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I can’t believe I’ve read 5 pages of weather there will be a Greenland high or not. With the propagation of the SSW, we have certainly seen an early divergence in the trop modelling. And this we have seen many times before has led one or more models down a garden path. Initially it looks that any Greenland high in the next ten days is unlikely, but with a resurgence of negative winds at the top of the strat, I wouldn’t discount this for too long. In a superstitious way, I wouldn’t rule it out either. The number of times I have seen Steve rule a scenario out and then see the models reverse within 24 hours are too numerous to mention. So I’m happy with that too.

We would much rather people use the ignore facility than negatively respond to posts they don't like, for sure. But I will add, we have absolutely no plans to put an age limit on this or any threads on this site. I joined this site when I was 15, posting on here helped nurture my interest in meteorology. That then lead to a degree in meteorology, and now I'm employed as a meteorologist and have been for the last 6 years. There will be numerous other young people on this forum who could potentially follow that path, and posting on here will continue to nurture that interest. So, yes, please use the ignore facility. But we have a wealth of knowledge and posts from all ages on this forum. Anyway, let's get back to discussing model output and put this evening's drama behind us, and thank you to all who reported posts - that's the way to deal with issues.

Sorry but I don’t agree with this. There are many young people, including myself, that enjoy contributing to this thread due to our love of weather and model watching. Dismissing people’s posts as ‘nonsense’ due to their age is unfair.

This SSW is producing some of the most insane synoptics for the NH we have seen in many years. The turmoil it is producing in the operational runs is crazy. But the underlying trend is extremely interesting if you like cold weather and snowfalls blocking your front door! We are endlessly looking for at least a 'chance' of something noteworthy/historical and that chance is certainly apparent with the current circumstances! As ever nothing is set in stone and we have the lesser trend of the Azores ridge/Euro high remaining and scuppering any really cold feed, however that is most definitely in the minority, but has to be factored in. Another real positive is that the main 'spill out' of Arctic air (as a consequence of the SSW) looks to be heavily trending to be heading to our third of the globe. Often we say that a SSW will bring the cold down to the mid lats but never know quite where it will head, well recent modelling says it is firmly heading towards the Europe/Atlantic sector. This is just me digressing so to be taken with a pinch of salt, but overall Id say as 'cold weather hunters' we are climbing that ladder at pace and hopefully we'll eventually get to the top and all be happy with the view

That's a shame, I paused the Eastenders omnibus to watch the drama in here unfold. Given the ECM has huge spread at just day 2, I'm not sure why people are worrying about what the model shows at day 10. We're seeing a period of high model volatility at the moment as they begin to resolve downwelling & impacts from the SSW. We've seen the entire GEFS suite shift from milder to colder in a single run. Worrying about an ECM day 10 chart is futile at the moment. 21st onwards. That's when the goods will come. Anything before that is a bonus.

As some have already pointed out, the GEFS 06z show a huge shift towards a colder outlook compared with previous runs. Not sure when the last time such a dramatic shift occurred, but 2010 stands out in my mind. GFS Op is a clear outlier now. I would also put more weight in the GFS(P) simply because it has more vertical layers so should resolve any SSW downwelling more accurately. After a tricky few days, things are steadily improving towards a colder outlook for the UK. EPS means/clusters are strengthening the signal with each model run. We're reaching the "tipping point" where we start to see increasingly cold and blocked runs appearing in the mid-extended. Buckle up!

Almost impossible to figure out what the outlook is going to be. I feel the usual scenario will occur around 12/13th Jan as we see a shift W of the high pressure to our NE and less progress from the Atlantic. Whilst I wouldn't expect this to change to sudden cold E,lys the effects of which have a knock on effect later on. We then have the added complication of the Arctic high and polar vortex bringing a bitterly cold airmass to NE Europe. The effects on the UK could be a bitterly cold, convective cold spell or a moderately cold spell but with battleground blizzards or even both. l haven't included the milder option because as I said in the covid thread, I do not want to see a severe cold spell this winter. I bet it will be sods law we get one when this is the last thing the country needs!

not really sure what to think the warming has been ongoing for almost a week now. the data is well and truly in the models and today, the starting data has reversal almost down to the trop. the broad picture is of an arctic high driving a part of the Asian vortex towards nw Russia. that will introduce frigid air into scandi and probably e Europe ( these areas are going to b v cold anyway before this vortex movement ) the question is how close we can get that air to nw Europe and more specifically the U.K that will depend on how upstream develops. The period T96 to T180 very uncertain as a weak Atlantic jet meanders around, especially so in the 4 to 7 day period. That allows the models to do some strange things in the medium term. and are they likely to be in the right place when that frigid air moves sw??? so we really have to just wait for the mid term to resolve itself before we can gain any confidence in how that surge of cold may affect us the Atlantic amplification looks solid but this mornings ops show that any greeny height rise could well come to nought. They may be unsupported in the ens and even outliers but whilst they produce output like this they do keep out feet firmly on the ground. im staying in the v cold camp beyond the 20th ......perhaps even a couple days earlier. The period has been signposted for some time. However, if the donkey, tail etc etc suddenly disappear again I won’t be searching around for an explanation....... some parts of the mid lats will have an very wintry period. it may just not be our turn ....

I had a look at temperature analogues from CET and found among those 1881, in fact the mean temperature now is a bit lower than it was on the 10th of that famous cold/snow month (1.2) ... blizzards hit the southern counties in a very similar looking evolution around the 16th to 20th of that month and severe cold followed. Another interesting factoid is that the only January which ever managed a 2 deg CET increase after the 10th before dropping to a lower end point was 1947 (2.6 to 4.6 to 2.2). Those numbers are all higher than this month's potential numbers, but the severe cold did not start until the 22nd and it did get very mild (probably milder than we'll see mid-week) for a few days after quite a cold start. I like to see cases where unusual synoptics on model runs have actually happened in the past, shows that nature can accommodate them. If I had to guess how this particular evolution might actually work out instead of what's shown, it would be a faster drop in the jet stream and for the channel low scenario to push more into northern France but with less slack flow over Britain, in other words getting the full extent of severe cold into the UK faster. It would mean the main mechanism for snowfall would have to be sea effect rather than synoptic however.

Netweather crew, does it get any better than this? Big block to NW. Freezing cold feed from NNE. Active Atlantic exiting via Bay of Biscay, with more lows lined up in the Atlantic to take the same route. Is this the dream? *In no way am I suggesting this is what I think will happen, btw

Good evening all. A few days off from the weather scene myself. Feeling hopeful for the rest of the winter given that the past couple of weeks has delivered on que - dozens of snow surprises delivering mostly to high ground & (some) lower elevation areas. The "model shift" which was discussed earlier in the week seems to be ongoing right now, the cause of this is related to the secondary SSW impacts (tropospheric) being inputted as a better-defined data source to the NWP. As this is resolved, so will be the output. This is not a linear shift - it is characterized by fluctuations as the NWP resolves the next wave of amplification which is likely to be the most defined of Winter 2020/21 so far. From an ensemble forecasting perspective it seems the trend towards a strong Greenland ridge is gaining momentum. The model shift, however, is even more defined in the 80 to 150 hour range. Look at the ECM for the 14th from 8th January. http://www.meteociel.fr/modeles/ecmwf/archives/2021010812/ECM1-144.GIF?12 Compare that to the current output for the 14th: http://www.meteociel.fr/modeles/ecmwf/runs/2021011012/ECM1-96.GIF?10-0 The significant increase in heights in just 48 hours as a model projection is clear evidence for a background factor being factored in the NWP - and it's impact being modelled. The upshot of this is rather high confidence that the D3+ period will be driven by the SSW downwelling, or at the least a mobile downwelling into rather favourable areas following the initial tropospheric zonal response around the North Atlantic period. This increasing our cold chances into late January quite considerably. Downwelling here is likely to have it's own tropospheric spatial pattern, i.e. move from east to west, a clear migration from Scandi, through the Azores and into Greenland is apparrent from 96h to 216h on some of the output. This is the fruit of that - http://modeles.meteociel.fr/modeles/gfs/runs/2021011012/gfs-0-192.png?12 As an outcome this is definitely within reach, this depends on clean high amplification, as per the GFSP this might not be as favourable as it could be. The strong signal for amplification, however, may override any "shortwave issues" etc, due to numerous factors, not only the strong pattern of oscillating bouts of amplification in the past 4 weeks as well as a more favourable downwelling pattern. All in all a very good chance of something very significant - and the synoptic caveats, as discussed, may be an issue however pose less of an issue than in some recent years. This gives us a strong fighting chance.

The 216 is even worse... As Said 2 days ago ..... Need to keep firmly grounded here. No booms or anything else until Euros on board.

Ladies and gentlemen, prepare your "BOOM" voice

Probably already said but the gem has the right idea. I've spent the day taking care of a very sick cat, and to some that might not mean very much, but my point is it's only the weather. There's a lot more important stuff going on. More important than poorly cats even. Let's not feel the need to be right, or argue. Take it all with good grace, without needing to be the top dog. After all we won't have to wait that long to find out. But if you suspect others aren't listening or seeing your point of view, chances are they won't anyway no matter how hard you attempt to convince them. Live and let live, and give the mods a break too. I think the expression goes "more runs needed"? Onwards to the pub (run).

As stated earlier fine lines for future development at the moment, but if this morning's GFS is anything to go by the signal for a backing west of significant Russian cold just acquired definite momentum........note the deepening and strengthening ensemble mean low pressure to our east. Much more likely to advect the cold more swiftly than the 10 days just gone by. And the op was none too shabby....and in January there is always a lot more cold to tap into than in December.... Temp anomaly has a good look to it

Some more photos from a local walk this morning. The freezing fog made everything special...

never mind Rob Van Dam there’s the 510 dam GFS P 00z current run and there’s only one word to sum up lots of the ensembles .. crazy gem ensembles the same, I particularly liked P18 & 20 Meteociel - Cartes Ensemble GEM (GENS GEM / CMC ENS) WWW.METEOCIEL.FR meteociel propose des rubriques météo temps réel, forums, modeles... And relax, stay calm KW

if we do somehow manage to get to this place (broadly), notice the cold upper ridge circled which is the remnants of the arctic high. It’s important as it would prevent the coldest air backing west at too high a latitude. Signs on recent eps means that this could well happen if we get the greeny height rise .

The Siberian express is returning the question is will it reach its final destination? (UK). GEFS are now also aboard something is afoot that is clear. For coldies we have had to wait for 3 years for any shot of proper cold spell, but it seems our patience could be rewarded.

This mornings magical pics from Epping Forest

UKMO latest fax at t72 compared to t84 from the earlier run shows a little change with the fronts coming in held further west. Looking east we can see that block of deep cold gathering. We have seen this before when a weak Atlantic comes up against a cold block it has trouble making inroads and as time ticks down modeling gets adjusted to reflect this.

CAUTION,...ADULTS ONLY!!! the control is very similar to the op run synoptically... great 12z so far except the parra,now come on ECM give us a BOOM!!! run.

Worth mentioning though, the GFS(P) to which you are referring, becomes the operational next month.....

ECM now develops some cold air into the British Isles next weekend with some fairly widespread snowfall across the east of England. C

Come onnn you beauties...its GAME ON,the ens are onto this cold snap like a rat up a drainpipe...let the drama continue.

Evening everyone. A fantastic set of GEFS 12z ensembles once again that average around -5C from the 15th onwards. The momentum is definitely behind the colder air winning now, at least for a time. I’m hopeful for a better ECM 12z tonight now.

At this point I'm not quite sure what can stop that big, densely cold area of Siberian air hurtling SW. There's barely any W'ly momentum in the system...

I expect the para to now be dumped and sent to the naughty corner ! In the model world you’re only as good as your last cold run! Even allowing for differences between the runs the latest GFS at day ten compared to the 06hrs run are on different planets !

Comparing last nights UKMO in the earlier stages and today’s shows how clueless it’s been in recent weeks . Really the last one to the party once again !

Some of the moderating in here tonight was so quick it would have make Billy the Kid wary on the draw! Well done!!

I am just going to post the 500mb geopotential height anomalies from the ECM/GEFS mean at day ten...,along with the EPS/gefs for the same time,now tell me that there is nothing wrong with regards to getting a cold spell towards the UK from those. i would bite anyone's arm off for those and sell them for a good head.

ECM op was an outlier at day 9 and 10...don't panic!

Interestingly the latest Met Office fax shows a slowing down of the warm front progress for mid -week. The NE of Britain stays in cold air. Would not be out of the question to see a wave development along the front with a risk of snow on the colder side. The UKMO model in my view seems show an upgrade , especially 96t-144t with a slower deconstruction of the high and transfer of energy further south and east. This progress then could release some real colder air from the north and east . A lot to be decided this coming few days. C

We have liftoff with the European Centre for Medium-Range Weather Forecast! 144

You won’t hear this one often...Snow..but only south of the M4!

Heavy frost here in Maidstone, still at 0c

Was just about the comment the same - the Arctic high coming down into Svalbard is a thing of legend and very rare to see - only if this happens will the extreme 850mb temperatures reach our shores. No point stressing about any output at this range yet as it will be many days before we know exactly how the Arctic high is going to manifest itself

Looks like the Atlantic amplification is heading towards a potent NEasterly if it doesn’t collapse too quickly

Almost half the eps in the extended are in a distinct greeny ridge cluster ?. Those clusters days 9/10 looked very amplified around in greeny aswell I’m not sold on anything more than a decent wedge at the moment .....may well be enough given a strong sceuro trough

It’s getting ridiculous in here right now, just over one for some not so favourable run, disregarding the overall patterns we have. Childish behaviour, I’m sorry to say...

Just catching up with an old South African friend now living in on East Coast of Iceland, and they had storms a few days ago, wind and ice.

GFS T288 - channel low deluxe! However, as much as I enjoy watching these runs coming out, I do get the feeling the models are not doing too well with this SSW. They've all flip-flopped with small features at D3/D4, and they are coming up with wildly different ideas run to run for D7 onwards. UKMO in particular, what is going on there, so often in the past the stable one, but nothing stable about it at the moment.

Lovely walk still icy at mid day

Day 5 swing back to cold for the SE -5c the midpoint & -8c the top out > could be some snow

Was just thinking that the comments above your post about ‘these charts never coming below day 10’ seems to miss the point that we still haven’t finished the cold spell we are currently in where many have seen lying snow and some had temps lower than for a decade .....

This spell for me has been magical, I know I have spammed you all with the pics haha but for me best spell (of snow...on ground, play etc) since 2010. My love of snow was given to me by my Dad, I remember watching little diamonds fall when I was little during a early 90s BFTE, I was mesmerised...and hooked. Since then we have had many a chopse on the phone about snow prospects etc. Obviously in his 70s he is not on here but still makes his predictions by wind direction and the BBC . Being a single chap my parents are my bubble so my Dad drove up to see the snow knowing a proper thaw was imminent. My Dad never does anything alone without my mum, so to have a few hours walking in the snow talking about all the falls we remember together and separately was so special. I told him to come up at 3pm to get the sunset etc and we timed it bob on. I was quite emotional when he left, definitely made a memory I will cherish.

It's not worth stoking worry over a day 8 chart, too much uncertainty past day 5 at the moment. Lots of swings between model runs at the moment. The 00z GFS PARA and GEFS mean at day 10 still keeps the party on track ...

Nothing to see here! Back to discussing the models.

Well, it seems the handsome Chris Fawkes has said it will possibly turn colder from Thursday onwards on the Countryfile Forecast! There is hope, and a mild spell isn't the end of the world.