Leaderboard

Reading this thread tonight has been a real rollercoaster....have to wonder why those who believe the weather is nothing but chaos with no discernible pattern bother to spend time on a forum where the main thrust is to try and make sense of complex signals and decipher a path forward - but there you go. Takes all sorts I guess.... ...and on the subject of signal deciphering all still looking pretty good, isn't it? I have a slightly warm and fuzzy feeling at the sight of this EPS chart for the 18th Good to know that GSDM theory has a basis that produces the goods. Signal for isolation of the trough underneath a growing band of high lat blocking is growing, and on schedule. To reinforce the fundamental reasons for this - time to post the MT chart that David has already put out there tonight...just for double emphasis It's a really very impressive spike at 30N - and to summarise David's detailed argument into a brief sentence - it very much increases the chances of our strat warming becoming a major one. This sharp increase in momentum will do all kinds of nasty to the vortex - but it also creates a signal for increased atlantic blocking as eddies downstream of the spiked pacific jet form. NWP has been slow to pick up on this - but that EPS chart suggests we have increased clarity now. From here? EPS at 10 days suggests again that the expected pathway may be accurate. The trough will sink south, and with it will come increasingly cold air and wintriness to high ground. This is the start of our winter proper (at least in my eyes) but don't expect widespread snow at low levels quite yet. However - this period will signal the start of the real cooldown. And from there? Time to return to GSDM forcing because strat reinforcement of the pattern will be a little way off yet. Tendency of AAM will begin its next downward cycle soon. This will signal in effect a reduced momentum signature at 30N and opportunity for enhanced momentum further north. However the difference this time is that our next MJO cycle has kicked off, with moderate wave activity emanating once again from the pacific. This will aid in preventing the pattern from becoming too flat, and I would suggest we will see a reinvigoration of the atlantic as we head into Xmas week (despite the higher than average pressure anomalies out west on that EPS chart) but with the trajectory to the south rather than through the heart of the UK (as is happening this week) as heights to our NW serve to deflect the jet on a NW/SE axis. Shamelessly cherry picking a GFS extended image from the 18z rolling out now this chart for Xmas eve would be about what I would expect though perhaps with a greater maintenance of heights over Scandy Systems tracking beneath the block heading towards mainland Europe. Polar maritime airmass mixing with a trough that is beginning to pull in air from the NE. In essence becoming progressively colder on average. So - when does all this give us snowfall at low levels in the south? Don't know yet - don't want to guess. Depends on how quickly cold air can be absorbed from the NE and just how entrenched the block becomes. But chances certainly exist prior to New Year if the flow is right. If not it wont be long after NY before we see 850s in the right kind of zone with a flow that will be evermore easterly on average. And all this being forecast on 13th December rather than 13th February. Warm and fuzzy all over again....

This place always reminds me of people in a queue at the bank of or the post office. You get those happy to wait because they know they,re going to get served and those indignant at having to wait,impatiently, shuffling and giving off signals of their of their right to be served immediately.

Seriously, if some people are getting 'offended' (maybe we should coin it faux offence, like we have faux cold?) by Matty7's post, you need to perhaps take a break from the computer because he's not said anything offensive there. Someone giving an opinion which isn't a prediction of the next ice age is also not automatically a case of trolling, and those who think it is, and worse still attempt to publicly call it out as that are more of an issue within the thread than a persons opinion that the models may not be especially reliable beyond a certain stage. That said though, a general comment on a hunch about the rest of winter is zero to do with the models, and should have gone into the general winter thread as it's not relevant to this one, so can we move it back to the models now please.

Happy with the ec46 update - high heights and slp to the northeast edging from scandi to Greenland weeks 3 through 6 with the storm track into Europe to our south - possibly edging a little too far north for comfort later on but we will take that for a third consecutive good run

Right.. stop with the childish behaviour or you will find that you won't be able to post in here again. Thank you.

It's cold today, the hunt is over

Ok here goes with latest thoughts from the team. Early next week wet and windy for the British Isles , especially west. Towards the end of the week the area of low pressure fills ( slow moving) over the British Isles and tracks into Europe by day 10. Now the interesting part ,the longer term charts between Christmas and New Year still shows a robust ridge to develop and push westward from the North Russian/ Siberian High to the North of Britain . This will help to bring in a cold .possibly very cold flow into the British Isles. This is a singular model output and maybe a rogue run but has a good record in the 10-15 day range. See if the bigger models pick this trend up soon. Meanwhile after a nice start in the village, outbreaks of snow moving in and current temp -8c. C

The hunt for cold is about to bear fruit, some snow to come in the short term further n / e..especially at elevation and I have a very good feeling about the extended outlook at Christmas or soon after..I think coldies have plenty to smile about..cr*p mild mush looks in short supply and for a change..predominantly colder weather looks the form horse!!!!!..fingers crossed fellow coldies!

I think you should re read your last posts. You say thay 5/6 days is good for forecasting but beyond that pointless but your first post suggested that the whole of the winter was going to be wet, windy and mild. So what we going with 5/6 days or write off the next 100 days?

Here's a chart! This is the latest GLOSEA 30 day Strat forecast (left hand side) the right hand side is from December 2012. Phase 6/7 is a displacement event, phase 8-1 is a split event. Very, very interesting indeed Stratospheric wise! GLOSEA going for a split into January after the initial displacement event end of this month.

Well there’s your Sudden Stratospheric Warming pre-cursor pattern..

I think you’d be better off in the short range models thread then mate.

Ok let's stop the bickering in here, 1000's log in for friendly informative model discussion, So let's keep it that way or posts will magically go missing.. Onwards and upwards

If you're going to reply to bb62-63 please don't quote the whole post! But as others have said a brilliant post yet again, makes everything a lot easier to understand.

And yet.. some models are showing exactly what some people have been saying they would show. GFS/GFSP/ICON all looking very good, height rises North either side of the filling low pressure system and the eventually connect to the North of it, forcing it Southwards ECM not quite managing to get there with too much energy coming out of Canada Though, largely on it's own at the moment, the UKMO would likely be in the GFS camp later on Big switch towards a blocked pattern for the Christmas period on the models this morning. Good GEFS mean Things ticking along nicely, very happy with the output this morning. Starting to think I might have been wrong about the transient heights idea..

As the best Christmas film ever says. Yippee ki yay, m****r f****r!

Potentially i see plenty of potential for some wintry weather in the run up to crimbo!

Things are starting to get very interesting

What a great cold, possibly snowy four day Christmas sequence this is from the GFS Para this morning: Yes, it's on its own, and Yes, it almost certainly will not happen, but it cheers me up just to think it's possible and I can't stop watching it!

The extended eps are dropping the low anomaly into Europe with higher ones appearing above ..... with the Atlantic jet remaining active we would presumably tend towards slider territory .....

Good news from the UKMO extended at 168t. Shows Atlantic trough sinking SE and mid Atlantic ridging. Looks more akin to GFS model at this stage. ECM out on its own. C

Find it laughable that people think dismissing scientific techniques of weather prediction and just making predictions based on a hunch is credible. Never mind that all the predictions linked to background signals have been right so far this winter. Makes you wonder why those people are even bothering to be on a thread like this. But that’s just my opinion!

Those charts have always been confusing to me, too much going on - It's the shaded green part you want to focus on and that's showing zonal winds reversing in the forecast period. All but 3 GEFS members going for a full reversal at the end of the month now, the mean solidly below. It'd be rather surprising if a reversal didn't happen now..

No nothing to do with your mild prediction it's your attitude towards forecasting itself. There are plenty of people in here who have spent years learning and researching the drivers of the world to try and understand how are weather funtions where they then form a forecast. Then you come in say anything past day 6 isn't worth looking into because no one gets it right. Do you understand how rude that it is? You basically discredit those who work hard and base their forecast on actual science rather than a 'gut' feeling? At the end of the day it is just a forecast, a prediction, a estimate it's not solid facts that in 3 weeks time it looks like there might be some blocking around but from our current point of view it's the best bet and that's all we're trying to do is get the best idea of the future.

The ECM less progressive on tonight’s run . The pattern has backed west several hundred miles. Early bellwether the two lows remain separated . Zonal winds slowing now beginning to effect the models .

@Daniel Smith Have you hacked into Exeter’s computers ..... glosea charts are tough to come by .....

If you are going to post about posting about the posts that are posting about the bb62/63 post, please don't post that either.

lets have a look at the facts or should i say fax charts lol. it was around this time last week i noticed most models toyed with the idea of an atlantic ridge getting into the southern tip of greenland. now if you look at the 144 hr fax your see it just starting to amplify this most likely caused by couple of weeks of wave attacks on the pv. and few models do see the vortex rather fragmented in and around the north atlantic and also on the eastern side of the states and around the east canadian area. there two main areas of interest scandi retrogress to greenland with perhaps a surge of heights from the atlantic into greenland or just like the first idea of the surge of heights from around bermuda into greenland. either way its not a certainty that it will be prolonged at the moment but it most certainly gives a better chance this winter. in my opinion its very possible when the jigsaw pulls together there could well be a winter to remember. these are only ideas based on what the models show but must remember we have suffered heartache us snow lovers so its always best to be level headed and except sometimes things don't go to plan, pretty much like my whole 24 years on this planet. but from a 9 year old till now i've loved the weather especially extremes, although i don't enjoy loss of life. but there more favourable patterns at the moment and lets no forget the zonal winds and vortex are not at there greatest, but this does not say it might not fight back. but its already under attack and an early strong warming event is another BIG bonus. cant wait for the next 4 or 5 days id expect some cracking charts to emerge. anyway here's the 144 ukmo 500 mb heights and ideas. and the 120 fax with the ideas.

What a Happy Christmas that would be. Dear Santa, I promise I've been very, very good..... Fellow excited weather watchers, if you thought Santa was watching and would put you on his naughty list for getting irritated with each other, would it make you shrug your shoulders and think 'never mind, it's just an opinion that's different from my own'?

I'm BANKING on a Merry Christmas

I saw no glosea charts. Neither did anyone else. In fact, what is glosea? What is the met office for that matter?

GFS and UKMO very similar at day 6 and suggest trough disruption over UK into continental Europe beyond t+144/day 6, thanks to amplification upstream over the N Atlantic and also block over Scandi / NW Russia preventing eastwards progression of Atlantic trough and jet. This will eventually lead to height rises over the top over the cut-off low forming over Europe as per recent GFS operationals = could be a cold few days before and perhaps through Xmas Day. UKMO T+144 GFS T+144 00z ECM wasn't keen on trough disruption though beyond day 6, instead the trough near the UK merging with another trough moving east over the NW Atlantic, preventing amplification over the Atlantic and keeping one large trough over the N Atlantic with blocking to the east. So be interesting to see if the EC caves in and follows in step with the GFS and UKMO later.

The Atlantic onslaught might be about to hit the buffers . Strangely it’s the ECM which has been most progressive with the GFS the first to pick up the trough disruption over the UK. An early bellwether for a quicker route back to cold is the phase or not upstream . You’ll see the ECM 00hrs run phases the low near the UK with the one further upstream around day 6 . You don’t want to see this . Because of the expected upstream pattern any initial cold has to come more from the ne. The UKMO has made a move to a less progressive solution. With low separation at day 6 . I’d be shocked if the ECM didn’t follow now .

Would concur with this, although NE vector may be more appropriate early Jan.

The propensity for amplification remains clear - both to our west and east ...... small changes in timing upstream and downstream will look different .......... hence the variation from op to op, run to run .........

Updated ICON 18z has 3 hours of snow in the SE sat AM... Thats all high res models with snow in the SE now...

Some of the posts in here with comments on charts from 192 onwards might well be less knee jerk if my suggestion of a few days ago is tried. Not comparing run to run at those time scales but like with like 00Z or whichever run you want to use. Do this down to about 144 then yes run to run and comparisons between the 'big' 3, GFS, ECMWF, UK Met. It will still give the enjoyment of watching the models but is almost always a less 'up and down' ride. Still if that is your preference then fine but try not to be surprised when, for instance the 06 Z is not even similar to the 00Z.

I think what you are missing is the fact that here on Netweather we are very lucky to have the input of some extremely knowledgeable people who study the vast array of climatic cycles and drivers which affect our weather. Of course making concrete predictions for our little island days and weeks in advance is an extremely difficult task but what they can do is give us an idea of how the possibilities and probabilities are weighed. I've been following the model thread here for years and the long term guidance on teleconnections from people such as GP, Tamara, Snowking, Catacol etc, while by no means always correct, is nevertheless very often in the right area - indeed far more so than you would expect with just chance. I think that's a slightly different point to examining the daily output of the op models but then we have incredibly knowledgeable people who do that - Steve M, Bluearmy, Nick Sussex etc - and are able to recognise model bias and second guess what might happen. Of course nobody gets it right all the time but if they did it would be incredibly boring.

White Christmas!

There’s something brewing in all this. The cold is breaking though and the are seeing very encouraging signs in the models for the next 14 days, yet some people on here seem to think that it’s all over and we might as well get the BBQ out. what a strange state of affairs

A tip for those who many not have seen it before.. you can select bits of someone's post and a 'quote' option will appear. It saves quoting monstrous posts and filling up a page.

I like that chart

I wouldn’t be concerned about anything the CFSv2 shows ........it’s up and down like a tarts draws ......

Always have to laugh when I see you post your weekly reminder of this, I can assure you early-mid jan has a much greater chance of seeing snow than April. Take a look at the mean CET records and compare January’s historical data to April’s, it will help you recognise the difference; it is very rare April is even within 2c warmer than January, often 3-4c warmer.

and this is a monster warming with a double whammy with on going wave activity happening right now.

Sunrise over Portree 13 December 2018.

GFS p goes for it this morning giving a white Christmas for many. Nice to look at but needs support to take seriously

‘Background signals’... that’s become the new way of saying ‘potential’. Means very little if nothing is actually produced on the ground.

Is that you, Chris Fawkes? Entitled to your opinion, of course, but it goes against nearly all background signals and developments.

Morning bill...have'nt viewed your profile !! But something tells me you live on the east coast....somewhere ? Anyway... I dont think you will have 2 delve into pertubations...and supports. The ops/raws-will begin 2 guide on the unfolding.... Have a good one.