Model output discussion - cold spell approaching?

[Daniel*]

ECM 12z is an excellent run and builds on nicely from ECM 00z - I think I’m persuaded buckle in folks!!! 

[Cold Winter Night]

ECM Conclusion: Pattern too far West. I fully agree with @sebastiaan1973 and @Mike Poole.

I see some calling boom on +168, but the 850hPa Temp chart (below) shows where the cold is going: spilling out towards Iceland. So Iceland is where you need to be, or a ship on the North Atlantic. Southern half of the UK is probably not going to be happy with this setup.

The real interest at the moment IMO, apart from the next few days, is the movement of the Arctic High, moving towards Russia, extending towards Nova Zembla and possibly Scandinavia, visible at +240h.

[Battleground Snow]

If the EPS show a 400 mile adjustment east of the Greenland high (which I think they may well do) it will produce a great ensemble graph, with snow chances appearing as early as day 7 and 8

[nick sussex]

I think the issue here is SSW expectations versus what the models are so far delivering .

Its a bit like expecting a gift to be a weekend at the Dorchester and then getting booked into the Premier Inn instead .

If the SSW had never happened then expectations would be much lower , that’s not to say that we won’t see some colder synoptics in future runs .

I think we’re currently in a holding pattern . 

Edited January 12, 2021 by nick sussex

[Cheshire Freeze]

My conclusion this evening- it's all looking too marginal. Those on low ground or in the S of the country will be disappointed if this transpires. Late December 2020 with a few weeks of sun strengthening added.

[jayb1989]

Again looking like we need to be patient. I think it’s clear that we aren’t seeing any deep cold to tap into again. Plenty of booms going on in here tonight, which is all well and good if you want a chilly wintery period. However, those of us who are more interested in a proper cold spell, i.e snow at all levels that actually sticks around, a dissapointing outlook.

[Badgers01]

13 minutes ago, Gadje said:

Thanks for the UK map. I wonder what people living north of the UK are getting regards weather.

Please feel free to post a map showing such ! 

[MKN]

5 minutes ago, Cold Winter Night said:

ECM Conclusion: Pattern too far West. I fully agree with @sebastiaan1973 and @Mike Poole.

I see some calling boom on +168, but the 850hPa Temp chart (below) shows where the cold is going: spilling out towards Iceland. So Iceland is where you need to be, or a ship on the North Atlantic. Southern half of the UK is probably not going to be happy with this setup.

The real interest at the moment IMO, apart from the next few days, is the movement of the Arctic High, moving towards Russia, extending towards Nova Zembla and possibly Scandinavia, visible at +240h.

Tonight's 168 ecm may not be a boom but in terms of an overall pattern it is very good and we would be unfortunate to see such poor 850s. Small tweaks would see big improvements for our little island. 

[I remember Atlantic 252]

1 minute ago, jayb1989 said:

Again looking like we need to be patient. I think it’s clear that we aren’t seeing any deep cold to tap into again. Plenty of booms going on in here tonight, which is all well and good if you want a chilly wintery period. However, those of us who are more interested in a proper cold spell, i.e snow at all levels that actually sticks around, a dissapointing outlook.

Aye, but more like 28th to 2nd Jan hopefully! uppers can be higher, decent snow here, and not like the crap 3-6 Jan period where uppers needed to be -10

[PolarWarsaw]

18 minutes ago, Djdazzle said:

ECM isn’t a bad run, but against the backdrop of “SSW’s”, “historic January” and “nailed on cold”, it seems poor.

Yes, but anyone mentioning this used the terms 'could' or 'might be' so anyone that loosely took that as the next ice age was a guarantee, are taking people's words and using them as a formality. IMO not a clever way to use an internet forum. 

20 minutes ago, sebastiaan1973 said:

At day 6 it is (my point of view) already clear we can't get any significant Arctic air. The Greenlandhigh is not powerful enough and to much to the west.

The problem is, this is alreay on day 6. So little room to improve.

With the greatest of respect, you have been a fantastic addition to this thread but I do sense a lot of IMBY to your posts. This is the UK not the Netherlands. 

 

19 minutes ago, AFCBSNOW said:

In the current set up, even for us on the South coast, the uppers will largely be irrespective, due to where it is coming from, we pulled from a warm plume last shot, this one is much stronger.  We will see upgrades, just if we go on the previous spell.  I just dont see the point in micro analysing every single chart.  The trend is your friend.

I'm firmly with you in terms of the fact that it's best not to over-analyse every different model suite. However, the old 'get the cold in and goods follow' - it's not as simple as that. We got the cold in for pretty much the last two weeks and snow was isolated and fell in lucky/favoured/expected areas. I admire your optimism though with your location. 

Aside from that, I'm a firm believer that the weather works in patterns. We seem to have been looking at a Greenland ridge at Day 10 for about 6-8 weeks now, what has happened every single time is that as it's worked closer to T0 - the ridge doesn't quite make it and another feature in our locale works against us. That is what I see happening again here. To me, I make a true BFTE or 'historic' cold spell as marginally odds against at the moment, probably just ahead of a full zonal reset in terms of percentages. 

Sounds really negative doesn't it? It's not intended to be that way this time. I suspect we will continue to see just enough ridging in the Atlantic to keep us 'cooler' than normal. A rinse and repeat of the pattern we have just seen. The only difference this time is that the air to the east is less marginal, favourably sourced and more entrenched over Europe than we saw recently. I mentioned above that I am a believer in 'patterns'.

With that in mind I can see the next 2-4 weeks switching between slightly milder interludes where the Atlantic may try and encroach or a relaxation of the ridge into Greenland, either side of that I can see spells of a few days bringing country wide uppers supportive of snow, frosts and probably a fair smattering of showers. With the added interest being southerly tracking lows and any milder interlude probably increasing the risk of frontal snow. 

In other words, no BFTE and no -14 screaming easterly's but a repeating pattern of cold and snow chances, cold enough for harsh frosts and debatable whether any laying snow or not would melt during the 'less cold' periods. Certainly not a classic, but I do feel virtually everywhere is in with a shout of frontal snow in the next few weeks and it probably wouldn't go anywhere in a hurry. 

It's clear that a lot of people have somehow invested in this SSW and have banked on it delivering a BFTE, historic cold spell - which is still possible. IMO we are slowly moving away from that. But I can see quite a cold/snowy pattern setting up, without an amazing set up and one that could last a good few weeks in terms of opportunities. 

I'd actually settle for either/both, quite happily and so should everyone else. 

Edited January 12, 2021 by PolarWarsaw

[IDO]

We have been struggling to get cold uppers post-GH due to the trough being cut-off by the Arctic High, so the Uk is basically sitting in a giant cut-off low.

The tPV has been kept from sliding into the Scandi region by the motion of the Arctic high and we can only feed off the scraps of cold uppers as they ebb and flow within and around the cut-off low. It has been an annoying feature of this winter so far and maybe some underlying background signal that will eventually come to light.

So from d6-d9 we rely on the cold within the low as it circulates the smaller features within. By d10 the GH relaxes and we maybe will get a nascent northerly? Whether that again gets cut off before it can deliver the good we will see, though at d10 that ecm chart is unlikely to land!

[Methuselah]

28 minutes ago, East_England_Stormchaser91 said:

It’s funny this obsession with a West based NAO. I’d rather see a West based NAO than a big +NAO

Also, if the West Based NAO is a very large one, it could still extend its influence and land us with some very cold weather and will drive the jet stream way south. 

I agree, EES: if we get LPs running along or near the South Coast, long-fetch dry, cold undercuts, from the nearby snow-covered continent, will be perfectly conducive to snowfalls. I guess it's just that 'things' don't often fall into place, these days?

Edited January 12, 2021 by General Cluster

[chris55]

2 hours ago, Tim Bland said:

Puddles or snowmen? That’s going to be the million dollar question for most I expect in the next few weeks! High risk but high reward and a lot more exciting than anything we have had for years! ️

I think this pretty much sums up the mid term output perfectly. The only thing I would add is that the snowmen will  deffo be built (and we will see the pics in the regionals) it just depends if that's north of the M4 or not

[NewEra21]

People worrying too much about the 850s etc at the moment, let's just get the high into Greenland set first and then worry about the rest. Because without the high into Greenland we aren't even in the game.

So overall I'm more than happy after that ECM run!!

Edited January 12, 2021 by NewEra21

[weirpig]

1 minute ago, MKN said:

Tonight's 168 ecm may not be a boom but in terms of an overall pattern it is very good and we would be unfortunate to see such poor 850s. Small tweaks would see big improvements for our little island. 

It is perfectly fine   the cut of low  looks like its resolved  ( maybe)  and it will get colder   we will see many options churned out  which many will be different to the ec 12z  some better some worse    all good model viewing none the less 

[Cheshire Freeze]

The issue we're seeing is that we're seeing phasing of the Atlantic LP and trough to our NE happen too far west. This then scoops any upper cold out of Europe with the main thrust of Arctic air heading into the Atlantic to our NW. 

It's just not good enough. All we will end up with is a slushy, marginal mess. 

[Allseasons-Si]

Taking a look at the gefs mean at day ten and i will side with it the ECM mean later but what a cracking mean with a closed off GHP with southerly tracking jet and troughs/lows running west>east underneath,this spells battleground scenarios at it's finest providing that it will work out like that

in motion from 192>384.

gefs ens and dew points(my local)

although not overly cold but these would be subject to change nearer the time and hopefully colder

 

 

[Daniel*]

People fearing about the 850s the dew points are more important and they look
 

[Gadje]

37 minutes ago, Johnp said:

Essentially to get proper deep cold in the  south, we usually require the winds to be curved around an area of high pressure (such as a scandy high) so that the winds have as little sea track as possible. 

These deep low pressures that move across us and take an age to fill just waste time down here. 

 

Back on track - phasing of the lows is going the right way for coldies. I don't think it will matter though. That might be a IMBY comment .

Edited January 12, 2021 by Paul

[Scott Ingham]

I dont think current charts are far off where we might be. 

My own thimking was greenie high backing west to west based - NAO i just expected far deeper cold to be in the mix.

The set up isnt great on the south coast but exciting midlands north as its set up for several high impact snow events 

From an imby point of view im quite happy with the winter so far

[danm]

Can we stop the IMBY posts from all sides? For those down south like me, please stop going on about any perceived lack of cold. There’s so much still to be resolved. Likewise for those further north, saying it’s all good for you (especially when you’re at elevation) doesn’t do much good either. Even more so at the range we’re at now when we really don’t know exactly how cold it will be and where the coldest air will be. 
 

It’s getting really tiresome now - both those complaining and those saying that’s it’s good for them personally. 

Edited January 12, 2021 by danm

[Frostbite1980]

6 minutes ago, Scott Ingham said:

I dont think current charts are far off where we might be. 

My own thimking was greenie high backing west to west based - NAO i just expected far deeper cold to be in the mix.

The set up isnt great on the south coast but exciting midlands north as its set up for several high impact snow events 

From an imby point of view im quite happy with the winter so far

As always a balanced view and totally agree with that

[carinthian]

5 hours ago, carinthian said:

Ok, I have an update regarding the above ( RE: UK snowfall ).The outer parameter results from the snow computer currently show snowfall tomorrow, mainly on the high ground of Northern England and Southern Scotland. It would appear that the progress of the front is of some concern in its analytical output. The upper 300mb wind flow from NW ahead of the front is still strong enough to retard much progress NE. So positioning of the front and movement is crucial to the potential snowfall. Looks like cold air block ahead of the front will not be that easy to displace based on this current output but flags up the area most at risk. Into Thursday , snow could come down to lower levels and a bit further west. Current confidence ratings increased to 40%  now  its shown with-in the 24 -48 hour time span but high level of complexity remains in providing snowfall amounts.

Hope this helps. Its definitely a period of now forecasting.

C

The latest fax shows another correction westward of the front alignment on Thursday  . Looks like limited progress tomorrow. Snow risk increases on Thursday but in more central regions than earlier anticipated . Looks like a growing trend in the short term that could throw all present model runs beyond the end of the week out of the window.

C

Edited January 12, 2021 by carinthian

[Zak M]

Good ECM this evening! The cold starts to flow towards us as early as day 7!

Hopefully it doesn't switch to the UKMO's path tomorrow!

My mocks was scheduled for this month and if schools didn't close then I would have been extremely busy revising. I am a little annoyed at this, but there are loads of positives - one of them being the fact that I can sit at home for most of the day watching the models, and, if this ECM run comes off, I could spend most of the day enjoying the snow if any falls.

Away from all of that, it is looking very promising towards the end of the month. Exciting times ahead!

Edited January 12, 2021 by Zak M

[Cold Winter Night]

7 minutes ago, MKN said:

Tonight's 168 ecm may not be a boom but in terms of an overall pattern it is very good and we would be unfortunate to see such poor 850s. Small tweaks would see big improvements for our little island. 

Well, that's the thing, I don't think that the pattern as shown now is very good. It pleases the eyes, with yellows in Greenland, but the location and size is not good for us. It takes more than a few tweaks to get it right.
The cold is sent Southwest too far to the West. Not just in this ECM run, but actually all models and ensembles support this.
ATM I don't expect it to be corrected much to the East. (I hope so I'm wrong about that!)

Don't get me wrong, this pattern will result in below average temperatures and falling snow, but will that snow last during the day? Will this spell be longer than a few days? With this setup I doubt it, and I just think that's such a pity with a troposhere messed up like it is now.