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Ok, I have a bit of an update. Looks like the correction westward for today got the predicted snowfall about right . Nowcasting really comes into its own for this weekend. The team think another correction westward on the frontal system moving into The British Isles on Saturday. Perhaps not as advanced as shown on the models or UKMO fax. So a slowing up or disruption of the trough could give a more prolonged spell of snow. The outer parameter of the snow computer flag up up the East of England with a moderate fall in places , especially East Anglia. That would indicate a wedge of cold still very close to the British Isles. The front is expected to move through by the end of Saturday . Long term very uncertain but likely to stay cold for many, how cold ? not sure but there is now some sort of thinking of undercut scenario to develop around the last 1/3rd of the month with Southern Britain trending to a snowy outlook ( more southerly tracking low pressure systems ) Hope that helps. C

When I was wee, like 9, I'd trace maps of GB umpteen times (on my mother's greaseproof paper) and then draw fantastical synoptic weather-patterns on them; and there were almost invariably both a Scandi-Iceland HP and a European low in evidence! My parents thought I was mad... But, what If I were merely anticipating this thread -- albeit 55-years ago? Once a nerd, always a nerd!

Well, another interesting day model watching. The main thing I see is that we have fairly similar patterns between the main three at day 6. If we were to pause at this point, and not know what was modelled after this point, then I think most of us would agree that this is a pretty promising position. And that’s what I see too. I think there are a number of directions the models can go after this point, including the west based -ve NAO. But if we were to stop there and imagine a slightly different direction than we already know the models are taking then the promise is great. And with the SSW downwelling and it’s influence displaying a range of different output and ensemble outcomes after this, I think that we should be very careful writing off any particular scenario. One thing we know is that following an SSW, the models can change direction very quickly - both the ensembles and the operationals. So still a lot to look forward to over the coming days.

GEFS are a massive upgrade, loads more members plummeting and for longer too.

12z Friday is one staging point then looking 'above' via strat plots this is really progressive from the 18z, not progressive as in it's the pub run doing outlier stuff, but more to okay what is is seeing as the NPAC takes effect. Friday 12z was the date I had pencilled for some 'settling' of the immediate SSW dynamics, then Tuesday - Thursday next week ( see strat thread gifs) for further ahead. The adage of compare 00z to 00z and 12z to 12z I get, but as we exit the initial chaos of the SSW each run heralds clues. The model watching folklore shout out I would call this week is the what the 00z takes away the 12z gives back ( whether this is due to the 12z being the fullest suite of data for NWP delivery - not sure). All in - patience folks - we have been served an SSW on top of some great blocking teasing things, we know SSWs main artefact is dissipation of cold and sticking to that evolution will temper help - hell we all want a holy grail 09 instant response, but lets just watch this play out. Think of it as you pressed play on the next run coming out, but you are watching it at 50% speed..

I would describe this winter so far as Synoptic Heaven but Surface Hell.

Bonjour A new thread for discussing the models. Please continue your discussions As warming events in the Stratosphere continue to have impacts on the models, what sort of weather patterns could we expect down the line? In a way, the models are offering varying solutions, some of great interest to those who love cold and wintry weather. One thing, though, that looks evident is that the weather around the UK side of the Northern Hemisphere continues to be quite slow moving with sluggish High and Low Pressure areas about. Not the typical, flat, Westerly Atlantic dominated pattern with a beastly Vortex to the North of the UK and over Greenland that we see during a number of Winters. There is, for the moment, a likehood for Pressure and increased heights to build to the North-West of the UK as we head into next week. Examples shown at 168 hours from the 18Z GFS, 12Z ECMWF and 12Z GEM, in that respective order, below. Although a block to the North-West looks very possible, there is perhaps some questions as to where it will occur (Greenland? Southern Greenland? Atlantic? Iceland? Mixture of all three?) and how big and strong it could be. A chance for Low Pressure to be sent on more of a Southerly track under the blocking towards the UK. However, as you can see above, it's all looking a fine line between whether they can track far enough South to plunge the whole of the UK under colder air from the North and East, or something that may be more restricted for Northern areas. If even that at all. An Icelandic or Greenland block being close enough to us without any higher heights to our South-East over mainland Europe getting in the way could help ensure Lows track far enough South to keep all the cold weather fans on the chillier side of the weather. Considering the situation we're in with the SSW (Sudden Stratospheric Warming), expect many more changes to come. I do feel, at least, some blocking High Pressure to our West or North-West is a good possibility at times, as it seems to be something these Stratospheric warming events would support. Though clearly nothing is ever guaranteed and the patterns lower down in the atmosphere at the tropospheric level may not be reflected in exactly the same way as those higher up in the atmosphere. You can also have some great blocking to the North of us, but still be on the wrong side of the pattern for colder weather. Can hope if you're after some further cold weather, that won't be one of those times, or that there is a gradual slide to something much colder and snowier. NOAA 6 to 10 day 500mb anomaly chart going for the build of heights to our North-West and some troughing South over the UK. An upper flow sourced all the way North from the East of Greenland, where it curves Eastwards through the UK. So their could be some chillier weather about at times, but where any sleet or snow occurs depending on the track the surface Lows themselves could take. Northern high ground quite likely fairing the best. No signs currently of any proper, freezing, conditions affecting the UK on this chart I feel. Some shift South and East of the pattern would help bring in some deeper, colder, conditions, with better chances of a more sustained flow from a Northerly and/or Easterly direction. This however still doesn't rule our marginal and transient wintry weather events and some days could easily be chillier than others. For some places, it could be very wet. The pattern could always evolve into something much colder, and considering the uncertainty again, there is room for things to improve or become more unfavourable for chilly weather prospects next week. The latest 6 to 10 day 500mb NOAA anomaly charts can be seen here: https://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php Hopefully, and especially for those who haven't seen some of the white stuff yet, all of you cold weather enthusiasts will get in on some snowy action. A good number of weeks to go for this to be possible. Compared to last Winter, things are looking more interesting for the cold and snow fans this Winter. While this is something a lot may want, there are a few of you who may want something stormy, wet, mild, dry, frosty or a variety of everything. Although it has been greatly discussed, the closer time frame does offer some wintry treats, especially for those towards Northern and Eastern areas of the UK. For example, the GFS shows some precipitation moving down from the North today as a little Low sinks South through the UK bringing the chance of some sleet and snow over Northern and Eastern areas (already reports of snow over parts of Scotland): There are variations from many different models to the track of the precipitation and how widespread the rain, sleet and snow could be. The general situation seems to be for the rain over Eastern areas to transition into sleet and snow throughout the day as the Low Pressure picks up colder air from the East (although with some cold air already over numerous Northern and Eastern spots, some of the rain could very readily turn into snow). Maybe some of this sleet or snow extending further South-West into parts of the West Midlands, depending how easily some of the milder air further South and West gets pushed away. Heavy precipitation will help play a part encouraging some evapourative cooling to occur and drag the snow line down to lower levels. Best chance of settling snow over high ground where there could be 15 plus cm's over the Northern hills, though some accumlations lower down is likely in some spots leading to some locaslised disruption, especially again over Eastern and Northern areas. A lot of looking out of windows and lamposts with this event I imagine. And it's always possible for everything to occur further West or further East than what many models show. A marginal event it may be, but something for some cold weather fans to look forward to. Please keep it friendly in here and stick to the models. Bullying will not be tolerated. These include posts that: Make fun of other members Disrespect other people's weather preferences (you don't have to like the type of weather others like, but please be respectful of other people's choices) Try to get a reaction from others Are weather guilt-tripping Belittle people due to them having differing opinions to you And anything else that is deemed rude and offensive. Those sort of posts will Off topic posts will also be put under the disappearing spell or moved to a more suitable thread. You can also report off topic or inappropriate posts and the team will deal with the situation as soon as possible. For general Winter chat, moans and ramps, please use this thread: https://www.netweather.tv/forum/topic/94934-winter-202021-chat-ramps-moans-and-banter/ Other suitable threads you could use: Met Office UK Further Outlook Stratosphere and Polar Vortex watch Regional Weather Chat I suspect it will continue to get very busy in here at times, particularly as many continue to hunt for certain weather types such as cold and snow, so we will accept a little bit of off topic content in posts at times as longs they're broadly about the models and don't derail the thread. We would prefer if the thread wasn't used for congratulations or thanks type posts (unless there is a very good reason for it and/or has some model discussion in the post). The use of the private messaging system or the 'like' or 'thanks' button would be much prefered. Thank you Model Output And Charts On Netweather: UKV (Extra subscribers) GFS GEFS Ensembles ECMWF ECMWF EPS NetWx-SR (3km) NetWx-MR (9km) Met Office (UKMO) Fax GEM Model Comparison Global Jetstream Stratosphere Previous Thread:

Yep, sounds positive to me!

I think folk are better off shutting their eyes for a few days and opening them after the weekend. Genuinely the route forward from here is nigh on impossible to plot and as you can see from the post above MJO RMM plots are about as wild as they can be. The hemispheric pattern is in a significantly chaotic situation, with patterns changing from run to run. Not much more to say and an unusual position to be in. The long term models have flipped to a generally -NAO for February which is good - but in general there is so much uncertainty about the direction of key drivers and their interaction that more than ever before dissecting each and every run at the moment will just drive you nuts. As soon as some kind of coherence can be picked, the best minds will put thoughts together. I will add though that this is a bit of a personal disappointment, and I'm left cursing the failed vortex split more than ever. The chaos is the result of the huge uncertainty around the behaviour of the displaced and very weak vortex and the extent to which downwelling impacts are going to override trop patterns. I dont think the models have strat behaviour nailed down, for our neck of the woods very small changes in the shape and position of the displacement have potentially huge impacts, and meanwhile we have very undercertain trop forcing patterns. I'll post a bit more later when I can pull up more info on all this - but I had hoped for near nailed on easterly proper cold for the last 10 days and while it may still happen it looks far less "nailed" than some had hoped. We wait to see how things pan out!

Worth noting that something has potentially improved a great deal since yesterday's 12z runs: The stall point of the trough near the UK is a good deal further south and west. I say potentially because this only plays into our favour if the low from the southwest doesn't start phasing with it too far north and west - if that happens, you head the way of the ECM 00z with cold air transported down a long way west of the UK where it seeds further development of low heights, allowing the trough off the USA to extend eastward faster and more strongly. Interestingly, UKMO has not only adjusted the phasing low even further south - having already been toward the southern end of the model run spectrum - but increased the strength of the ridge to our west. That's a two-fer of positives!

Yep, I think too many may be guilty of looking too far ahead, rather than concentrating on the short term building blocks that we see currently modelled. I mean how many people would be fretting if they couldn’t see what was modelled past day 6?

Good morning.

Just for some context, we’ve had 2-3 inches of snow here in low lying Wakefield today, and the scene is repeated across much of Scotland and the spine of England - and this is the chart. You wouldn’t have thought it would you? By which I mean, you don’t need pretty charts for a brilliant snowy outcome as we’ve had today.

Pure joy FullSizeRender.mov

Relieved to see ECM budge having been so stubborn for several runs. Sizeable jump close to the UKMO-GFS group. It’s important because it shows that adjustments toward a better placed trough by the UK and slower trough progression out west of us both have some merit.

Boom. Snaw still going. Currently, 0.4°C/0°C.

We've done not bad. Started with noisy sleet lunchtime yesterday, it's been snowing since. Not as dry and powdery as it was over New Year, it's 'snowman' snow! We've had 2 days since Dec 28 without a snowy/icy covering.

I feel like I’ve been looking at charts like this that have consistently been 10 days away since late November.

the anomaly charts remain in the cold region and meridional in pattern ECMWF/GFS DAY 8-10 MEAN 500MB HEIGHT COMPARISON WWW.METEO.PSU.EDU Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV

Not sure about the "up North" comment. We take it on the chin, rain snow, floods ete. We don't make headlines ie se England and we don't complain about crap summers. Think on. Anyway the model output and nhp don't really support a true Gh ete. The SSW is just coming into the mix model wise and I'd suspect a lot of change on all models over the next 7-10 days. Whatever that delivers be it a north south divide cold and snow ete its in the hands of the gods. Enjoy whatever the weather

Wish that I was still living up near Aberfeldy in Highland Perthshire at times like this. Here are the roads out from there earlier this morning including the main low road to the A9. The last one is towards Crieff at Amulree.

Wasn’t expecting anything after a minging day here yesterday. Don’t this the motorbike will be used today!

I'm hoping to move back up to the highlands at some point this year, seeing all this snow makes me wish we'd done it last year!

We see time and time again there is an algorithm for the morning runs through to the 18z. Rather than view them as downgrades from a previous evenings runs and avoid using such words it's a good idea to view them as scenarios. So for example... 0z compare with yesterday's 0z runs. 6z compare with yesterday's 6z 12z compare with yesterdays 12z 18z compare with yesterday's 18z You will then get a much better analysis and avoid any morning disappointments based on a previous 18z. The following image sums this up nicely and how I feel models should be perceived based on consistent observations to an algorithm.

Curiously, IDO's favourite model has adjusted pretty much the entire Atlantic-Europe pattern a little southward. That'd be a good trend to see continue for at least another few runs.

Afternoon all Loving all the pictures! Very local walk (17 minutes) up to Gourock golf course - snow fix sorted! Three/four inches in the highest parts. Highest point was glorious - could have stayed there all day. More of these days please through the rest of the month/February at least! All the best to you all.

Winter wonderland on southside of Glasgow. The 100m asl must be making a difference

Not quite ready to replace the profile pic yet. A round 6 inches! Sweet spot indeed.

About an inch of heavy wet snow from the heavier part of the front, light snow still falling and misty. What a winter this is turning out to be! Trees looking lovely out the back...

People bemoaning the 850s not being very low should consider the dewpoints. Marginal Thu but low enough Fri pretty much everywhere. As far as I can discern, the air behind the initial cold front starts out near the southern tip of Greenland. Then, air from north of the UK starts to wrap around - this more efficiently done than in the previous few runs.

Woooooohooooo 15 cm and still coming this morning. Preliminary bench photae time. #sledgeday

Stolen from Twitter ....

I see that fergie is thinking that models aren't seeing the big picture and expects colder weather than what os shown on the models... hmmmm what's going on I wonder early signs of sudden flip??

Curious about this, I ran it through NOAA's HYSPLIT model for a central UK location (using the available GFS 6Z output) and found this: On Thursday the 21st: - Air at 10m agl would come from Taimyr Russia, through Greenland and Iceland. - Air at 500m agl would come from the central Atlantic looping through the Norwegian Sea. - Air at 1500m agl would come from Labrador, doing that same looping. On Friday the 22nd: - Air at 10m agl would come from Taimyr Russia, through the Barents Sea. - Air at 500m agl would come all the way from the Bering Street, doing a tour along the Russian Arctic coastline and the Barents Sea. - Air at 1500m agl would come from Ireland, moving through Greenland and back.

Maybe you should only comment when you have seen both sides of the story Daniel and not what 1 side wants you to hear. You were not privvy to the Private Messages Ed received which were worthy of a total ban and you only have to look at his response on twitter recently to see the language still being used. Can we move on now from the Steve Murr debate, he isnt posting on here anymore, if you want to go to one of his concerts then he is appearing on TWO or Twitter End of story lets get back to the weather now can we

So I just got woken by the kids screaming “Dad can we go sledging again?” I said “what on earth are you on about?” “It’s snowing again” they said. Looked outside and I couldn’t believe my eyes. It was pouring down with rain at 1am when I arrived home at work. Yet another surprise snowfall. Happy days

Early days but this latest Gfs run is ever so slightly more amplified than previous and weaker Iceland low. Small earlier differences can be magnified later

Been busy workin fae hame the day.

The GIFS I posted above hopefully help a little in terms of what is being modelled currently, I wish I had all the answers ! The Berlin GIF above shows the core of the vortex shifting to the Siberian side at 10hPa and in doing so it becomes coherent again, interesting dynamics as it is almost magnetic in absorbing the Greenland Daughter Vortice, in doing so this whips across the Atlantic. Thereafter, the US side of the hemisphere appears drained of core vorticity. Granted this is higher up in the strat and a longer term direction of travel, also how does this imprint into the troposphere remains a question. Then the other GIFs further down, see the hPa labels show just how chaotic this process is in terms of that same transition, the energy which has vacated the Greenland locale at 10hPa is still 'active'. Hence, the singular slide for Tuesday where it would appear wave breaking maxes out. This makes working out what is next massively difficult and will defer to experts on Twitter for views here in terms of latent impacts. D10 @ 10hPa D10 @ 50hPa D10 @ 100hPa Berlin / d 5/7/10 @ 250hPa NASA The last series is clearly quite chaotic as energy transfers beneath the block and we can see the alignment somewhat in the NWP model output. If the longer direction of travel is for a picture to develop where we see the 10hPa and 50hPa profiles eventually imprint on the troposphere, well - one can imagine. A big avenue for a block and a mass of cold to tap into. The vortex regrouping at 10hPa as per above will also account for the reasonable / strong recovery in u wind which some may look at to say, oh well that's the SSW done with. Here is the warming profile and zonal wind profile vs deviation from previous 60 day mean, and I think they show the 'slow-motion' transfer down the column of the SSW. Looking at all things considered, the daughter vortice - it's disruption, how quickly the energy transfers to the larger vortex are a great example of why it's all a good watch as another 'flavour' of SSW unwinds. We know to expect volatility in output and hopefully the above kind of outlines why to some extent. Hopefully some others can join in to add further insights. It is a monster W1 and remain hopeful we will still be seeing impacts lagged for some time. Right now in conclusion it is just too difficult to call with certainty. It's a new SSW and still learning from it.

Much like @Stormeh went to bed around 2ish and was miserable outside - all hope lost. Woke up this morning from my manager texting to make sure all our buildings have been opened, was like "Eh?". Opened blinds and aye knew what he meant right away. Main roads in Glasgow gridlocked around half 8 this morning. Working from home now, was meant to head into office today - result! Still coming down just now.

A lot can change while you're asleep! Heavy snow this morning and everything covered

The Atlantic ridge that is a 100% requirement of any cold spell is getting very close to disappearing around 120h with just a small cut off high standing in the way of us and Atlantic zonal Fortunately it is enough so far to stall the low approaching Greenland and give us some more much needed WAA reinforcements and undercut. UKMO is even more delicately poised with less amplification the pattern further SE by 144 I think maybe people just see the Northerly and not worry about upstream but UKMO continues to be stubborn . It would probably be okay with the next low reinforcing the ridge and undercutting but we really could do with being more amplified and further W. Here is an example of what happens with P11 having the ridge a little too far E, no undercut and toppler type scenario so people can better understand my angst. After Yesterday mornings output it is definitely reason to be upbeat but just as a reminder of how much that ridge has been downgraded and forced East over the last 2 days of output 2 days ago for 19th V today for 19th Jan and that is the same with ECM. So any more corrections really need to be back west and restrengthening the ridge to make sure we get the undercut Overall this mornings output still suggests a cold plunge last 3rd Jan with a battleground type set up last week between milder Atlantic air to the SW and colder Arctic air to the NE. The colder we can get with the initial plunge the more chance the lows will disrupt and be further S for that period which could be very snowy for some with a bit of luck.

Excellent update EC46.

Went for a wee walk a couple of minutes drive away. Amazing the difference just a couple of hundred feet altitude made. Even up there though it has turned to rain and a bit slushy underfoot. Felt a bit sorry for the small calves and the ducks.

I am sorry most of you are not getting the snow you are yearning for, but for little it is worth, there is plenty of the winter to go yet and some reasons to look towards the latter part of this month and into February when prospects may be more conducive. But such rationale behind this is for the right place. For my own part, I am still waiting to leave to get to my new home in Portugal, which has seen unprecedently low temperatures going back many decades since last seen previously. I think that part of this has been down to the Iberian continent effectively generating its own surface cold pool following the, again, unprecedented snowfall over the Spanish interior, and albedo type feedbacks from consolidated snow-pack effectively setting a very low 'fridge' type thermostat across the expanse of the land-mass. In that sense, not too much different to an east or south-easterly drift around winter anticyclones that can bring deceptively low temperatures from the nearby continent into this region. Following the storm that tracked across Portugal and Spain last weekend, high pressure descended across the land mass and this has created some very intense inversion cold - if one looks at the actual upper air mass it would suggest nothing at all of what the surface conditions have been like. Over the coming week, that cold air is set to relax and mix out - and as the jet-stream invigorates from upstream as cold air this times spills into the CONUS upstream across the Atlantic, then much warmer air will arrive from across the fetches of the more southern parts of the Atlantic as a western based -NAO profile sets up. With this in mind, I am personally wanting some sun and warmth on my face, but that will have to keep waiting for, for a longer time yet. At least a couple of the builders at my new home, doing some work on mew piping and plumbing and fitting new bathroom and kitchen units, have contracted COVID, and my Portuguese friend and her little family who live at the annex there, are being tested very shortly this afternoon, and it is of course therefore a worrying time. Suffice to say it precludes me from leaving here any time soon, and with the work on the new house delayed for an unknown time, it looks as though I will be continuing to look at UK and Northern Europe weather maps for the time being! But here is some Portuguese sun from a pic taken there recently this week - and my friends cats seem happy as well

In spite of the fairly solid pattern of meridional flow the 500 mb charts show, I posted earlier this link to the ECMWF output does not http://www2.wetter3.de/Fax/00_ECMWF_ENS_p0_500hPa+144_240.gif So which will be nearer the actual weather pattern in 6+ days time? I have to say I do not know. I cannot recall seeing the anomaly charts so consistently showing a meridional flow without the weather following what they suggest. The ECMWF output is something that has only recently become available, so I have no idea how reliable it is. I do have to say though that I am beginning to wonder if it is not doing better, at the moment, than the anomaly charts? See for yourselves, the anomaly charts were posted earlier but I'll drop them in here for an easier comparison ECMWF/GFS DAY 8-10 MEAN 500MB HEIGHT COMPARISON WWW.METEO.PSU.EDU Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV The 8-14 NOAA carries on with the meridional flow and it shows a pattern in the far west that one would expect to support the pattern in the UK area.

Some great output from @carinthian and @Singularity above,its not worth getting to hung up over these current twists and turns with the models just now..Yesterday the output was poor during the morning,before improving during the afternoon. As it stands perhaps colder with Snow risks for the Midlands Northwards...that doesn't sound great for those of you further South,but keep in mind there's so much going on. The next mini warming continues at 10hpa. The estly zonal wind reversal continues to strengthen at 10hpa 6oN...currently 5.6/M/S Etly..courtesy of Marco P...so I would say more headaches for the models down the line. Edit...the Stly tracking lows could bring a larger area into the Snow equation next week..The pattern is far from sorted though.

It has snowed all morning here. Just not particularly heavily so only a bit of a wet and slushy covering. Seems to have been a case that since conditions have been right for snow, we just haven’t had the intensity of the overnight rain. I thought the sweet spot would have been the higher parts of Lanarkshire but it seems to have been the Dunblane area and heading up towards Perthshire. Parts of the Glasgow area have done surprisingly well. Still, nice to see and some great pictures on here this morning.