The hunt for cold - Model discussion (late November)

[BlueHedgehog074]

The models do seem a bit gloomy this morning for cold and wintry weather possibilities, at least for low levels areas mostly towards Southern UK parts. 

The 00Z GEM, however, looks interesting with its cut off heights to the North and I do feel things could get a bit more interesting towards the New Year (or just after). Maybe a chance of a white Christmas itself could still be possibility, too, since it’s ten days away. 

Edited December 15, 2018 by DiagonalRedLine

[Man With Beard]

1 hour ago, Man With Beard said:

Clusters this morning: if there's going to be a cold snap during the Christmas period, the ECM ensembles suggest it will be earlier in the period rather than later (if at all, of course). By the 23rd, we see positive height anomalies in the Atlantic to our west, and clusters 1/3 look promising for getting a northerly flow down into the Atlantic shortly after (level of amplitude to be decided). 

The key for the UK is getting the trough to push east, as the FV3 is currently doing, but the ECM op is reluctant to do. 

However, after Christmas day, the clusters are not overly interested in cold, as ridging tends to move from favourable spots (control cluster perhaps excepted) 

 

Looking at this again, I've changed my mind a little. I'm guessing a trough might sneak through the Greenland area on clusters 1 and 2 at D8

[nick sussex]

A lot of the uncertainty is whether there’s a quick or slower trop response to the SSW.

Theres no way of knowing what it will be until closer to the time . This is reflected in the UKMO further outlook .

Don’t rule out a sudden model switch showing some much more interesting set ups as we move into Christmas week . It might be a delayed response so then patience will be needed .

 

[MR EXTREMES]

30 minutes ago, lorenzo said:

 

Anyone looking for some HLB  these MJO plots should satisfy...

Also chucking in the strat view..

Fairly confident this block will deliver a wave 2 split of the vortex and finish it off. Fun times ahead..

 

 

 

excellent stuff thank you very interesting stuff.

[Easton Luna Boys]

2 hours ago, draztik said:

Probably best not to be looking for that type of cold in the UK, tho? Well, that’s if we are being realistic? 

In late November we were told to expect this forum to be hyper busy into 2nd wk of December (due to possibility of severe cold)... then it was pushed back to Christmas. Now we are talking about early January & beyond .... 

A definite and all too familiar theme. 

Exactly. Too often, some people forget we are a maritime climate - and a maritime climate that is seeing ever increasing global temperatures on the rise. You tell me the last time you can remember even a significant screaming northerly having an impact on our shores south of the border? A 48hr toppler?? They are like goldust now. Take that out of the U.K. equation and we are left with the nirvana that is an easterly. A rare rare feature indeed (forget the token gesture that is a polar maritime NW, that doesn't really cut the mustard for anyone east of the Pennines). And as for the latest fashion that is strat warming, well not enough is known about this area so don't hang your hopes on this being the magic bullet in terms of SSW = cold and snow. There's even speculation that it can actually scupper the chances of cold, so be careful what you wish for. 

So calm and level headedness is what is needed over the next fortnight. Maybe a good time to have a break from model watching for a few days. Stay safe everyone and enjoy the weekend

J 

 

 

[MattStoke]

5 minutes ago, Easton Luna Boys said:

Exactly. Too often, some people forget we are a maritime climate - and a maritime climate that is seeing ever increasing global temperatures on the rise. You tell me the last time you can remember even a significant screaming northerly having an impact on our shores south of the border? A 48hr toppler?? They are like goldust now. Take that out of the U.K. equation and we are left with the nirvana that is an easterly. A rare rare feature indeed (forget the token gesture that is a polar maritime NW, that doesn't really cut the mustard for anyone east of the Pennines). And as for the latest fashion that is strat warming, well not enough is known about this area so don't hang your hopes on this being the magic bullet in terms of SSW = cold and snow. There's even speculation that it can actually scupper the chances of cold, so be careful what you wish for. 

So calm and level headedness is what is needed over the next fortnight. Maybe a good time to have a break from model watching for a few days. Stay safe everyone and enjoy the weekend

J 

 

 

Last December. Frequent snow showers here and for many other nothern and western areas, followed by a 'slider' low that brought heavy snow for many central areas (10 cm of snow here and over a foot in Shropshire).

Edited December 15, 2018 by MattStoke

[Snowjokes92]

These evolutions from the models certainly paint the picture that its not going to be as straight forward to get a white xmas here. Am assuming the less amplified and more default solution we are seeing today for next week, might be due to the SSW been forecast as its a lot more complicated for the models to forecast. I remember how last year the models would flip with the ssw forecast in feb

[Fourty Point Three Degrees]

An SSW isn't always a ticket to cold and snow  - Winter 2000/2001 is an example

[Snowjokes92]

2 minutes ago, 38.5*C said:

An SSW isn't always a ticket to cold and snow  - Winter 2000/2001 is an example

Agreed am just pointing it out because what ive read with the current ssw forecast on here and the experts, the building blocks appear to be in a good position to give us a decent shot. Especially also seeing the ssw LRFs that get posted on here for northern hemi. A lot of high pressure anomalies showing in the prime areas for greenland and the arctic from teleconnections ive seen on here

[Methuselah]

25 minutes ago, Easton Luna Boys said:

Exactly. Too often, some people forget we are a maritime climate - and a maritime climate that is seeing ever increasing global temperatures on the rise...

That's not true, ELB...

We all know full well that we are in a maritime climate; and, apart from one or two 'oddballs', we are also all fully aware that global temperatures are on the rise...?

That said, we do all have a certain liking for cold and snowy weather, which is what this thread is all about? Models flip and models flop - flip and flop, flip and flop - it's what they do... 

In the mean time, we all must take whatever we get?

Edited December 15, 2018 by Ed Stone

[Wilxy]

17 minutes ago, Easton Luna Boys said:

Exactly. Too often, some people forget we are a maritime climate - and a maritime climate that is seeing ever increasing global temperatures on the rise. You tell me the last time you can remember even a significant screaming northerly having an impact on our shores south of the border? A 48hr toppler?? They are like goldust now. Take that out of the U.K. equation and we are left with the nirvana that is an easterly. A rare rare feature indeed (forget the token gesture that is a polar maritime NW, that doesn't really cut the mustard for anyone east of the Pennines). And as for the latest fashion that is strat warming, well not enough is known about this area so don't hang your hopes on this being the magic bullet in terms of SSW = cold and snow. There's even speculation that it can actually scupper the chances of cold, so be careful what you wish for. 

So calm and level headedness is what is needed over the next fortnight. Maybe a good time to have a break from model watching for a few days. Stay safe everyone and enjoy the weekend

J 

 

 

Yet I bet your here for the same reason as all of us! Its still a long way to go yet until spring and its already been a unique year of weather!  I'm happy with the current charts some of the most memorable winters never got going until after Xmas not saying that is where we are heading but its also the reason why its far to early to write winter off! 

[Frosty.]

Sigh of relief regarding longer term outlook, Exeter shows no downgrade from yesterday..that's a big box ticked!..as I've said earlier, hopefully the operational output improves regarding christmas and longer term..potentially early 2019 could deliver for coldies in the hunt for deep entrenched cold and snow / snaw!

Edited December 15, 2018 by Frosty.

[Fiona Robertson]

OK, the whole gaggle of you.... STOP!!!!! Seriously, you lot are incorrigible. I go away for 24 hrs and come back to over a dozen pages of posts. Man, only the terminally enthusiastic could manage to wade through that little lot so I scanned it and now I'm terminally confused. There are cheers, tears, mild snivelling, someone doing a barn dance. What my quick scan has managed to glean is that the SSW is "nailed on" and is gonna happen with a PV displaced and wandering in our direction, but a PV split is more sorta held on with a post it note. Please, someone, take pity on this bear of little brain and give me a short summary... 

[johnholmes]

31 minutes ago, Easton Luna Boys said:

Exactly. Too often, some people forget we are a maritime climate - and a maritime climate that is seeing ever increasing global temperatures on the rise. You tell me the last time you can remember even a significant screaming northerly having an impact on our shores south of the border? A 48hr toppler?? They are like goldust now. Take that out of the U.K. equation and we are left with the nirvana that is an easterly. A rare rare feature indeed (forget the token gesture that is a polar maritime NW, that doesn't really cut the mustard for anyone east of the Pennines). And as for the latest fashion that is strat warming, well not enough is known about this area so don't hang your hopes on this being the magic bullet in terms of SSW = cold and snow. There's even speculation that it can actually scupper the chances of cold, so be careful what you wish for. 

So calm and level headedness is what is needed over the next fortnight. Maybe a good time to have a break from model watching for a few days. Stay safe everyone and enjoy the weekend

J 

 

 

Welcome to the forum, you do not tell us where you live, perhaps you could drop your nearest town in your avatar please?

thank you

Perhaps you have forgotten late November into December 2010? You can see where I live and I had 35 cm from that, and there have been several instances in December when snow has lain, even only for 24 hours. Northerlies, even a deep cold NW'ly can and does now and then, especially with 'help' from a trough give snow in this area.

I do agree with your comment 'calm and level heads', but as I am sometimes told in here it is the hase that keeps this thread ticking over the pages each day.

ps I know the December 2010 was a NE flow but it had originated as a NW-N'ly.

[Mike Poole]

30 minutes ago, Easton Luna Boys said:

Exactly. Too often, some people forget we are a maritime climate - and a maritime climate that is seeing ever increasing global temperatures on the rise. You tell me the last time you can remember even a significant screaming northerly having an impact on our shores south of the border? A 48hr toppler?? They are like goldust now. Take that out of the U.K. equation and we are left with the nirvana that is an easterly. A rare rare feature indeed (forget the token gesture that is a polar maritime NW, that doesn't really cut the mustard for anyone east of the Pennines). And as for the latest fashion that is strat warming, well not enough is known about this area so don't hang your hopes on this being the magic bullet in terms of SSW = cold and snow. There's even speculation that it can actually scupper the chances of cold, so be careful what you wish for. 

So calm and level headedness is what is needed over the next fortnight. Maybe a good time to have a break from model watching for a few days. Stay safe everyone and enjoy the weekend

J 

 

 

I cannot let the bit in bold go unchallenged.  The Met Office have invested significant resources into improving the representation of the stratosphere in their models (GloSea5) precisely because it has a huge influence on the potential for severe winter weather in this country.  

Its why there has been a dedicated thread related to the stratosphere here on Netweather going back years, championed by the very knowledgable @chionomaniac, maybe you should read it.  An awful lot is known.  Yes there is a chance it could go wrong for the UK, but, well, anything can go wrong for the UK - it's why we are as a nation obsessed by the weather!

 

[johnholmes]

14 minutes ago, Fiona Robertson said:

OK, the whole gaggle of you.... STOP!!!!! Seriously, you lot are incorrigible. I go away for 24 hrs and come back to over a dozen pages of posts. Man, only the terminally enthusiastic could manage to wade through that little lot so I scanned it and now I'm terminally confused. There are cheers, tears, mild snivelling, someone doing a barn dance. What my quick scan has managed to glean is that the SSW is "nailed on" and is gonna happen with a PV displaced and wandering in our direction, but a PV split is more sorta held on with a post it note. Please, someone, take pity on this bear of little brain and give me a short summary... 

Hello Fiona

I'll try but my calm reasoning may get swamped by replies!

We have an interesting 12-18 hours perhaps 24 coming up, the threat of snow, rain or even for some (in my view largely above 500 ft), and severe gales for some. Beyond that and the title of this thread gives the clue. It is far from clear when the cold and even more searched for snow will return or for many arrive. Try the Met O 6-15 and 15-30 day outputs if you want a level headed and unbiased view on how our weather may turn out. IBut stay with this thread if you have time to trawl through the helter skelter of dissecting every frame of every run. It's fun if that is your preference.

Best I go!

Hope that helps.

Edited December 15, 2018 by johnholmes
spelling

[Mike Poole]

14 minutes ago, Fiona Robertson said:

OK, the whole gaggle of you.... STOP!!!!! Seriously, you lot are incorrigible. I go away for 24 hrs and come back to over a dozen pages of posts. Man, only the terminally enthusiastic could manage to wade through that little lot so I scanned it and now I'm terminally confused. There are cheers, tears, mild snivelling, someone doing a barn dance. What my quick scan has managed to glean is that the SSW is "nailed on" and is gonna happen with a PV displaced and wandering in our direction, but a PV split is more sorta held on with a post it note. Please, someone, take pity on this bear of little brain and give me a short summary... 

Hi Fiona, good post, here's my bullet point summary

• Christmas, northerly still possible to bring some wintryness but chances are it is more likely to be mild.
• SSW is nailed on.
• Split strat vortex following SSW is now very likely.
• This split in turn looks likely to lead to severe cold in January, 80% chance, not guaranteed! well never guaranteed at that range in the UK!

Hope that is useful.

[Derecho]

After the hints from the swingometer things may turn cold, subsequent runs have really gone the other way. The 18z set was particularly woeful and the runs that have a rather cold christmas day are those of the cold zonal variety. A step back unfortunately but its still 240h away. I can't say I'm confident we will see any northern blocking in place around christmas time unless we see a sudden swing in the ensembles.

Those claims of lowland snow in November, severe cold spell by christmas are on thin ice now.  The global temperature anomalies show that pesky cold blob in the North Atlantic again, helping fire up the jet and ruining our December. Last year it took an SSW event to overcome it.... will we succeed this time?

Its been more like a believers winter then a deniers winter so far....

Edited December 15, 2018 by Quicksilver1989

[Frosty.]

2 minutes ago, Mike Poole said:

 

• Christmas, northerly still possible to bring some wintryness but chances are it is more likely to be mild.
• SSW is nailed on.

Yes mike i noted there is still a small chance of a colder showery incursion at some point during xmas week..let's get next week's milder dross out of the way and hope the experts are right about January!!!

[MattStoke]

11 minutes ago, Mike Poole said:

Hi Fiona, good post, here's my bullet point summary

• Christmas, northerly still possible to bring some wintryness but chances are it is more likely to be mild.
• SSW is nailed on.
• Split strat vortex following SSW is now very likely.
• This split in turn looks likely to lead to severe cold in January, 80% chance, not guaranteed! well never guaranteed at that range in the UK!

Hope that is useful.

Would add that signals point to plenty of high latitude blocking from late December/early January, favourably positioned for cold in north west Europe. Increases the likelihood of a SSW bringing severe cold to our shores but can bring significant cold even if a SSW doesn’t materliase or materialises in such a way that doesn’t favour cold here.

[Froze were the Days]

16 minutes ago, Mike Poole said:

Hi Fiona, good post, here's my bullet point summary

• Christmas, northerly still possible to bring some wintryness but chances are it is more likely to be mild.
• SSW is nailed on.
• Split strat vortex following SSW is now very likely.
• This split in turn looks likely to lead to severe cold in January, 80% chance, not guaranteed! well never guaranteed at that range in the UK!

Hope that is useful.

You sound confident...severe cold in January 80%!!! we have to wait and see if we have a displacement or split of the vortex, personally I'm a lot less confident than you are. Saying that it's hasn't been since 2009/10 in my neck of the woods and probably in general we last experienced a cold end to the year into the New Year, surely that has to change at some point...maybe this is the time?

Edited December 15, 2018 by Froze were the Days

[MattStoke]

12 minutes ago, Quicksilver1989 said:

After the hints from the swingometer things may turn cold, subsequent runs have really gone the other way. The 18z set was particularly woeful and the runs that have a rather cold christmas day are those of the cold zonal variety. A step back unfortunately but its still 240h away. I can't say I'm confident we will see any northern blocking in place around christmas time unless we see a sudden swing in the ensembles.

Those claims of lowland snow in November, severe cold spell by christmas are on thin ice now.  The global temperature anomalies show that pesky cold blob in the North Atlantic again, helping fire up the jet and ruining our December. Last year it took an SSW event to overcome it.... will we succeed this time?

Its been more like a believers winter then a deniers winter so far....

What claims? Apart from a few brief chilly spells, for several weeks focus on significant cold has been on late December/early January onwards.

[bluearmy]

18 minutes ago, Mike Poole said:

Hi Fiona, good post, here's my bullet point summary

• Christmas, northerly still possible to bring some wintryness but chances are it is more likely to be mild.
• SSW is nailed on.
• Split strat vortex following SSW is now very likely.
• This split in turn looks likely to lead to severe cold in January, 80% chance, not guaranteed! well never guaranteed at that range in the UK!

Hope that is useful.

Can you change the very likely to very possible ??  A split vortex post the displacement remains unclear 

and 80% is way too high for January at this range Mike ...... especially ‘severe cold’. 

Fiona will be even more confused! 

[lassie23]

41 minutes ago, Fiona Robertson said:

OK, the whole gaggle of you.... STOP!!!!! Seriously, you lot are incorrigible. I go away for 24 hrs and come back to over a dozen pages of posts. Man, only the terminally enthusiastic could manage to wade through that little lot so I scanned it and now I'm terminally confused. There are cheers, tears, mild snivelling, someone doing a barn dance. What my quick scan has managed to glean is that the SSW is "nailed on" and is gonna happen with a PV displaced and wandering in our direction, but a PV split is more sorta held on with a post it note. Please, someone, take pity on this bear of little brain and give me a short summary... 

It's always confusing in here, not just today 

[Mike Poole]

8 minutes ago, Froze were the Days said:

You sound confident...severe cold in January 80%!!! we have to wait and see if we have a displacement or split of the vortex, personally I'm a lot less confident than you are. Saying that it's hasn't been since 2009/10 in my neck of the woods and probably in general we last experienced a cold end to the year into the New Year, surely that has to change at some point...maybe this is the time?

My 80% figure is from my understanding, such that it is, and what the models are saying, including the long range ones that I have seen.  But you could draw exactly the same conclusion from the Met Office 16-30 day forecast - they would not be so bullish if they weren't pretty damn certain.