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Good afternoon gang ,its nice to be back reading all the posts again ,although i have been lurking .(Thanks to all friends on here for my much appreciated messages over the loss of my wife recently ,THANK YOU ALL ) .Its great to see that the charts are showing some Winter weather , really warms the cockles of my heart .And its the charts which keep us interested not always showing us what we want ,and i,m certain that over the coming winter there will be Prozack moments and of course STella times ,so with the Meteorological Winter looming we can look forward to 364 roughly Runs of the good old GFS ,182 of the ECM , AND HUNDREDS OF OTHERS .Looking around the Internet back last year i looked at many weather forums etc ,and found that ours is by far the best and most interesting around .In my next post i will stay on Topic ,just wanted to start with a light Hearted post today .Let the hunt for Winter Synoptics commence ,Curtain twitching ,hiding behind the settee etc ,cheers gang ,.

So just to finalise my thoughts / comments on the 12z suite.. We often find ourselves in Winter with an atlantic high ridging into the pole- & the longivity of that wave / ridge remaining in situ before getting flattened ( as well as the final height ) is directly related to the general consistency & strength of the pacific jet - because after all thats what normally comes barrelling over the top shearing the top of the highs- Its also important to remember that at this usual point in late November the heights over pole @500MB are generally sub 516DAM & this more often than not coupled with a strengthening zonal wind means the tip of the ridge usually gets to the southern point of greenland before the westerly directional flow is already getting to work on moving everything East - So on a 'typical' Early winter chart we see a Northerly toppler - Day 1 we have our ridge & 4 days later its been flattened- look at the pacific jet blasting away- no sustainable meridional flow going forward , just a temporary interuption to the sinuous flow... Also notice the persistent low heights over the pole - Now look at the starting point when the second wave of ridging occurs at 120- * The all important residual +VE heights over the pole consistent with the original -4 AO ( which is why people like me / Bluearmy always refer to it ) * The fairly strong but still attenuated pacific jet & weak subtropical jet - with this attenuation there is now an ripple in the jet over the states which is a sharp +PNA pattern creating a big 'dig' of cold air in the NE is, that dig then supports the returning flow upwards back towards the pole @144 Post this ( from the GEM ) @144 the entire hemispheric jet is rippled & attenuated creating a 'weak' easterly component in terms of a zonal wind. Not only this but the stratosphere is decelerating at the same time - With the detached tropospheric negative anomaly almost upwelling with time- This shows a decelerated zonal flow around the pole So all the fall out means that based on the starting point of T96 & the rupture to the jet - combined with the persistance of higher heights over the pole makes any eastward progression of the jet a lot Weaker than normal- & with considerably more North / South components - more so than westerly ( moving East ) Its a rare scenario - but based on the starting point at day 4 the continuation of Cold is odds on favourite, maybe not quite to the magnitude of the ECM in terms of outright blocking, but solid in terms of the pattern remaining blocked & slow out to day 10- I would go with the final solution being less extreme than the ECM but overall closer to the ECM than the flat GFS .... best s

synoptic Nirvana

Don't know why we can't all just get on, without the digs and quips- there's one thing that unites us all and that's that we are all weather enthusiasts...otherwise we wouldn't be here. The day 10 mean chart isn't great IMO and that cannot be denied...so don't be shocked if the 12z GFS is closer to reality or if the 0z ECM is no where near as good. However, there is a positive, pressure remains relatively above average across the polar regions and that can clearly be seen. This suggests we may have further opportunities moving forward.

Hiya Just for clarity - a wave once peaked wont become a GH so if you have a wave where the 552 Line has just reached the tip of southern greenland then it will close off in the central atlantic - thats that wave over & done with- To reach a Greenland High you will need another wave with a higher amplitude to take the 552 line much further North- Tonights ECM ( nothing short of spectacular & alligned to GEM & UKMO ) shows this secondary wave perfectly 120 > 144 > 168 Starting over NE US the jet is kicked Northwards taking high pressure with it- at this stage there is almost a point of no return which is once the centre point of the low gets North of the western tip of Greenland it will continue NNE... The models tonight continue off where we thought & 'hoped' they may go yesterday which is elongating a cold snap into a cold spell- Initially the North & elevation would see uppers cold enough for snow - however should the pattern continue as modelled by the ECM - so the deeper cold will gradually seap back south through Scandi towards the UK... Exciting times but we need that secondary ridge with the same amplitude at 72 > 96 > 120 for 100% confidence & of course the GFS on board.. S

Holy ice cubes! Quick, to the ensembles Robin! What an Ecm run, another upgrade..could we see a prolonged cold spell?..really hope so Meltdown alert..Boom..Stella..if Carlsberg....etc??

It's great to see the models and Exeter firming up on our first proper taste of winter (in late autumn!) with wintry ppn, frosts and ice likely to feature in the forecasts from later this week and at times through next week with snow in places, especially with elevation but some on low ground too, especially further north and east. PS..Great to see legritter back, netweather will be even better with his contributions..Welcome back

It’s good to have you back! We’re certainly always here to support you and other members going through various situations

Lower heights over Iberia on this run. If ever we are too get a true Greenland high then this will be a precursor. Still think it is the highest toppler ever!

Sure. GFS 12z Ensembles. I think we can agree there's a lot of scatter in the extended. There's a cluster for continuing the cold and a cluster for less cold. Fairly even though perhaps a few more favouring the mild. The GFS ensemble mean for the same period. Looking at that, you'd think that there was zero ensemble members going for cold weather because the mean is so watered down that it doesn't really show anything, when in actual fact 60/40 favour colder weather. I'll have to use the ECM clusters from this morning because they wont be out for a few hours yet but I'll also use the ECM 00z ensemble mean. First, the 00z ECM mean. It doesn't really show a great deal of interest. A cool North-Westerly low, no massive block at the Atlantic looking fairly flat. What about the clusters? The clusters tell a very different story. Ample blocking across the spectrum, cluster 3 likely the mildest of them all which would skew the above ensemble mean. So my argument here is that the means are absolutely useless because they are skewed by other solutions. Whether cold/mild is what you're after, the ensemble means are skewed towards a more neutral pattern. They have uses in the short term when spread is less, but not in the long term when there's a big spread. The clusters are more useful to get an idea on, as are the individual ensemble members, but not when they're grouped together into a mean.

I'm not going to attempt the detail over the next couple of days as that can be found elsewhere so suffice it to say the main concern is rain, first in Scotland this morning and then later today and tomorrow in the NW of England as a complex systems of fronts and associated lows traverse the north of the country Elsewhere south of these areas cloudy, some sunny breaks and very mild. It topped 17C yesterday. So on to this morning's gfs. At midnight Thursday there is a positively tilted upper trough orientated SW > NE to the west of the UK giving a complex surface analysis with small lows littered about and a marked delineation between the warm and cold air. Over the next 24 hours one of the lows to the west becomes more organised and tracks into Scotland and could well bring some snow in the mountains in the north and the associated front has tracked south to be over the channel with a link to the extended trough in the south west. It is here that a little low develops and intensifies as it tracks NE to be 989mb over the west Midlands by 06 on Saturday It is quite possible the precipitation will fall as snow on the leading edge of the front over the higher ground in Wales and the Midlands as it engages the colder air but that will need to be sorted later as that's pretty much very dependent on detail. By 18 the low is west of Denmark and the UK is in a cool north westerly with wintry showers in many places, particularly the north and west, and the high pressure attempting to ridge north to the west. I say the HP attempting to ridge north advisedly as it merely ends up ridging across the UK on Sunday, albeit it does cut off the cool north westerly as the next upper trough tracks east from Canada putting it under pressure and at the same time creating another complex low pressure area to the west of the UK with rain and front already over Ireland by 12 Monday. Over the next 24 hours the front traverses the country and the depression becomes more organized and by 12 Tuesday is 979mb approaching the western Isles and perhaps more snow to the mountains in Scotland. To cap this we now have HP ridging (tenuously) north towards Greenland which forces the low south to be in the Channel by 12 Wednesday, Throughout these shenanigans the temps are around average, perhaps a little below. Best left here I feel

Lol! It’s an Amber Green combo ! The committee meets tomorrow morning to discuss going to green!

As you were from the latest NOAA 500mb outlook and very similar to last night's but a bit more ridging in the atlantic sector showing a more NW flow instead of WNW tonight's last night's i know these are the dutch ens but we need took look at these as oposed to ours to see if an easterly is on the menu temps show good consistancy for a cooldown there as i have shown with the two black lines dew points show a drop as well but we need to see these flatlining to -5 or below(red line) now the wind direction of which i find interesting because there has been a shift in direction from the ones i have been viewing for the last fiew days,the black arrow shows us going for a northeasterly then easterly but is a split decision but minority going for it,we need more in the purple circle over the next few runs to se and if/when we get this easterly debuilt also showing a cooldown too means from gefs ens and ecm ens at day ten,pretty good cosistancy there from both,the means are broadbrush and will not show you the detail other than trends here is a link to snow charts(forecast),a good site i use for when i go out walking/hiking http://www.snow-forecast.com/resorts/Snowdon/6day/top my dogs reaction when i said snow is on it's way .......... ........we hope

I think the Scottish Ski resorts will be pretty pleased with tonight's ECM

Regardless of how garbage the GFS is in the nearer term, an early-mid December warming would go down a treat for longer term prospects- it still has that signal there

A bit of talk earlier around a Greenland blocking high v Atlantic ridge. Out of interest for a short time tomorrow/thursday we do see a Greenland high.We can see the jet split off as the block establishes-the cut off northern arm looping up over the top of Greenland helping too advect the polar south towards the UK. It does fade away and then we see a further attempt at Atlantic ridging next week but see the difference this time No closed off Greenland high this time even at the peak of the wave virtually all the jet energy is held over the top so the wave(ridge) eventually topples. Just to give an idea of the difference between a block and a ridge and the jet flow involved. This pattern though does enable reloads of polar air as long as we lie on the cold side of the Euro trough/Atlantic ridging setup.

Well a lovely EC- cold locked in as per meto update -maybe not bone chilling but the euro low should prevent any zonal much for a wee while, what a nice festive way to bring in December

GEM with a stonking run this evening. It may be a lower ranked model but have any of the models been good in the last week? How about ECM follow this?

That’s a surprise heavy snow in the south pushing in south east England nice to see but I doubt it won’t come of..

There is of course one problem..........How on earth do we top that in the morning

Following on from the above post. The view of the experts over here has been to highlight the feature of persistent lower heights over the Azores and the alignment of the jet into NW Europe for some time with a mostly NW/SE axis. The view regarding UKMO is any weakness in the Atlantic high should allow potentially to send troughs SE wards in the t168-240 t time span. ( Picture below ) therefor a flat Westerly is not likely. Looking into the outlook past this weekend, a significant trough is visualized extending in an axis from the White Sea to Biscay. That's some development, keeping NW Europe in the colder flow. The cold pool between Iceland and Scotland to move to Scandinavia and deepen next week. If heights can be maintained in Mid Atlantic to Greenland, some sort of / North/Easterly component can be expected for the UK next week. Certainly a milder few days here in the Alps but the prospect of a Scandinavian deep cold pool on the cards is encouraging for most snow lovers..

The ecm doesn't agree with the gfs take for Saturday and has the front tracking south across France on Friday and no developing low to the SW to track north east. Thus the UK is already in the cool north westerly/northerly over Saturday into Sunday. And still going for a high pressure dominated Atlantic with the warmer air just a flick of a squirrels tail away.

Another run ticked off with no major early dramas. Not the greatest week for the GFS with the overblown low crossing the south which is now just a shallow feature and its flat bias coming to the fore upstream. The shortwave to the nw still needs to be nailed down in terms of track and depth , that might still produce some interest. Overall coldies should be happy and we’ve seen quite a turnaround after the initial west based neg NAO trauma of last week.

Fax charts updated. The 96hr chart for Saturday shows the 528 dam line nearing central France. Yesterday's 120hr chart for the same time had it just into the north west tip of France. Short term upgrades are always a good precursor to decent cold spells.

Just to give an idea of what EC shows compared to the average for time of year- fri sat sun tue wed thu fri Europa looks below average acc to that run ..Greenland looks waaaaaaaaaaay above the norm ..

Simply one word.......WOW

11,000 + Greenland high, doesn't get any better than that...! ???????

Great model runs from the 12z suites apart from the GFS but that doesn't really bother me too much at present it is just good to see some consistancy between the models and the ECM 12z giving us all what we want to see tonight all the way to 240hr and even giving hints at extending beyond. If we look at 192 when the ridge has already made its push north for greenland we can see the first signs of another attempt at ridging already getting set across eastern canada as circled in this shot here Which then further develops on into the 216hr chart again circled Then as we hit the 240hr chart the low following along behind slows as it approaches the ridge and we see the contour lines on the eastern side of this start to straighten Then we see the start of another push of hieghts which look set for the eastern side of greenland and would hopefully help to keep the block in place here instead of hieghts falling more into a scandinavian block and the further push can also start to be seen from the 850 temp charts as a slight push of warmer uppers start to appear Now not that a scaninavian block wouldn't be nice but it also comes with downside like it getting sucked into an siberian high but in this situation i feel it would be our longer route to the colder uppers and some proper snow where as if the block was to stay east greenland based and would tap into the deeper cold upper air temps residing across siberia much quicker and pull them towards europe Now of course this is all depending if the overall pattern is correct which as we know it is probably likely to change but with alot of models being in some agreement then it may be right that we will have to wait and see but we all need to remember a pattern doesn't always set on the first push of ridging sometimes it can take several goes to get that block to stick and set up right. As for the GFS i am not too worried about it going zonal after all if you look back the archives it didn't really cover itself with glory in how it handled the block back in 2010 at extended range. A good days model watching and onward to the 18z and hope the other models can keep the pattern up over the coming days and we see lots of the white stuff.

Great ECM run for the Scottish ski resorts aswell as those across mainland Europe. After the mediocre GFS good to see the ECM continuing with its festive spirit. As long as the UKMO remains onside then confidence increases. Hopefully NOAA trash the GFS in their state forecasts!

Steve Murr on board Gawd this place is something else when colds on the menu....makes all the pain worthwhile EC is just synoptic heaven- Northern blocking galore, wonder if that all that WAA pumped up into high latitudes will serve to prolong the seasonal weather- bye bye Dec 2016 you wont be missed.

The NE'ly train coming in

Big EC tonight- i'd be shocked if it looks anything like gfs - shocked and...

GEM is known to massively overestimate 850's - you can knock a good 3c of the 850's it gives for the UK. It is actually a cold run throughout, the coldest we have seen for some time. GFS control run in disagreement with the Op, much more amplified. Rest of the ensembles fairly well split some much more amplified than previously, some flat, some a mess Op has less much less than 50% support for the flatter pattern so good news there.

Some coldies are so hard to please but i'm delighted with the ukmo 12z which has a locked in cold look about it at T+144 hours with wintry weather for the uk..Welcome on-board ukmo!

You can add me to that list.... I rate it very highly....(now) Won't be getting my hopes up though, does look pretty marginal and my mind now is a bit more on the long game for some proper cold as we head into December. Nice to see though.

EC locks in European Low pressure by day 10 - Looks a bit toasty over Greenland .. Not a bad way to bring in December

Charts tonight still showing promise ,just hoping that next weeks northerly will get upgraded as we move through this week .This weekend could very well see snow falling although most likely further north and with some elevation ,next week if we do get what charts are currently showing and we can get locked in for a few days or more ,could see more of us snow starved posters get in on the act ,Very early days but interesting times i,m sure . Ecm full of promise ,cheers all .

Beautiful run.. Evolves into a peach!!!

GEM probably the pick of the models this evening thus far

UKMO is tremendous this evening - looks much better than GFSs at 144 with a much cleaner route to retrogression in the Atlantic

GFS takes Saturdays low further North whilst the APERGE sees a more Southerly track and as a result, the snow risk is further South too. Now, given the GFS's love of tracking low pressure systems too far North in these situations I think the APERGE will probably be closer to the mark bringing the risk into Southern England, rather than the North Midlands.

The control run gets there Steve from 192,then meanders around up there in low res,not a bad chart that with hp cell to the north and lp to the south,it would be nice and crisp with a continental flow too,many outcomes from there in....if of cause we get there the end result of the control run not only gives us a cobra run but a scorpion sting

I think we might be seeing changes upstream beginning to effect the brief model consensus . The ridge over the west coast of the USA is expected to break down early next week , in terms of the PV over Quebec which had stalled its what happens to that. Does this edge east as per the GFS or does this head more ne. The GEM goes with the ne helped by a bit more amplitude over Canada . Given the GFSs recent performance and it’s known upstream flat bias I’d tend to put more weight on the ECM. Its only a few days ago that the GFS made the wrong call within T120hrs. If the ECM goes flatter then fair enough but given tonights UKMO I’d be surprised if it follows the GFS.

Evening, following on from the above post. Make no mistake the latest UKMO run is a big upgrade at 144t. The trough alignment is forming in the right place. Firstly, get the cold in place, that is now taking hold with much of Scandinavia and out across the Norwegian Sea to Iceland in a freezing air mass. As highlighted in the above post a flat westerly seems unlikely in the period 144t -240t. C

Slight Eastwards shift at +96 and slightly stronger blocking going North in the Atlantic too. Very minor changes but upgrades nonetheless.

Caution as always but I'm starting to get a tingle of excitement in anticipation of the cold air sweeping majestically southwards across the uk later this week!

Yes matey it sounds very much like Exeter are happy that EC 00 operational has the correct handle on the extended outlook (and by proxy GFS6z) with low pressure across Southern Europe and the UK in a cold flow - certainly a far cry from last years zonal hell fest.

ECM mean and Op in good agreement once again for the entire run

Gales possible in the mix for Saturday, Blizzard conditions over the hills for some..

When it walks like a Block, talks like a Block, it’s a Block! long live the pub run!