Altohumorous

It's a tricky situation to predict where might get the coldest, as the cold is arriving in complex and uncertain ways. The easterly cold is mainly east, central and south east half of England, maybe northeast England. But the northerly cold may not properly hit some of these areas. If it does, then somehwere in North or Northeast England could get a very low temp after the northerly dies down. If the northerly hits Scotland well, then north central/northeast scotland looks favoured for a very low temp somewhere, if the wind drops after snow, but a high really needs to form somehwere with snow lying to get a "biggie" (minus 15 to minus 20)

SOme sharp bursts of rain here this evening and lighter showery rain tonight, a little hail in the heavier bursts, feeling quite cold. Here's something we havent seen very often! (scroll down to "maps", then scroll across to about "thursday night" - just look at all that blue!!) http://news.bbc.co.uk/weather/forecast/32?&search=oslo&itemsPerPage=10&region=world

Will the ground under the snow be cold enough to allow such temperatures? We havent had a prolomged cold spell like we had had in 81, and to some extent 95. I mean there must be some effect of unfrozen ground underneath the snow? I'd love to know what the sea temperatures were in both those years just before the time the very cold temps occurred Lowest Max - North-central Scotland, (or possibly somewhere in North England if they get snow from the easterly, then sufficient cold from the northerly) - minus 5. Lowest min, minus 15 if a high forms over the snow valley areas

You got it right with the one on the right! Nice. Have you posted it in the "Lamping" thread?

There's definitely a robot in some film or tv series looks like that - Probably Star Wars?

What an insane and wonderful thread! :lol: "When I was just a little boy, I asked my mother, what would I be, will I be...............a lamper? :lol: Yes many, many dark hors watching those lamps, those sodium orangey lamps of the suburbs where I grew up (many times), the old fashioned backyard lamp at our house (shrouded in snow sometimes), the white-light lamps at my aunt and uncle's place near Burton on Trent (1978), the lamps outside my brother's house in Swords (March 24th late 80sish), the lamps outside my schools, and as I got older and more adventurous, the big lamps of the city centre. Now I have new lamps to look out at, but I've never seen snow fall in their glow. My best memory of lamping was of course 1982. The Met service here said, in their 6pm shipping forecast, that rain sleet and snow would affect southernmost areas. By 9.30 that night, even the lamps in the street were talking a different story, and the rest is history

Some promising upgrades of potential snow/cold today, I might have to put the weeping, wailing, and gnashing of teeth on hold again! Probably all change back again tomorrow, perhaps what matters is the timing of the last set of models before the main events themselves. If tomorrow is downgrade, then thursday might be perfect timing for upgrade :lol: Easterly/NEasterly and instability now looking very good for east and parts of central and southern England. If it comes off for that lot I wont begrudge, I'll just be happy to know it can happen still in these islands. What happens on the coast will be of particular interest. Liking the look of the showery troughs progged in the flow on the northern side of the low too, and the tighter isobars, will certainly feel bitter in that. Will be very interested to know the actual temperatures that result from this, SST's must be relatively high. At least it looks like eastern areas here and our southeast will get some heavy wintery showers, snow on hills, by thursday, with scattered wintery showers into friday. The way it's gone this week, the 4 days before the northerly incursion proper now seem like a lifetime so not much point commenting on that scenario yet. Still, will be interesting to know if that stalling Arctic cold front will pep up and turn to snow in Scotland and the north of Ireland, once the cold tries to dig in behind. Time to hold the breath, tomorrow likely to be a swing the other direction again

Some promising upgrades of potential snow/cold today, I might have to put the weeping, wailing, and gnashing of teeth on hold again! Probably all change back again tomorrow, perhaps what matters is the timing of the last set of models before the main events themselves. If tomorrow is downgrade, then thursday might be perfect timing for upgrade :lol: Easterly/NEasterly and instability now looking very good for east and parts of central and southern England. If it comes off for you lot I wont begrudge, I'll just be happy to know it can happen still in these islands. What happens on the coast will be of particular interest. Liking the look of the showery troughs progged in the flow on the northern side of the low too, and the tighter isobars, will certainly feel bitter in that. Will be very interested to know the actual temperatures that result from this, SST's must be relatively high. The way it's gone this week, the 4 days before the northerly incursion now seem like a lifetime so not much point commenting on that scenario yet. As for FI - not even on my radar! Still, will be interesting to know if that stalling Arctic cold front will pep up and turn to snow in Scotland and the north of Ireland, once the cold tries to dig in behind

Looks like an interesting pic Ronan, can you re-post as resized? Some sharp bursts of rain here this evening, and a bit of hail mixed in. Gone quite cold too, maybe snow over the higher hills. This is the middle part of the long tortuous process of the troughs pushing down/in from the northeast and east I can't see that widespread snow on sunday, that slow-moving cold front may turn to snow in places, but will it be dying out? We badly need more penetration of the initial cold burst from the north, followed by forming troughs - still looks like that will only happen in North and east Scotland and east England, with scatter showers around coasts elsewhere. The front seems to be arriving in air that's too mild to give snow itself except over high ground, and not great amounts unless it peps up, which is possible

People are right to be positive, and I'm hopeful too that the rest of winter might give us something special. Have to talk about the present though, it's the fallout of an intensely discussed and forecast spell of weather in very rare synoptics. Better out than in! With that in mind, I've just looked at the UKMO T120 and I'm afraid it shows the cold front held up again, pressure remaining high here on saturday at least. I wonder is this a product of two different cold airmasses colliding, a cold trying to move into another cold? It's ironic that the northerly blocking that we so much want to stay, and which is being forecast in FI to disappear quickly, looks like what is the main factor scuppering our chances of anything exciting from these cold airmasses/weather systems. I have to keep reminding myself - it's nothing new! This kind of thing happened often in the 70s and 80s at least

That warm sector at the start of the northerly seems to be more significant than I would have expected, and I also assume that the sea temperatures are having a big impact on the whole thing. That said, we have seen cold snaps recently in November giving snow in places so it's a surprise that the cold from these current air masses seems so moderated, even though I expected it to be more moderated than was being suggested in the discussions on Netweather over the past week or so. Certainly looks like a significant downgrade on what had been considered to be possible, and even forecasted to be likely

Sounds very promising!One more thing about the showers in the northerly, one of the reasons I'm very skeptical about it and why maybe you're more enthusiastic is that it is the middle of winter. If it were March/April/May or October I would be more positive, because in those months the strength of the sun aids a convective aspect to showers over land as the air moves across. In mid-winter it relies almost entirely on the strength of penetration of the flow and the relative instability of the air. As we have seen time and time again, once this flow comes south over much warmer ocean, and once it hits land, in mid-winter it tends to lose alot of potency and instability. As you live further north you probably have much better experiences of showers from a northerly (though maybe not a northwesterly!) than us further south and east and people inland (west/northwest facing coasts can do much better) And finally, we have to see the high pressure over us decline/move away quick enough/at the right time

Watcher, I do understand all of that, but our discussion is about whether that cold air and the instability will penetrate far enough south to hit Ireland seriously and bring significant and possibly widespread snow (other than Ulster, which if things dont go better than some models currently predicting, would mainly be hit on the north and west coast), whereas the trough itself coming down the North Sea is in the right place to hit north and east Scotland, and the east of England. The less unstable air to the west of the trough (that heading our way) needs to penetrate far enough south and remain quite potent in strength in order for the showers to remain heavy, to penetrate, and for other features to form and come over us. Imagine, this was our cold spell for the winter and then Jan & Feb turned out to be mild! Maybe I shouldn't even put that idea out in the universe!!

I'm not sure I agree with what you say about the low coming from the Arctic, it may give us very cold air, but that air is often very dry (coming from The Arctic/Greenland). It's only close to the low itself that the air is unstable enough for precipitation, unless other features develop (due to the very cold air crossing relatively warm ocean) and move over us, however these other features are often also a problem in that they stall the progress of the cold air going south. With the higher pressure close by I'd say it's only the north half and the east of Scotland and England that will do well out of that low, with some scattered snow showers in the North of Ireland, mainly near coasts, northern coasts could get quite a few showers. If the "other features" form and run south, this would be our best chance to see significant and more widespread snow. The easterly looks interesting for 24 hours, as the trough moves, but the trough is weak, pressure relatively high, the air becoming increasingly dry, and the isobars not tightened enough to drive the trough and the cold through as much as we would need to get any significant snow. That's my take on it all, sorry it's sceptical, but that's from many years of many disappointments, I prefer to be realistic. As ever, of course, hope I'm very very wrong (in the right way!)

Lads & lasses, isn't it great to have our own little thread, wha? Today there was a warm sector crossing within the weak trough, tomorrow will be a bit colder and tomorrow night very cold, so wednesday will be noticeably colder again. In theory!

I think though that comes up from the south? Might not have enough cold in it if it takes up that position. Need it slightly further south and east to set up a battleground situation between the cold over us and the atlantic trough

Only if that colder easterly air gets in while the instability is still there. And that's assuming both of those things actually come to pass, which cant be taken for granted, still 3 days at least before we'll know for sure, there's alot of uncertainty still, and it's a marginal event at best anyway by the looks, not a blast, rather a messy, long-drawn out struggle to get that trough and the colder air to come across us, very possible that the high will block it more (same with the northerly later), that would be my main fear the way the trends are looking. If the very cold air can get in from the northeast by friday, then as you say, any instability that may still be around could become more potent over the Irish Sea, that would be a massive bonus if it came off. Regarding the temperatures issue, we also must take into account that the sea is still relatively warm in December, and it's warmer now than it would have been globally the last time we had a chance of cold like this. That factor seems to result in things like more shortwaves, and disruptions of cold air being advected towards the margins of the colder areas of the hemisphere. There is also the old problem that we always have in these situations, that of the difficulty getting precipitation in very cold conditions

Speaking of old weather signs, I've seen alot of geese around here lately, I know we always get them but I'm sure there's been more than usual. Also I saw alot of seagulls (together with crows!) feeding on some scraps near where I live, havent seen so many seagulls up so close in such a built up area and I find it strange they would allow crows to feed with them A chilly day here today, after a fairly cold night. A friend reports a sharp frost last night in Castletownbere ( a very sheltered, Atlantic dominated spot) So here we go wiht the action, this is it, the speculation can now be tried out for real! By the way, are all these area threads a kind of competition for most posts? So far we are about 4th, The Southeast of England is running away with it, only the Scots giving them any sort of a run for their money. Do the SOuth Central English actually know that's where they live? Perhaps some of them are posting in the SE thread, so we could get them docked posts!

Dia dhuit, hello, failte and wilkommen to all! Jeez lads and lasses, a week ago I was in Frankfurt, if only it was this week! Still, looking on the bright side, come the weekend we might actually have a better chance of snow here. My take on this week is that Ireland comes off badly in terms of snow at least, we are nearest the high pressure through out, something very unexpected would have to happen. There just isnt the potency nor the instability in that easterly (IF) when it finally arrives. So maybe some wintery showers between about thursday night and saturday morning in east Leinster and Ulster. The weekend throws up a huge debate, as to how much will that northerly, and the instabilities/troughing with it penetrate south, and to some extent west? Again the high may scupper us, so at the moment I'll hold fire on that, too far out, Ulster looks to have a very good chance of something significant, and maybe some snow showers into parts of Connaught especially in a northwesterly. That warm sector has to be shunted too for us to be certain of snow rather than sleet at or near sea level, and that will also depend on the penetration southwards of the trough and its cold front(s) Whatever happens looks like a gradually increasingly cold week, with hard frosts in many areas by the end, probably lasting a few days then. Let's enjoy, it makes a fantastic change from what we've had most of the last 10-15 years!

Is it a singular virtue?

It shows a large part of England in the -10 to -15 range anyway

The synoptics that I have seen in the last few days to me did not support the predicted temperatures, I was surprised by what looked like a contradiction, now it seems like the numbers are coming into line with the synoptics, (which havent really changed much)

Yes that's kind of what I'm getting at, and you could add in the easterly to that. The high pressure over us kind of holds everything back at arm's length, as it were. And strangles the life out of the instability, at least somewhat. The advection in both the easterly and northerly does not look like really penetrating, and the risk is that this is a trend now just being modelled, so more to come. I would think our best hope is that with the fairly cold air that will be over us by the weekend, if we get any sort of instability as the high declines/moves (assuming it does!) then snow showers can form. We may well get a local event/events. What you say about the possible breakdown also I agree, it looks like the momentum of the circulation drags in warmer air from the south. Again there's a hope that we could get a battleground if the high/relatively cold air over us and the approaching low (if and when it does) engage in the right way for us. In the past in situations like this (Jan 1985?) despite all the blocking and cold air in almost all directions, the flow swung up a low from the southwest resulting in a sudden unexpected breakdown. Let's hope later models dont progress these possibilities

I dont think it's delayed, it actually doesnt happen properly at all according to this morning's runs, IN COMPARISON to what they were mostly showing the last couple of days (at least in the case of the northerly). I never felt that the easterly looked like bringing much of the very cold air that came with the Arctic highs that are over/coming down over Scandinavia and East Europe. IMO the coldest air that had been forecast to hit these islands is now not going to, with the exception of the south east corner of England. ColdER air does filter through to all parts IF that last short wave gets its act together as forecast, but the air that actually ends up over us is a (and looking somewhat slack) remnant of air that is currently over Scandinavia and the Low Countries. The isobars by friday make it look like the air is coming from Russia with love but that set-up doesnt last long enough for us to get the feed from further east than I've said, before pressure rises, and then the northerly. The penetration of the real cold from that northerly now looks to be held back to our north, we get a bit of it in what looks increasingly like a situation where instability over the ocean just to our north will take over and prevent the advection of the very cold air from the north. Of course it's a long way off, but the trends seem to be showing that to be very likely. And of course again, the air we get in the end is overall very cold by our standards, cold enough for snow which will hit eastern England to some extent on thursday/friday, and then from whatever showers/short waves that hit and form during the northerly, mainly in the north and northwest, possibly further south and east if the low penetrates. In the meantine tomorrow and wednesday look to have snow potential in England as the first short waves engage and generate some colder air during precipitation. It will be interesting to see what way the models go the rest of today and tomorrow, but agreement now looks strong for the next week. In summary for most, a bit of wintryness in the next 3 days, possibly more in east England if the shortwave potency increases and if the easterly delivers on the coast, which it looks certain to for a day or possibly two; increasingly frosty for all, then possibly some significant snow for the northern half of these islands at least over the weekend IF both the cold AND unstable air make it far enough south. My hunch is that for most it will stay mostly dry with high pressure blocking instability. Then when the high declines from us, it's very unclear what it leaves. By the way, the warm sector of the arctic low hits Scandinavia but it's very unclear how it might affect us. If the cold front is held up by lack of penetration and instability forming just to our north then it will just be assimilated into the overall. If the cold front penetrates then I think the warm sector will in any event stay away to our north and northeast, possibly clipping the far north/east of Scotland. That part of the warm sector becomes, in effect, the air that is just north of these islands on friday, the southerly bit of the Greenland high, which of course is warmer than the air behind the cold front anyway.

Well, I've been following the phenomenal intensity and volume of discussion about the models over the past week or so, and I have to say I'm very impressed that the predictions of a week ago are still more or less on target. Considering how unreliable the models have proved overall at that range it's really quite an achievement to have seen such general (if not smaller detailed) consistency. Especially when you consider that we are dealing with a set-up that is so rare (once in the last 20 years? once in December only in the last 28 years) And yet strangely enough, it seems that so extraordinary/unusual is this currently developing situation that perhaps that's why models have picked up on it so well. I'm also delighted that signs and signals, however tentative, during the later autumn that this kind of block was a real possibility of developing in winter have proven (albeit quite possibly by chance?) so far accurate. And that what seemed a defunct weather pattern possibility of the past appears to be quite possible in the present (IF it comes off). The intensity of debate and analysis of the models on here over the last week or more must mean that many who have participated are exhausted and somewhat memerised by the whole thing. I know for sure that I've kept out of it to avoid that fate. I'm just delighted and very satisfied that the current patterns are interesting, different to recently, and bringing badly needed dry bright weather here with light winds and some night frost - that alone is something to be thankful for in "the even larger teapot". And that the predicted patterns/set-ups are so damn interesting to watch and speculate about. It currently looks like a nice chilly few days will be followed by something of a colder blast, which may or may not include some significant precipitation. Unlike many on here, I cant be as certain that it will be snow. First of all, those that live on the coast know that it requires a very special set of factors to allow an on-shore wind to bring snow to the coast. It almost always has happened in the months of January to March in my part of the world, and we are currently in mid-december and following a prolonged mild wet spell. Therefore I assume that seawater temperatures are significantly higher than they would be in late Jan/February/March. I would also wonder if seawater temps are higher now than they were 20 years ago for example? Then you take into consideration the seeming fact that our sources of serious cold (Arctic, North and east continent) are not as cold as they used to be when cold and snow were a more common occurrence. I wonder does the block need to be stronger/more intense/more wide-ranging in the current climate in order to hold, and is the block itself in at least some way dependent on how cold it is to our north/NE/NW? With all those factors, when I look out the model output possibilities for this week, I see that there could well be snowy precipitation for some, or even many, but that it's unlikely on the windward coasts, it would require a super-cold burst of air to move quite quickly across from the continent, and that currently looks very unlikely. Having said all that I'm very much looking forward to the models/patterns for this week, and to enjoy at the very least the seemingly almost certain upcoming spell of very cold weather, with hard frosts (away from windward coasts!), freezing winds, mostly bright days and maybe, just maybe, even a little of the falling white stuff. Am I just confused when I seem to recall that during the 78/79 winter the pattern that developed in january/feb was one with an Arctic/Greenland block, vortex over Scandinavia and unsettled with repeated (fairly slack for winter) low pressures bringing a mix of northerlies and easterlies? That it was in this way very different to the other prolonged very cold spells of 47 and 63 and 81, where there was a fairly constant widespread block to our north, NW and NE? It looks to me like this is the type of pattern that the ECM wants to develop in FI. If only it proves to be correct I think I could say that it would be an incredible spell of weather upcoming. And finally, it also shows something we previously discussed and all cold/snow lovers dream of - polar lows moving towards/over these islands! Here's to a fascinating week, and whatever you do, take time to just enjoy whatever comes.