Model Output Discussion - Christmas and New Year

[Mike Poole]

1 minute ago, Geordiesnow said:

So they are not classic charts, synotopics wise, you may argue they are but come on, we seen alot better charts than these in the past.

I'm seeing a set up which brings the risk of transient snowfall and for lower levels, it gets less favourable after Monday as the thicknesses start to rise and so do the uppers marginally. I think frost will be more of a dominating weather type than snowfall I feel looking ahead. The charts cold wise are poor for end of Dec start of Jan given the set up on offer. 

And yep in winter we get polar maritime set ups fromm the Atlantic which brings - 8 uppers into North Western areas and snowfall in lower levels also, do you count them as a classic set up? 

I don’t live in the NW mate, so that is not a normal winter for me, hardly ever snows in Oxfordshire in a ‘normal’ winter.  But that is IMBY talk which wasn’t what I wanted to get across, which is within the bounds of what’s available given distribution of cold air in the NH, we are in a good position.  Maybe I’ve used language that could be construed as ‘ramping’.  Surely not!

[bluearmy]

Whether the gefs are worth anything individually at the moment I’m not sure but there seems to be a fair cluster broadly going for the lw trough extension across the Atlantic into nw Europe days 9/10 which presents the kind of evolution seen on the 12z gem ..,.. been a gfsp theme of its last few runs too. Be interesting if ecm op throws out a run like that and could be a  sort of compromise between the recent flatter output some have noted and the amplified which still exists across the ens ..... 

[swfc]

Phew lot of anguish this evening altho the only thing looking like varifying and subsequent wind and rain. If you look at a ten day chart and expect it to varify then your going to be disappointed. Gfs isn't great today or for the last few days. Yes it has dropped of slightly on its amplification and also been irratic. That's not to say it's wrong or correct. Cross model agreement has been scuppered a good few times the gfs. Personally I think the outlook is good, not great but again folk compare it to recent winter's so you have to take what you can out of it. If someone sees a poor outlook ie change in synoptics let them comment. Afterall were not run by a dictatorship. I think ec will keep feet on the ground and be OK, just my opinion but there's zero chance for me of any substantial snow in the reliable. 2 good months of winter to go and folk stressing over Monday-Tues on a band of sleet and snow??? Enjoy the cool/cold spell but don't be over playing it. Enjoy your evening

Edited December 26, 2020 by swfc

[danm]

9 minutes ago, Geordiesnow said:

So they are not classic charts, synotopics wise, you may argue they are but come on, we seen alot better charts than these in the past.

I'm seeing a set up which brings the risk of transient snowfall and for lower levels, it gets less favourable after Monday as the thicknesses start to rise and so do the uppers marginally. I think frost will be more of a dominating weather type than snowfall I feel looking ahead. The charts cold wise are poor for end of Dec start of Jan given the set up on offer. 

And yep in winter we get polar maritime set ups fromm the Atlantic which brings - 8 uppers into North Western areas and snowfall in lower levels also, do you count them as a classic set up? 

No one has forecast snowmageddon or December 2010/Feb 2018 depth of cold at all though. We all accept that this is the start of a colder spell which could bring some snow and with the shredding of the PV, potential SSW and other background factors promoting amplification this could be the start of a protracted colder spell, something we’ve lacked now for many years. Will it mean wall to wall sub zero temperatures and weeks of laying snow? No, not initially at least. So with respect I think your engaging in a straw man argument. 

Edited December 26, 2020 by danm

[Kasim Awan]

3 minutes ago, bluearmy said:

Whether the gefs are worth anything individually at the moment I’m not sure but there seems to be a fair cluster broadly going for the lw trough extension across the Atlantic into nw Europe days 9/10 which presents the kind of evolution seen on the 12z gem ..,.. been a gfsp theme of its last few runs too. Be interesting if ecm op throws out a run like that and could be a  sort of compromise between the recent flatter output some have noted and the amplified which still exists across the ens ..... 

This post fully has my backing

[Catacol]

1 hour ago, Kasim Awan said:

I spoke about waves yesterday & penultimately we're in a pattern of sharp mid Atlantic ridging and wave breaking. Don't be too disheartened during the trough of these waves which will deliver misleadingly flat synoptics!

Indeed. We are currently approaching the crest of the amplification caused by the jet streak from approx 21st Dec. The next, potentially bigger, surge will be at New Year. Given lag expect renewed height signal by about 5/1. In between these crests there will be a relaxing of the pattern, but there is so little grunt to the Atlantic that the worst that could happen is a short shift of a U.K. high - and then off we go again with amplification. I suspect we will still be under an easterly influence myself and the models will be too quick to “relax” things - but this is all part and parcel of an amplified pattern. The pattern is not flattening....it is a wax and wane thing....

Lots of interest before 5/1 approx in any case. Note, however that once we get that reenergised amplification signal it will probably overlap with the projected SSW and potential reversal....and then things could get tasty.

[Snowman.]

10 minutes ago, Kasim Awan said:

A slightly flatter pattern at that locale probably wont mean a very significant difference in surface conditions at UK if anything it may push everything south of where the GEM.00Z had things which is a positive. In either case the energy is more likely to undergo trough disruption than topple.

13th Jan 2013 is a good analogue for the pattern in discussion because the Greenland polar jet became increasingly immobilized under high pressure leading to cold. 

Jan 2013 is looking very similar to the upcoming January period. It must be noted there was still large differences between most models at T96 area during that period.

P3 is strikingly similar too. 

 

Edited December 26, 2020 by Snowman.

[Biggin]

1 hour ago, CreweCold said:

Yes, getting the feeling we're starting to see a general flattening of the pattern upstream now being advertised. 

Hoping we can pull that SSW out of the bag as it will be needed as we progress further into January

Can I ask, do the models take potential ssw into consideration  or ignore it till it happens ?

[Matt H]

4 minutes ago, Skullzrulerz said:

I'm think I'm going to call it quits with this cold "spell"

Sadly like or not this is no longer the fantastic charts we have been seeing the past few days 

First it's the lack of Heights we have gone from a "black hole" Greenland high to now a Graceland high and it seems that the favourite outcome at this rate is for high pressure to be close or over the UK 

Secondly we have snowfall forecasts remember the ECM snow charts a few days ago where large parts of the UK had snowfall? No longer there and any snowfall seems to be around the hills of Wales/Scotland but at least Ireland will be getting some 

And the increased uncertainty now starting to derail the once crossed model agreement for a actually cold spell is gone instead we have many options on the table though thankfully none seems to go back to a mild route 

Seeing the posts now where we are starting to favour the models because of the outcomes that are showing isn't the greatest idea 

At the end of the day the prime thing we need a cross model agreement and we don't have that

Though thankfully it does seem a SSW does look likely so maybe further cold spell/snaps could be on the cards 

For now I'm going to be a spectacular for the time being 

This is a perfectly valid and justified viewpoint and other experienced members have also shared similar opinions this evening. But would it be possible for you to occasionally post some charts/data with your thoughts so we can understand more easily where you’re coming from because your posts do confuse me sometimes? Thanks.

[Weathizard]

I’m surprised by the way the GFS squashed the attempted ridge northwards between 120 & 144, there is a perfect ridge of heights being undercut by a LP system and the high gets pushed SE whilst being dragged westwards thus the pattern flattens slightly.

I would expect something much more like the UKM

[Catacol]

1 hour ago, booferking said:

Parallel leading the way greicland high incoming. 

Remember this is the upgraded gfs model higher resolution. 

There’s our +EAMT jet streak modelled, and if it happens while the Atlantic pattern has only relaxed back to that then we are golden. Great charts - popped up at a very timely moment as I trawl through the thread! Thanks.

[Scott Ingham]

3 minutes ago, Catacol said:

Indeed. We are currently approaching the crest of the amplification caused by the jet streak from approx 21st Dec. The next, potentially bigger, surge will be at New Year. Given lag expect renewed height signal by about 5/1. In between these crests there will be a relaxing of the pattern, but there is so little grunt to the Atlantic that the worst that could happen is a short shift of a U.K. high - and then off we go again with amplification. I suspect we will still be under an easterly influence myself and the models will be too quick to “relax” things - but this is all part and parcel of an amplified pattern. The pattern is not flattening....it is a wax and wane thing....

Lots of interest before 5/1 approx in any case. Note, however that once we get that reenergised amplification signal it will probably overlap with the projected SSW and potential reversal....and then things could get tasty.

This couldnt be anymore alike to my thinking.

Well still be on the right side of the jet when things relax in my opinion so i still believe were on the cusp of one of the longest periods of below average temperatures for a long long time 

[MATTWOLVES 3]

1 minute ago, swfc said:

Phew lot of anguish this evening altho the only thing looking like varifying and subsequent wind and rain. If you look at a ten day chart and expect it to varify then your going to be disappointed. Gfs isn't great today or for the last few days. Yes it has dropped of slightly on its amplification and also been irratic. That's not to say it's wrong or correct. Cross model agreement has been scuppered a good few times the gfs. Personally I think the outlook is good, not great but again folk compare it to recent winter's so you have to take what you can out of it. If someone sees a poor outlook ie change in synoptics let them comment. Afterall were not run by a dictatorship. I think ec will keep feet on the ground and be OK, just my opinion but there's zero chance for me of any substantial snow in the reliable. 2 good months of winter to go and folk stressing over Monday-Tues on a band of sleet and snow??? Enjoy the cool/cold spell but don't be over playing it. Enjoy your evening

Yes mate you have a good point...firstly I just want to Thank You for the good deeds you did over Xmas,regarding food distribution to the homeless..thats a fantastic thing to do and kind of brings home how lucky most of us are...there are far worse things in life to deal with..but give yourself a big pat on the back mate.

Secondly things may have gone off the boil a little with GFS the last few runs...but hey ho its GFS,and its great for spotting these pattern changes before others...running with it..then dropping the idea when the Euros come onboard...We have a cold snap starting tomorrow,so it kind of shocks me that some could say they give in with it now...at least give it a chance to start The ECM will be running shortly,and if that's as positive as this mornings run,and the ens and mean to boot...then I'm Happy with that and I'm sure most will be..Thus Winter is only just starting out in its journey...And I'm pretty happy about were we are at this precise moment in time..

Enjoy the rest of your Xmas...likewise to all on here..

[Scott Ingham]

4 minutes ago, Catacol said:

There’s our +EAMT jet streak modelled, and if it happens while the Atlantic pattern has only relaxed back to that then we are golden. Great charts - popped up at a very timely moment as I trawl through the thread! Thanks.

The GFS P is bang on the money for me

[Anthony Burden]

Continuation of very good charts up to reliable time frame for cold and snow in the forecast.

Some suggestions in fantasy island of a more easterly set up but to far out to be sure, looking

foreword to ecm to follow met office upgrade from rather cold to cold.

 

[Kasim Awan]

3 minutes ago, Scott Ingham said:

This couldnt be anymore alike to my thinking.

Well still be on the right side of the jet when things relax in my opinion so i still believe were on the cusp of one of the longest periods of below average temperatures for a long long time 

Never 100% in meteorology but I would call likelihood (60% confidence) in the next wave break to be more easterly in nature w/ trough disruptin.

It's not only waves of amplification but, at a larger temporal scale, a single wave of an increased amplification signal through time. This meaning subsequent attempts may produce more optimal jet tilts. 

 

maybe

[Weathizard]

Think it’s worth remembering for some ‘giving up’ etc that the UKMO still looks good at 144, the GFS and the ICON flatten the pattern more but still aren’t bad.

From experience with height rises in the Greenland/Iceland corridor the GFS can really struggle with it, I remember I think Jan 2013 when we had the low from the NW sliding down into cold air with a small wedge of heights around that area the GFS struggled massively as did many of the other models.

 

 

[Griff]

3 minutes ago, Scott Ingham said:

The GFS P is bang on the money for me

There have been runs over the last few weeks where I distinctly recall a couple of wobbles where I half joked that people shouldn't worry as the GFSP and GEM were on the money and leading the way. Now going forwards who knows, but that was just to get the door open, to where we stand today. All fun and games, but not to be discounted

[Scott Ingham]

9 minutes ago, Kasim Awan said:

Never 100% in meteorology but I would call likelihood (60% confidence) in the next wave break to be more easterly in nature w/ trough disruptin.

It's not only waves of amplification but, at a larger temporal scale, a single wave of an increased amplification signal through time. This meaning subsequent attempts may produce more optimal jet tilts. 

 

maybe

Yes! I agree with you this is why i expected each attempt to have a larger effect each time

[Weather vane]

35 minutes ago, PolarWarsaw said:

I'm glad to see you have that same view point. 

Like it or not, the last 2/3 days have seen a gradual watering down of amplification later into FI - whether it's 'flat' in the usual form isn't up for debate, but IT IS FLATTER currently than what was advertised for the previous few days, which is the point people are making. Considering that wasn't Narnia anyway - less amplification is not good news, regardless of whichever positive spin we all want to put out there.

Is nobody else a little bit disappointed with what's on offer for next week? This is a pretty rare set up. The charts themselves would have delivered a very exciting spell of weather in many years gone by. But apart from the wind and a chance of some light snow/flakes Monday AM - the charts look far better than they are delivering at the surface. Really is a very frustrating set up.

A week of frost, dry and sunny weather is as much of a waste of winter as a raging Atlantic.

It feels like we have been waiting weeks for 'Christmas-new year week' and in reality, it's looking like a wasted pattern. I don't fancy another Day 10 chase into January, or relying on an SSW to not only happen, but then land in our favour - we just don't get that lucky.

Let's hope we get one as it could be a long couple of months otherwise IMO, especially with patience so frayed. With the set up and over-hyping for what are, average charts are the surface - it feels like this season has been long already! Mentally it feels like winter has been great on the internet, but the story outside is very  different. 

Here are to upgrades - Merry Christmas all. 

Agree, things looking a little flatter, and a UK high could easily be the result 10 days out (although majority of Gfs members still going with lower heights from NW). But at least we are now definitely entering a much colder set up, and it will definitely feel like winter, at least by our standards at the eastern edge of the Atlantic. As rare as the current set up is, IMO its even rarer to get significant widespread snow events. I tell myself this constantly to keep my sanity with the hunt for exceptional cold !!

[Scott Ingham]

9 minutes ago, Griff said:

There have been runs over the last few weeks where I distinctly recall a couple of wobbles where I half joked that people shouldn't worry as the GFSP and GEM were on the money and leading the way. Now going forwards who knows, but that was just to get the door open, to where we stand today. All fun and games, but not to be discounted

Mate there should be no negativity from anybody people are jumping on a few flatter model suites and calling an end to cold.

Its a wane period. End of.

This will still be a noteworthy cold period of winter that we havnt seen in January for a long long time.

 

[Scott Ingham]

1 minute ago, Weather vane said:

Agree, things looking a little flatter, and a UK high could easily be the result 10 days out (although majority of Gfs members still going with lower heights from NW). But at least we are now definitely entering a much colder set up, and it will definitely feel like winter, at least by our standards at the eastern edge of the Atlantic. As rare as the current set up is, IMO its even rarer to get significant widespread snow events. I tell myself this constantly to keep my sanity with the hunt for exceptional cold !!

There will be no UK high in the next 10 days. 

Its a complete over reaction to a couple of flatter suites.

[MattStoke]

Latest Euro4 snow accumulation up to Monday afternoon. Still a lot of uncertainty with this one.

[Scott Ingham]

Just now, MattStoke said:

Latest Euro4 snow accumulation up to Monday afternoon. Still a lot of uncertainty with this one.

Wow! I rate the euro4 very highly as well

[Kasim Awan]

2 minutes ago, MattStoke said:

Latest Euro4 snow accumulation up to Monday afternoon. Still a lot of uncertainty with this one.

Parts of northern Lancashire will likely get hammered late tomorrow experience tells me.