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I must be the only one then that looks at these chart and walks off satisfied. Anyone hunting wall to wall snow in November needs to read their history. The pressure differential between Greenland and Scandy on those charts is pretty good for vortex disruption when combined with the Aleutian low in the North Pacific. November is nothing but a setup month - no low ground product in terms of snow is realistic. In addition the pattern is effectively blocked, and people need to realise that a block creates a more meridional flow that promotes warm flows from the south as well as cold flows from the north. The fact that the Scandy anomaly helps pull warm air up over the UK is part of life in this part of the world at this time of the year. The pattern is not one of raging zonality, the strat/trop disconnect remains in place at least for now, and vortex stress looks likely. Winter doesn’t start for 3 more weeks, and realistically doesn’t really kick in until mid December which is 5 more weeks. If you need to cheer yourself up in the search for snow try reading up about the Feb 18 reversal that led to that beastly spell. The Atlantic preconditions are not dissimilar and while every patten is unique we are certainly in with a chance of a cold outbreak this season. Just don’t expect it in November and don’t expect it to last all winter. 1963 was unique and a year I don’t think we will see repeated for as long as the world continues to warm.

Good to see things ticking along nicely WRT pressure rising to the North & the atlantic systems being ushered on a more southerly track- Some may remember me commenting 2 days ago on the GFS being to far NE with its angle Well now look V the 2 charts from the other day Original prognosis at 84 was all the enery moving NE Now the same timestamp this eve on the 18z Note the swift change to the jet alligning SE This will stop the low ploughing NE through the UK which would have blocked the small ridge of high pressure moving NW towards Iceland- Now this ridge looks like developing so the return to colder runs has returned At this point in the year im glad the main thrust of cold is still 8-10 days away as for us down south thats really the earliest window we could really hope for snow anyway.... First Air frost here last night @ -0.5c Cheers

@Allseasons-si A classic 3 wave pattern. Anyway I think the key watch here over the next 14 days appears to be the amount of 'undercutting' we get from a high that aligns NW up towards Greenland... Very very interesting times - Early snow potential available for the North...

Once again some great and insightful posts, sorry about running out of likes! The 12z ensembles to me look just fab, the mean has come down further, and we are now looking at a fair amount of sub zero runs, I've even noticed a few potential snow makers on a couple of em. It's blatantly obvious things are shaping up well at the moment due to the increase in posts. This could be one hell of a busy run up to Xmas and beyond. 2010 repeat!! Let's go one better and have a 47/63 combined effort.... Could we cope with that! I'd like to think so.

The usual (probably quite dull by now) advice from me We should not be too quick to dismiss a single deterministic run, even if it is out of kilter with its own suite (caveat: I have not yet seen the EPS suite), particularly given the higher resolution of the deterministic run in trying to resolve some delicate balances over the atlantic. We simply don’t know at this stage where to judge this run and will need to wait for further runs. My second and definitely tiresome piece of advice is to be very cautious when looking beyond day 5 in the Greenland locale and particularly with regards to any suggestion of increased heights (those lovely greens and yellows on the H500 charts) - we have seen season after season a bias towards increasing heights too much in this area beyond day 5, only for this to correct itself the closer to T+0 we get. At some point, like a stopped clock, the models will sniff out one of these Greenland height rises correctly (and I do fancy that to be this year incidentally), but for now I would urge caution before we drive ourselves towards an early season meltdown. With Brexit coming Nick might struggle to get the Prozac over the border.

It's great to see all the gang back on the strat thread - I did nag @chionomaniac to join in the fun. @Recretosgreat blog on Severe EU and always love seeing what data crunching . RAM abusing graphics are up next. @zdlawrence prettty much a privilege to have you here Zac, your website is a real benchmark for Strat monitoring after years of peering at the Berlin charts. I think the testament is that even a year on the 3D work is catching the attention of esteemed pros such as Mike Ventrice. I loved the fact that #stratpants appeared this season when last year we had saw the same split troosers ( Scottish for Jeans / Trousers / etc). Best contribute with some commentary too other than say what a great season ahead, am personally loving Novembers now - it's the chase of the what happens next as much as the will it won't it herald negative AO/NAO or a decent winter.. By that I mean the down-welling question and the concentration of minds on this. Stop and reflect for a moment on how we were only 5 years ago working out precursors or Displacement / Split Dynamics.. Loving this ! Gnarly old vortex aint enjoying the Anticyclonic stuff happening right now.. can't do what it wants... Get your crayons out... Not a forecast there are two other years in the mix for Solar QBO similarity...however 95 worth a look..

Very cold with some Sleet / snow across the UK... Wait to you see the 850's

I agree that we weren’t lucky last year. We got about 85% of the way towards the cold blast the models kept seeing, but the split ended up being a bit too far west, and SSTs in the Atlantic conspired with the very cold air spilling out of America to prevent sub tropical ridging on the back of some solid tropical forcing to create the high lat block. I think it was a very fine balanced thing...and we got close but not close enough to tip that balance in favour of cold. I don’t see our current kind of mobility in November as a bad thing at all. For a start it isn’t conventional mild zonality - the trough over Europe is helping keepthe trajectory of the Atlantic assault quite steep with residual heights to the north remaining in play, and we have heights to the east in the right place to upset the vortex. Over on the other side of the globe the North Pacific ridge is set to topple, and a period of Aleutian Low action will also help fire warmth into the vortex. Later in the season what we need is a block to the north/NW/NE that can cause a reverse flow and bring in continental cold and this is very hard to achieve when the vortex dominates. So all remains good as far as I can see, and anyone hopeful of widespread snow right now is hoping for the near impossible. Perfect Synoptics right now in most places would bring nothing but drab, cold rain....so let’s “enjoy” the current setup that is about as good as it could be to set the vortex up for a fall and create the background conditions that could bring something special when winter proper is here.

It doesn't seem logical take to take the 0600 out of context with the previous two runs and the the ecm After all it was only the other day when you stated 'bin the 0600' because it didn't agree with your preferred outcome.

To me, the Ecm 12z operational looks even colder than the 0z..hope this trend continues guys!

Not sure it’s worth taking the current outputs at face value in terms of precise detail , better to look at the overall NH picture which is positive for coldies . The overnight ECM is a big improvement in terms of reducing the strength of the PV and moving it further to the nw. I’d give it a few days to see where the pieces might fall. Writing off mid November cold at this point seems very premature .

EC46 not too different from the ext EPS knocker posted earlier on. Heights generally to the N/NE with temperatures below average for the first part of November Blocking relaxes during the second half but interestingly a signal for blocking to the east returns during December, though little point worrying that far ahead at this stage.

Morning all . Woke up to a nice covering of fresh snow. The fine mesh model we use forecast 20cm at our location with-in 2 Sq M perimeter and guess what ? Spot on. Just blows me away with the numerical accuracy at that range. A great tool for the resort planners. The winterview chart below from CDPS model seems to continue the rather cold unsettled spell over much of NW Europe at 144t with further snowfall over the Alps and increasingly so over upland Northern Britain. There appears some uncertainty at this range from this mornings big main models. Both GFS and ECM seem to water down the prospects of a developing Scandinavian with a shift to a more Northerly flow and mid- Atlantic ridging but the British Isles remains in the cold side of the trough throughout. Will get the views of the team with regards to their own medium longer term outlook. In the meanwhile just received latest snowfall portal service report and that's for 30cm more snowfall before the end of Sunday. C

what!,your eyes jokes aside theres incremental adjustments in the 18z but not much even WZ has frozen at 189 will have to view the run in the morning a final note before i turn in,my partner is in a stable condition and will be reviewed on over the next couple of days,i feel so lonely right now sorry.

Lovely ECM 168 ( Euros on a par at 144 ) which is always a good thing..

FWIW the JMA probably the most likely to deliver a flake or two, or maybe more, here at T192: Didn't know JMA did strat charts, but some forcing on the vortex as early as T192: Very interesting to read @Tamara thoughts above. Couple of thoughts, re the idea of lower AAM as per La Niña atmospheric setup, could the Indian Ocean Dipole as mentioned as a reason for the +NAO forecast in the MO contingency planners forecast, be contributing factor here? A strongly positive IOD adds easterly winds at the equator, so seems to support. (Usual caveat, I can't claim to fully understand this area so maybe barking up wrong tree!) Second thought, like I was saying the other day when a new probabilistic model shows results that echoes the others, it doesn't actually change the probability of cold or mild, I think most of us now have factored in that there is a certain weight of evidence against a cold winter, Tamara's post backs that up. However, in my mind, weight must be given also to the arguments about what is seen here and now in models regarding both the trop and strat, and persistence of a -NAO regime, and the extreme solar minimum, which I believe the science is lacking a bit on. If the coldies get nothing this year i.e a 2013/14, I will eat my pants. But the fact that we're up against it, makes the jackpot sweeter when it lands! Going to be great model watching as winter proper is now fast approaching...

If anything, the Ecm 0z ensemble mean has trended even colder longer term..could get very interesting next week!❄

At 192 hrs time for changing on next run ,sit back relax STellas and sausage baps all round .But very interesting times at present even before winter begins .

This is insane! Right at the end of the run of course but to see a chart like this being progged for almost the end of November is rather incredible! SPV/TPV vortexes in the shredder for December if that were to verify. The GFS mean is spectacular

The North Atlantic surface analysis and the 0400 UK chart and 0300 WV image The deepening low is in the process of crossing the country through today resulting in bands of heavy rain associated with the fronts in the circulation effecting some areas. In particular Wales, the south west and northern Scotland and this will be accompanied by strong winds particularly in the south west and along the southern coast. Suffice it to say already gusts of 50kts down here. Overnight the low is now centred in the North Sea so a continuation of the rain belts running around within the circulation and still mainly effecting Wales, the south west and eastern Scotland A not dissimilar story on Sunday as low low slowly fills so a day of sunny intervals, heavy showers and longer periods of rain but the winds should be decreasing. But further troughs have joined from the west and the eastern Atlantic is now a very complex area of low pressure Over Sunday night through Monday the filling low is absorbed into another low within this complex trough which is now becoming positively tilted courtesy of the subtropical high temporarily amplifying in the west. Thus another day of sunny intervals, heavy showers and longer periods of rain and the orientation adjustment has introduced a cooler north easterly wind in the north By Tuesday the north easterly wind prevails over much of the country so generally a drier and cooler day but the remnants of the low are still effecting the south east so cloudy with some rain here. But note the ridge is under pressure in the west After a frosty start Wednesday should be sunny for most but further troughs have suppressed the ridge and made inroads from the west and the associated occlusion will bring rain the western regions in the latter part of the day which could fall as snow over the high ground in the north now that the colder air has been introduced

Another great run from the 6z , as in the NH pattern and that warming is really starting to show at the back end of the op runs . Exciting times ahead .

I agree with @s4lancia from my POV and as I posted last night still every chance we could get an easterly flow and actually the 06z GEFS were better < those are the perfect setup for snow streamers here. Again the focus is on the position of the lower pressure if it is to the S / SW of the UK we will have a good chance of getting the easterly, if it moves N / NW over the UK that will ruin the chance. Still all to play for and even if we dont end up getting the easterly we are only in November so anything wintry at this stage is a bonus and we still have the possible effects from the stratospheric developments with zonal winds getting ready to decrease and still signs of warming (how significant still to be resolved) . Also how often in the past have we went from A - B into colder weather without the usual upgrades / downgrades cycle - example from Jan 2009 days before the famous Feb 2nd 2009 event in the SE GFS 0Z 27th Jan GFS 12z 27th Jan GFS 18Z 27th Jan GFS 0z 28th Jan Actual charts Even just 5/6 days before there was lots of chopping and changing of the position of the cold pool so how people can take the exact positions of the setup for a week from now is beyond me, with the memories of last winters failed easterly I would agree that a cautions approach is needed but remember that the models have the tendency to underestimate blocking areas of high pressure...

Here cool, cloudy with showery rain later in the afternoon. 3.9C The Crieff Road South of Aberfeldy this morning. Second picture is off the same road taken by Philip Struthers. Nice picture of snow but can you see his dog in it? (Dalmation).

Yeah..layer warmth @Eurasia.. And an-operantional stomping latter frames.. Tbh..tricky to think of better dynamics...as we roll forward!!!

It’s the middle of nov Tim ! more inclined to take the NH profile more seriously on this gfs op as it’s much slower to a big neg AO split

Great posts folks.... Check Out of likes..... Check. Get back to you later.... Check. Today's ECM ensembles colder than last nights..... Check. Looking pretty good..... Check.

It’s an ensemble mean chart - and check more carefully re points 1 and 2... no Euro high and Greenland positive anomaly in place.

The trend for the ECM to make the GH more pronounced continues with the fabled black hole anomaly developing at day 9 & 10. Europe into the freezer- UK on the periphery but no signs of the GH abating at the end if anything its getting stronger

Ecm ends of synoptical high note.. And as again...that pooling looks ripe and perhaps prime!!! Resolve of annomaly blocking formats the only real worry...although atm it's looking trough primmed for our shores!= and any reform of the usual limpet base for the [email protected] plot...looks to possibly be a short affair...with bundles of room for drain and syphon!!!

Yes, Matt Hugo mentions the same thing as Judah Cohen yesterday about whether the combination of aluetically low and scandi-high in mid-November can disrupt PV and possibly lead to an SSW subsequently, as it lies on each side of the Arctic. This is exactly what led to an early SSW in 2009/10. It is good that PV is stronger than normal, which can collect very cold in the upper stratosphere. If it is quickly attacked afterwards, an SSW allows to push very cold air away from the Arctic. Interesting things are already appearing in the PV forecasts despite the strengthening. In 2009, PV also strengthened first, while November transitioned from -NAO to neutral NAO. It provided high pressure over Scandinavia-Eurasian and the North Pacific, which weakened PV via energy transfer. We had a blockage in the troposphere and fast wave 1 and 2 activity. It reminds me this year? Solar minimum? And so I think everything continues to go against the season models until day 7-10. It is only afterwards that you constantly see the peak of PV in the forecasts, while it changes continuously for the first 10 days.

Morning peeps! Plenty of scope for a seasonal start to November, with frost and fog looking evermore likely...And, frost-encrusted trees come a close second, to snow of course, at this time of year! And, the ensembles are now showing less scatter than they were so, hopefully, the models won't be too far off the mark...? It's a shame the kiddies are no-longer allowed to make ice-slides on school playgrounds: Ay, lud...them were the days!

Thought I would pop in with a wee post as it is sad to see the tumbleweed blowing through here...even @Summer Sun has given up posting the Convective Weather daily outlook! Had some torrential downpours and nice cloudscapes over the past week - also Asperitas clouds last month. (Anyone seen them before?) Now that Summer/thunderstorm season has gone I thought I would look back at my favourite pictures I had taken of convection/thunderstorms from June/July/August - great season up here. And lastly I wanted to take some pictures after the thunderstorm/convection had cleared - which made for some dramatic scenes/sunsets. It really was a glorious Summer for warmth, convection/thunderstorms and skies - one I will never forget! Hopefully next Summer delivers the same (up here) and more thunderstorms for all of us! All the best! David

I'm liking the 12z ensembles... We have a fair few cold ones and again it's being highlighted that there is a large cold pool potentially building to the NE. Just imagine an early SSW with it falling in the right place this time!! Froffing at the chops just thinking about it... I'm liking these signs, I maybe wide of the mark, but I feel this year could be delevering early!!

Some astonishing surface temp anomalies in the SE US next week

Yep..but the.... highlighted forms of flux and pressure grades are [email protected]!!! Take ya pick what way ya want your cold to come [email protected]

Sorry, can't post the charts right now but the GEFS 6z mean indicates a cold shot next week followed by another cold shot into the following week with a risk of snow on northern hills and perhaps some lower ground, and overnight frosts / icy patches... a wintry flavour, especially further north..as I said earlier, next week could become very interesting with colder air gradually filtering further south combined with continued unsettled / cyclonic conditions and further ahead there continues to be a signal for scandi height rises so perhaps a cold block could become established further into november!.

Sorry for the delay. Interannual variability in the polar strat is very low this time of year, but I received such a large number of requests to put up the NH charts that I went ahead and switched stratobserve back to NH mode. Cheers

Masie just out. What can I say..... ESS 101K increase. Laptev 80K increase. I call that a flash freeze. We now have the imminent situation of the central ice pack linking to the Siberian coastal ice in ESS, as well as it has already achieved in Laptev. This leaves it more likely that more rapid ice gains will be made filling in the still open waters. Elsewhere Beaufort added +11k Km2, and Barents added +13K KM2. The ice pack is being pushed by the wind into these areas, with the ice around F.J. and Svalbard looking very menacing. Even Chukchi moved forward with +6K Km2, for the first time this year. Zoom in the charts below for detail. If further proof is needed of the rapid increase in sea ice, the time taken to get from 5000K to 6000K is now the second quickest in the last 10years, For example last year took 14 days as did 2015. Both years were considered quite a fast rate of increase - whereas it has taken just 9 days this year.

Ive dismissed the ECM op for its progressive nature over the top of Greenland ( 168 > onwards ) NB same the other say- where it sweeps the high pressure aside from the west ... ECM mean looks much lower with better pressure over NW greenland, also the 192 mean a lot closer to GFS mean- ironically the swing to cold from ECM mean is almost identical to the GFS swing I posted earlier

Well it's that time of year when it's time to dust off the keyboard. I hope you have all had great summertimes. What a thing of beauty the GFS12z is today. It's been in the offing for 48 hours and, truth be told, we'd all much rather we saw it in December than October. Still, it's comforting to know that blocking hasn't disappeared from the earth or that the fabled Greenland High is just a thing of legend.

This band of precipitation took one look at Scotland and thought "I ain't going there": Some difference from the GFS earlier in the week which smashed it right through us.

If we ignore the upstream vicissitudes of the North American troughs which promotes Mid Atlantic amplification then the mean GEFS is still moving towards a position previously indicated. But all of this maneuvering is leaking somewhat colder air over the UK

Thames and Humber streamers lining up galore.

The midnight and 06 outputs. Ooh la la

GFS 00Z Operational maintains a block, throughout, this morning. So, so far, so good? But it is very-much on the colder side of the ensembles: Ergo, any ejaculations regarding 'how much snow and where' are a tad premature...?

One for the Scotland thread, methinks...? Quadruple rainbow photographed in Orkney WWW.BBC.CO.UK The photographer who captured the image of the third and fourth arcs described the sight as "amazing".

I must admit I got a bit carried away yesterday and the models have again pulled the rug from under me. There is still some cold potential within the GEFS 0z but less so than yesterday and currently there is more chance of a mild or indeed warm late october and start to november..apologies if my excitable comments / tone misled anyone.

What is it with the control run of late spawning charts worth dwelling over lets take a look at it it all happens around day ten(yes i know it's day ten sigh) deep trough in N Canada forces WAA ahead of it up the west side of Greenland(black arrow),also notice the arctic high(white circle) creating some reverse -AO(arctic oscillation)(orange arrow) forcing the trough west of Greenland south lets have a look at the animated sequence of both the 500mb height's and 850. ' will it set a trend?

Aye Inverness looked nice and eerie for Halloween today -6c this morn at the house is the coldest start we’ve had, places reporting a bitty lower further inland

gem day 10 NH is amazing for the back end of October ....