Early run up to Winter 2020/2021 discussion

[Kirkcaldy Weather]

3 hours ago, LRD said:

I agree - mid-December to mid-Feb for cold please. Dec 2010 was a 1 in 100 year event (probably even worse odds than that as we're warming up) and we won't see that again.

 

Not aiming this as an argument however, I have said a few times before but yes we all know about the warming side of climate change however it continues to amaze me just how many on here seem to either ignore or simply miss the cold side of the story too, we seen it last year with record breaking cold and snowfall events around the world as I highlighted in my snow and ice twitter thread and already if you look at this years there have been record snowfalls in Minneapolis and a few other areas, these vary on the amount of years the record has stood for obviously but usually u are talking about a 50-100 year old record which is equivalent of a 1 in 50/100 year event so I’m not sure we can say with certainty that a December 2010 will never happen again

[LRD]

2 minutes ago, Kirkcaldy Weather said:

Not aiming this as an argument however, I have said a few times before but yes we all know about the warming side of climate change however it continues to amaze me just how many on here seem to either ignore or simply miss the cold side of the story too, we seen it last year with record breaking cold and snowfall events around the world as I highlighted in my snow and ice twitter thread and already if you look at this years there have been record snowfalls in Minneapolis and a few other areas, these vary on the amount of years the record has stood for obviously but usually u are talking about a 50-100 year old record which is equivalent of a 1 in 50/100 year event so I’m not sure we can say with certainty that a December 2010 will never happen again

There will still be some cold somewhere on the planet but most of the records broken are of the warm variety, especially in Europe. It's in Europe where winters have been really impacted by global warming

Bearing in mind Dec 2010 was, in itself, a 1-in-100 year event even without the warming trend, then by definition, it's unlikely we'll see it in our lifetimes again. I hope I'm wrong. I wish every December - or at least every other December - could be like that (although I could have done with a bit more snow in the north home counties) but it's just not going to happen. Even a cold, dry frosty and foggy (but not necessarily snowy) December seems to be an increasingly rare thing these days

[Mr Frost]

I see this thread is as positive as ever! 

Interesting thoughts from everyone - we still have another five weeks of Autumn to get through so no excitement/doom from me at this early stage.

Nothing to worry about until the end of November at least - model outlooks are pure cannon fodder at this range. 
Good for discussion though of course.

I understand the frustration - last Winter was pathetic from a cold/snow point of view!

Cant be any worse this Winter...can it!? 

Just relax and enjoy the snowy scenes from the home of Santa Claus - Rovaniemi (Lapland) Finland. 

All together now...jingle bells...jingle bells...

Have a good weekend everyone - all the best to you all!

Edited October 23, 2020 by Mr Frost

[bluearmy]

17 hours ago, Paul_1978 said:

Why’s that then?

+ NAO

above average temps

euro heights high anomoly

[Don]

3 minutes ago, bluearmy said:

+ NAO

above average temps

euro heights high anomoly

What’s new as winter draws near?!

[northwestsnow]

7 hours ago, booferking said:

Full of joy i see the day again.

I thought exactly the same thing!!

[sebastiaan1973]

Latest update by weer.nl in corporation with WCS.

DTN and WCS, with which we work together in drawing up these types of forecasts, also foresee a switch to colder weather in the course of the first half of November. With the blockade on the Ocean now also drawn by the European model. Whether that cold trend continues in December and January depends to a large extent on the development of La Niña, the experts argue there. When La Niña becomes strong, with the greatest deviations in the central Pacific Ocean, a return to a westerly circulation situation is likely, as was the case last winter. The chance of such a scenario is estimated to be approximately 25 percent.

If La Niña continues to focus on the east Pacific Ocean and does not become more than medium strength, the Arctic vortex appears to weaken over December, making westerly circulation less likely. Especially when the influence of the start of the new sunspot cycle comes into play. It is then more likely that the colder regime will continue in December and January. The chance of this scenario is estimated at 20 percent.

Early winter forecast still stands
We still prefer the scenario as outlined in the early version of our winter forecast. A build-up to a pressure distribution that leads to colder weather in the course of November with a chance of early winter weather towards the end of the month and in December. From January then probably the transition to a western circulation that lasts for the rest of the winter. So a bit of both extremes.

The above text by Talpa Weer R vd Born.

https://www.weer.nl/nieuws/2020/30-daagse-geleidelijk-kouder-en-daarna-ook-koud

[blizzard81]

12 hours ago, LRD said:

I agree - mid-December to mid-Feb for cold please. Dec 2010 was a 1 in 100 year event (probably even worse odds than that as we're warming up) and we won't see that again.

However, I presume from bluearmy's post he's suggesting that EC46 looks particulalry bad. Moan alert but I've just got a sinking feeling about this winter again. In fact my hopes are sinking south about as fast as a promising ridge of winter high pressure around Greenland and Iceland 

Well nobody could ever blame you for being a little pessimistic after all the let downs over the years. I always seem to have some optimism at this time of year but then come late February I just think......What a fool I am

[blizzard81]

I'm 'hoping' for something similar this coming Christmas. One can hope. We are seriously overdue a seasonal one. 

[I remember Atlantic 252]

7 minutes ago, blizzard81 said:

I'm 'hoping' for something similar this coming Christmas. One can hope. We are seriously overdue a seasonal one. 

best winters! and I thought 80's and 90's were good, another 'fantasy' winter chart, from 'the weather of Britain by Robin Stirling' book

 

[blizzard81]

24 minutes ago, I remember Atlantic 252 said:

best winters! and I thought 80's and 90's were good, another 'fantasy' winter chart, from 'the weather of Britain by Robin Stirling' book

 

Wow that's a cracker. I remember seeing the 1927 archive years ago but I had forgotten. Don't know how

[Don]

On 23/10/2020 at 22:21, blizzard81 said:

Wow that's a cracker. I remember seeing the 1927 archive years ago but I had forgotten. Don't know how

Rest of the winter was pants apparently.  However, the boxing day snow storm would have made that winter!

[Weather-history]

On 23/10/2020 at 21:55, I remember Atlantic 252 said:

best winters! and I thought 80's and 90's were good, another 'fantasy' winter chart, from 'the weather of Britain by Robin Stirling' book

 

That was a south and especially SE event. Started off rain but turned to snow. 

Your area got next to nothing from it. 

[SLEETY]

Started about 6pm in the London area Christmas Day 1927 from a weather book i was reading years ago.By midnight countless roads were blocked by snow  and a train become snowbound in Alton,Hampshire.Their was an 8ft high snowdrift a mile long in the Chilterns!

 

Repeat this year would be most welcome.

[SqueakheartLW]

My third CFS Christmas update here for you all to read today containing the next 10 days worth of analysis from the CFS 9 monthly runs from meteociel

My first and second updates came in with the following figures

Update 1

26/09/2020 to 05/10/2020 Data

Temps            0z          6z       12z          18z     TOTALS

V Mild                                                                    0

Mild                 2                        1              2          5

Average          4            6          5              3         18          AVERAGE TO COLDER THAN AVERAGE CHRISTMAS

Cold                 4           3          4              3         14          PREDICTED IN FIRST UPDATE

V Cold                           1                          2          3

LEADER        AV/CD    AV    AV/CD    AV/CD    AV

Precip            0z           6z         12z      18z      TOTALS

V Dry                                                                     0

Dry                  2             4          3           7           16

Average          4             2          4           2           12          DRIER THAN AVERAGE CHRISTMAS PREDICTED

Wet                 4             4          3           1           12          IN FIRST UPDATE

V Wet                                                                    0

LEADER     AV/WET     AV       AV       DRY       DRY

Update 2

06/10/2020 to 15/10/2020 Data

Temps           0z           6z         12z       18z     TOTALS

V Mild                                                                   0

Mild                1                                                    1           UPDATE 2

Average         7             7             6            3       23          AVERAGE TEMPERATURES PREDICTED FOR CHRISTMAS

Cold               1             3             2            5       11          COLDER THAN AVERAGE MOST LIKELY ALTERNATIVE

V Cold            1                            2            2        5

LEADER        AV          AV           AV         CD      AV

Precip           0z           6z           12z       18z     TOTALS

V Dry                                                                     0

Dry                 2             2              2           1         7           UPDATE 2

Average         6             4             7            6        23          AVERAGE PRECIPITATION EXPECTED FOR CHRISTMAS

Wet                2             3             1            3         9

V Wet                            1                                      1

LEADER        AV           AV          AV          AV      AV

LATEST UPDATE - UPDATE 3

Now it is time to reveal the latest 10 days of analysis from the 9 monthly CFS runs for Christmas 2020. The change from the previous update is shown in brackets next to the figures in the totals column.

16/10/2020 to 25/10/2020 Data

Temps          0z           6z           12z         18z         TOTALS

V Mild                                                                        0 (No Change)

Mild                                                              2           2 (+1)

Average        5             4              5              3          17 (-6)          AVERAGE TO COLDER THAN AVERAGE CHRISTMAS PREDICTED

Cold              5             3              5              4           17 (+6)

V Cold                          3                              1            4 (-1)

LEADER     AV/CD     COLD     AV/CD      COLD    AV/CD

Precip           0z           6z           12z          18z       TOTALS

V Dry                                                                         0 (No Change)

Dry                1             3              3               3         10 (+3)

Average        6             7              4               5         22 (-1)          AVERAGE PRECIPITATION PREDICTED FOR CHRISTMAS

Wet               3                             3                2         8 (-1)

V Wet                                                                        0 (-1)

LEADER       AV           AV           AV              AV       AV

Overall Temperatures for Christmas 2020 based on the last 10 days worth of CFS 9 monthly run data show a general shift back towards colder than average again compared with the second update and we are now more back in line with what the first update was showing. Good news in general if you want a colder than average Christmas in 2020. A perfect tie between average and colder than average this time around with 17 hits each. V Mild continues its drought with 0 hits yet again, good. Between Mild and V Cold it is V Cold that has generally won out with around twice as many hits as mild has been getting so far. The good news is that V Cold has generally performed better compared with Mild in more recent updates compared with the first and probably most unreliable of the updates with been furthest away from the day itself

Overall Precipitation for Christmas 2020 based on the last 10 days worth of CFS 9 monthly run data continues the average precipitation signal which has stuck but with drier than average the most likely alternative option if this one doesn't come off. Could be a chance of snow here but to get anything other than a slight dusting at best we would really want to keep the colder signal and shift more towards wetter than average.

My 4th CFS 9 monthly run Christmas update will be due in another 10 days time on the 04/11/2020. Lets see what may have changed by then.

[Sunny76]

I’m still predicting we won’t see any snow or real cold before Christmas 2020, bar the odd few chilly sunny or cold cloudy ones.

I think New Years Day 2021 until mid January will produce something very cold this time round. 

[Eagle Eye]

I believe it was in 2010- 2011season that the whole of britian basically froze now were ramping up a flake of snow oh how winters have changed 9 winter seasons later and now were getting excited of a bit of snow again. Mother nature has surprised us this year so far i see no reaason why we should be surprised if we have a season like 2010- 2011again. I imagine that if we keep looking at models we'll get ourself down becuase they won't be as cold as we were expecting. however these models aren't exact a 0.1% change could be the difference between snow and no snow. Good luck to everyone and thier winter hopes. 

[sebastiaan1973]

On 23/10/2020 at 17:39, bluearmy said:

+ NAO

above average temps

euro heights high anomoly

Therefore, based on the well establishing basin-wide La Nina development, it is intuitive to expect the added westerly inertia within the atmospheric circulation to be very rapidly scrubbed out once more, and the cue for angular momentum tendency to collapse once more. As a result ,there is anticipation of the upstream pattern showing signs of re-amplifying. The GWO manifests such an upstream deceleration of momentum by a fast orbit back to the La Nina transitional Phase 8 and likely resume a re-coupled atmospheric/ocean phase state  Phase 1/2/3

What does this mean in simple NWP related synoptic weather terms?

Numerical models quite likely to start advertising this decelerative upstream process more comprehensively through the first part of November. This manifesting as discontinuous retrogression of the downstream European ridge and attempts for the upper trough to edge eastwards towards Scandinavia, and return of that Atlantic ridging. However, the fulcrum of late autumn w/QBO influenced vortex development will determine how much amplification is possible within the Atlantic sector and it is quite likely that polar maritime incursions will alternate with warm sector low pressure and create a quite typical late autumn scenario.

Quote

 

Combining EC46 forecast for late november and Tamara's comments we can't expect much of the second half of november in terms of northern blocking.

Tamara interpretation for the Pacific is a basin wide event. So according to WCS this means a zonal winter.

[sebastiaan1973]

This study suggests a contribution to a positive NAO for winter 2021 from the stratosphere situation of 1 november 2020.

The North Atlantic Oscillation (NAO), the regional manifestation of the Arctic Oscillation (AO), dominates winter climate variability in Europe and North America. Skilful seasonal forecasting of the winter NAO/AO has been demonstrated recently by dynamical prediction systems. However, the role of initial conditions in this predictability remains unknown. Using a latest generation seasonal forecasting system and reanalysis data, we show that the initial upper stratospheric zonal wind anomaly contributes to winter NAO/AO predictability through downward propagation of initial conditions. An initial polar westerly/easterly anomaly in the upper stratosphere propagates down to the troposphere in early winter, favoring a poleward/equatorward shift of the tropospheric mid-latitude jet. This tropospheric anomaly persists well into the late winter and induces the positive/negative phase of NAO/AO in the troposphere. Our results imply that good representation of stratospheric initial condition and stratosphere-troposphere coupling in models is important for winter climate prediction.

Stratospheric initial conditions provide seasonal predictability of the North Atlantic and Arctic Oscillations - IOPscience

IOPSCIENCE.IOP.ORG

To represent the variation of initial stratospheric zonal wind anomalies, a stratospheric zonal wind index Ui is defined by averaging the zonal-mean zonal wind anomaly on 1 November over (60-90N 1-5 hPa) where the positive correlation with the predicted winter NAO/AO index is strongest.

[Bradley in Kent]

Good afternoon all on this very autumnal Sunday!

Some really useful and informative posts on here; can't really add anything more technical to be honest!

I'm rather hoping the Atlantic will get bored of throwing low pressures and Westerlies towards the start of winter. You can play now but your bedtime in end of November!  

The reason why last year was a frustrating winter was that the Atlantic was dominant in November but didn't really let up until March. I can deal with wet and mild spells so long as they are only 'spells' and not an entire season...

[swfc]

Seen quite a few musings over front loaded winter, new year will bring a change to winter. This may be true but if I said I think wel have a average - mild winter given the last few years it possibly would be a good punt? I'm hoping for anything better than last year either way which wouldn't be difficult. Crystal balls not available so I guess it's keep watching and keep hoping

[sebastiaan1973]

We have to check these profiles. Anyone ? 

[Penicuikblizzard]

3 hours ago, Sunny76 said:

I’m still predicting we won’t see any snow or real cold before Christmas 2020, bar the odd few chilly sunny or cold cloudy ones.

I think New Years Day 2021 until mid January will produce something very cold this time round. 

What is your prediction based on?

[Penicuikblizzard]

34 minutes ago, swfc said:

Seen quite a few musings over front loaded winter, new year will bring a change to winter. This may be true but if I said I think wel have a average - mild winter given the last few years it possibly would be a good punt? I'm hoping for anything better than last year either way which wouldn't be difficult. Crystal balls not available so I guess it's keep watching and keep hoping

Average winters are good too and can throw up the odd surprise snow event!!

The 2018 beast from the east arrived during a average winter 

[Sunny76]

4 hours ago, Penicuikblizzard said:

What is your prediction based on?

I have predicted this since the middle of the year. Just sticking my neck out, and have no concrete evidence to back my prediction up.

I just have a feeling this coming winter will be different to the last two years, and a much colder one than what we had in 2017/18, or at worst, something similar to that winter. But, with a more severe spell of snowy weather.