ITSY

This is it in a nutshell. And for us, right now, the most important thing is the continuation of this interest in a High Latitude Block gravitating north/north west/north east of the UK. Run to run variation this far out is to be expected - all that matters at this range is the broad pattern. And we can tick another run off as far as that goes with the 06z...to say the least!

A lot of comments this morning on the poor ECM vs good GFS. But they extend to wildly different timeframes, and the point of interest is pretty much only after ECM stops. For argument sake, this is the good GFS at +216: And this is the bad ECM at +240: There are clear upstream differences that will affect later frames, but they are not oceans apart. The broad pattern is similar, and indeed there's a case to be made that the ECM has actually done a better job at that range of shifting parts of the PV toward Scandinavia. The point I'm making is that we're still a very long way away from being able to identify medium-term cross-model support. By the time the period of interest gets to +216/+240 then we can start worrying about X-Model support. For now, it's just building blocks and trends that we're looking for. Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4972036

A lot of comments this morning on the poor ECM vs good GFS. But they extend to wildly different timeframes, and the point of interest is pretty much only after ECM stops. For argument sake, this is the good GFS at +216: And this is the bad ECM at +240: There are clear upstream differences that will affect later frames, but they are not oceans apart. The broad pattern is similar, and indeed there's a case to be made that the ECM has actually done a better job at that range of shifting parts of the PV toward Scandinavia. The point I'm making is that we're still a very long way away from being able to identify medium-term cross-model support. By the time the period of interest gets to +216/+240 then we can start worrying about X-Model support. For now, it's just building blocks and trends that we're looking for.

Some people are so reactionary! Guys and girls, we're looking for trends at 300hrs+. Commenting on the orientation of a given blob of high or low pressure at that range is daft. The key question is are we seeing a continuation of a trend to get HP advecting northwards, first to the UK and then into either Scandi or the Mid-North Atlantic. If the answer to that is yes then, for the next several days at least and likely a week, we're doing fine. If the answer is no, then you can be disappointed. UKMO is flat, certainly. But it's flat-ish at a range when that is within the options without disturbing the chances for what we're looking at 2/3 weeks down the track. Don't lose hope team! When it's hopeless, I'll be the first to say so. But we ain't anywhere close to that.

One other thing to note on this... Look at the wind direction column on the 06GEFS suite, for the tail end of FI. Overwhelming consensus is from the northerly quadrant. At this range, details don't matter - only the underlying direction of travel. And then the 850s declining as a cluster as per the 00Z. These are positive, if early and tentative signs, of something seasonal afoot.

Exactly. A clear northward push for HP towards Greenland and a clear southward push for part of the PV to relocate towards Scandi. It's basically a continued acceleration of the trend outlined earlier.

I can't respond in detail to this but the models are already beginning to show similar outcomes. What the EC46 is showing is essentially ridges of HP moving gradually away from the UK and into the Mid-North Atlantic towards Greenland and, at the same time, lobes of vortex moving gradually away from Svalbard and towards N and NW Europe. It's a little more fine than that but that's the jist of it. Now if you look at some of the recent GFS OP runs, here's what they show. None of them are immediate nor nirvana. And we should always, always, take what deep FI is saying with a pinch of salt. But, as of now, the very far reaches of FI are beginning to show something that resembles, at the right timeframe, the latest EC46. And if we look at the latest GEFS 850 trend line, you can see this reflected in the downward clustering in the runup to the festive period - again in line with both the UKMO online wording and the EC46. Nothing is banked or close. Indeed, there's a lot to get through and if it can go wrong it will go wrong. But the chase is certainly on and there is some early indications of Euro/American model alignment on the type of pattern evolution we could soon see. It's boring I know but for now the best we can do is look into the crystal ball of FI and see whether it resembles what the long term computers, and some pros, are seeing. I would say they are beginning to do so... Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4971522

I can't respond in detail to this but the models are already beginning to show similar outcomes. What the EC46 is showing is essentially ridges of HP moving gradually away from the UK and into the Mid-North Atlantic towards Greenland and, at the same time, lobes of vortex moving gradually away from Svalbard and towards N and NW Europe. It's a little more fine than that but that's the jist of it. Now if you look at some of the recent GFS OP runs, here's what they show. None of them are immediate nor nirvana. And we should always, always, take what deep FI is saying with a pinch of salt. But, as of now, the very far reaches of FI are beginning to show something that resembles, at the right timeframe, the latest EC46. And if we look at the latest GEFS 850 trend line, you can see this reflected in the downward clustering in the runup to the festive period - again in line with both the UKMO online wording and the EC46. Nothing is banked or close. Indeed, there's a lot to get through and if it can go wrong it will go wrong. But the chase is certainly on and there is some early indications of Euro/American model alignment on the type of pattern evolution we could soon see. It's boring I know but for now the best we can do is look into the crystal ball of FI and see whether it resembles what the long term computers, and some pros, are seeing. I would say they are beginning to do so...

Astonishing rain here in Temple Fortune, NW London. Tropical storm conditions outside. Leaves and small branches down; continuous thunder and the odd flash. Was blue skies 30 mins ago!

Not sure if this is the right thread but this is really interesting and suggests the recent historic anomalies we’ve seen - together with the current record breaking warmth of the North Atlantic basin - is about to worsen

It's incredibly marginal for those of us in the (northern) North London region. I woke up to a couple of cms of snow this morning which has now largely melted despite some moderate snowfall during the day. The angle of attack from the West vs SW vs South will be important in determining upper temperatures and dew points over the afternoon. I benefited from marginality back in December - my heaviest snowfall for 9 years - and may or may not this time. As Blue said, the perils of spring snowfall...

Yup. For both main models to be this well aligned, at this range, with such an unusual setup - building out from the same major background signals (MJO state/PNA slowdown and SSW propagation) - shows that something is stirring. The GEFS and the ECM Ens are producing near identical trends from early March. That does not mean - not by any stretch - that this is sown up but it does suggest (as indicated by the latest UKMO long range written forecast) that there is reasonably higher-than-average confidence in this materialising to some extent or another. But whether it does or it doesn’t, it’s getting thoroughly boring listening to people complain about things staying at 10 days out. This has always been about an end of Feb transition and early March delivery date. That remains so. If we’re here next week with nothing any closer then moan away - until then, just enjoy the charts for heaven sake!

Superb end chart. Like the control earlier. Let’s see if it comes forward…

Tbh I'd say even GFS is somewhat flat. I think we have our mystery solved now and, after a couple of weeks of really low temps and some snow, with a further week of model intrigue, we're back to mild for a little while for the vast majority in here. Enjoy Christmas/Eid/Chanukah (whatever you're celebrating) folks and let's see what the next two months of winter brings. Lot's still to play for with a memorable spell for many already in the bank.

This is essentially the conundrum. The left of this frame is an emerging signal for an Icelandic block across the latest GEFS suite. This would *ordinarily* be associated with much colder weather. The right of this frame is a clear signal for strong heights across the European mainland across the same suite. This ordinary would bring warmer/mild southerlies and SWlies. What we're left with is a standoff involving mean North/North Easterly signals for the northern third of the country, and mean southerly signals for the southern third of the country. In between this - the middle third of the British isles - is the golden zone for boundary/frontal snowfall. For the short-term (aka Xmas-NY period), the question is simply which of these two blocks wins out. We need the low pressure off Iberia/Biscay to travel into and trigger lower heights into Europe if we're to bring the cold boundary south. Alternatively we need a trigger low in the North Sea to do the same thing. It's a really interesting setup though and not one I've seen played out before! EDIT: The control shows this perfectly as a battle of the blocks (see the one to our NW over Iceland and the one to our SE over central Europe. In this particular scenario most of England is mild but it doesn't take much reconfiguring to turn it all white. It's a tightrope... Original post: https://community.netweather.tv/topic/98132-model-output-discussion-the-run-up-to-christmas/?do=findComment&comment=4774093

This is essentially the conundrum. The left of this frame is an emerging signal for an Icelandic block across the latest GEFS suite. This would *ordinarily* be associated with much colder weather. The right of this frame is a clear signal for strong heights across the European mainland across the same suite. This ordinary would bring warmer/mild southerlies and SWlies. What we're left with is a standoff involving mean North/North Easterly signals for the northern third of the country, and mean southerly signals for the southern third of the country. In between this - the middle third of the British isles - is the golden zone for boundary/frontal snowfall. For the short-term (aka Xmas-NY period), the question is simply which of these two blocks wins out. We need the low pressure off Iberia/Biscay to travel into and trigger lower heights into Europe if we're to bring the cold boundary south. Alternatively we need a trigger low in the North Sea to do the same thing. It's a really interesting setup though and not one I've seen played out before! EDIT: The control shows this perfectly as a battle of the blocks (see the one to our NW over Iceland and the one to our SE over central Europe. In this particular scenario most of England is mild but it doesn't take much reconfiguring to turn it all white. It's a tightrope...

The GFS Control says yes to its sibling's Griceland heights. The intrigue continues. It must be said that if GFS has this one then it's one of its better winter performances for sure - which, together with its summer accomplishments, would be noteworthy indeed!

Trending colder but the Op certainly at the low end of the pack. My gut says the GFS will end up with egg on its face - both because the reload cycle is so rare and the background signals are so uninspiring in the medium-long term - but then again, that's what I thought over the summer when it first started pumping out 42c in London. Two weeks later I was walking across the Heath watching fires break across the SE in 40+ heat. So never say never...

Late to the show today but UKMO and GEM look lovely in the final frames from a hemispheric POV. GFS...well, not so much!

The differences at +96 are staggering! Just shows that the models don't have a scooby. That guarantees us absolutely nothing but it makes for such interesting viewing! Take everything - Narnia and Tropics - with a big pinch of salt.

You'd take that on Xmas eve - dry or not, it would be the most festive in many a year!

Just for the imaginative people among you lot, we're awfully close to a full on snowstorm for the South on this chart. Probably one of those high-risk/high-reward scenarios but it's not without support. Good that the 06 GFS has followed the 00Z ECM. As we *slide* closer to the 144-168 timeframe things will start to firm up in the next few days so the trend is our friend...

An almost unbelievable twist again. GEFS back the op here, up to the medium term anyway. It’s on the lower end of the pack but it’s not an outlier - the clue is in the name, it would have to be outside the rest of the pack to be an outlier and until the mid point anyway, it’s certainly not. Very encouraging for a prolongation of seasonal weather after this weekend. Let’s see what ECM throws up. Even the hemispheric profile on the UKMO is excellent, even if it’s slightly off for our locale.

If cold is your thing that’s a great set from MOGREPS this eve

Let's remember that the 00Z was (regardless of technicalities and what others have said) an outlier, in that it was on its own for much of the second half. So the fact it now has some support, however minimal, is again a good indicator of a trend brewing...