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Furthermore to this it may just as well help by backing this up with some facts. So to recap where we are this winter: We have a descending solar cycle aligned with an descending eQBO - historically most NH blocking episodes and -NAO have been seen during this time - we have previously shown the papers that suggest this. EDIT I have got this bit wrong - so apologies for misleading - for a descending solar cycle the NAO is mostly positive - but this data was taken with far higher solar max values rather than the subdued cycle max we have just seen - so at the end of the descent the results may be more closely aligned to the minimum rather than the descending phase. Paper is here http://onlinelibrary.wiley.com/doi/10.1002/2013JD021343/full We have a disrupted trop polar vortex that has been ruling the roost over the lower strat vortex - hence the mean zonal mean winds (u winds) at 30 and 10 hPa are significantly lower than we are used to with no signs that any upper vortex intensification (VI) is likely to occur and filter down anytime soon. The MJO forecasts in a Nina'ish year are surprisingly good http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml and I am sure that @Glacier Point and @Tamara can come and confirm how this affects the GWO. But if we look at the composites for December for this type of set up then we see this Without the Nina then these height anomalies are stronger over Greenland. The trend is definitely for a southerly tracked jet in a NW to SE axis exactly as we are seeing currently and I don't see anything that will change that in the short term to the usual SW to NE axis. That does leave the door open for Scandi height rises so well done to GP and Tamara for suggesting this. But overall the pattern forecast by the models looks 'right' and I would be highly dubious of any that suggest a return to mild zonality for a while. Now all we need (on a personal note) is for the snow charts for this weekend into next week to include Sussex!

Hi Several posts since early-mid November have anticipated possible developments and detailed thoroughly in each post both the upside and the downside of the way ahead. My own initial doubts are well documented that weighted a milder trend, but increasingly plenty of evidence posted to show why "usual service" this season may not be so straightforward Also just yesterday I suggested that too much face value paid to intra day operational and ensemble suites could lead to quick and not necessarily correct reaction in terms of the implications of any milder phase mid month. It might be worth reading yesterdays post carefully Its clear, I believe, from there where the boundaries lie, and why there is reason to believe that any milder phase could be a bridge towards a pattern that changes emphasis towards looking across the North Sea Finally, as stressed fairly recently, my interest is very much driven by enthusiasm and curiosity of how patterns might pan out, not just based on weather preference and ideals. On that basis, creating a skewed basis for fitting evidence around either a cold or mild outcome would be futile, self defeating and a waste of my own spare time putting together some thoughts purely intended to help discussion on the thread

Sorry, but for starters, it’s Friday night and it’s work enough pruning the off topic stuff without worrying about a thread title being a week old. Moreover when we change threads, we have to lock the current one which means anyone in the middle of posting (and we’re getting several posts a minute at the moment) will lose what they’ve gone to the effort of typing out. Sometimes it’s quite a lot. Hopefully the title isn’t affecting everyone’s overall experience of the thread generally.

I'm not seeing that. For me it looks like any westerly mild attack get put back with the emphasis more on any mild weather being watered down as we get each run. The trend is definitely cold with short lived mild rather than what we are used to - mild with short lived cold getting watered down as we close in. If we can keep this trend up and then get a Scandi high as suggested by models and GP/Tamara then who knows........

Hear hear. I hope any newbies on here take heed of this. Madden is a charlatan who has zero clue about meteorology, and I am very disappointed that his name is getting any credit here.

00z and 06z GEFs continue to advertise the speculated trend days 12-15. EPS not as progressive, but hinting the same way. Westward positioning of the North pacific ridge becoming more polar in location. Polar vortex being pulled west with it, away from Greenland. Building height anomaly to the NE. To reiterate, this is not likely to be rapid transition, and a milder phase is not without question, but the broad trend is exactly what I would be looking for with regard to January's evolution.

I know everyone is excited about the weekend - not quite so much me in Somerset - rain all the way here on Sunday I reckon. However my eye has been caught by the latest WDT update today - images in particular: Simple explanation here is that momentum budgets continue to hold up very well despite our Nina base state. MJO is hammering pretty quickly towards phase 7 which should support return of high lat blocking. In essence - the pinch of salt advised yesterday in terms of trusting model forecasts pointing towards any lengthy spell of westerlies just got pinchier. Decent amplitude looks likely to continue...

The confidence of no snow south of M4 imo is way too high. This is a volatile and cold set up we are in with further near time adjustments, changes to come. Indeed snow accumulations that have happened already surprised many imo I think Madden needs to do the lottery tomorrow.....I saw back in October he highlighted 7-10 of Dec as a disruptive snow period...no lie. Models for me showing a further adjustment south..all to play for. Also the Atlantic ridge for mid month, I think it will manifest in blocking being influential and no westerly flattening BFTP

I’m half way to talking the wife into a trip to the midlands with the kids tomorrow and a hotel stay, with the promise of shopping on Sunday!! Luckily she never watches the weather! Snigger snigger! Fingers crossed

This thread is turning into a snow watch thread - please read message at the the front of the thread before posting, i.e if you are going to just talk about snow prospects please use the regionals - otherwise it is just going to get cluttered up with such talk over the next 48 hours. Back to the models - best stick to the reliable and the theme remains cold but with a shortlived westerly feed on Wednesday a 24 hr wonder, and another northerly for next weekend, about the sixth northerly in a sequence...

Northern hemispheric base state remains the same for the foreseeable - so expecting u-turns over the weekend back to the predominantly cold outlook with the atlantic never breaking through fully - a temporary westerly mid week, before cold returns later in the week. Models as they often do probably overreacting to the incoming westerly feed, powering up the jet. I'm still seeing a signal for height rises to our NE as we approach christmas.

Looking through those (probably overexagerated) snow charts on weather.us - EC 12Z ensembles out to Monday - that slider low is nothing for uncertainty on this new event!! We have up to a foot of snow and no consensus at all on where it's going. Some go SW. Some go central south. A few go SE. Only about 20% fail to produce heavy snow south of the M4. And we're now inside T72!

This is a slider free zone! Putting aside the above, the medium term is beginning to look a bit more promising with the Atlantic onslaught beginning to hit the buffers. Its noticeable that we're seeing some trough disruption in the GFS 12hrs run to the main upstream trough with some energy heading se, you would expect some pressure rise to the east/ne but it looks a bit messy at the moment but the trend is there. The UKMO has backtracked from its woeful morning output with a bit more amplification upstream . Theres still quite a lot of uncertainty with the exact set up re that deep low in the east USA. More amplified there will build a better ridge to the nw but it will take a few more runs before we're sure of the upstream pattern. I'll add this in from NOAA, this would tend to support the more amplified solutions: 00 UTC GEFS/ECMWF ENSEMBLES OFFER A WELL CLUSTERED FORECAST SOLUTION INTO DAY 6 OR SO THAT MAINTAINS MAX WPC CONTINUITY AND FORECAST CONFIDENCE. A FAVORED COMPOSITE SOLUTION LOCKS IN A FULL LATITUDE WRN NORTH AMERICAN RIDGE/ERN NORTH AMERICAN TROUGH PATTERN ALOFT. THE 00 UTC GEFS MAINTAINS THE WRN NOAM RIDGE MORE THAN THE 06 UTC GFS/00 UTC ECMWF ENSEMBLES DAY7/NEXT FRI AND THAT MAY BE A PRUDENT WAY TO GO GIVEN INITIAL AMPLITUDE

I think we've seen so many great charts over the last few weeks maybe we're getting a little worn down! This at 144 is another cracker....just think of the doom last December!!! And decent uppers compared to 12z at 150

Of course there is a point - that is what the model thread is all about - looking at charts that we dream would come to fruition. They are as valid as any. It's hardly as if those charts are in FI! (note - the only chart that ever really comes to fruition is T+0)

Some pics of my home in Shropshire - it's throwing it down again now. I'd say we have has about 8 inches but its at least a foot deep on my lawn ans surrounding fields.

Very tasty this morning folks, its dry, very powdery snow, so drifts around the house and the area. Really pretty wild when the showers come through, blizzard like at times. Scottish highlands has its proper December coat on -3c Local roads A pair of startled bins, caught in a head light

Sorry Sean, Feb is miserable because ecm has moved the snowline 20 miles south for Sunday and is commenting solely on ecm op to day 10 whilst I am commenting on the gefs to day 15. No problem with consistency there ...........

Nope. Re-read. A milder phase is perfectly feasible.

This slider low has turned into Play Your Cards Right! Instead of couples you've got the southern v northern contingent. Each output is met with desperate pleas of higher or lower or in this case go north or go south! Given the timeframes its less likely you'll get any big corrections but still room for some changes. Anyway the next instalment of the slider low saga or better named attention seeking model celebrity will soon be arriving!

17cm of level snow. That's more than Dec 2010 or Dec 1995 managed. It's certainly the most round here since Feb 1991, possibly 1987. 4 years without any significant snow ends like this.!

Morning all Twas Christmas Eve on the Control Run: And all through the Suite Only one creature was stirring A Beast From the East Apologies but it's an evolution we could well see. The orientation of the ridge is more WNW but could we see the Atlantic regime pushed back westwards from this ? It's not entirely without support as others have stated and the most extreme example probably P5: Fans of cold would love it.

12z ECM v 00z ECM

A few posts have been hidden following a misleading post. Please keep on topic

two weeks since this gefs mean anomoly took our interest - just shows sometimes they aren’t as worthless as some think

Afternoon- Things looking pretty set now for a tasty snow event for regions North of the M4 coridoor - Whilst the tracks have generally corrected south - we are now seeing minimal adjustments - Also if we look at the finer detail over the last 24 hours the Entry point over Ireland hasnt swayed to much, its the extension of the snow belt over the south - caused by the elongation of the trough - Monday is more concerning for a smaller concentrated area - so whilst there will be good coverage over a wide area sunday, Monday have some really focussed heavier bursts of snow along the boundary of the -1c isotherm- Elevated areas in the SE could find rapid build up of heavy wet snow- but there will be a sharp cut off point to rain ( expected in Mid Kent ) Anyway - enjoy the snow if it arrives !! S

This was about an hour ago... Blue sky now, -0.3C, gentle breeze. (Apologies to NW - it wasn't an uploader fail, it was my stoopid.)

I'm contacting some people directly anyway, but for the avoidance of doubt - please only post model discusison in here. Please head to the regional threads for general snow chat etc - there's tons of action in them today so you'll not be alone!

I had to dig my way through 2" drifts and risk frostbite to take this... Whiteout again now, power keeps flickering, shop shelves are bare, we're all gonna freeze / starve / die of alcohol poisoning. (Got to keep up with @More Snow and @snowidea)

Epic snowstorm for someone...

When it comes down to it, we have in the 8-10 day range a not all that strong or flat jet (compared to what it can be... as we're seeing for early next week) coming up against some significant cold pooing in what looks likely (as of this evening at least) to be a pretty slack setup to the E and NE, which has an increasing amount of aid of background forcing as we move between mid and late-Dec. So not surprising to see the models trying out some trough disruption with the Atlantic being held off. Whether this can actually be achieved without the Atlantic westerlies ever really getting in will depend on a combination of the pattern continuing to look supportive of deep cold pooling next Sat-Mon plus enough of a nudge in the right direction from the tropical teleconnection. There is a Bay of Bengal tropical cyclone that could complicate matters, but today has seen wind shear impeding the system and keeping it weak (https://www.accuweather.com/en/hurricane/indian) which, given an expected poorly-conducive environment for development in the days to come, reduces the likelihood of much impact on the extratropics .

Very happy with both the ECM and GFS in terms of developing some further interest in the run up to Christmas. The key thing here is to get that trough disruption upstream. It does seem that the outputs over reacted to some eastwards push of the PV as the strongly positive PNA relaxed. However I'd like to see a few more runs and get that key trough disruption within T144hrs. The pattern does look condusive to a Scandi high developing as energy digs se. But that's still way ahead.

Good trends from the GFS and ECM with the troughing disrupting to the west at T168 and T192hrs , energy heading se'wards. A chance we could see our Scandi friend pop up in future runs if this continues.

Erm, discussing the prospect of the low sliding in a north-west to south-east direction? It is a model discussion thread My sense is that the LP isn't intense enough, the airmass ahead is deeply cold, and the trajectory is insufficiently west-east for the fronts to advance as much as was being shown over the past 48 hours. The overnight 0z's reflect this from UKMO to ECM. The Fax charts are also showing this, which at short range we disregard at our peril. If that trend continues, which seems quite possible, the centre of Sunday's LP (not talking about the secondary Monday event) could move along the M4 corridor, or as I suggest even more likely, entering around the Severn estuary and exiting around Eastbourne. Whilst some might be irritated at the GFS if it does continue to shunt the low southwards, I think we should remember that on the general picture it has been brilliant over the past 10 days. They say that 'the trend is your friend.' All eyes on the 6z and Fax charts then.

With the EC clusters showing the odd doubtful outcome at the moment, I've looked through the EC ensembles this morning and made my own rudimentary clusters: D10: Westerly/Southerly influence over UK: 70% of runs Northerly: 10% Easterly: 5% Unclear/battleground: 15% D15: Westerly/Southerly: 45% Northerly: 25% Easterly: 15% UK High: 5% Unclear: 10% In a nutshell, better longer-term than last night's ensembles, but westerly influence between D10 and D15 still in the ascendancy, in my opinion.

Gents, two completely different ideas hear of the same model, Not good for newbies, Feb91, look at the bigger picture, the Pacific ridge relocation, waxing And waning lobes of the vortex and ridges causes mayhem with the models, best to sit back and watch the models toy around for the next few days whilst they get to grip on a shift. I think we may get a 2/3 day more mobile pattern before deeper cold takes hold.

Thanks for your post Tamara. Your comment "Looking across the N Sea" gets me excited. Speaking of excitement I will take this run from the NMM http://modeles.meteociel.fr/modeles/wrfnmm/runs/2017120806/nmm-1-49-0.png?08-11

I love this thread and this isn't a personal dig at anyone but the personalisation of the slider position is starting to become a bit frustrating in here, yes discuss it's projected movement but not just an emotional response. Personally I don't want it to slide any further south as I personally will miss out but I save my frustrations for the regional thread. I am totally up for the excitement of where it will end up, as for me the positioning has been interesting to say the least, but the "Yey, it's moving south" is getting tiresome...as I'm sure the "Yey, it's moving north" would be the same too if that were the case. This forum is fantastic for learning and have learned so much since I joined but I think I might have to give the thread a miss for 24 hours just for my own sanity.

Very exciting Gfs 6z with a southward adjustment meaning the south and southeast is coming more into the snow risk zone on sun and overnight & throughout Monday..could be a big dump for southern uk..fingers crossed!

Would you believe it? It's Blawin' a proper blizzard oot there! About 7 this morning there was the merest dusting of lying graupel and now it's a white out! I don't expect it to last though but it looks great! I hear kiddies squealing with delight somewhere so I guess the sledges are out! Will try and get some pictures later.

For Sunday I would go for the general consensus of snowline north of the M4 and north of Greater London, where it settles more of gamble, but parts of Wales and Midlands and southern parts of N England esp. The Peaks look to stay all snow. I don't think there will be anymore nudges north in track more likely south if there is anymore changes. As for Monday's low, more difficult as the centre and the precipitation circulating around it may end up missing SE UK altogether!

I think I just found the reason for ecm 12z having the snow line as far south as the n Home Counties a discreet little low at the extension of the trough at 9am Sunday

Hello A lot of attention obviously on Sunday and Mondays events, though I'm also looking to see whether we can sustain the cold. Admittedly it will be quite tricky but there seems to be a Scandi high popping up in the operationals again. I'll highlight the key to look out for. First to stop a zonal onslaught, it's vital we prevent the polar vortex from creeping into the Atlantic. Here is the 12z GFS operational later on in the week: The Polar vortex is held back and heights are allowed to build northwards from the Azores. Whereas the control.... Is poor and we see a return to more familar territory. Thankfully the ECM supports the operational instead. Next step to hold on to the cold can be achieved in two ways; either trough disruption (ECM) or a held back polar vortex over NE Canada (GFS). ECM GFS operational For good trough disruption cold air over the UK is a big help (as shown by this weekend) so we want to see as much cold pooling as possible on Thursday. The 06z GFS operational was actually very cold with sub zero maxima at times in central and northern areas but that was because of a snow event on Thursday. It will be difficult to get more snow on Thursday though there is still uncertainty about the incoming low. Overall the 12z's lack the stronger cold later on and would probably result in a CET of around 4.0C by the 18th. They are ok though but the threat of a return to zonality is there later on. Lets hope the Scandi high builds or we get more trough disruption in around 10 days time!

My Mrs said she was expecting 8 inches, I don't think it will snow either..

Aside from worrying about the post-mid week breakdown and who or where will the snowfall be, which parts will see rain etc. How often do you hear the media forecasts state these words for lowland parts of the UK, let alone England? DISRUPTION and SNOW in the same short sentence. The latest Beeb forecast, for instance, reminded me of situations from past classic Winters )and I was born in the 1970s), it is well worth a view again if you haven't seen them. Granted, we're not all going to get the snow, and a few of us might care for it too much but it is what it is and the next few days are FASCINATING to say the very least. Enjoy! Check out the above Fax Chart; it truly is one for the archives. All this within 72 hours as well. The t+60 chart is worth checking out as well. EDIT: Here's the t+60 Fax Chart, see what I mean. Bleedin interesting setup, I say.

Out and about this afternoon, western Black Isle. It was pretty snowy! I pretty much missed last winter's snow because of work so I'm pleased as punch to get out in this.

ARCTIC

The Gfs 12z shows a major snow event in sunday, the snowy sweet spot could get 8 inches or more and then the south / southeast joins in the fun on Monday with back edge snow...good luck guys.

While we await the 12z GFS, its worth mentioning that while this slow southward modelling has occured over the last 24 hours, many models are now showing quite large snowfall totals further south. London grinds to a halt after 2cm of snow, imagine 10-20cm? WRF highlighting this now Of course, these high res or 'rapid refresh' models are always all over the place with their predictions, worth a watch as we go over the 24 hours. Oh and how about strong winds to boot come Monday evening rush hour? I think we are now slowly starting to get a better grip on movements of the Low now, but what an interesting time to be model watching! (Head still hurts from last week)

Still trying to scrape myself off the bathroom floor from when I fell over in shock. We probably have around 5cm lying snow and another shower has just topped that up. Never seen this here in early December. Can I borrow some children to take sledging, all mine have grown up and either aren't interested or moved away. Nah, you're ok, I don't mind Will be out for photos soon enough.