Stu_London

I don't disagree that a few surprises might pop up. I don't think air temps and possibly more importantly ground temps will support any long lasting snowfields that would support any lower of temperatures near the surface. More likely some might awake to a covering that is largely disappeared by the middle of the day. As most in the forum appear to be seeking a cold spell with a perhaps more than a few hours of snow cover, away from 300m + elevation, I don't see this set delivering. I'd be happy to be proved wrong however.

It's only brilliant output if you like looking at projections at D9, D10, D11 onwards etc. There is a shorter interlude of below average temps, which as ever at this time of year, has potential to deliver a few transient snow events in favoured places. At present there is no evidence to suggest any sustained cold spell.

Still bags of potential beyond day 7 - getting that into the reliable timeframe remains problematic as anyone who has any experience of watching model output will be able to testify to. Looks like the 27-29Dec period will only deliver to the minority now and there is now a strongish signal for the trough to remain close to us, which will probably create too much mixing. We really needed things to be that bit colder to start with - it's still relatively early in the season and we will always have to overcome the fact we are an island with relatively warm waters around us. That said, as others have noted, there is still genuine potential down the line - we just need to get dealt the right cards. For the last two years, we have been stuck outside the casino in the mild rain!

In terms of upgrades/downgrades for 850temps, I've seen on a lot of occasions, slight upgrades in the just out semi-reliable time frame - this is what we are seeing over the last couple of runs for the period 27th-30th and there is still a little bit of scope for improvement. Often when we get what I would call the reliable timeframe (96hrs and under) there is a very small backtrack. Happened in Feb/March 18 which started as -15C ish - nearly made it to -20C at about five days and ended up being -18s and -19s in some places. That spell wasn't an issue as there was nothing marginal to worry about. This one is a more of a problem, so some expectation management is not a bad thing. However, in here, expectation management for some is about as feasible as trying to get your cat to understand the concept of Norway.

-1 is not a severe frost

I think the 27-29th period will see lots snow falling from the sky, but away from elevation quite a lot of wet slush. Still a bit marginal and ground and soil temps could have done with a couple of severe frosts into them.

More difficult with background warming, but as Dec 2010, Mar 2013 and Mar 2018 proved - not impossible. Maybe when the gulf stream finally chucks in the towel - they will be more frequent

I noticed a few similar models scenarios cropping up in October and November that had shades of 2010 - however, 2010 was a one in 50 year event, even disregarding background warming. I'd be happy if 1990/91 proved a good analogue match - I don't know if there was a SSW in Jan 1991, so i might be talking rubbish.

As I thought, not quite as tight toward the end of the run - but the majority still stay cold and its too far away to worry about anyway. The critical period 27-29Dec, the op is still a little higher than the mean - so there is still an angle to achieve some short term upgrades which would reduce the marginality worry for those areas. Different synoptically, but reminds me a bit of December 1990. Most areas midlands northwards got a pasting, but some areas close to sea level saw little settling snow. I lived in Darlington at the time and was most frustrated to hear on the radio that all main routes into the town were impassable due to drifting snow, yet it was a wet slush fest outside. Soon forgotten however, as February 1991 made up for it BIGTIME

That can't be a bad thing. A seasonal if largely dry Christmas Day is welcome after the last few. Some snowy weather is starting to look more likely (for some, at least) thereafter. My biggest concern on the 18z would be how quickly the heights over Greenland collapse compared to previous runs - we still end up with a good run for cold - but there might be some other perturbations that aren't as pretty.

I think there will be more scatter on the long ensembles than recently. Days 8-16 were remarkably tight (and cold) over the couple of runs

Colder run Not sure about the end of it - as a lot of blocking has melted away - but meaningless anyway at that range and strat might come to the rescue shortly afterwards.

Agree 24 did take longer time wise to get going and although a weak cycle, generally speaking once it was up and running there were very few spotless days 25 is starting to feel like we are at that point - so I am not expecting many more spotless days - but I could be wrong

Less than 10 - last minimum feel away very quickly and I think this will also

Don't have the technical knowledge of Steve, but experience of model watching over 2 decades leads me to the same conclusion. As soon as the Icelandic low gets established and starts spinning secondary systems, it is a sure sign the the Western hemisphere PV is in rude health and not likely to go anywhere soon. Add to that no sign of lowering of heights in the med and it becomes a bit of a stuck pattern. Nov/Dec 2010 archives are often used as examples and to a degree are the holy grail. But one must remember that 2010 would probably rank as a 1 in 20 year event in the pre-warming era, so it gives an idea of how rare an event it would be in these times. In the absence of any major stratospheric forcing events, best hope for the first third of winter will be northerly topplers or perhaps wedges of heights cropping up at short notice, but even these will probably fall the wrong side of marginal given the generic warmth in northern Europe. The only positive is the a strong PV might bottle up extreme cold that can be tapped into later if a pattern change does emerge.

I'm seriously thinking of packing my things and moving to FI - the weather seems great there. Does anyone know what the cost of living is there? In all seriousness, for coldies, it all comes down to the fact that for our maritime climate, there are many, many more paths to mild or not cold, than there are to cold and snow - so it stands to reason that cold/snowy will always be the outsider. The 06z op looks pretty flat again compared to recent output, however I wouldn't be surprised to see some more blocked scenarios crop again in the 252-300 hour range in the next day or so as GFS has a habit of teasing in the very long range, dropping the idea and then picking up on it again. But, despite advances in supercomputers in the last 20 years, I'd give the same advice I did when I started looking at forecast models in 2000 - which is, until anything is in the 72-96 hr range, don't believe any of it.

Using the Space Weather methodology the solar min is now 801 spotless days - which is the same as the amount of spotless days in the last minimum. Be interesting to see how strong SC25 is as this will give pointers as to whether this this is just 2 consecutive deep minimums, or the start of a more significant grand minimum.

It would be a remarkable minimum if there are anywhere near that amount of spotless days in 2020. It would exceed the number of spotless days in the last minimum (which was the deepest in almost 100 years) and by spring 2021 would be pushing towards the all time records in the late 19th and early 20th century, when it is likely that less sophisticated methods of measurement meant that there were many days recorded as spotless that wouldn't be in this day and age. Personally, I think we will see an uptick in activity in the second half of the year with far less spotless days. If I had to guess, somewhere between 50% and 55% of days to be spotless in 2020. Agree with other contributors about colder NH winters tending to be at the end of cycles. Whilst a rock solid scientific causal link is yet to be established, the anecdotal evidence seems to suggest that any effect on climate and weather patterns appears to be cumulative in nature. I would expect if we do see a grand minimum with 3 or more low cycles then those effects will be cumulative too. Of course, there were plenty of mild winter months in the Dalton minimum, so even if there is a link, then there are no guarantees. It might just mean the dice are loaded slightly more in favour of severe winter cold. With background warming seemingly accelerating, we will need all the help we can get.

Tomorrow likely to the 600th spotless day of the minimum. Still a way to go to beat the 801 days from SC23/24 transition, but not completely out of the question given how few sunspots have been on offer during the second half of this year.

Thank for the review - a good read. I think we have to accept that in a temperate maritime climate such as ours, the form horse will always be the least extreme option on the table (the form horse doesn't always win, but statisically is most likely). The notable thing for me this winter was how badly at times the main global forecast models performed. I began model watching over 20 years ago and as winter output goes, this has been one of the worst performing I have seen. I'm struggling to see how they have improved that much in terms of accuracy over 20 years. Perhaps this year the SSW threw them and they are maybe playing catch up with emergent patterns resulting from changes to climate and sea ice, but in an age when technological advances are accelerating as quickly as they are, I'm slightly disappointed that global forecasting models have not really progressed in terms of cracking the 96-168 hour period. I firmly believe that severe spells in winter will still occur in future and with a climate as complicated as ours, things are sure to fall right for us again sometime, although as the author of this thread notes, the dice might be loaded slightly more against us than has been historically. We can console ourselves that the last decade has produced two and a half months (Dec 10, Mar 13, Mar 18 H1) of severe winter weather that would be notable in any historical era, so it stands to reason that this will reoccur sometime in the future.

18z offers an FI that would be anything but mild. Not exceptional cold and nothing that would offer anything but a transient cold snap but it better than previous output and whilst close to 0% chance of verifying, does show that there are other options than just mild zonal type set ups. Notable that recent output blast the jet through into western Russia, so we can probably forget the siberian high coming into play (which would be fairly rare anyway) so any easterly would need to come from a toppling Greenland high or a wedge of heights establishing itself from the north. The 18z operational wouldn't need to evolve that differently for either scenario to come into play. For those bemoaning this winter, I have witnessed 3 separate (albeit minor and non-disruptive) snow events this week which is about the same as I witnessed between when I moved to the south east in 1992 to about 2002.

At 16 days out that could be a lot worse. Cold pool to the northeast in place. Dig the trough a bit further south west - ridge the high further north - get rid of that monstrosity to our west and hey - it a chart full of potential

I do think we will get some sort of attack from the East, but probably not until week 3/4 of February or maybe early March. Not sure if it will be sustained or how severe it will be and a spell that late has to overcome higher solar influence - but I still think it might deliver for some.

6z as bad as it can get for cold hunters. +144 is for fun only, but some of the building blocks within the next few days that were there previously are being eroded.

damp squib in Orpington - looks like I will have to go to work.