Model output discussion - another cold spell on the horizon?

[Scott Ingham]

9 minutes ago, feb1991blizzard said:

We still have a sniff of a chance here, that chance being that sometimes a rogue op (which i expect it to be) can tend to drive the eps TOWARDS a solution, so if the op is even a tad more moderately blocked on the next run at the end, there is a good chance the eps mean will revert back to the 0z with the ridge longer lasting and further North.

We are in a great position. Full stop.

Taking emotions out and seeing the bigger picture the ecm is just another variation of a very cold post ssw theme

[Daniel*]

13 minutes ago, Man Without Beard said:

I'll post images of some of the ecm ensembles later to show if there are any true Greenland Highs (haven't looked yet for 12z)

Correct me if I'm wrong but the definition of a high is when an area of pressure is higher than the pressure that surrounds it - is everyone working off the same definition?

I suppose so, but what many people on here consider a Greenland high which exerts no influence. Cold highs are normal a true Greenland high involves WAA you see yellows at 500mb centred right over Greenland not touching southern Greenland that isn’t a Greenland high. I must say it bugs me a bit

December 2010 the real deal oranges! Greenland highs are extremely rare well in winter time I seriously think out of 100 which are modelled only 1 verify it just seems a very hard task. 

[Frostbite1980]

Is this a situation where cold air moving into the Eastern US could help our pattern to cold also by creating low pressure moving off the Eastern seaboard and creating WAA into Greenland creating a Greenland high? One of the few scenarios where both sides of the Atlantic are cold? 

[Harsh Climate]

I think if your going to be neutral and give a balanced view it's clear to see that we are going to be in somewhat middle ground, between colder air to the North east and milder air from the west/ southwest. Unfortunately it looks like we are going to be just on the wrong side, with Denmark looking prime position.

I see a lot of hopecasting going on, there's people who have predicted these 'holy grail' winter setups are just around the corner since late December and just keep cherry picking the best charts/ data to back themselves up ignoring all the negative signs. You just know there going to keep bashing that battered drum until there's nothing left of the bloody thing, we're in May or by the law of averages they get lucky a month later .

You can see who the experienced long serving members on here are because it only takes a fleeting look at gfs, ecm and ukmo to know when things aren't that great for us coldies because we've seen that many charts/setups and letdowns you pretty much can give a good analysis from just the quick feeling you get from those 3 models. 

Its clear to see that from the big 3 models iv mentioned any blocking looks transient for the next 10 days or so, we will have cold and mild shots with maybe some transient snowfall probably on high ground. There is no suggestion of a meaningful Greenland high thats going to set up a corner shop for any meaningful length of time and the Atlantic just has a little too much bite at this time.

After that though my opinion is we should start seeing more blocking into February as the SSW comes into play and the Atlantic starts losing its bite. But that is still no guarantee any deep cold will be channelled our way. Patience is required here im afraid.

 

Edited January 10, 2021 by Harsh Climate

[Guest]

11 minutes ago, Steve Murr said:

I will give you 15% > that includes some goodwill

So are you saying the GFS is a waste of space for sniffing out UK cold?

[SMU]

7 minutes ago, Scott Ingham said:

Your assesment of the 12z is correct if not a slight exaggeration with some good political language thrown in but after a ssw you cant take any model or even set as gospel really after 120z and there is Steve a large amount of support at that range for a greenland high/north atlantic ridge whatever youd like to call it in a logical place after shifting of the vortex back to asia and scandi

Possibly > Thats included in my 15% though > also inc is the GFS op. Thats all your getting...

I think really its just a matter of differentiation between an atlantic ridge & a true GH as remember there may be newer members that cant quite tell the difference yet - Some may see Greenland heights & think its the same as a true GH...

Also a GH would certainly guarentee the jet track in the atlantic being steered south now we are 'hoping' it stays south...

I would say 'moderate' optimism tonight for cold weather in the 7-10 window but maybe not deep cold.

Rain turning to snow thurs could be another curtain twiching moment this week...

Edited January 10, 2021 by Steve Murr

[SMU]

2 minutes ago, Snowmut said:

So are you saying the GFS is a waste of space for sniffing out UK cold?

No thats 15% for a true GH

Also see above post...

Edited January 10, 2021 by Steve Murr

[ICE COLD]

What really gets me confused is we are always bemoaning the pv to are north west , euro heights and the jet stream at full speed stopping are chances of getting a cold spell ( proper one ) . But at the moment all of the above has been removed no jet power no pv to nw and no euro heights but still we can’t get no proper cold to the UK ? It’s a shame because we don’t get many chance like this over here . As @nick sussex would say , feels like we’re missing an open goal from half a yard . 

[Scott Ingham]

10 minutes ago, feb1991blizzard said:

I still think there could be an in between solution and until the ECM i always thought this the most likely solution - 2-3 days of very cold air - toppling - yes, but would slow the Atlantic and give further chances as well afterwards.

Which would be a greenland based on steves 552 contour rule.

Just to say this chart is my landing point for this time frame.

A middle ground

[MATTWOLVES 3]

Right folks it appears the ECM op was an outlier,doesn't surprise me..I was getting a tad worried...not by the output..but the way it was becoming like a punch and Judy show in here...oh yes it is....oh no it isn't.. Just to drop a few things in If i can..Marco P stating the zonal mean at 10hpa 60N appears to have flipped back wstly today...May be causing some volatility.. further warming next week should flip them back Estly though. And Matt H pointing out the difference with the GFS and the Ecm Could be to do with whether a region of the Strat Vortex that breaks off gets pulled East or not...GFS does this..ECM does not... so there is again alot going on...

And just to finish Countryfile forecast says going colder later next week....oh dear...looks like cancelling the sledge then only joking... I think Chris Falkes  is a great chap...so as the age old saying goes....MORE RUNS NEEDED..Good lord thats the Doctors orders of relieving stress from my life gone for a Burton...

Edited January 10, 2021 by MATTWOLVES

[Tim Bland]

6 minutes ago, bluearmy said:

He was speaking about the following week .... but maybe worth seeing what the 10pm news 24 says ....

Have we really got that desperate it’s like the old days ..discussing the country file / long range forecasts...I can phone ‘weather call’ & check teletext if that helps They (Meteogroup) just present the ECM

[chris55]

20 minutes ago, Uncle_Barty said:

Exactly.

It's why I don't take too much notice of the mean (other than for a quick comparison with the op), but wait for the clusters.

In a less volatile, quieter time the day 8-9-10 mean can be very useful. Im just reserving judgment for now. 

[Guest]

Just now, Steve Murr said:

No thats 15% for a true GH.

bugger, I was hoping for an early night!

[Man With Beard]

Ok sorry mods for so many images but here's the op, control and first 10 ecm ensembles for D9, looking at North Pole view at 500mb. Won't do this again honest;)

 

I'd describe 3 of them as Greenland Highs (a couple are a Greenland/N Atlantic combo), 1 or 2 others as a close shave. So in the minority at D9 - not quite as prevalent as the 00Z set, if the same proportion is evident in all 51 ensembles. Will check now, along with other dates

(Edit - note these are 500mb charts, not Z500 - it makes a difference to the numbers)

 

Edited January 10, 2021 by Man Without Beard

[Sweatyman]

14 minutes ago, Djdazzle said:

Almost don’t want to see the GFS 18z because it sets you up for disappointment on the 0z!

I'm always set up for disappointment on the 0z!

[SMU]

5 minutes ago, Man Without Beard said:

Ok sorry mods for so many images but here's the op, control and first 10 ecm ensembles for D9, looking at North Pole view at 500mb. Won't do this again honest;

I'd describe 3 of them as Greenland Highs (a couple are a Greenland/N Atlantic combo), 1 or 2 others as a close shave. So in the minority at D9 - not quite as prevalent as the 00Z set, if the same proportion is evident in all 51 ensembles. Will check now, along with other dates

 

 

0 Greenland highs....

 

Edited January 10, 2021 by Steve Murr

[CSC]

I see a lot tonight suffering from post Chart watching depression. Remember this is ONE run. Albeit, it didn’t go the way some may have hoped but it’s ONLY ONE run. Wait until tomorrow before having any more predictions!

I think all scenarios are still on the table and even t120 no one knows, so for those guessing what’s happening in 6 weeks time saying cold is gone and our hopes our lost, baffle me to be honest. 

Cold is in our sights and I believe one way or another, it is coming in it’s masses! Best opportunity here in a long time. Heads up NW community! Onto the pub run now...

[winterof79]

1 minute ago, CSC said:

I see a lot tonight suffering from post Chart watching depression. Remember this is ONE run. Albeit, it didn’t go the way some may have hoped but it’s ONLY ONE run. Wait until tomorrow before having any more predictions!

I think all scenarios are still on the table and even t120 no one knows, so for those guessing what’s happening in 6 weeks time saying cold is gone and our hopes our lost, baffle me to be honest. 

Cold is in our sights and I believe one way or another, it is coming in it’s masses! Best opportunity here in a long time. Heads up NW community! Onto the pub run now...

Quite ill leave it until tomorrow I'm having a Greenland headache.

[Scott Ingham]

2 minutes ago, Steve Murr said:

Possibly > Thats included in my 15% though > also inc is the GFS op. Thats all your getting...

I think really its just a matter of differentiation between an atlantic ridge & a true GH as remember there may be newer members that cant quite tell the difference yet - Some may see Greenland heights & think its the same as a true GH...

Also a GH would certainly guarentee the jet track in the atlantic being steered south now we are 'hoping' it stays south...

I would say 'moderate' optimism tonight for cold weather in the 7-10 window but not deep cold.

Rain turning to snow thurs could be another curtain twiching moment this week...

Your right. This is where weve had disagreements.

For clarity then so people know what im suggesting could he the outcome.

1) Greenland high (Contour line up one 3rd of Greenland

2) Cut off Greenland high (Same but cut off with low pressure under the high propping it up.

3) Greenland Ridge (Contour to the tip of Greenland)

4) North Atlantic High (Contour not reaching Greenland)

I see 168 to 240 us developing option 1 with a backing south west of the cold in Scandinavia

240-360

A WEST based option 2 - cut off from energy from the eastern seaboard. Slider and battleground snow favouring areas north of Southern Wales

So based on them terms what is it your saying you think will happen?

There is support in both eps and gefs for option 1 but this has dropped since this morning 

 

[bluearmy]

3 minutes ago, MATTWOLVES said:

Right folks it appears the ECM op was an outlier,doesn't surprise me..I was getting a tad worried...not by the output..but the way it was becoming like a punch and Judy show in here...oh yes it is....oh no it isn't.. Just to drop a few things in If i can..Marco P stating the zonal mean at 10hpa 60N appears to have flipped back wstly today...May be causing some volatility.. further warming next week should flip them back Estly though. And Matt H pointing out the difference with the GFS and the Ecm Could be to do with whether a region of the Strat Vortex that breaks off gets pulled East or not...GFS does this..ECM does not... so there is again alot going on...

Seriously - if it’s flipped back westerly it’s marginal and would it make any difference ..... its still reversed at 61N. The chat about tech ssw is imo full of naval gazing. Looking at the whole strat is way more important than the particular zonal flow specifically at 10hpa at 60N 

it will remain reversed in much of the strat above 60N for the next 10 days .....

 

 

[booferking]

5 minutes ago, Steve Murr said:

0 Greenland highs....

 

1st march 2006 was true Greenland high cut off. 

[SLEETY]

Watch Ecm go frigid in the morning and other models showing the crud ECM   from this Afternoon,whatever the pub run shows later. I have seen enough model runs over the years to see this happen exactly like that with the roles flipping overnight.

Edited January 10, 2021 by SLEETY

[IDO]

22 minutes ago, chris55 said:

What if 17 went for a solid Greenland high, 17 went for an Atlantic ridge, and 17 went for an Azores/Euro ridge. How would that show in the mean?

 

 

 

Hi

If only statistics was as easy as you make it sound! You have to build into that 17/17/17 the ratio of those d10 Greenland highs, Atlantic ridge or Azores high being the solution by T0. Of course, we know that a d10 GH rarely lands at D0 so we would factor this in with an equation with those odds, ditto the other two possible outcomes. 

So although a 33% chance sounds great for a GH, the reality is that in a large sampling the chances are significantly less by d0. There are obvious caveats, but the mean is a balance to any "out there" solutions. If this was a plume from sub-tropical forcing then we would maybe have sub-set binning to qualify any results. Or if this is the imprint of an SSWE and we knew that for sure, then we would bin that factor. 

I think what we can say is that if the means are synoptic-wise correct (Scandi trough) then we should see increased chances of forcing to the Greenland region if we get a clean evolution. A real-life GH though, mostly in my dreams or in models in FI sadly!

[SMU]

3 minutes ago, Scott Ingham said:

Your right. This is where weve had disagreements.

For clarity then so people know what im suggesting could he the outcome.

1) Greenland high (Contour line up one 3rd of Greenland

2) Cut off Greenland high (Same but cut off with low pressure under the high propping it up.

3) Greenland Ridge (Contour to the tip of Greenland)

4) North Atlantic High (Contour not reaching Greenland)

I see 168 to 240 us developing option 1 with a backing south west of the cold in Scandinavia

240-360

A WEST based option 2 - cut off from energy from the eastern seaboard. Slider and battleground snow favouring areas north of Southern Wales

So based on them terms what is it your saying you think will happen?

There is support in both eps and gefs for option 1 but this has dropped since this morning 

 

Somewhere between 2-3 - Maybe we can prop a wedge that sinks East slightly....

[Chertseystreamer79]

3 hours ago, Allseasons-si said:

IF the gfs was to be correct someone is going to get plastered with snow big time from the 20th>

 

 

Start that 10 day countdown....AGAIN! cross everything!