting in a monster easterly.

P19 seems a good match at 144hrs. Seems to take a promising evolution afterwards.

[shaky]

Have a feeling pub runs gona go on the bender as it always does and show something completely different at 120 hours tonight!!probably something more like the ukmo!!

[Singularity]

The GFS 12z sort of looks like an attempt to adjust toward the UKMO way of doing things, but only half-hearted and resulting in a sort of strange in-between state that soon gets brushed aside by the model's usual zonal enthusiasm.

It will be of great interest to see whether or not ECM sides with UKMO this evening. Key - and unusually large for such range - differences are evident between UKMO and GFS at just four day's ahead. Madness!

[chris55]

59 minutes ago, mountain shadow said:

Eh?

The UKMO shows a very brief burst of North Easterlies into Kent before the Atlantic piles over the top of the ridge. In what way does it have a prolonged look about it?

 

Looking at UKMO on Wetter I'd say it has some potential to build the ridge over Scandi. 

Im an old school boy and can read the way the charts are rendered on wetter much better then Metiociel. To me UKMO 144 looks pretty good.

look at the vertical advection north of Iceland, should build the ridge. (Haven't seen the 168 mind)

 

 

[Catacol]

7 hours ago, Daniel* said:

If it stopped our winters would be freezing probably! Would be very significant on our climate.

http://blogs.ei.columbia.edu/2017/06/06/could-climate-change-shut-down-the-gulf-stream/

Apparently it has slowed down between 15-20% since the 1970s this is indicative below the linear trend from 1900 to 2013 North Atlantic has cooled, a slow down of the circulation is discernible; imo that’s all the ‘cooling’ can be attributed to really or indeed the fresh water melt, however it sticks out like a sore thumb compared to other cold regions which have warmed despite the melt. Which therefore makes me think it’s not the melt entirely, but I think they overlap with another, saline currents bringing warmth are being disrupted IMO by all the excessive fresh water melt. In 2014 & 2015 area south of Greenland had record coldest anomalies going back to 1880, this should not be happening really everywhere else has warmed there was a lot of discussion on here, regarding a cold North Atlantic blob which seemed to go on and on. Clearly the world warming at an unprecedented rate at least recorded there are going to be winner and losers. Where we are positioned there truly could be an impact however it will be lessened by AGW there could still be a noticeable impact but some scientist theorise we could be a while off that. 

 

Though that interesting phase of mid atlantic chill seems to have faded. We now have an SST pattern supportive of the +NAO winter we are having with warmer than average temperatures to our SW helping sustain the azores high. Low AAM at the equator also serving to strengthen sub tropical ridges. End result is a very tough pattern to break out of. We have an uptick in positive forcings at the moment (torques aligning with MJO progress) but nothing suggesting a solid impact in the near future to build a block in the right place... What about Mid February? Cant rule anything out in the world of weather, but the return of strong north American cold will do nothing to weaken north atlantic cyclogenisis and it will need to be one mighty big MJO cycle to give sufficient westerly additions at the equator to reduce atmospheric momentum at high latitudes significantly. Vortex developments also looking less and less helpful. I think I suggested a mid lat block was the best we might get out of the current pacific spike, and nothing yet to change that interpretation.

We are all still glued to developments and there is always a chance of a sudden change - but the window for any realistic chances of significant and sustained continental cold with snow is steadily closing. Some really interesting tweets out there today and yesterday about the season in general - I'll put something together on the teleconnection thread later for viewing and discussion.

 

[Chesil View]

Just now, chris55 said:

Looking at UKMO on Wetter I'd say it has some potential to build the ridge over Scandi. 

Im an old school boy and can read the way the charts are rendered on wetter much better then Metiociel. To me UKMO 144 looks pretty good.

look at the vertical advection north of Iceland, should build the ridge. (Haven't seen the 168 mind)

 

 

Couldn't agree more Chris55 meteociel Euro/Atlantic charts are very poor compated to wetterzentrale for showing whats really going on geographically.

[mulzy]

26 minutes ago, Johnp said:

P19 seems a good match at 144hrs. Seems to take a promising evolution afterwards.

P19 is truly a marvelous run!

[nick sussex]

It’s amazing just how much of a drama the models have made of the upstream pattern.

Tonights differences between the GFS and UKMO from an early timeframe continue to show divergences.

The UKMO looks like it will force that lobe of high pressure further ne at T168hrs so quite a nice run.

Ironically the GFS which was much more keen on the better evolution has now dropped that.

Lets see what the ECM has to say.

[Decemberof2010]

3 minutes ago, mulzy said:

P19 is truly a marvelous run!

Indeed. If that had been what the op had shown tonight, we would have been on page 100 by now!

[Duane S.]

OK, I won't be betting my house on it but... the quickly easterly evolution is still showing in the 12z GEFS set, until this disappears completely for a few runs, I won't be discounting it...

 

[ArHu3]

And gone is the cold signal in the GEFS plume 

[feb1991blizzard]

4 minutes ago, s4lancia said:

OK, I won't be betting my house on it but... the quickly easterly evolution is still showing in the 12z GEFS set, until this disappears completely for a few runs, I won't be discounting it...

 

I wouldn't completely rule it out but I would now rule it out within any sort of reliable timeframe - forget it within 192 but theres no reason to say it wont start to re-appear post 300, as the next atlantic ridge ridges up towards Greenland and then topples.

[Daniel*]

It’s like a critter that will not die. It’s back for now....