Winter 2022-23 early thoughts - general chat

[Sunny76]

3 hours ago, Bradley in Kent said:

...And yes, the disaster of the cold spell that never was last Christmas felt like the last ever opportunity for a trop led, longer term cold spell. 

Without wanting to go on too much about CC, we've left the days of chilly winters with different snow producing scenarios from November to April, and now enter territory of reaching 40c in summer, with 16c NYE and 20c in February. Yes, these are the highest end of our records, but here in Kent it's silly to expect or hope for a cool winter let alone cold, although as muted in my previous post, SSWs are still on the cards.  

In more ways than one, we've entered a new chapter.

Summer 2021 was an appalling summer, and 2022 was a hot sunny one.

Even in warming times, we could still get a cold winter and a poor summer with long periods of dull grey weather.

[Don]

14 minutes ago, SqueakheartLW said:

The last SSW was in 2020/2021 winter which had both a mature WQBO and a moderate La Nina too

I was actually trying to think whether winter 2020/21 had a SSW or not.  When did it occur?  I'm guessing it was partly responsible for the cold April and May?

10 minutes ago, Sunny76 said:

Summer 2021 was an appalling summer, and 2022 was a hot sunny one.

Even in warming times, we could still get a cold winter and a poor summer with long periods of dull grey weather.

A strange one summer 2021 as it was better the further north west you went, the complete opposite of normal!  It was a good summer for Scotland.

[Sunny76]

11 minutes ago, Don said:

I was actually trying to think whether winter 2020/21 had a SSW or not.  When did it occur?  I'm guessing it was partly responsible for the cold April and May?

A strange one summer 2021 as it was better the further north west you went, the complete opposite of normal!  It was a good summer for Scotland.

Yes further north it was ok, but in the southern part of the country it never felt like summer really got started, not to mention we were trying to shake off the cold damp weather from May and the very cold sunny April. 

[Don]

28 minutes ago, Sunny76 said:

Yes further north it was ok, but in the southern part of the country it never felt like summer really got started, not to mention we were trying to shake off the cold damp weather from May and the very cold sunny April. 

The 3rd week of July last year was the highlight of summer in the south, which was hot but nothing like the heat spike of July this year!

[Sunny76]

Just now, Don said:

The 3rd week of July last year was the highlight of summer in the south, which was hot but nothing like the heat spike of July this year!

Yes I remember that, but it was only hot for a week, and a 7-10 period in early June.

August was a gloom fest in 21.

Would take summer 2022 over 2021 anytime.

[Cheshire Freeze]

The good news is, like the EC seasonal, the CFS is trending more blocked

There is the hint of a Scandi trough running through all 3 winter months.

[Uncertainty]

2 hours ago, CreweCold said:

The good news is, like the EC seasonal, the CFS is trending more blocked

There is the hint of a Scandi trough running through all 3 winter months.

I see your CFS and I raise you a CMCC

If Glosea goes blocked tomorrow then I’m going all in!

@Don 5th of Jan 21 mate. It was a very drawn out affair that kept the winter blocked and kept things interesting but never really stepped into memorable winter mode.

 

[Don]

3 hours ago, Uncertainy said:

@Don 5th of Jan 21 mate. It was a very drawn out affair that kept the winter blocked and kept things interesting but never really stepped into memorable winter mode.

 

No, it looked like the February cold spell could have gone on to deliver something memorable but never quite made it.

3 hours ago, Uncertainy said:

I see your CFS and I raise you a CMCC

If Glosea goes blocked tomorrow then I’m going all in!

@Don 5th of Jan 21 mate. It was a very drawn out affair that kept the winter blocked and kept things interesting but never really stepped into memorable winter mode.

 

C'mon GLOSEA!!

[Kirkcaldy Weather]

10 hours ago, CreweCold said:

The good news is, like the EC seasonal, the CFS is trending more blocked

There is the hint of a Scandi trough running through all 3 winter months.

 

7 hours ago, Uncertainy said:

I see your CFS and I raise you a CMCC

If Glosea goes blocked tomorrow then I’m going all in!

 

 

 that's syncing in with my thoughts I mentioned previously, I was wondering if the warm Atlantic would lead to HIGH pressure as its done for a number of consecutive winters over in the Pacific with the high SST's there and those charts show that as a certain possibility

[Cheshire Freeze]

9 hours ago, Uncertainy said:

I see your CFS and I raise you a CMCC

If Glosea goes blocked tomorrow then I’m going all in!

@Don 5th of Jan 21 mate. It was a very drawn out affair that kept the winter blocked and kept things interesting but never really stepped into memorable winter mode.

 

Only concern being it looks a bit west based. However even if it is, we should find ourselves on the cold side from time to time.

Almost certainly the seasonal modelling is now responding to the anomalously warm N Atlantic.

Edited September 10, 2022 by CreweCold

[Don]

17 minutes ago, CreweCold said:

Only concern being it looks a bit west based. However even if it is, we should find ourselves on the cold side from time to time.

Almost certainly the seasonal modelling is now responding to the anomalously warm N Atlantic.

Lots of time for corrections, too.  Good to see models pointing towards a more blocked outlook now!

[SqueakheartLW]

11 hours ago, Uncertainy said:

I see your CFS and I raise you a CMCC

If Glosea goes blocked tomorrow then I’m going all in!

@Don 5th of Jan 21 mate. It was a very drawn out affair that kept the winter blocked and kept things interesting but never really stepped into memorable winter mode.

 

2 hours ago, Don said:

Lots of time for corrections, too.  Good to see models pointing towards a more blocked outlook now!

I can see things playing out 2 ways for possible cold from that pattern

Either

1. Big high in western Atlantic means troughing around the UK or just to the south of the UK putting us in a colder airmass from a northerly direction
2. Or the troughing sets up out to our W or SW, opening the door to a Scandi high to set up giving us shots of cold from the east instead

With the Atlantic basically walled off by that high pressure this means no raging jet to dislodge any Scandi high that sets up or any trough that sets up there doesn't see nuisance shortwaves coming in from the west as the jet won't be headed in the usual W to E direction near the UK.

Possible Tripole Status

Just have to look at these charts with coldies delight when you look at how the changes in SST's and SSTA's are shaping up. Getting warmer near Greenland and in the sub tropical Atlantic whilst cooling down in the mid latitude Atlantic, long may that trend continue.

[Don]

3 minutes ago, SqueakheartLW said:

Possible Tripole Status

Just have to look at these charts with coldies delight when you look at how the changes in SST's and SSTA's are shaping up. Getting warmer near Greenland and in the sub tropical Atlantic whilst cooling down in the mid latitude Atlantic, long may that trend continue.

Good to also see the cooling continue in the North Eastern Pacific, too!

[Mike Poole]

Good idea to open this thread, we can have more of a discussion here than just commenting on the seasonal models in the MOD.

I think it is potentially a very interesting winter season upcoming.  

I take a Bayesian approach to things connected with uncertainty, and with that in mind it is worth considering what the prior distribution for winter possibilities is for the UK in this warming world, before considering the specifics of this year, and how that might modify it.  Like others, I take evidence from the last 10 years or so to reluctantly conclude a SSW is pretty much a requirement now for a memorable cold spell for the UK with one proviso.  The proviso is specific synoptics that might arise to cause a front loaded winter - I think December 2009 and December 2010 are still recent enough to be relevant possibilities.  For cold once the PV is established in the later part of the season, I think we are now reliant on a SSW - and when this goes well, a narrative evolution over weeks can be told either side of the SSW date that ends with a UK cold spell.  But it doesn’t always go well, even if we get a SSW, there is only about a 2/3 chance of it causing cold in the UK, and even then it may occur too late.  

Now to this year.  Since the SSW in early 2021, we have experienced very little weather dominated by the Atlantic, so that last winter I was giving more likelihood than usual to some kind of early season cold - but it didn’t happen (and there was no SSW either, or even a hint of one being likely if I remember).  I think the same argument for some kind of December cold snap might be made this year, as there is no hint of a strong jet across the Atlantic into October now, and the seasonal models all seem to be showing a blocked pattern right into winter.  

I would like to see more evidence from the seasonal models as we approach the winter that the blocking predicted is in the right places, a worry is we might end up with some periods of mid latitude blocking that doesn’t really deliver cold to the UK.  I think a raging Atlantic dominated winter is unlikely given the seasonal models, so one hopes we have a weak strat vortex - we need to see the precursors to this develop over the next few months.  We have a west QBO, that is a negative.  We have a negative IOD, that is a positive .  We are likely in a strengthening La Niña, which gives the context for other indicators.  And we have that anomalous hot patch in the north Atlantic, noted on SST anomaly plot:

This looks quite unusual to me, might aid a ridge in the Atlantic, other things being equal.  I would like to increasingly see low heights into Southern Europe on the seasonal model output.  

I am not of the view that years with warm weather in September gives a mild winter, one might as well ponder whether years with a change of Prime Minister precede mild winters!  I also wonder if analogue years are very helpful given the changing climate, but I incline slightly to us being in a similar overall weather pattern to point to 1975/76.  

Well, pick the bones out of that - hopefully we’ll put some meat on them as we get closer.  

Edited September 10, 2022 by Mike Poole

[damianslaw]

25 minutes ago, Don said:

Good to also see the cooling continue in the North Eastern Pacific, too!

Perhaps another factor that forced the government to hand out monies to offset impending energy costs was looking at long range forecasts for winter ahead..

[Don]

8 minutes ago, damianslaw said:

Perhaps another factor that forced the government to hand out monies to offset impending energy costs was looking at long range forecasts for winter ahead..

Hmm, who knows?!  I believe the Metoffice warned the government about the chance of a very cold late autumn/early winter in 2010.  However, I suspect it's currently too early give a strong indication of what late autumn and winter may bring and might be a precaution at this stage?

Edited September 10, 2022 by Don

[Chesil View]

23 hours ago, Mike Poole said:

Good idea to open this thread, we can have more of a discussion here than just commenting on the seasonal models in the MOD.

I think it is potentially a very interesting winter season upcoming.  

I take a Bayesian approach to things connected with uncertainty, and with that in mind it is worth considering what the prior distribution for winter possibilities is for the UK in this warming world, before considering the specifics of this year, and how that might modify it.  Like others, I take evidence from the last 10 years or so to reluctantly conclude a SSW is pretty much a requirement now for a memorable cold spell for the UK with one proviso.  The proviso is specific synoptics that might arise to cause a front loaded winter - I think December 2009 and December 2010 are still recent enough to be relevant possibilities.  For cold once the PV is established in the later part of the season, I think we are now reliant on a SSW - and when this goes well, a narrative evolution over weeks can be told either side of the SSW date that ends with a UK cold spell.  But it doesn’t always go well, even if we get a SSW, there is only about a 2/3 chance of it causing cold in the UK, and even then it may occur too late.  

Now to this year.  Since the SSW in early 2021, we have experienced very little weather dominated by the Atlantic, so that last winter I was giving more likelihood than usual to some kind of early season cold - but it didn’t happen (and there was no SSW either, or even a hint of one being likely if I remember).  I think the same argument for some kind of December cold snap might be made this year, as there is no hint of a strong jet across the Atlantic into October now, and the seasonal models all seem to be showing a blocked pattern right into winter.  

I would like to see more evidence from the seasonal models as we approach the winter that the blocking predicted is in the right places, a worry is we might end up with some periods of mid latitude blocking that doesn’t really deliver cold to the UK.  I think a raging Atlantic dominated winter is unlikely given the seasonal models, so one hopes we have a weak strat vortex - we need to see the precursors to this develop over the next few months.  We have a west QBO, that is a negative.  We have a negative IOD, that is a positive .  We are likely in a strengthening La Niña, which gives the context for other indicators.  And we have that anomalous hot patch in the north Atlantic, noted on SST anomaly plot:

This looks quite unusual to me, might aid a ridge in the Atlantic, other things being equal.  I would like to increasingly see low heights into Southern Europe on the seasonal model output.  

I am not of the view that years with warm weather in September gives a mild winter, one might as well ponder whether years with a change of Prime Minister precede mild winters!  I also wonder if analogue years are very helpful given the changing climate, but I incline slightly to us being in a similar overall weather pattern to point to 1975/76.  

Well, pick the bones out of that - hopefully we’ll put some meat on them as we get closer.  

Great Post Mike.  I too would like to see the predicted high pressure anomalies looking stronger in the right places, To me at the moment they look stronger in the mid latitudes rather than classic northern blocking. That is of course assuming of course that they are anywhere near correct. 

[Cheshire Freeze]

GLOSEA September update summary- meh

There are some positives and some negatives-

We haven’t got the deep blues over Greenland there and we’ve got troughing over the UK…which doesn’t preclude some decent polar NWly incursions. 

[damianslaw]

3 minutes ago, CreweCold said:

GLOSEA September update summary- meh

There are some positives and some negatives-

We haven’t got the deep blues over Greenland there and we’ve got troughing over the UK…which doesn’t preclude some decent polar NWly incursions. 

Main feature no azores or euro high on the scene. 

[sundog]

4 minutes ago, CreweCold said:

GLOSEA September update summary- meh

There are some positives and some negatives-

We haven’t got the deep blues over Greenland there and we’ve got troughing over the UK…which doesn’t preclude some decent polar NWly incursions. 

Still got the poxy hp in the northern Pacific 

[damianslaw]

7 minutes ago, sundog said:

Still got the poxy hp in the northern Pacific 

Permanent feature in winter nowadays it seems. 

[SqueakheartLW]

13 minutes ago, CreweCold said:

GLOSEA September update summary- meh

There are some positives and some negatives-

We haven’t got the deep blues over Greenland there and we’ve got troughing over the UK…which doesn’t preclude some decent polar NWly incursions. 

Looking like cold rain with that chart

Will be good for ending the drought but when it's the wrong side of marginal and you get cold days with rain it's a waste of a winter really, cold enough to feel like winter but a wet and cold mess is worse than a mild and wet winter.

If it's cold it may as well snow rather than rain, far better than a cold washout

[SqueakheartLW]

12 minutes ago, sundog said:

Still got the poxy hp in the northern Pacific 

That is a La Nina feature but also aided by the warm N Pacific too, a feature since 2013/14 really. Someday it may swing back cold again

[sundog]

9 minutes ago, SqueakheartLW said:

Looking like cold rain with that chart

Will be good for ending the drought but when it's the wrong side of marginal and you get cold days with rain it's a waste of a winter really, cold enough to feel like winter but a wet and cold mess is worse than a mild and wet winter.

If it's cold it may as well snow rather than rain, far better than a cold washout

Indeed and if there is blocking to the east  as shown wouldn't want a winter of stalling low pressures cos they can't get further east. I think blocking to the east can be more of a hindrence then a help.

Edited September 11, 2022 by sundog

[damianslaw]

1 hour ago, sundog said:

Indeed and if there is blocking to the east  as shown wouldn't want a winter of stalling low pressures cos they can't get further east. I think blocking to the east can be more of a hindrence then a help.

Could produce battleground snowfall events, tug between cold SE airstream and milder SW airstream.. ideally for cold snow rathee than rain  you would want heights stronger near Iceland. The north though could sit on colder side of polar front jet.. cold zonality. All conjecture..