Leaderboard

Dear forum members, For the hardship caused to many of you over the weekend period by my, what I can only describe as, schoolboy efforts: I would like to offer the below as a means of apology... I hope you will see it to yourselves that I was having a bit of an off spell, having been out on an all night bender on Friday night with the GFS 18z. I believe I have learnt the error of my ways and hope we can continue on, as we left off, before this whole sorry debacle. Yours, The ECM

One set of 6z = party poppers at 7.30am, wax the sledge! stockpile coal...! One set of 12z = nope, it’s all gone wonky, we told you so, get your bulbs planted. This is the very definition of model volatility. We knew it would happen, so let’s not get hung up when it flips the ‘wrong’ way. It will! *sigh* it’s going to be a long week in here if folks are going to pick apart every.single.frame. all bets are off beyond 120? No?

Well the mood changes again as the models swing yet again. I find it amusing that when they swing to cold all previous issues with whichever model seem to disappear. Anyway to add my bit of 'science' to the pot. The anomaly charts have had quite a change or rather changes over the past 3 days. Their latest offerings are linked below. What is most noticeable to me is the marked change in the 8-14 NOAA. Until last evening it has shown no desire to extend any ideas of blocking in the right place for cold over the UK. Pretty much out of nowhere is shows the chart you can click on to in the link below. I am not sure it is to be believed unless it shows this for 3 days running then it has to be taken seriously. Anyway the charts do for once support the up beat mood on here this morning. http://www.cpc.noaa.gov/products/predictions/814day/500mb.php I have to say I am not really convinced with the 8-14 above. Nor is it clear just where any surface blocking may end up. No sign of deep cold from either NW or NE but time will tell. http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html Overall, taking the 3 models then there seems to be some kind of concensus for blocking to the NE of the UK? ps never sure the correct spelling for concensus/consensus and others!

So, at day 6 ECM we see a promising chart and yet you would rather give up instead focusing on the day 10 chart? Mystifying. Especially as it wouldn't take much change in the modelling to be in the cold to the east post day 10 I think some expect to see Armageddon charts every run. Remember I will reiterate - if the hoover is turned off then don't expect it to suck up the dirt just because someone says it will. Treat the charts with the same scepticism because each SSW is different and not necessarily easy to model.

In the nicest possible way, I think a few members need to get a life.......or a girlfriend or something.....open your stuffy dark bedrooms and let some fresh air in....lol.......Models are all over the place, this is what happens when you get a potential pattern change, i.e model volatility!......all one has to do is to go back 10 days or so and the potential for much colder weather is much better now than it was then......take the model runs for the past few days...yes, there has been volatility, but the general theme is for colder weather with an easterly component and I'll quite happily bet a few quid that that's what the UK will end up with eventually......So let's have a bit of sanity prevailing and no more "waaaa..waaaa, it's not showing -50C easterlies!....it's not fair!.....my life is over" nonsense!....cheers all

So quick update, not even a page into the new thread and that's two more people added to the restricted list in here. Fun times, like trying to herd cats... The odd o/t post is ok, sometimes a bit of thread drift happens, but continuous, repeated off topic stuff is not.

My word if you do not like a cold, blocked weather pattern then look away now because my post today looks at the output from a different perspective. Firstly with the ECM on board we have decent agreement of an E,ly arriving around the 21st Feb. After the intial E,ly we then have pretty good agreement of the blocking moving towards Greenland. As this occurs we then unsurprisingly see pressure lower over Scandinavia towards the end of the run. This is supported by a drop in temps over this region. The above is a classic cold blocked pattern that you have to visit the archives to see. A pattern which can often be prolonged and last for weeks. As many of you know I am sceptical of Teleconnections. However when you view todays N Hemisphere charts nobody can discount the effects of a SSW on the Polar Vortex!

who cares on the timeline- but for low lying England this is the chart of the winter - !! 2009 redux

The models are still struggling with the initial amplification of the atlantic - But also notably is the continued corrections across the polar height field - In terms of increased heights- If we take the IKON for example: Tonights 18z 120 is CLASSIC cold evolution coming @144-168 Great cross polar ridging & split vortex- Now take the 18z V the last 2 proceeding days Again illustrating the development over the pole - & something that should be noted for any future warmings - Is that there is no 'sudden' flip to cold but a gradual change over the pole that sees more & more +Ve heights as you get in the sub 168 timeframe- As for any scatter on the 12z 850 ENS- This should be taken for what it is - * Variation in Timing of cold- thats all... Some are slow on thr evolution by keeping the initial ridging flatter - some optimal like the 18z IKON - as a result London will sit initially on the periphery of the cold .. so 'slight' variations = swings from -2c uppers to -12c uppers... In terms of longivity- as highlighted now this is expected to be a 2-3 week event, possible wax & waning of blocking through that period but the UKs best opportunity of deep cold since 2010... S

Couple of tweets from Ian F regarding the bolstering of the cold signal as of the 12z runs.

The eps and spreads are impressively cold by day 10 and moreso thereafter. Omega block establishing to our north (Iceland) and the stronger push against it coming from the east . i hope you all jumped on board yesterday ............

I’m not saying an easterly won’t happen but at this rate we’ll still be chasing it as we open our Easter Eggs! It’s irrelevant IMO what the GFS shows in its outer reaches , it could show -20 850s but until these synoptcs get within the reliable timeframe they’re nothing but more gold at the end of the rainbow. It looks like we’ve missed the first chance and now will have to wait longer unless the models bring back the trigger shortwave. Anyway for fear of being renamed the poster who killed Santa that’s my last rant until the ECM comes out!

A lot of daft posts in here this evening. We all know the charts were/are going to be all over the place. Why the surprise when we get them? Those unable to control their emotions need to take some time out I think, the ride is not going to get any smoother for a while yet folks.

Ooh I like this post - thanks Rory. Stick around - I’ve always felt we needed a bit more input from career physicists on this forum. A few on here could do with taking note - dynamically changing variables = wildly fluctuating output. Our atmosphere has just experienced a very very rapid warming, and a deceleration of upper wind speeds to levels not seen in the modern record. There is more warming on the way, hitting the Canadian vortex shard and causing yet more disruption. Bottom line - human interpretation and a bit of experienced logic currently trumps NWP output. We need to intertwine the hard, but fast changing, data available with predictable process. Meaning? Pressure will rise in between the two vortex shards and the longevity of the reversal (still to be sorted but likely to be extended) points to a pattern that will retrogress. To see an Atlantic return in the medium term is counter intuitive, and the destruction of the vortex looks so extensive that longer term predictions of an extended winter and cold early spring look well founded. We mustn’t forget Pacific forcing when judging pattern progression from here, however; I think the impact of the reversal is going to outweigh the dynamics of the ocean/atmosphere but tropical forcing will be an important partner in longer term shape once the reversal settles down. Steady as she goes. We are living through a very significant event - enjoy the ride.

Great model output from the 0z's and then the GFS 6z with amazing GEFS's. Looking forward to the 12z's eagerly now. I just hope that come mid March we don't have a new member called: ThatECM-thatGFS-thatUKMO-thatGEM-thatGEFS-thatICON-thatGLOSEA5-thatMORGREPS-thatTELECONNECTIONS

Morning All Today is a record breaker ( I can hear Roy Castle !!! ) The longwave patter is beginning to become a little clearer now with what we observed from day 1 - the migrating Canadian High migrating east before launching itself NE towards Scandi- There appears to be an interim period of stability whilst located over scandi ( Days 8-11/12 ) before retrograding against the flow to Greenland- With that in mind from Day 8 its going to be cold- With the level of cold decided by how much lattitude we get & also how much energy we can see returning under the high - Worst case scenario appears to be a light continental flow with below ave temps, best case scenario - scenes like 1991/1987 --- So with that in mind we now need to track the evolution in the 168-192 window - The ECM gets to the maximum really Notice the core of the High is centred North of Scandi - Thats where were aiming for.. So its a case of round 1 ( hopefully ) followed by round 2 with a whopping GH -- S

I think we’re going to have to accept that the models seem to be clueless with some wild swings between runs. If that day ten ECM chart verifies I’ll join the Moonies!

The eps spreads reveal a cluster going for an even more extreme version of the 00z run with the low dropping close to se England on its return around the building block days 7/8 whilst there also seems a cluster with the low heights Griceland days 9/10. no need for too much concern imo. We may go the slow route, we may go the quick route .......

At what point can I discuss these events with family and friends? Its normally guaranteed to fail at that point.

Very interesting tracking the recent GFS/ECM ops for 19th February (now T144): GFS: All over the place! ECM, though, interesting trends, and is an example of why it is more stable at the D6/D7 timeframe - but - Here, you can see it's pretty confident about there being a low just west of Iceland and a ridge trying to get ahead if it. Bit all over the place to the east. But I note two trends. First, the ridge by the UK is getting progressively centred further north, and is progressively losing its connection with the Azores High. Second, the system in the NW Atlantic is disrupting a little more every run. Complete hypothetical, but if it carries on down this road, will the ECM be tilting the main Atlantic low negatively by this time tomorrow?

Stopped off at Arrochar for twenty minutes on the way to my brothers house. Who needs the Swiss Alps when we have the Arrochar Alps? Unbelievable scenes - always breathtaking in Winter when snow is about.

Latest 30hpa temperature over the North Pole

Is it safe to look in yet? Do I need to hit the scotch on a school night, or are we going to be able to all behave like civil measure humans? Please keep commentary civil- and the voodoo/gut feeling/bumsqueezing sorcery one liner stuff in banter.... ?

Morning all As the old song has it "there are three steps to heaven" and the same is true if considering the path to a very cold and snowy outlook so let's look at the three steps: 1) Build the block - some runs a few days ago had the Azores HP ridging north to the west of the British Isles and then NE into Scandinavia. This was, to paraphrase another song, "the motorway to cold". A more scenic route has the HP moving NE through the British Isles and into Scandinavia and that was advertised widely in last evening's output. 2) Get it in the right shape - HP over Scandinavia only works in terms of cold if it is positioned and oriented correctly. It's perfectly possible to have a HP oriented so feed warmer SE or S'ly winds across the British Isles so the right shape (aided by lower heights over southern and central Europe) is a necessity. 3) Find the cold air and bring it in - it's no use having an E'ly if there is no cold air to advect and that's the important part. Ensuring the HP is far enough north so the cold air is not advected too far south and making sure we are drawing our air source from a cold rather than warmer SE source is the most important aspect of the evolution. So is heaven on the horizon this morning, close at hand or is it going to be purgatory for the coldies with France in the freezer and Britain balmy or chilly ? Today I'm looking out to February 23rd and starting with ECM 00Z at T+240: The Azores HP builds across the British Isles and over to Scandinavia and draws in an increasingly strong and cold E'ly feed through next week. One suspects the blast of colder air might dissipate as the HP looks to be orienting slightly more to the ESE but not much. GEM 00Z OP at T+240: A slightly different evolution from GEM which moves the HP core to Iceland so more of a ENE'ly flow. The first puch of very cold air passes just to the south but the weave of frigid air approaching from Scandinavia looks to have our name on it. GFS 00Z OP at T+240: More anticyclonic and perhaps not as cold. A large HP sits to the NE covering the North Sea and a noticeable SE'ly flow covers southern and western England but it's dry at this time. Further into FI, the HP trends NW toward Greenland and forms a substantial HLB. There is one pulse of very cold air which crosses the British isles but at the very end of FI more than a hint of something much warmer. GFS 00Z Control at T+240: Very anticyclonic but with the coldest air just passing to the south of the British Isles. The evolution further into FI is a coldies' nirvana - the HP retrogresses to Greenland and an LP moves east into northern France drawing in some very cold air from the east. The GEFS at T+240 are one of the strongest for cold I've seen for a long time: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240 Life has moved on and we now have the GFS 06Z OP at T+234: Very anticyclonic but with the coldest air just to the south of us at this time. The evolution into far FI is more complex with a slackening of cold air and a more SE'ly flow. GFS 06Z Control at T+240: Not much for fans of cold to complain about. The evolution into far FI is frankly as good as it gets if you want cold or snow. In conclusion, one of the strongest suites for cold I've seen for a long time but to stress a) it's not a done deal and b) for fans of snow there are still hurdles to jump. Some evolutions are more anticyclonic initially so the journey to snow is delayed further while others bring in colder air more quickly. It's hard to see how this can upgrade much further so it's now about consistency, severity and longevity. Some keep any cold air short-lived and return to a much milder SE'ly airflow while others are much more bullish about a 7-10 day severe spell.

So 10 days after the warming date, we get first wave of tropospheric blocking developing: Next wave between days 20 and 30 although no detail on placement of that - so first week March. Peak effects around days 35-50 (mid March onwards). Spring looking on hold, and cold Cheltenham Festival beckoning. What have we learned so far ? Well, even though the warming was predicted by the models, they only managed to capture a tropospheric response until it was underway, so some way to go there in improving strat-trop modelling.

never....remember the first rule of MOD club....

I would rather be able to look at the models rather than deleting off topic posts and restricting posters. Please please make my job a bit easier...

The fixation on this thread with operationals beyond their reliable timeframe never ceases to amaze me. Ecm clearly went awol with its jet distribution early in the run. Now it’s possible it could be onto something but the eps disagree so we bear it in mind for the 18z and 00z to follow but no need to make a song and dance over it. It’s currently a low probability outcome and interestingly, the run still manages some vertical WAA at day 6. Btw, the differences in the strat on this op run compared to its previous output also makes it questionable. Solid extended eps wrt to a v cold period. The NAO shows a massive spread by the end of week 2 but the mean is very low. at the moment, i would be looking a the blocking edging away nw later week 2 and allowing the low heights to edge further n in general. That brings the Atlantic slowly ne towards the uk too along wit( the euro trough.

Look at how some of the great memorable winters started below. 1947: 1987: 1991: To conclude even beforehand to some great wintry weather looked mundane very quickly given the signals which we seemingly have, something really interesting developed. As where we are now.

While the ops toss, turn and fight, the ensemble means make fairly good friends tonight - see D10 below: Very good agreement on a very good easterly

Sorry Chio, I can`t help it. Does this mean the PV is going to Dyson?

The definition of insanity is doing something over and over again and expecting the same result. A bit like predicting the worst winter weather in a generation/living memory and it not materialising. Nice runs but again a long way off. Lots of evolution to come. Moderating expectation would be good to avoid big disappointment but promising it is.

True but now we’re taking the scenic route to cold and have to rely on an evolution much further into FI . As we’ve just seen we didn’t even survive the T144hrs hrs mark before the wheels fell off.

I think it should be made obligatory that anybody who keeps harping on about how 'lovely and warm' it will be in the 'strengthening sunshine', should be made to go outside in a short sleeved t-shirt, beach shorts and flip flops when (if) this occurs.

Yes - the op gets the southern arm distribution wrong quite early. Well we hope it does ...........

Hi ( If anyone follows my posts I did say yesterday we could blend the GFS & ECMs evolution to have a slightly later start to the cold - The transitional period is still there & it will be luck if we get in early So we have transitional phase 144-216 where the high gets to scandi & builds in Situ- If we get the cold under the block then great - If not just chilly at the surface However - The period post 204> onwards ( 21st ish ) I would say 99% dead cert a Greenland High with deep cold from the East - As for watered down - The depth of the uppers etc arriving late month are not really watered down with -16c still on tap- What is stronger is the suns strength & the amount of daylight hours - so net the maxima could creep up *If it was sunny* So pound for pound if -10-11c brings in 0-1c at the surface early feb the same airmass may well deliver 1-2c at the surface... Im setting my benchmark at -12c somewhere Thurs - Sun Next week with continued blocking into mid March... S

blimey, thought I'd dropped into the wrong thread!.....Nope, it does say 'model discussion'....could've fooled me .....lol talking of which, I noticed a few days ago that the GFS was interested in initially ridging the AH towards the UK and then displacing it over the UK allowing the possibilities of low heights over Iberia encouraging a muh colder easterly feed over the UK and this was before the SSW was imminent....despite some flip flopping (especially from the o6/18z runs and the ECM) it's really encouraging this displacement of the AH coming into the reliable now (T84 onwards)....Yes, there are always possibilities that things go wrong in the short term modelling, but this time, I'm genuinely thinking that we might just have got in our possession the golden ticket in the cold lottery

Quite a marked change from the last 2 EC deterministic runs to bring forward the tanking of the AO and NAO. Most of the op runs since the 9th Feb, apart from the 12z yesterday, were only going negative with both indices until after the 23rd, now they are doing it as early as the 17th which is Saturday. Can see most op runs recently keeping positive through to day 10. also impressed by 00z EPS strong ridge in means and height anomaly at day 15, not often you see such a strong signal in that area at that far out, normally it’s the -EPO ridge doing this. If this is anything like the day 15 pattern, we are truly locked in to a rather cold pattern extending into early March. interesting times ahead ...

Control run brings what would be a snow event to remember for the south, what I wouldn't give for that to verify

There are a lot of off topic posts tonight which would give the mods a lot of extra work in deleting/moving them so I will give you all a quiet little reminder... USE THE MODEL MOANS THREAD TO MOAN!!!!! Thanks

In just about an entire page worth of posts, literally one or two have actually been about the models. I get that this thread is popular, and so it's a brilliant place to have your posts seen, but I assume the majority of people can understand what a mess it would become if it was just left as a free for all. So, any chance of those who keep posting whatever they fancy showing a bit of consideration for the wider community please. Alternatively, we can keep adding to the list of people who have been stopped from posting or had their posts pre-moderated in this thread this winter... And on that note, am locking this now, new thread here:

METO update singing off the same song sheets as the models now - game on for next week.

Bitterly cold control from GFS 06z

It’s an interesting one this - maybe @SnowBallz could add some flesh? True to say that GFS was solid for at least 5 runs in a row (I stopped counting at 5) when next week was at 320h plus range. High pressure to the north with low pressure to the south. It then dropped the idea in the mid range, as did ECM for a time, before picking it back up again as the ssw occurred. Not the first time that extended modelling has picked up something, dropped, and then come back with it. Maybe it feels more common than is actually the case.... don’t know cos I don’t keep records about this... but it feels as though it is not that uncommon. Is there something in the model algorithms that puts greater emphasis on different factors when looking at extended range than when the clock moves into medium range? Do they function in exactly the same way at all time scales? We know resolution improves at 72h (at least that usd to be the high resolution point - is it further out now?) but is there anything we can learn about medium v extended? We are approaching crunch time now - the general pattern looked great a good few days ago now... but now we need a bit of luck to kick in. From around tomorrow we may be able to see whether we are set for dry and cold, or snowy and cold - this relationship likely to wax and wane throughout the cold spell according to orientation and block movement... but I think we will be unlucky if at least once in the spell we don’t get alignment of the block and frontal system development to bring a snow event of substance. Having said that - scars from March 2013 are still raw as nothing arrived here from that setup... so there is no guarantee of anything when it comes to weather watching.

EC clusters between D12 and D15 are nearly game, set and match for a ridge to the N or NNW (ending with this at D15): Even by D10, 4 of the 6 clusters have significant cold potential (and snow potential on 3 of them):

Not sure the strength of the sun will be felt over night.... if it is we are is serious trouble.

Never quite understood why the models are only "struggling", when they don't show what you want.

we just had some very wet snowflakes here.....so wet in fact that they were spherical, and transparent, most unusual so I had to google them.....apparently they're called 'rain drops'

I see you -12 & raise you to -16

GFS 00z ensembles, coldest set yet Love they way it dips again in deep FI