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Remember reminder: Its only an island if you look at it from the water Feb 2018 : Massive poleward tropical momentum transport + tidal surge of +AAM tendency > +MT > fast orbit Phase 5/6 GWO Nino attractor in extra tropics (this weeks easterly 'jab around the edges') >stratospheric pathway dissolution/feedback from dateline convection > -AO/-NAO. Allowing for some deterministic model variations of forecast, based on the fundamental changes that are underway in the Pacific eastern and central waters, good supporting reason to 'cherry pick' the ECM to illustrate impending ultimate change downstream in terms of the state of Annular Mode I don't make forecasts as such, but lets just say the Global Synoptic Dynamical Model (GSDM) timetable is evolving very close to its defined timeline schedule from inception date ~ 22 January when the starting pistol was fired in the tropics c/o the MJO and the poleward momentum process was underway. The extent of the extra tropical +MT propagation sure reflects the huge amplitude of the tropical convection rossby wave trigger Back to a previous posted comparison made in last 2 weeks: Feb 1978: Spent most of the month in GWO Phase 5/6 c/o high amplitude MJO and led quickly to a strong -AO/-NAO combination. Differences? There was no La Nina lag underpinning an entrenched sub tropical ridge +NAO pattern and so the tropospheric/stratospheric pathway was unhindered to a much greater degree. Well, that and of course the absence of so much anomalous homogenous warming of tropical oceans which are skewing and rather neutralising the natural effects of strong tropical poleward feedbacks - in addition to the alarming atrophy of sea ice which correspondingly unbalances expected albedo feedback relationships to an increasingly unprecedented state : Feb 2018 is indeed proving to be a slower burner with, overall, increasingly less cold air relative to 1978 in the NH to share around in terms of cold air advection from the pole and which inevitably therefore favours much less dilution through continental landmasses like Canada, than downstreamacross oceans) But, all that said: There is an abundance of pretty cold air to the NW as we watch the next phases of trough disruption. Based on the spatial arrangement of cold vortices which look set to ultimately implode - that doesn't mean (by any means) that the UK and Europe won't yet see their coldest weather of the winter, as the end of official winter gets closer and closer March 2013 provided this on the Costa del Cinq Ports of the SE: It was even worth capturing some So, still very much the sort of thing that is more than possible late winter 2018, a few weeks earlier than the fun and games of March 2013 - and so there is no need for anyone to be miserable

LOL. If @Catacol or I could have drawn the run that we expected from day 10 then the GFS 12Z has just saved us the bother! This type of SSW and the way it has evolved was always going to deliver a quick trop response. Always the question though that will we see the cold when it drops into the mid latitudes. As I said the other night we have the best chances for a long time.

Yep - that 12z backs up the 00z and the 06z - block building and atlantic disrupting and being driven in reverse. :-) The most interesting bit to me is that each of those 3 runs has brought the strength of the block forward. 12z has it gripping the pattern from Friday week - with the reversal set for the 12th I reckon this could creep a bit earlier still... meaning we are setup for some awesome charts for return to school week. I know its eons out in FI and normally I would laugh at these - but as we have ducks in a row and the GFS consistently modelling this setup now I have to throw this out: Run the images from 240 onwards - low pressures are running east to west underneath the growing block. This will be seriously cold : -12 850s on that FI setup. The east coast will be buried... and for those of us snow starved southerners (nothing again today :-( - we have to hope there is enough of anything in the atlantic to provide some frontal system action somewhere along the line. Someone call the White Witch. Aslan's off on holiday.

As far as I can tell many (who know more than I) are expecting a very FTR. Dr Amy (Butler) posted yesterday (I think) on twitter showing a FTR of just 3 days from the SSW event. It’s worth bearing in mind when looking at the charts as clearly the MetO are picking this up as exceptionally fast (Fergie RT Dr AB post which just adds more weight to it in my eyes) right now and I’m not sure how well the models will handle things happening quite so quickly. It’s certainly looking like a very exciting period of model watching continues and it’s great to see that despite downgrades happening and things today not giving us what was expected towards the end of last week, the models continue to keep giving us a reason to keep our eyes on the charts and that flicker of hope alive for those of us that live for this time of year. I’m dreading spring. Don’t get me wrong, I love spring as a season. Everyday is a nature school day for the children and having the garden to get invested in and plants for them to grow is most welcome after the winter months. But doing all this, checking each run and poring over them 4 times a day gives me so much focus for my overactive mind and I really miss it when it’s gone. Tried getting into model watching at other times of year but it just doesn’t interest me. So I’m extremely happy to continue having these excitIng Synoptics continue to feature for the foreseeable future.

The last February SSW did deliver a quick trop response. We’ve had some minor warmings in recent years but not a major one so this one doesn’t come around that often . If I remember rightly the reversal there saw the outputs suddenly start correcting west but this wasn’t shown at the longer range. Until the actual reversal occurs I’d be wary of anything shown.

Great reporting from the Daily Mail again

whiteout here and here's the pic to prove it

Short of time at work - but we are slowly, slowly seeing the models get a handle on what is going to happen next week and resolve the pattern. Note the rising pressure to the NE - and near cross polar ridging. Vortex shard to our west is sitting almost stationary in situ. From here, given MJO forcing through 7/8 the path has surely got to be for that monster undercut of already very cold air to the NW dropping underneath a steadily building ridge backing west a bit. Not sure we are yet seeing the models push the storm track as far south as it may end being... but falling pressure of the Azores High is noticeable. It's all about the trend here. Dramatic eye candy charts not quite visible this morning... but I have to believe they are around the corner.

Hold the phone - GFS 6z at the far reaches of FI brings out something not a million miles away from the predicted pattern direction.

A nice dusting so far here in North Norfolk. Notice the ideally placed lamp post 10 foot from the house

Oh ok then if we have too?@rosbby waves @ssw @mjo @serious blocking. There is no-reason 'given the signaling, and evolution that we will not end up like this...i think coming into nearer time frame also...as we gain on atmospheric responses!!! Classic end to winter!!?? Likely imo! Lets just wack-the 6z london ens on this. And await for compare the 12z set... to which i'll add to the post when they are out!!!

For me the key date remains aound 19th Feb when we could see a blocking high develop. I still favour Greenland or slightly E which is even better for us. Iceland SLP holds at 1015mb but note few runs go above 1030mb. Just a waiting game as I don't expect anything to suddenly change in the model output beforehand.

It's a long way out and not much to go on but something like this could be very snowy (or wet) Anyway continues the theme of better dig SE and lowering of heights into central Europe. PS I see I said the Russian high further East when I meant West yet again. Let's just assume I'm going to get that wrong every time. Ageing is a terrible thing.

There would be colder showery spells too with a risk of snow and frosty, icy nights, there is some pretty cold uppers at times on the Ecm12z. And the above brilliantly describes why new folk get confused. Both reading the same model and output.

This is probably the biggest "shower" I've ever seen, then..

Early March are when the North Sea temps are at their lowest lol- I will try & dunk a post in about 930 tonight S

All I would say to all our cold and snow loving members at the moment is that some of the FI ops and ens are just starting to sniff a change in the air. Although I think you'll find that the abrupt change in flow will be brought forward somewhat over the next few days modelling. As Blue army hs just posted it is already starting to look like quick trop response. It is easy after the disappointments and disasters of the last few few winters to build up a glass half empty attitude almost as a self defence against being let down by suggested cold synoptics. However what is starting to be shown is a very very real possibility. This winter has already shown in some regions what can happen with just a nw/se diving jet in place . Imagine what could happen with that jet and a genuine monster cold block to the North or North east..................

Here she comes ?

I prefer the chance of wintry showers and frosts that the Ecm 12z shows between the milder wet and windy spells..rather that than a sw / ne aligned jet with constant tropical maritime mush..anyway, hoping the SSW lives up to coldies expectations and that the best of this winter is still to come!!

Caithness skies continue to be wonderful: this was at about 8 o'clock this morning and I could have done with a fish-eye lens because the whole sky was interesting In the hope of finding a blizzard or two, I detoured home via Altnaharra... and found one fairly prolonged but not very heavy graupel, sleet and snow shower near Bettyhill, otherwise just lots of thin cover all disappearing in strong sun. Nothing settling on the Black Isle (that I saw anyway, I didn't go looking hard) and the one shower mid afternoon that seemed to be heading for a direct hit, just fizzled out. Same old story really. This is the great big lump of Ben Klibreck from Vagastie which would make a nice winter retreat but would be hell on earth in summer. Next ppn I'll see will likely be rain on Thursday. Starting to feel a bit, 'roll on spring'...

GEFS H500 mean/anomaly certainly suggesting its perhaps going through the motions of a tropospheric response to the SSW as we head towards late month, hopefully this is signs of a quick response to downwelling. The trop vortex over Greenland over next 8-9 days looks to shift into northern Canada day 10 onwards, perhaps due to the strat-trop coupling response to the split over Greenland area forecast by the models. As a result, this opens up for height rises over Greenland, GIN corridor, Svalbard across to Russian arctic sea as below A look at the GFS zonal wind cross section shows the SSW occurring around the 12-13th Feb, then a reasonably quick downwellng of the wind reversal from zonal winds throughout the trop and strat currently, so no wonder the GEFS will picking up on this in mean heights later in the month. <---- click on image to run the loop EC from yesterday on Berlin sight shows downwelling by day 10 too. <---- click on image to run the loop Still uncertainty this far off over how quickly the trop responds to the downwelling - which will depend on how the PV splits which will determine where the trop responds first, so we won't know exactly which areas of the northern hemisphere will be impacted with regards to a upper flow pattern change for now. Certainly plenty to be optimistic about but no guarantees, but based on previous SSW in February, no reason to think the intense PV over Greenland will be driving the weather for the rest of this month. Certainly the PV to our NW looks unlikely to extend its influence further east across Scandi / NE Europe, as a large upper block looks to hold sway over the coming 10 days or so, so the deep cold should be preserved should we tap into later this month as high latitude blocking perhaps develops in response to the downwelling of the SSW.

GFS 06Z keeps us mainly under colder uppers through to the end of the run and then tries to build a block towards Greenland, bringing even colder air back towards tthe UK..... Is this the beginning of something worth watching, as predicted by some of the really knowledgeable posters on here? I realise its way beyond the reliable timescale but there also signs in other long range models (CFS for one) that late February and early March will see Winter going out with a bang this year. It looks like a colder than average February anyway, and possibly less rainfall than usual EDIT: OOps - this seems to contradict the immediately preceding post from my much more knowledgeable mate, Stodge! If I am misunderstanding these charts I apologise for any misleading info posted.... Ignore me until I have been back and learned some more....

God forgive me for posting a 384h chart from the 06z GFS but this is the sort of outcome we should be aiming for. Poor old vortex well and truly smashed.

A boot 4 inches O' Snaw here this morning! Big Innes

Standard backdoor shot. No TOORP'ing from 101 this morning as there's easily 4cm (car and grass, slightly less on hard surfaces) and it's still snowing

Brilliant spot !! I'm still laughing Residents of Saddleworth Moor had to clear snow from their windscreens. Chaos indeed

Beijing model monthly forecast: High latitude blocking fairly extensive, blocking over Greenland & likewise CFSv2 certainly a signal there for the elusive Greenland high and decent cold anomalies.

Great Pic, I'm in Rheanbreck above Lairg looking north towards Ben Klibreck, we had about 5cm in the early hours after earlier rain then some hefty snow showers including this one pictured about 530pm this evening. No thaw today here and freezing hard tonight already. Second picture from top of Choc na h Inghinn looking over Loch Shin towards Ben Hee. this afternoon.

Get the cold in first and all that ?.

The lamp post outside my house conveniently decided to pack up the weekend, but after an email to the council concerning ‘safety’ oppose to saying I need it to work to see snow falling tonight, has just been fixed ?

Loved today's snow event. Even managed to build a snowman..??

On the train from Prague to Vienna now, gorgeous sunshine and outside temperature hovering at 0C. A dusting of snow, here and there in the countryside. Prague was chilly this morning (-5C) but beautiful in the sunshine. Hope the SE sees snow tonight!

Just following on from Tamara's great post above..... Frictional Torque is currently going into a negative trend. After a FT peak, then followed the current MT peak, that has sent the AAM to it's current position. Below is my thoughts, based on my observations and forecasts of the key drivers. The FT will continue to decline into the negatives, and bring the AAM into a negative trend, towards a GWO Phase 7 & 8. But the question is will the MT make a full decline as well? Yes, you could try and use NWP to try and work out whether the EAMT will take a dive, or what will the Rockies MT do? These are the questions that need to be asked. I am referring to the massive +EAMT, and the currently -RMT. Despite the sudden MT dive in the Rockies, the EAMT has been driving the Worldwide MT to levels that are quite literally off the charts. It is this, that has caused this AAM progression, that nobody forecasted and seems to defy the Niña base state. Whether this is an indicator of Niña weakening, or just a minor hiccup, isn't my question to answer, but many experts have been questioning the dominance of a Niña base state. Anyway, this is my 'forecast'(yellow line), with annotations included. This assumes that the MT has a large negative trend, maybe it doesn't, and acts like a Niño GWO cycle. But I personally doubt this will happen, IMO that shouldn't happen so suddenly. It's one thing to have a +AAM, and another to have a Niño like GWO cycle. Anyway interesting times ahead, let's keep watch for the next steps of the AAM's progression.

That, my friends, is a qtr (although it took a few days to get going with the SSW around the 12th!) typical hemispheric strong neg AO signature would be nice to think that the gfs op has now got the strat evolution in the right place by day 10 so that the low res portion becomes consistent from now on ......

Bad pun inbound in 3, 2, .......well done @Hawesy our very own Nostsnawdamus ? About 7 or 8cm back at the hoose, give that man a cookie

A nice variety of FI charts now beginning to show up in FI. I think we’d all take the Control run! The EC now showing the SSW to be at least a four day affair. Looking good. Pin the tail on the donkey time soon though. In 6 days time that organised rotation of the strong upper vortex is going to be hit and hit hard. Happy model watching days.

As I keep saying the 19th Feb is a day to note on your calender. ECM shouid make interesting viewing towards the end of the week!

Could @Paul maybe add QTR to that word describer thing which is used for the likes of ECM, UKMO etc it is popping up a lot in this thread but many don't know what it stands for

Yes! Now that the models are latching onto a QTR I’d expect that to be accelerated.

P11 plonks a ~1060mb high to the north of the UK Though plenty others develop strong northern blocking and a few building pressure over Scandi next week so as has been said, perhaps the effects of the SSW starting to filter into the model output.

Appreciate this isn’t strictly a weather model as it’s the rainfall radar but I’ve been tracking it since 4am with friends all over and is reliably falling as snow with the sleet consistently stopping as it comes inland. Ironically there seem to be an additional band of snow (over Gloucester ish area on this SS) which from following it seems it’s residual PPN that came in from the SE yesterday, has hit the front from the west and reversed while organising itself into an additional front that wasn’t forecast. It’s ironic because that front is just creeping over me, definitely falling as snow and yet today is the first time it’s changed to say snow won’t happen today. It’s a perfect example of how snow can pop up anywhere when the conditions are right.

Oooooh, snowing hard now, Blawin' a bit o' a blizzard! ❄❄❄❄

Right, official TOORP from me......I've just had it confirmed that there is an inch of snow (2.5cm) in Crail.

-0.3c here everyone waiting with baited breath today... I would love to see some more tonight - what was great yesterday was the characteristic of the flakes being so dry light & fluffy ! like bunny’s ears .... Ahhh

@Hawesy Probably about right again.

Another marginal improvement on this mornings 00z by 144. Azores a little further SW and Russian high at tad further East. Possibly of more interest is the embedded trough in V cold PM flow. It is just an illustration of what could happen at this range though Likewise UKMO improved with trough digging SE and very cold PM flow.

Hey I just advise how much snowfall you’re going to see accumulating. It’s your responsibility to look after the snow once it’s on the ground.

There was about 1cm in Clarkston this morning, 2cm on the Cathkin Braes and 1cm in Hamilton. I think I can see myself taking a longer break from my cycle in the summer than I did today. The view over the city is stunning.

You know you have a problem when you tell your wife to shhhh whilst radar watching....

10cm on top of the bins this morning, where the four X did that lot come from?!