Early run up to Winter 2021/2022 discussion

[Dorsetbred]

On 12/11/2021 at 16:54, Bradley in Kent said:

On that basis, I won't get sucked into anything, as interesting cold charts are!

Will all the mechanisms have a break at the same time? Thankfully they do once a year...

I think EVEN that depends where you live in the UK, last winter down here was a complete "Never happened"..

Edited November 12, 2021 by Dorsetbred

[Anthony Burden]

The stand out in weather terms so far this early part of winter is dry and mild,will that continue 

into mid winter is what we all would like to know.I feel that a good percentage of us expected 

northern blocking due to  LA-NINA and EQBO encouraging pressure rise in Atlantic / North Atlantic.

At present that has not happened,instead high pressure to our south/southwest has kept us in 

this mainly dry mild theme.Remember November can  on average be very wet and some times stormy 

so not the average November so far. Lots for the cold fans to be positive in my opinion the Atlantic 

is still relatively slack,a pressure rise in mid Atlantic is the starter for 10 perhaps not so far away

we shall see.

 

[SqueakheartLW]

On 12/11/2021 at 14:38, LRD said:

I don't know enough to be absolutely certain but that example you've cited - I don't recall it but I'm assuming that if the atmosphere was primed in such a way, that low wouldn't have derailed things. Instead it was the overall, broad atmospheric state that allowed that low to change the course. But, as I say, I might be wrong. The thing that says to me I might be incorrect is, if the broad atmospheric pattern/state is what it is, then it could be argued models should have picked up on that

The one massive cold forecast fail that I remember was John Kettley, 20-odd years ago, confidently stating a massive E'ly cold wave was incoming but, then, it didn't. I must admit, though, I don't know enough about it but someone on here might. 

You might be thinking of February 2001 when we got a very cold day, I think it was 1st February 2001 as well. Freezing fog all day and some snow pushed in from the west on a front in the evening. Very cold temperatures for the time of year over northern Europe, Scandinavia in particular during the January to March period in particular

Was predicted to get NE winds straight from there at one stage in February, hence John Kettley predicting we would get minus double digit daytime maximums but this never happened. Low pressure moved up through the UK and ended up too far north to really tap into this cold. We turned less cold instead and had high single digit maximums before a mild dry spell the following week and double digit maximums instead. It only turned colder again from the 23rd when the high pressure to our south retrogressed up to Greenland and we got an Arctic northerly.

That was one big fail by John Kettley but then he was about the only one claiming this was going to happen.

[E17boy]

Morning peeps

Nothing exciting yet on the horizon in terms of cold for the next 10 days or so.

Surprise surprise Met office have again changed their extended outlook. Gone are the northerlies and conditions staying as they are currently drier in the south and more unsettled in the north, with short lived colder incursions. Temperatures above average.

Saturday 27 Nov -Saturday 11 Dec

Conditions similar to earlier in November will continue, with the northwesterly flow dominating. High pressure close by to the south and southwest will bring a good deal of dry and settled weather, where frost and fog is likely overnight, the fog often slow to clear in the morning. The weather will be more changeable further north, with spells of rain, and occasional strong winds, this interspersed with sunshine and showers. Temperatures above average overall, but short-lived colder spells are likely, with the risk of snow and ice, especially in the north.

Updated: 15:00 (UTC) on Fri 12 Nov 2021

Looks like we got a typical mild set up with high pressure to the south and low pressures to the north. As I have said many times once locked these patterns can sometimes last a while. Many of our winters have been spoilt with this type of set up before, where pressure has remained high to the south of southeast of us and SW winds have prevailed

The crumbs of comfort here are hopefully this set up we are in will not last all winter. It’s only nearly mid November and we still have over 2 weeks for proper winter to start.  Things can change and things will. Sometimes  the change surprises us all. So keep heads up.

Have a great Saturday all

stay safe

regards

[SqueakheartLW]

There may be good news for cold weather fans for this coming winter with what is happening with the La Nina.

It seems it is shifting from a CP event towards more of an EP event

The last 7 days have seen a general steadiness or slight warming in the western equatorial Pacific whilst the more eastern areas have got colder. These line graphs also show the recent trend well too

NINO 4 and NINO 3.4 have generally remained quite steady between -0.5C and -0.8C

It is NINO 3 that is showing the biggest cooling recently and NINO 1+2 has generally become quite cold over recent times hovering around -1C below normal.

If we do end up with an EP La Nina then this very much isn't the best news for December 2021 as EP La Nina winters tend to have Decembers as their mildest or least cold months.

However it becomes game on for January through to March as these months tend to be colder than average in EP La Nina winters on average. Doesn't mean other factors won't override the La Nina signal though.

[Catacol]

Welcome to the weekend everyone. Snow Optimism index analysis today:

The good=

- Nina continuing to look like it will avoid modoki and the overall ENSO signature remains similar to the 2010 Nina event

- Indian Ocean Dipole avoiding any shift towards a positive signature

- Snow coverage generally across Russia looks good

- No sign at this stage of the vortex powering up significantly above normal expectation

- eQBO has now descended to 50hpa

 

The bad=

- ECM op today out beyond 5 days loses the ScEuro High / Aleutian Low combo which is a solid precursor to stratospheric disruption

- ECM extended anomaly forecasts have trended flatter 

 

15 more weeks of snow potential still lie ahead.

 

Edited November 13, 2021 by Catacol

[Don]

On 11/11/2021 at 23:11, CreweCold said:

The worry is that it’s a very good stratospheric modelling tool. I believe it has more data layers than any other model when it comes to the strat. I think it missed last year’s until quite close in but I think the odds of it missing two SSW events on the bounce are quite slim.

True, but I'm taking heart that the latest BCC update was decent and that model seems to be pretty good, too!

[blizzard81]

I'm certainly liking the fact that this November is more sunny than normal. Most November's are dark and miserable. Not the case with this one so far. 

[Shillitocettwo]

   Current CET predictions....

 

  December 2021 - 5.5.C   Slightly milder than average with a lot of settled weather and fog....often on the South side of the jet so not desperately cold and struggling to get below zero even in those settled conditions. Very dry.

 

  January 2022- 3.8.C More unsettled but occasional Northerly feeds. Most snow showery in nature rather than persistent.

 

  February 2022 0.8.C A notably cold month with a Beast from the East type weather pattern mid month with minus daytime temps and minus double digit night time temps with a juicy snowfall event as milder air takes back over.... a very mild end scuppering what looks like could be a sub zero CET for much of the month.

[SqueakheartLW]

Further to my post earlier on about the La Nina possibly shifting from a more CP event to an EP event I have decided to work out why the EP La Nina is better for cold than the CP La Nina. First I have generated the general temperature anomalies to average during all EP and CP La Nina years between 1953 and 2021 from November through to March. This is what I got as my result.

It is quite clear to see here how much an EP La Nina favours colder temperatures overall, particularly later on in the winter and into the early spring too whilst it appears to have little signal either way during late autumn and early winter. The CP La Nina appears to have a mild signal overall for the official winter months at least whilst there's little signal for November or March.

Comparing 500hpa anomaly charts for each month under each La Nina type

Below I go through each of my 5 featured months in order to see the differences between each La Nina type

Novembers

CP La Nina                                                EP La Nina

Not a great deal of difference between the signals for the Novembers with a mid Atlantic ridge blocking signal for both CP and EP La Nina years on average with a slightly stronger mid Atlantic block for the EP La Nina years. The main difference is the positioning of the Pacific ridge. This has little impact on the Novembers but this difference in positioning of the Pacific ridge is the crucial factor that separates the CP and EP La Nina winters from Decembers through to the Marches.

Decembers

CP La Nina                                                EP La Nina

The differences between CP La Nina years and EP La Nina years start to show themselves now.

With the CP La Nina years we lose the mid Atlantic ridge signal and instead see the Azores high resume it's usual home over you guessed it, the Azores whilst we see the polar vortex ramping up over Greenland. Zonality comes to the UK in full force here and we swing milder than average.

This is in contrast to the EP La Nina years which in general keep the mid Atlantic ridge signal going into December too and the polar vortex remains disorganised too. It seems the crucial factor that decides this is the more poleward Pacific ridge which amplifies the pattern across the northern hemisphere as a result unlike the CP La Nina version which flattens everything in general.

Januaries

CP La Nina                                                EP La Nina

Into the Januaries the differences start to grow more.

In CP La Nina years we keep the zonal signal going although less strong than December's signal is but we retain the milder signal for Europe in general and the very cold signal for northern USA. The flatter Pacific ridge is generally responsible for most of this signal.

In EP La Nina years the northern blocking signal increases but at this stage it isn't quite perfectly aligned for the UK to get any significant cold although this is a colder than average signal so cold snaps are definitely possible here. The crucial factor here is the more poleward Pacific ridge amplifying the pattern again but also the Ural ridge signal which means the Stratospheric polar vortex is TOAST !!!

Februaries

CP La Nina                                                EP La Nina

The Februaries contain probably the biggest differences between the CP and EP La Nina years.

In CP La Nina years we have a generally organised polar vortex delivering cold to Canada and the N USA but this is displaced further away from Europe. As a result the signal for Europe is for more of a ridge and drier conditions as well as a milder than average signal. A welcome relief for the UK no doubt after the wetter December and January signals.

In EP La Nina years we hit the jackpot for cold in the Februaries. A strong northern blocking signal as well as a split polar vortex unleash the beast from the east onto Europe and the UK. Not only that we see a cold signal for the USA and Canada too under the other half of the polar vortex. If we can get our current La Nina into EP territory, watch this space and look out for what February could bring.

Marches

CP La Nina                                                EP La Nina

The patterns between CP and EP La Nina tend to close up somewhat on each other.

CP La Nina years see a return of some northern blocking to Europe by March, although quite a weak signal. This can result in a colder than average March but not by any significant margin. The northern half of the USA and Canada retain the coldest signal however and it seems CP La Nina years are particularly good for the USA and Canada to get cold winters.

EP La Nina years see the northern blocking signal from February carry over although less strong than in Februaries. This results in a colder signal for Europe but the anomaly is likely to be less severe. The cold USA signal also continues on. Between EP and CP La Nina I think CP La Nina is better for the USA cold but EP La Nina can be good for them too.

Summary

Basically all I can say here is if you are a mild winter fan, pray that our current La Nina stays or becomes even more Central Pacific based to kill off the chances of northern blocking. However if you are, like me, a cold winter fan then pray all you can to hope the La Nina becomes Eastern Pacific based to strengthen northern blocking signals for the winter.

Watch out in February and March in particular if we can get an EP La Nina going. If we can't then hope other signals can override the CP La Nina signal to give us blocking after all and a route to cold.

[Thunder Snow]

When does netweather release there winter forecast? And when does the Christmas updates start

 

[Roger J Smith]

I think an adjustment is in order for the winter outlook issued earlier. I was saying mildly optimistic about wintry outcomes by mid-January, best analogue available 2011-12. However, things are rapidly starting to resemble autumn 1981 and that could mean an earlier start to wintry synoptics. The GFS 00z run has picked up this theme too. 

Currently a very severe rain and wind storm on the west coast of Canada and the most similar November was 1981. Winters with a lot of Pacific storm activity, chinook warming and large amplitude patterns over N America often couple with blocking over northern Europe. 

So will now go with a much more optimistic forecast and say look out, modified early winter weather may be coming in about two weeks perhaps intensifying to an epic situation later in December. 

[SLEETY]

Met forecast beast from East end of February 2018 very well, I remember the 10 day trend at end of January talking about SSW event that the models had picked out

 

 Could happen and it did and hence the very cold end of February. 

 

Very hard to forecast 3months ahead then if events like SSW can pop up out of nowhere during the winter like 2018. 

Edited November 15, 2021 by SLEETY

[Bradley in Kent]

It feels like this winter the opportunities for cold weather will be early on before La Nina kicks in plus other factors.

If I had the choice mind, I'd rather have the cold early as the sun is weakest 21st Nov to 21st Jan and doesn't ruin any lying snow. Plus it makes the darkest depths more bearable. By Feb I'm more in the mood for a bit of warmth like 2017 or 2019. All the above is my opinion of course!

[AmatuerMet1963]

Well I'm back for winter frolics with my new upgraded windy site. I notice East China has just had a huge snowstorm beating records from 100 years ago. I like start to manage my events of note. As this is a unusual sudden and of course intense event, it goes onto my computer files as one of many events linked to climate change. Here in UK it's not normal tempatures for November. Guy Fawkes night was always very cold, hard frost, and you needed a duffle coat gloves and scarf, at just about the start when I was born in 1951 pre industrial out of control coal gas and oil, but cars remained virtually none existant until early sixties, EVEN then, cars were luxuries that few could afford. Its telling that co2 levels, despite we all had lovely coal fires with a back boiler still CO2 was in the realms of normalites , where the dogs sat, and we roasted crumpets on a fork.. Earlier in August /September, news of the AMOC was getting slower and weaker, is quite alarming, and while Artic ice continues to  melt with gusto, the increasing fresh water is eventually going to have profane effect on weather we keep the gulf stream as it is now. 

I actually believe this will be the Day After Tommorow winter in Europe this year  and  22. So many active pointers can't be ignored. We will see

Edited November 15, 2021 by AmatuerMet1963
Added text

[damianslaw]

1 hour ago, Bradley in Kent said:

It feels like this winter the opportunities for cold weather will be early on before La Nina kicks in plus other factors.

If I had the choice mind, I'd rather have the cold early as the sun is weakest 21st Nov to 21st Jan and doesn't ruin any lying snow. Plus it makes the darkest depths more bearable. By Feb I'm more in the mood for a bit of warmth like 2017 or 2019. All the above is my opinion of course!

Agree my preference is for cold weather in December and January, when the sun is at its weakest, rather than February. Statistically the coldest period of the year is roughly last third of January through to middle of February though.

I also prefer a cold second half to December than first half. In recent years we've had quite a few Decembers featuring cold weather in first half, which then dissapeared run up to christmas, 2008, 2012, 2017 and last year to an extent did this. 2006 and 2007 featured cold frosty weather that dissapeared by christmas. 2008 and last year did see a return to cold weather from christmas. 

 

[Wimbledon88]

20 minutes ago, Battleground Snow said:

How many days out in 2010 was there broad model consensus? My memory isn't great... 

With 11 years advancement in models you would hope they have got more accurate in the mid term.

I think the drivers were similar back then, apart from QBO was westerly.

 

Here's the met office extended forecast from this day 11 years ago. 

[Midlands Ice Age]

Whilst its fairly quiet, before the next runs, it is worthwhile looking at the similarities in the Northern Hemisphere with regards to  snow and ice coverage from the apparently similar 2010 event.

Obviously very similar with slight changes in snow cover, with more in the east and less in the US.

2010/14/11                                                                                                 2021/14/11 

                                           

In addition we are at a very similar stage of the solar cycle, (recovering 2 years from the solar low) and we also have a similar global  and PDO with a moderate La Nina  setting up.

Is it all coincidence, or is this what is leading the models to a similar outlook?

MIA 

Edited November 15, 2021 by Midlands Ice Age

[virtualsphere]

2 hours ago, Wimbledon88 said:

With 11 years advancement in models you would hope they have got more accurate in the mid term.

There's some interesting data on long term model verification from the WMO Lead Centre for Deterministic Forecast Verification, and you can create your own plots: https://apps.ecmwf.int/wmolcdnv/

These are all based on northern hemisphere 500hPa.  At 144 hours out, there seem to be significant improvement in the lead up to 2010, then what looks like better verification between around 2015 and 2018 but perhaps a slight drop back with more variation since.

Out to 168 and note the scale is different, similar kind of pattern with biggest improvements to 2010/11, ECM especially performing well in the years leading up to 2020 but then a bit more variation in the last couple of years.

192:

and 240:

So while there's certainly been improvements in verification (and admittedly this only looks at one particular forecast type), nothing perhaps as significant in the last decade as the years between say 2005 and 2010.  With the slight drop back in the last couple of years at the mid range, we're maybe still on a par with the period around 2012 if I've interpreted these correctly.

Interesting to compare with shorter range forecasting: e.g. ECM at 72 hours seems to show improvements in the last few years so perhaps this is where they are concentrating their efforts.

 

[RabbitEars]

Having read all the recent posts and seen the charts (not that I understand a great deal) on the MAD thread, would it not be nice to just have some colder temperatures... maybe some weak late autumn / early winter sunshine, crisp frost mornings... Do we have to have a big freeze.... I think it will cool down - so a drop from a high today of 11C to something more seasonal would be nice. Some of the “boom” charts could create shocking cold weather warnings, with severe impacts on society... do we really want to be digging our cars and vulnerable neighbours out of snow and ice just for the kicks of getting our lust for snow satisfied? 

[Puddy Galore]

7 hours ago, RabbitEars said:

Having read all the recent posts and seen the charts (not that I understand a great deal) on the MAD thread, would it not be nice to just have some colder temperatures... maybe some weak late autumn / early winter sunshine, crisp frost mornings... Do we have to have a big freeze.... I think it will cool down - so a drop from a high today of 11C to something more seasonal would be nice. Some of the “boom” charts could create shocking cold weather warnings, with severe impacts on society... do we really want to be digging our cars and vulnerable neighbours out of snow and ice just for the kicks of getting our lust for snow satisfied? 

Yes, I can understand that point of view.  However, the same can be said in the summer months to be fair when some are constantly looking for the high 30’s all the while with wall to wall unbroken sunshine.  For me, I so wish we could have the seasons back as they used to be.  It seems to me the seasons have shifted. We have seen winter arrive when spring traditionally kicks in and summer hangs on now well into October and November!   Like other members back in the 60’s I well remember both Halloween and Bonfire night being cool possibly cold affairs with one needing a coat, mittens and scarves - not so these days.  As well as sound proofing ear muffs it seems all one needs these days is light clothing the weather is often so warm through October and into November.

Edited November 16, 2021 by Snowycat

[Sparky68]

1st proper frost on the car this morning , nice to see.

[Snowyowl9]

 ‘Blizzard from east’ could disrupt Christmas, warns Boris Johnson (msn.com)

What strange language they are using...

https://www.msn.com/en-gb/news/uknews/covid-blizzard-from-east-could-disrupt-christmas-warns-boris-johnson/ar-AAQIZ8T?ocid=msedgntp

 

[Buzz]

1 hour ago, Snowyowl9 said:

 ‘Blizzard from east’ could disrupt Christmas, warns Boris Johnson (msn.com)

What strange language they are using...

https://www.msn.com/en-gb/news/uknews/covid-blizzard-from-east-could-disrupt-christmas-warns-boris-johnson/ar-AAQIZ8T?ocid=msedgntp

 

This isn't about snow though, it's just Boris burning more bridges with the EU.

[Snowyowl9]

6 hours ago, Buzz said:

This isn't about snow though, it's just Boris burning more bridges with the EU.

It sounded good maybe not haha...

Edited November 16, 2021 by Snowyowl9