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C'mon guys lets give @Paul and the mods a break with the bickering and personal digs type of posts after all it is a WEATHER forum and this thread is for WEATHER MODEL discussion I can only imagine how hard it is for newbies to try and decipher what is going on among all those types of posts so if anybody has any issues with posts / members perhaps it would be better to use the report post button / ignore member button or try and settle it like adults through PM's and also remember the couple of banter threads that exist Now onto the models I will refer back to my post from 8th Jan some statements / thoughts that I made in the post on 8th Jan "I still believe that any low pressures that do develop will begin to take an ever increasing NW - SE track (with the majority perhaps struggling to get much past the UK) resulting in some northerlies / North westerlies bringing the first hints at something cooler / colder to the UK " "My key period for this would be 17th Jan - 21st Jan " starting on this point, I am fairly happy with this still as we move towards those dates as it looks like around the 17th will be the first (of what I think could be quite a few within the next few weeks) at a sliding low attempt dont take the position / strength of the low too seriously as this is still changing from run to run but the NW > SE movement is there and a run showing possible north westerly / northerly / north easterly air by around the 21st onward for a few days onto my next statement / thought from 8th Jan "So what could happen after that?" "Well IMO it looks like being the last week of Jan from around 24th Jan - 31st Jan that the possibility of some fun and games with blocking and colder charts will reach its maximum potential so far this winter." Again I remain pretty confident with this, why? IMO there is still a signal for the last week of Jan for blocking to start to develop / take hold there are some more ensembles showing this but I think this demonstrates my point clearly enough AO still set to nosedive first hints that the NAO might head the same way And with the MJO looking like possibly heading back toward / through phase 6 / 7 by then that could also help aid blocking (again I am only going off my limited knowledge on the MJO and also might need to factor in some lag time) (some of the other MJO forecasts look a bit more uncertain / slower to go toward those phases ATM) Also still worth factoring in effects from the strat warming event(s) that have took place during late December / Early Jan. some more thoughts / statements that I made on 8th Jan "A word of warning / potential spoiler would be a west based - NAO which remains a possibility http://theweathercentre.blogspot.com/2012/10/east-based-v-west-based-negative-nao.html Key Points keep an eye on these beginning to nosedive once the blocking gets nearer https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.shtml https://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.shtml be wary of the west based -NAO" All of the above are still true / possible IMO but with regards to the west based - NAO perhaps the chances of this wont be know until nearer the last week of Jan and where the models are seeing the potential blocking setting up / developing keep an eye on the ensembles for more and more BOOM type charts appearing in the run up to the last week of Jan I think the first area to focus on ATM would be the potential for slider lows and the possible snowy conditions that they may bring but I still believe the amount of BOOM charts will be on the rise the nearer we get to the last week of Jan. A few extra points I would like to make 1. I wouldn't worry too much about differences in each GEFS suite on the graphs (rises in 850 hPa temps) as slight changes in positions of possible slider lows and later on blocking highs can shift those 850's heavily in one direction or the other and I think we are seeing the usual ebb / flow of the models trying to grasp exactly where each low / high is likely to set up (possibly whilst trying to factor in ongoing effects from start event(s) and MJO etc) 2. How quickly have we seen in the past that things can change and head down a colder / much colder route a la Nov / Dec 2010 & Feb / March 2018 etc (yes there have also been occasions where charts such as "that ECM" where the cold looked like it was on route to the UK and suddenly diverted but I much prefer to look at things with a glass half full rather than immediately thinking that we have no hope / chance of the cold / snow reaching our shores / back gardens) using the 2 years mentioned above as examples and again I am not saying that anything of that severity is heading our way I am just highlighting how much can change within the space of a few weeks (using today's date 14th Jan and 2 weeks from now would have us in the last week of Jan , 28th Jan) taking the 25th November as the end date as that was when the colder air was spreading right across the UK then 2 weeks before was the 11th November 11th November 2010 > 2 weeks later 25th November 2010 11th November 2010 25th November 2010 an example of how quickly things can change / blocking can develop February 2018 - again I will use the 26th February as the end point as this was when the colder air was spreading across the UK so 2 weeks before was the 12th February 2018 > 2 weeks later 26th February 2018 12th February 2018 yes there was some snow around for some but I am highlighting how quickly more blocked conditions can develop 26th February 2018 Keep calm everyone and try and enjoy how the rest of January and beyond plays out, I still think we are in for some fascinating model watching. And I just want to remind people I am certainly no weather expert, I am just having a go at trying to predict where we are heading and seeing how close or far away I am (and if I am miles off the mark I will own up and try and examine the charts to see what happened and how we ended up with scenario A or scenario B etc) ensembles GEM 0z ensembles FNMOC/NOGAPS 0z

So here's where it feels like we're playing meteorological Russian roulette, only the bullet is a marked step change in the hemispheric circulation towards a -AO / -NAO regime. Control run 06z GEFS goes from this .. To this ... In the space of 6 days. The Control has the same data as the operational, so it's not a question of data differences, rather resolution although at that range resulting in differences between ops and control. High resolution on a broad scale change isn't necessarily a good thing. GFS Northern Annular Mode projection, in line with AO forecasts, suggesting strat downwelling now coming into view. MJO also arriving in phase 7 at the same time, which would be conducive to blocking formation.

I'm just about to the end of my rope in terms of the way some members are behaving on here. The moderation team do their best to make the best decisions for the forum - we are all human though and may miss things/get things wrong at times. The whole community benefits from the fact the forum is moderated - threads are generally on topic, abusive posts are removed, much of the time everything runs smoothly. The balance between keeping threads on topic and structured and allowing them some scope to drift, have humour etc is a difficult one. We aim to achieve that, but may miss sometimes - again we're human. Those who enjoy those benefits of moderation but take exception the instant their own posts are subject to any form of moderation are being entirely unfair the team and in the case of public rants, to everyone else on the community too, by allowing their own issues to disrupt threads. The same applies to those who rant publicly about posts being off topic or whatever else. (Particularly, as in the case of earlier, when no time at all has passed since the post was made) It is everyone's responsibility to look after this community, whether that be in considering what to post, using the report function, communicating ideas and thoughts and feedback with the team (in appropriate places - eg pm's, feedback forum, private team forum etc).

good post, just hope nobody quotes the whole damn thing,

Absolute stonker of a set of ECM ensembles tonight. For the 24th January, 42 out of 51 members are certainly cold enough for snow in most places. Up from 27 out of 51 this morning!! What's noticeable is pretty good agreement on the pattern - deep trough just SE of the UK. In the sweet spot! But will it stay there?

So happy to see such joy in here tonight.. GFS ---

We will start to feel the chill at the end of this week - but ensemble guidance firming up on the beginning of the main event which looks like Tuesday/Wednesday. Overnight EPS guidance provides a very easy guide to the track of a low diving NW/SE into Europe to establish the trough we need down there. Using the same 00z start point for a GFS take on things we see the same trough angle, but much less in the way of heights to the east and up over the arctic to help deflect/disrupt....and this is why we have a more easterly solution and a low pressure looking rather well formed on the op runs There was a lot of talk last night about whether GFS models the exit of systems from US/Canada better than others....perhaps a red herring in this case? Of more importance is the modelling of the block in front of it, downstream of the US, and we know GFS is not good at gripping atlantic blocking. EPS favoured I think. However if upstream is examined for a moment, a good image ripped from Twitter of the problems facing US forecasters as that Canadian lobe decides what it is going to do - and you can see quite clearly that we have all kinds of different solutions in there! Once the major diving low comes the angle of attack may still end up too far east to be a snow scenario for most - though the MetO wording of "rain could turn to snow almost anywhere" has ensured that they have covered all bases neatly. This is a high risk scenario that could deliver some substantial snow for parts IF (and the capitals are deliberate) we get the angle and the disruption just right. We will see. Anything beyond that is worth discussing later in the week - I'm focused at the moment on Tuesday/Wednesday, extent of arctic/scandy heights to disrupt and deflect that incoming trough and extent to which the incoming air carries very cold or just cold air with it. Right now it looks pretty darn frigid as an airmass, and as a result will be a fabulous trigger to what follows afterwards, regardless of whether we can get everything backed west enough to turn it into a major snow event midweek or we have to wait a little bit longer.....

If anything, tonight's Ecm 12z ensemble mean ends even better than the operational !!!..what a fantastic finish with the following days putting us well and truly into the freezer!!

ECM breaks out the champagne again- This time its just 168...

The ECM weeklies are below average for the entire run Week 1 Week 2 Week 3 Week 4

Yep - it's been there for a few days to be honest....but too many on here jump and shout at individual op runs. Right now we are in that middle ground between teleconnective long term forecasting (which has nailed this cold spell as a process,all be it a good while after it was initially thought to be incoming...) and the microscale stuff within 72 hours - and that really means leaning on ensembles and looking for the trends. I was musing earlier - we get quite excited about chasing heights to our north, but possibly should spend just as much time looking for low heights to the south - and in fact possibly more so given that this is where the precipitation signal comes from. Anyway - the low heights are coming. And once the trough dives south (perhaps giving snow for some) we are in a cold position for the longer term because strat and pacific forcings are going to hold us here. It's great stuff, it really is - and so soon after the extraordinary burst of wintriness back in March. So - keep checking the ensembles. Let's play spot the best ensemble. 3 images for Tues 22nd - first one is the Sat run, then the Sun run then the Monday run. Which is the best? Steeper the gradient the better...and that means we are in definite upgrade territory today in terms of what happens in 8/9 days' time. Everything before that is about getting cold air in situ, lowering ground temps and getting as much of a frigid air mass in place as possible to disrupt the trough as it comes in. I haven't lost sight of Feb 96 yet - except it would be better cos this time around the cold is here for the longer term. And could it come in as a pretty fearsome snowstorm?? Yes - it definitely could. Remember those temperature gradients @knocker noted the other day...……….. "Daddy - where were you when the Great Storm of January 2019 happened???" Blimey.

Could be some major drama coming up if this new ECM evolution is the new trend . A correction further west and bedlam is likely to ensue in here !

Evening everyone- Minima time available today but always lurking- Firstly its nice to see the GFS getting a hard time as its really really struggling here- but remember I said sunday 24-36 hours & it would come aboard ! - The FV3 has finally landed & the GFS will arrive at the party- it Must... Probably 12z tomorrow. So what party are we arriving it? My nerves & frustrations have been tempered today as we seen correction back west, & what comes with it is more influence from the continent - The continental feed is crucial if anyone in the south / SE wants to see Snow -along any frontal boundary The slider then - its on, whats it got to slide into? - The upper air will be about -5/-6c with lowish dewpoints, So there will likely be an area along the boundary of Wintry weather- Obvious caveats are - The further North & East you are the better ( as long as you are in the PPN belt ) - Elevation makes a difference >150M ideally. - The frontal zone wont be that large - Heres a plot of my thoughts ( also includes NI late Thurs as well ) Post this the little area of High pressure to our north east in the North sea will support cold uppers (-6c) moving back west which may well support snow when the altlantic dives that big storm South East ( See FV3) Best Steve

As always, It’s more about the actual people themselves who are posting these constant downbeat comments, than the prospects taking a turn for the worse. Some just go looking for it, it’s in their nature. No downgrades, no guarantees, same entropy, same great potential. Yet some, always the same ones, are evidently completely incapable of just enjoying the unfolding ups and downs.

ECM mean superb with a more surpressed low- 192 Shows a great snow slider...

They're an absolute snorter!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! YYYYYYYYYYYYYYYYYYYYYYYYYYYYYEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEESSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS http://effis.jrc.ec.europa.eu/applications/monthly-forecast/

Ec46 week 5 is more of the same ...euro trough then pulls back west later week 6 which relaxes the uppers for week 7 basically ...... cold ......and potentially snowy ......

Looks to me like the Exeter 5/15 day forecast .:... getting colder with snow possible pretty well anywhere not sure what else people are expecting ...

GFS just beginning to realize the low will slide.. What a donkey of a model.

Interesting medium range EPS mean anomaly this evening Upstream still the Aleutian low and strong ridging in the east Pacific into the Arctic But the vortex and trough has slipped a little south down eastern America which in turn results in the subtropical high amplifying into south Greenland. And with the trough downstream becoming a tad more positive tilted south of the UK some adjustments to the thinking required. The strong Canada > UK corridor is now not so evident and although systems can still move along there would appear much greater chance of slipping Arctic air into the mix so portending unsettled with a temps perhaps significantly below average, But the surface analysis could be quite complex and take some sorting by the det run The GEFs is not so bold with the downstream amplification

UkMO and GFS now meet up, I like the 12z, decent runs imo and very plausible. Superb PV displacement.....snow is coming I’m sure BFTP

GFS 12z runs for midday Friday 10th Jan 11th Jan 12th Jan 13th Jan 14th Jan

Clusters tonight are basically awesome for cold, as you'd expect, but this is the most awesome of all - the D15 chart. 66% of runs going for the Greenland ridge!

Looks like a NE flow to me - expect the Greenland heights to be maintained - take back what i said - possibly migrating scandi at the end, its the NW where we have below average PPN on there, the blue colourss are in the NE, you wont get massively above average PPN charts with those charts with blocked signals - don't forget, you only need average, even slightly below average - weekly averages for this time of year are around 20-25mm of PPN, so even if you get half of that - you are looking at 10-12cm of snow!!

At no point has the model output shown a plunge into the deep freeze and a snowfest. It has always been a downward trend in temperatures and a gradual increase in wintry potential over a fairly long period of time, and that remains the case. The up and down mood in here is due to people getting hung up on and sucked in by individual models and charts.

The GEFS mean is still trending much, much colder through late January with widespread moderate / severe frosts, ice days and an increasing risk of snow..no downgrade that I can see from the 6z !

To date a storm that deep has never crossed North to South across the UK so chances are a watered down 'spread' version could be on offer with a sharper trough axis & more in the way of continental influence in the flow ! We shall see ...

I'll jump in here and say no. The Beast was primarily a strat driven event - it was visible up to 2 weeks away and was caused by the speed and extremity of the downwell. The vortex shard that could be seen tracking east to west pulled the trop with it - and it was all about cyclonic energy running the wrong way. The lesson of Feb/Mar 18 was that, when in full bloom, an effective warming bosses the pattern. People have got very hung up on the route rather than the destination here this evening. Whether we get a full blown slider scenario or a more defined low tracking SE the trend is for a deep Euro trough to establish with a signal for heights to spike to the north once it is in place. This is where we are going - but will it be 3+2 or 4+1 in getting there? The models are really going to struggle with resolving the amount of energy in the Canadian lobe with a slow SSW downwell and a pacific pattern that still wants to work a meridional solution. We all have our favourite run - for me, once you get within 72 hours and looking at the specifics of the pattern around the UK the UKMO is best - and nothing to do with national loyalty! ECM has a tendency to overmodel the amplitude of the atlantic at times, and GFS definitely has a tendency to wind up lows too hard and force everything too far east. My best guess is that the GFS scenario is underplaying high pressure resistance and the fact that ECM is very much in line with the UKMO modelling at 96 means we have a solution that will trend closer to slide than not.....but ultimately it all seems a bit irrelevant to get hung up on it because it's where we are once the trough drops into Europe in the middle of next week that counts. Anyway a mostly enjoyable day. I fully expect more drama tomorrow as the landing zone for cold creeps ever closer....

I see @Catacol has made a similar point above but for the benefit of everyone as a reminder - Crewe, you’re hardly the first person to do this this season and is suspect you will be far from the last, but those meteociel strat charts only show temperature at 10mb - and temperature is not the indicator of where the vortex is/isn’t, you need to look at GPH for that. So, here’s where we were on the 12th: In fairness, the stratospheric high not too far from the north of Scandinavia, but certainly not a ‘direct imprint’ indicative of Scandinavian blocking. This does not, of course, mean that we won’t see a Scandinavian high in the tropospheric pattern, as we don’t always get a direct vertical downwell of the stratosphere into the troposphere, but drawing this conclusion based upon the stratospheric pattern on the 12th is I’m afraid not quite right.

I've just corked a bottle of Prosecco! I wasn't expecting much if I'm honest from the 122z runs apart from the far reaches of FI, but to my surprise thing are starting to look really interesting, I'm in love with the ECM and para 12z's. I'm thinking to myself now that February this year could turn into one of those epic cold and snowy one's from yesteryear, I'm certainly expecting lots of weather porn charts to pop up in the next few days. The para shows decent snow cover countrywide from next Tuesday onwards, amazing.

ECM days 9-10 look highly improbable in detail but if you reduced the intensity to something more credible, it would still be a good outcome and would be followed by many days of northeast winds and cold uppers, building pressures over Scandinavia to Iceland, and a weak Atlantic storm track running around the southwest margins of the high pressure into Spain and the western Med. The strong low would continue to move away to southeast reaching about Corsica by day 11 (975 mb) and Albania day 12 (980 mbs) then it would eddy around the Balkans for several days, would be my guess anyway. ... we are still groping in the dark for the actual solution, the only worthwhile take-away from all the model analysis is that it will likely turn much colder and stay colder than normal 80-90 per cent of the time well into the first half of February apparently.

Very nice looking 240 hrs from the ECM. Top right corner.

Wet and windy you say? Looks snowy and windy away from the far south. A beast of storm that next Wednesday. Looking further ahead, the GEFS shows quite well the trop PV dropping south over N America while same time downstream response to amplify a ridge across Greenland and drops south another lob of the trop PV / vortex over Europe - so looks game on for end of Jan for a more protracted and colder cold spell

This morning's ecm 50mb geopotential Ht chart has a familiar ring to it. Aleutian low, Alaskan ridge into high pressure over the Pole and two vortex lobes norther Canada and southern Europe. Oh my giddy aunt

Looks like someone has been out celebrating last night snow with a bottle of my favourite Spanish Cava !

Ok guys. Let’s agree that Germany has a coastline and get back to the models.I

The glosea posts have been removed as it all stems from an out of context snippet from a random tweet that serves not much purpose but to muddy waters on that basis. Which is why we don't allow tweets etc in here.

Whilst many factors are marginal for snow on the ECM, don’t forget the DAM / thickness. 528 or lower is usually what’s required for snow ....

Looks as though GFS is finally sliding the low further south on each run Manchester mean ensemble 850hpas for midday 18th January 0Z run: -1.7C 06z run: -2.6C 12z run: -4.3C

I wouldn’t be making any assumptions of warm sectors - with cold air following from the wnw, we may see occlusions headed se into slack flow ukmo day 5 has reasonably low uppers and a continental flow

London eps graph will be impressive later here in the Home Counties, ave maxes below 2c from day 9 thru 15 ......

We will see if the next eps suite is as wintry but this one provides a very positive snow total by day 10 no way would you take this as anything more than indicative but it’s impressive with 5cms + across most of the uk

People might scuff at the ECM 46 day model showing a cold outlook, as it’s been showing it for ages, but it’s been showing it for the same time period for ages. That being late January into February, starting in just a week’s time! It’s been remarkably consistent.

WOW ECM. Ummm just the ‘smallest of hints’ to drop the trough on a NW to SE axis through us then... Had to double check these were mean D7 to D10 charts. Incredibly strong signal.

ECM ensemble mean at T240, supportive of the op I would suggest: Actually this looks great!

Regards the initial slider, IMO, unlikely too be much of a snow event for the masses (possibly a bit of backedge). Worth reminding some that it was never really touted to be at that stage, if it does ending up producing a few cm away from the normal elevated areas, to be treated as a bonus. Quick question though... Why, when we all (surely by now) know that the models are going to struggle with the SSW and its subsequent effects on the troposphere, are we expecting, of all things, consistency!? I come on this forum and read pages of people apparently in absolute shock and horror that the latest suite is wildly different to those of previously. Be it 'better', or 'worse' No downgrade trend. Same entropy. Same potential. Just enjoying this evolve

Ooh er, missus? Could this be the long-yearned-for High-Latitude Block? Yes please!!!!

Interesting comment from Mike Rantanen……. "The decelaration of stratospheric winds is slowly propagating downwards. ECMWF is now forecasting an easterly zonal mean zonal wind at 50 hPa (~20 km altitude). Note that in the #SuddenStratosphericWarming of 2018 the wind at 50 hPa never reversed".

I see two main causes of uncertainty; the strength of Pacific MJO influence sharpening the upstream pattern starting around about D10, and the interaction of the Canadian vortex 'drain' with regional +ve GPH forcing from the stratosphere and a surge in AAM, both of which encourage height rises just N and NE of the UK. It's most intriguing how all but GFS had a brief fling with a much stronger regional stratospheric impact yesterday. Seems they saw less resistance to it from the Atlantic sector - perhaps a bigger AAM surge than they've been going with so far today. Question is whether that regional stratospheric influence is being underestimated and if so, is the difference to reality going to be large enough that the major trough from Canada gets disrupted after all, even if it's vigorous and the N. Atlantic pattern offers little assistance? ECM D10 suggests it could be, but GFS remains keen on a diving low rather than a disrupt-slide outcome. Of course, given the known AAM bias, the N. Atlantic might help us out more after all... hence two main causes of uncertainty. Confidence in the modelling is unusually low until further notice!

So it's like 're assuring kids that there are no monsters under the bed..... Draining of the sister still forecast and the split complete on ECM GFS good run draining away and going in right direction....come on guys if you can't read the charts don't comentate incorrectly please