Winter 2022-23 early thoughts - general chat

[SqueakheartLW]

1 hour ago, Don said:

Keeping a close eye on September currently!

We want to keep that September CET below 16C if possible and preferably below 15C as we know 16C+ Septembers very much have mild winters following them as well as many of the 15C Septembers too.

[Don]

55 minutes ago, SqueakheartLW said:

We want to keep that September CET below 16C if possible and preferably below 15C as we know 16C+ Septembers very much have mild winters following them as well as many of the 15C Septembers too.

I think anything 15C or above will be bad news for the coming winter.

[SqueakheartLW]

27 minutes ago, Don said:

I think anything 15C or above will be bad news for the coming winter.

Not the best of starts based on this

[Sunny76]

Hmm September 1981 was quite wet and unsettled, and look what happened that year.

Warm Septembers can lead to cold winters also though, such as 2009 and 2010.

[virtualsphere]

Well according to Roger's stats on the CET thread Sept 1906 started higher than this year and finished at 13.9, so anything is possible...

[Don]

4 minutes ago, Sunny76 said:

Hmm September 1981 was quite wet and unsettled, and look what happened that year.

Warm Septembers can lead to cold winters also though, such as 2009 and 2010.

Those Septembers were not especially warm though.  1981 had a CET of 14.4C and 2009 14.3C.  Also, September 2010 had a CET of just 13.8C, which was close to average.  As I said above, it's seems to be very warm Septembers (15C or above) which do not bode well for colder winters.  

1 minute ago, virtualsphere said:

Well according to Roger's stats on the CET thread Sept 1906 started higher than this year and finished at 13.9, so anything is possible...

Yes indeed!

Edited September 8, 2022 by Don

[Northern Sky]

Just now, virtualsphere said:

Well according to Roger's stats on the CET thread Sept 1906 started higher than this year and finished at 13.9, so anything is possible...

What was possible in 1903 might be rather less possible today. Looking at the models any notable cool down seems unlikely at the moment.

[Don]

11 minutes ago, SqueakheartLW said:

Not the best of starts based on this

No, but there is time for a significant drop later in the month.  September 2020 was warm for the first half, but a cold final third brought the overall CET down to 13.9C

Edited September 8, 2022 by Don

[damianslaw]

2 minutes ago, Don said:

Those Septembers were not especially warm though.  1981 had a CET of 14.4C and 2009 14.3C.  Also, September 2010 had a CET of just 13.8C, which was close to average.  As I said above, it's seems to be very warm Septembers (15C or above) which do not bode well for colder winters.  

Yes indeed!

More a warm dry combo than warm wet combo. Wet in Sept normally associated with atlantic which unless SW sourced is not a warm source in Sept, wet cyclonic warm synoptics as we are seeing this month is interesting.. warm Septembers usually due to anticyclones and continental air which is still warm.. 

[Don]

6 minutes ago, damianslaw said:

More a warm dry combo than warm wet combo. Wet in Sept normally associated with atlantic which unless SW sourced is not a warm source in Sept, wet cyclonic warm synoptics as we are seeing this month is interesting.. warm Septembers usually due to anticyclones and continental air which is still warm.. 

Given how warm September has started, it has certainly been wetter than you would think, so is more unusual in that sense.  However, I would still not want a very warm and wet September!

[Sunny76]

17 minutes ago, Don said:

Those Septembers were not especially warm though.  1981 had a CET of 14.4C and 2009 14.3C.  Also, September 2010 had a CET of just 13.8C, which was close to average.  As I said above, it's seems to be very warm Septembers (15C or above) which do not bode well for colder winters.  

Yes indeed!

I think there’s more at play than just a warm September. A mild and cloudy October tends to be the thing that sets up a mild winter. If there’s a late leaf fall, that’s usually a sign of a very mild winter.

1987 was a late autumn, and so was 2006, to name a few. Both of these winters were snowless. 

Edited September 8, 2022 by Sunny76

[Weather Enthusiast91]

I personally don't believe in the theory that warm Septembers lead to mild winters. Winter is 3 months away and many things can happen in that time.

Yes, there have been many warm Septembers followed by mild winters but I believe that's purely coincidental. 

Edited September 8, 2022 by Weather Enthusiast91

[damianslaw]

6 minutes ago, Weather Enthusiast91 said:

I personally don't believe in the theory that warm Septembers lead to mild winters. Winter is 3 months away and many things can happen in that time.

Yes, there have been many warm Septembers followed by mild winters but I believe that's purely coincidental. 

Given the very warm.SSTs courtesy of the very warm Summer, along with a very slowly cooling continent perhaps no surprise September will turn out warm. 

[Don]

5 minutes ago, damianslaw said:

Given the very warm.SSTs courtesy of the very warm Summer, along with a very slowly cooling continent perhaps no surprise September will turn out warm. 

Yes, plenty of residual heat that's for sure!  However, September 1995 was not warm and that followed a very hot summer?  I suspect warm SST's are having more of an effect this year as well as the warm continent?

Edited September 8, 2022 by Don

[damianslaw]

6 minutes ago, Don said:

Yes, plenty of residual heat that's for sure!  However, September 1995 was not warm and that followed a very hot summer?  I suspect warm SST's are having more of an effect this year as well as the warm continent?

The warmth this month simply courtesy of the synoptics, an airstream from between sw and se.. lots of cloud as well, such synoptics first week of Sept will always be warm, on the back of a very warm summer even more so.. i'd be more surprised if the airstream was more westerly. As said need to look at the synoptics.. anticyclonic warm in Sept seems the killer, think 2006 and 2016.

Edited September 8, 2022 by damianslaw

[Catacol]

17 hours ago, SqueakheartLW said:

Not the best of starts based on this

I think this tells us all we need to know about winters in the UK beyond the climate tipping point. For an island positioned where we are, CET monthly averages at +1 to +4 spell disaster for ice and snow. And importantly we are progressively losing our supply of cold even when the wind swings around to north or east. The continent is warming, the arctic is melting and the seas are warming meaning more modification.

I am past the point where I think we can have a spell of sustained really cold weather from "conventional" means. Now we need either an extreme event or an SSW.

This gloomy post therefore ends on an upbeat note. I do think that SSWs are on the up both in terms of frequency and severity. And this in turn means that the extreme event brought about by an extraordinary movement of airmasses is more likely now than in the past.

So....where once we got a cold winter in every 5 (very approximately) I think these odds have lengthened. However, the opportunity for extreme atmospheric stress to drop an arctic airmass over us remains and another 2018 style event won't be too far away. In conclusion the likelihood is that this winter is unremarkable. Early season Nina ridging may serve to make December close to long term averages but not cold enough for widespread snow. Hope though will lie in tropospheric patterns enabling an SSW and in turn throwing proper cold out of the arctic to lower latitudes. This is pretty much the only thing keeping me on the snow hunt....because the rest of the climate context - demonstrated so clearly by that CET snapshot above - is grim beyond reckoning.

 

[MP-R]

17 hours ago, damianslaw said:

The warmth this month simply courtesy of the synoptics, an airstream from between sw and se.. lots of cloud as well, such synoptics first week of Sept will always be warm, on the back of a very warm summer even more so.. i'd be more surprised if the airstream was more westerly. As said need to look at the synoptics.. anticyclonic warm in Sept seems the killer, think 2006 and 2016.

Neither of those were particularly anticyclonic though... both just brought winds predominantly from a warm direction, as you say between SW and SE, not dissimilar from this September. Just have a look through the archives.

WWW.METEOCIEL.FR

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Archives NOAA NCEP de 1836 à maintenant

WWW.METEOCIEL.FR

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Archives NOAA NCEP de 1836 à maintenant

 

[Chesil View]

2 hours ago, Catacol said:

I think this tells us all we need to know about winters in the UK beyond the climate tipping point. For an island positioned where we are, CET monthly averages at +1 to +4 spell disaster for ice and snow. And importantly we are progressively losing our supply of cold even when the wind swings around to north or east. The continent is warming, the arctic is melting and the seas are warming meaning more modification.

I am past the point where I think we can have a spell of sustained really cold weather from "conventional" means. Now we need either an extreme event or an SSW.

This gloomy post therefore ends on an upbeat note. I do think that SSWs are on the up both in terms of frequency and severity. And this in turn means that the extreme event brought about by an extraordinary movement of airmasses is more likely now than in the past.

So....where once we got a cold winter in every 5 (very approximately) I think these odds have lengthened. However, the opportunity for extreme atmospheric stress to drop an arctic airmass over us remains and another 2018 style event won't be too far away. In conclusion the likelihood is that this winter is unremarkable. Early season Nina ridging may serve to make December close to long term averages but not cold enough for widespread snow. Hope though will lie in tropospheric patterns enabling an SSW and in turn throwing proper cold out of the arctic to lower latitudes. This is pretty much the only thing keeping me on the snow hunt....because the rest of the climate context - demonstrated so clearly by that CET snapshot above - is grim beyond reckoning.

 

I,m tending towards the same outlook as you Catacol.  It does seem that sustained or severe cold now only arrives via ssw's, the upshot of your prognosis that these may become more common ties in with my belief that climate change will see more extremes at both ends of the temperature scale  , obviously far more warm ones than cold ones but nevertheless the cold ones could still be very notable.

 

[Don]

50 minutes ago, Chesil View said:

I,m tending towards the same outlook as you Catacol.  It does seem that sustained or severe cold now only arrives via ssw's, the upshot of your prognosis that these may become more common ties in with my belief that climate change will see more extremes at both ends of the temperature scale  , obviously far more warm ones than cold ones but nevertheless the cold ones could still be very notable.

 

Not sure of the chances for a SSW this coming winter as we will be in a mature W-QBO combined with a likely weak to moderate La Nina?

[damianslaw]

1 hour ago, Chesil View said:

I,m tending towards the same outlook as you Catacol.  It does seem that sustained or severe cold now only arrives via ssw's, the upshot of your prognosis that these may become more common ties in with my belief that climate change will see more extremes at both ends of the temperature scale  , obviously far more warm ones than cold ones but nevertheless the cold ones could still be very notable.

 

Last time we endured a sustained cold spell upwards 2 weeks not courtesy of a SSW was late Nov - Dec 2010. Factors that contributed would be very welcomed. I think that spell comes under the umbrella off a one off extreme event. Mid Dec to mid Jan 10 probably last time we had a cold period that perhaps can't call a one off, that was attributed to the El Nino modoki I think. I am not calling off the chances of very cold weather other than from a SSW ever again, but agree the likelihood of notable cold other than from a SSW appears to be much slimmer in these warming times. 

[Bradley in Kent]

Can't see an SSW happening either. What we could do with is a very mild winter, but with a 1 week BTFE somewhere in the middle. Less strain on heating overall but a snow fix for the coldies!

[Bradley in Kent]

...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.

[damianslaw]

2 minutes 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.

This statement could have been made in the late 90s, we had a 11 year run from 97-98 to 07-08 when only short term cold spells and nothing severe happened. Up popped 08-09 the precursor to 09-10. Mind we are now at the 10 year point of a similiar run.. wouldn't be surprised for a rogue notable cold one to pop out of the bag again. Perhaps more wishful thinking..

[Don]

56 minutes ago, Bradley in Kent said:

Can't see an SSW happening either. What we could do with is a very mild winter, but with a 1 week BTFE somewhere in the middle. Less strain on heating overall but a snow fix for the coldies!

Unlikely to get a BFTE during a very mild winter with brief cold snaps more likely.  However, they can crop up during winters that are otherwise unremarkable like in January 1987 and February/March 2018.

[SqueakheartLW]

3 hours ago, Don said:

Not sure of the chances for a SSW this coming winter as we will be in a mature W-QBO combined with a likely weak to moderate La Nina?

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