Winter 2023/24 - Discussions & Forecasts

[Cheshire Freeze]

4 hours ago, Mike Poole said:

Thanks for starting this thread, @Blessed Weather , there does already seem to be plenty to discuss regarding the coming winter, so good to have it all in one place.

I am looking forward to the coming winter with the usual trepidation, but this year with a tinge of anticipation as well.  I will try to explain why.

First, the state of play re some key drivers going into winter:

• ENSO - El Niño, but uncertain as to how strong, uncertain as to whether East Pacific (EP) or Central Pacific (CP) aka Modoki.  Perceived wisdom would suggest we don’t want it too strong, otherwise we can work with it.  CP preferred.
• QBO - easterly.  Nailed on.  This is a big one, and we’ve been short changed by it in recent years with a seeming tendency for easterly QBO’s to go awry.  This one hasn’t.  Big plus.
• Solar activity, close to maximum - probably slight minus.
• Indian Ocean Dipole (IOD) - likely positive, possible spoiler if gets so far positive it overrides everything else like 2019 - I’ll come back to this.
• Wild cards - more than you can shake a stick at. 

I’ll start with the wild cards.  The weather, globally, is currently all over the place.  For example, there’s the Tonga volcano having ejecting copious amounts of water vapour into the stratosphere.  There’s climate change, obviously, but this year is just off on one.  Take SSTs, I didn’t mention them in the list above because I don’t know what to make of them.  Look at this graph:

Not just record warm, but the whole evolution this year is a massive outlier compared to all previous years.  So we currently have this SST anomaly:

Cooler now SW of the UK after the June spike, much warmer near Canada, as far as the Atlantic is concerned.  I am not sure what kind of winter this pattern might equate to.  Where I’m going with this is that I don’t think the perceived wisdom about what translates to what applies this year, and pattern matching to previous years won’t help either.  All bets are off.  

Which is why I think watching the models as we approach winter this year will be paramount.  As I sometimes comment in the MOD, the seasonal models are not programmed with any knowledge of past patterns, they simply start with a best estimate of the current T0 conditions of the atmosphere and oceans, and simulate the laws of physics on from there, right out to 9 months in the case of the CFS.  (Caveat, some AI models are trained on the past, I believe).  So if we are working blind this near, the models may not be.  

Given the UK default is mild, mild and more mild (especially in recent years), the massive unknowns this year have to shift the probability dial in favour of UK cold chances.  Has to!  Because it just couldn’t really shift it in the other direction.  There is already evidence over summer of northern blocking, and stuck patterns.  No reason per se why this should carry on into winter, but at the moment the models are starting to suggest that it will.  

Worth noting that if we get zonal, UK=mild.  If we get blocked, UK=cold or mild, dependent on where blocking is placed.  So no guarantees if we get a blocked set up, there are guarantees if we don’t - it is mild.  

What’s appearing on the seasonal models is very promising, e.g. ECM seasonal pressure anomaly for January:

Similar to the CANSIPS model, and the previous July runs of most of the models looked blocked.  The August update of the rest is due in a week or so.  

We have tickets to the raffle this year, at the moment.

The main threat as I see it, that could take all those tickets away, is the IOD.  Current model estimates for the peak in October:

As I understand it, this would have to be 2019 standards to be the overriding factor (it was over +2.0 then).  You can see that the ECM is edging that way (not sure if this is the same run as the blocked January chart, it’s an obvious question to ask).  The other models are more moderate.  I will be watching this carefully, we don’t want another 2019.  El Niño also needs watching.

But, my overall take, is watch the models.  Something is off this year, will the positive signal for blocking on the models continue, or will it vanish into thin air, as we approach December?  I am prepared to expect the unexpected this year, and actually wonder if an early season SSW might be on the cards (to explain the current model output).

We will see…

All the best, Mike

 

Great post Mike, thanks.

I'm waiting with baited breath for the GLOSEA update in a few day's time. It will cover up to Nov-Jan so it'll be interesting as to what we take from the update. It'll be a big positive if it shows any sort of +ve anomaly in the N Atlantic/Greenland area.

[Cheshire Freeze]

Nice seasonal Christmas Day on the latest CFS daily run

[Weather Enthusiast91]

2 hours ago, CreweCold said:

Nice seasonal Christmas Day on the latest CFS daily run

Be nice if that comes to fruition. We have had no cold Christmas day here since 2010, so it's long overdue.

[SollyOlly]

I know that it never comes off, but I love these charts at this range. Gives one hopes and dreams...one day, surely, it will come true! 

[Cheshire Freeze]

Just a heads up, the latest CMCC update should be out tomorrow. This was the December chart of the July update-

[Uncertainty]

Bcc adding fuel to the -NAO fire. 
 

 

if Glosea and the CMCC are onboard when their output comes out, this will be the strongest signal I have seen since 2009 for a -NAO…

 

[Cheshire Freeze]

5 minutes ago, Uncertainty said:

Bcc adding fuel to the -NAO fire. 
 

 

if Glosea and the CMCC are onboard when their output comes out, this will be the strongest signal I have seen since 2009 for a -NAO…

 

Wow that is some signal.

There seems to be a key recurring theme- southerly displaced jet stream and Greenland heights

Edited August 9, 2023 by CreweCold

[Don]

When is Glosea due to update?

[Cheshire Freeze]

2 minutes ago, Don said:

When is Glosea due to update?

Friday I think

[Don]

Just now, CreweCold said:

Friday I think

Come on Glosea, you know you want to join the blocking party!! 

[Sun Chaser]

As long as we get a sunny mild springlike February and March, the rest of winter can do what it likes! I would like a cold snowy December or January but I won't be devastated by a mild winter. In fact I enjoy mild if its dry

[Sunny76]

Just now, plymsunshine said:

As long as we get a sunny mild springlike February and March, the rest of winter can do what it likes! I would like a cold snowy December or January but I won't be devastated by a mild winter. In fact I enjoy mild if its dry

I think a mild winter would be welcome this year.

Lots of days around 13-15c and sunshine. Would make up for the poor summer.

[Uncertainty]

15 hours ago, Don said:

Come on Glosea, you know you want to join the blocking party!! 

 

The seasonals have update and just look at the euro low anomaly for NDJ on Glosea Don! What a chart! You would absolutely be looking at an ssw with that Aleutian low / +SCAND setup too.

So we have Glosea, system 5 (ECMWF) and the bcc seasonal on board, 3 big hitters. But what about the rest?

The ECCC is, frankly, ridiculous. 2009 redux there.

The JMA, which incidentally was +NAO in its last update, joins the UKMO with a scandi high / SE euro low combo

Meteofrance has a stonking Greenland high 

Just a slight nitpick with the hint of Iberian heights, 2018/19 had that issue. Still, follows the blocking trend.

DWD joins the party

 

The cfs, typically, is different and has a broad U.K. trough. 

And all this despite all these models forecasting a strong, perhaps super El Niño that, at least initially, looks to be east based. Both of which are canonically +nao promoters.

 

 

[Cheshire Freeze]

8 minutes ago, Uncertainty said:

 

The seasonals have update and just look at the euro low anomaly for NDJ on Glosea Don! What a chart! You would absolutely be looking at an ssw with that Aleutian low / +SCAND setup too.

So we have Glosea, system 5 (ECMWF) and the bcc seasonal on board, 3 big hitters. But what about the rest?

The ECCC is, frankly, ridiculous. 2009 redux there.

The JMA, which incidentally was +NAO in its last update, joins the UKMO with a scandi high / SE euro low combo

Meteofrance has a stonking Greenland high 

Just a slight nitpick with the hint of Iberian heights, 2018/19 had that issue. Still, follows the blocking trend.

DWD joins the party

 

The cfs, typically, is different and has a broad U.K. trough. 

And all this despite all these models forecasting a strong, perhaps super El Niño that, at least initially, looks to be east based. Both of which are canonically +nao promoters.

 

 

That Euro trough is the main thing for me on GLOSEA. It’s half the battle won if we can see that manifest.

Musing a bit here, but I do wonder if it’s possible that we’re looking at an order of events such as this…wet, mild November. Early Canadian warming of the strat. Blocked, cold December. Relaxation of pattern into January but with a mid winter strat warming which leads to a cold February.

[Rain All Night]

How well did the seasonal models predict the cold setup of December 2022?

Edit: Just remembered that we have the tools for me to answer this question for myself...

The JMA model seems to be the one deserving of the prize here.

It looks overall like an Atlantic block was expected, rather than the Greenland one we got. We did later get an Atlantic block in the second half of January.

Edited August 10, 2023 by RainAllNight

[Cheshire Freeze]

1 hour ago, Uncertainty said:

 

The seasonals have update and just look at the euro low anomaly for NDJ on Glosea Don! What a chart! You would absolutely be looking at an ssw with that Aleutian low / +SCAND setup too.

So we have Glosea, system 5 (ECMWF) and the bcc seasonal on board, 3 big hitters. But what about the rest?

The ECCC is, frankly, ridiculous. 2009 redux there.

The JMA, which incidentally was +NAO in its last update, joins the UKMO with a scandi high / SE euro low combo

Meteofrance has a stonking Greenland high 

Just a slight nitpick with the hint of Iberian heights, 2018/19 had that issue. Still, follows the blocking trend.

DWD joins the party

 

The cfs, typically, is different and has a broad U.K. trough. 

And all this despite all these models forecasting a strong, perhaps super El Niño that, at least initially, looks to be east based. Both of which are canonically +nao promoters.

 

 

Actually I don’t think that GLOSEA is updated yet even though has a 1st of August time stamp. It’s identical to the Oct-Nov-Dec chart from last month and it hasn’t updated on the Metoffice site yet. 

[Dorsetbred]

1 hour ago, RainAllNight said:

How well did the seasonal models predict the cold setup of December 2022?

Edit: Just remembered that we have the tools for me to answer this question for myself...

The JMA model seems to be the one deserving of the prize here.

Crikey if we rely upon the JMA, it'll be a long mild winter!

[Mike Poole]

2 hours ago, CreweCold said:

Actually I don’t think that GLOSEA is updated yet even though has a 1st of August time stamp. It’s identical to the Oct-Nov-Dec chart from last month and it hasn’t updated on the Metoffice site yet. 

It’s updated now on Meteociel.  

December, surface pressure and heights anomalies:

January, surface pressure and heights anomalies:

Bank.  December pressure anomaly reminds me of a type of sausage we used to talk about on here, and January, well, looks bang on to me…

[Don]

7 hours ago, Sunny76 said:

I think a mild winter would be welcome this year.

Lots of days around 13-15c and sunshine. Would make up for the poor summer.

That's no excuse for a mild winter is it?!  That's like me saying a cool/wet summer would make up for a mild winter!  

I think you're a mild winter fan at heart, which is ok of course! 

Edited August 10, 2023 by Don

[Don]

18 minutes ago, Mike Poole said:

It’s updated now on Meteociel.  

December, surface pressure and heights anomalies:

January, surface pressure and heights anomalies:

Bank.  December pressure anomaly reminds me of a type of sausage we used to talk about on here, and January, well, looks bang on to me…

Great to see, just a pity it's so early with these long range models.  However, I would rather these blocked charts showing than Bartlett esque.  Just have to hope trends are maintained during the coming months!

[Bristawl Si]

Charts 4/5 months away...hmm locally, this Summer, we've had some dramatic forecast fails less than 24 hours away

[Weather Enthusiast91]

14 minutes ago, Don said:

That's no excuse for a mild winter is it?!  That's like me saying a cool/wet summer would make up for a mild winter!  

I think you're a mild winter fan at heart, which is ok of course! 

If anything, a good winter consisting of snow and many cold and sunny crisp days would be most welcome after the poor summer we've been having. I like weather to be seasonal.

Edited August 10, 2023 by Weather Enthusiast91

[Cheshire Freeze]

50 minutes ago, Mike Poole said:

It’s updated now on Meteociel.  

December, surface pressure and heights anomalies:

January, surface pressure and heights anomalies:

Bank.  December pressure anomaly reminds me of a type of sausage we used to talk about on here, and January, well, looks bang on to me…

Looks potentially cold that. All good there.

[Coldilocks]

7 hours ago, Sunny76 said:

I think a mild winter would be welcome this year.

Lots of days around 13-15c and sunshine. Would make up for the poor summer.

I don't like this whole "this season suffered so the next season should suffer too".

[SqueakheartLW]

4 hours ago, Uncertainty said:

 

The seasonals have update and just look at the euro low anomaly for NDJ on Glosea Don! What a chart! You would absolutely be looking at an ssw with that Aleutian low / +SCAND setup too.

So we have Glosea, system 5 (ECMWF) and the bcc seasonal on board, 3 big hitters. But what about the rest?

The ECCC is, frankly, ridiculous. 2009 redux there.

The JMA, which incidentally was +NAO in its last update, joins the UKMO with a scandi high / SE euro low combo

Meteofrance has a stonking Greenland high 

Just a slight nitpick with the hint of Iberian heights, 2018/19 had that issue. Still, follows the blocking trend.

DWD joins the party

 

The cfs, typically, is different and has a broad U.K. trough. 

And all this despite all these models forecasting a strong, perhaps super El Niño that, at least initially, looks to be east based. Both of which are canonically +nao promoters.

 

 

What a good early start to the winter discussion with those blocked looking charts.

One crucial thing I have noticed on all of them which is absent this time on long range model output which has been a default certain addition before now is .....

 

 

NO NE PACIFIC RIDGE

 

 

Maybe puts us more in the game this time with the NE Pacific trough this time around.