BJBlake
  • BJBlake
  • Advanced Member Topic Starter
05 August 2023 00:12:12
Here we are, already past midsummer’s peak, with some unusually autumnal weather for early August, the jet stream seemingly locked into a winter latitude, and delivering weather to match, while other parts of our N hemisphere burn in record heat. The seas are simmering, and the El Niño builds - all beginning to tap the shoulder and nudge the dawning question - just what will all this do to our winter weather here in little old Blighty? My thoughts are that we may see the first effects of a weakened North Atlantic Drift, and of El Niño, which just might create a puzzlingly cold winter here, against the back cloth of global averages reaching record highs. But I am far more interested in hearing all of your thoughts on the matter. So please tell and any evidence would be most welcome.
Brecklands, South Norfolk 28m ASL
CreweCold
05 August 2023 00:34:46
Originally Posted by: BJBlake 

Here we are, already past midsummer’s peak, with some unusually autumnal weather for early August, the jet stream seemingly locked into a winter latitude, and delivering weather to match, while other parts of our N hemisphere burn in record heat. The seas are simmering, and the El Niño builds - all beginning to tap the shoulder and nudge the dawning question - just what will all this do to our winter weather here in little old Blighty? My thoughts are that we may see the first effects of a weakened North Atlantic Drift, and of El Niño, which just might create a puzzlingly cold winter here, against the back cloth of global averages reaching record highs. But I am far more interested in hearing all of your thoughts on the matter. So please tell and any evidence would be most welcome.


I actually agree with you and have been thinking the same thing. I actually think winter may shock a few and be of the cold and snowy variety.

Crewe, Cheshire
55 metres above sea level
johncs2016
05 August 2023 01:17:32
The last two summers here before this one were decent, and we even had a decent start to this one. Had this summer been decent overall as well, I would have been very concerned about the coming winter because when we are in a run of decent summers, I would expect the corresponding winters to be mild.

However, this summer is shaping up to be a front-loaded summer, but a poor summer overall. Poor summers tend to be more likely to be followed by cold winters, so I agree that this could act in our favour. There are a number of factors to consider though.

Firstly, there is El Nino. If that becomes too strong as it did in 2015, there is a danger that this could in a 2015-16 style very wet, mild and stormy winter. Also, I believe that if El Nino is mostly east based and focused right next to the Peruvian coast, that could also against us getting a cold winter. However, a Modoki or central or western based El Nino could improve our chances of getting a cold winter.

Then there is the solar activity. At the moment, our position within solar cycle 25 is analogous to where we were in solar cycle 24 back in 2015. We are probably only around 2 years away from solar maximum and regardless of how the rest of solar cycle 25 pans out, we already know that this will at the very least, be a slightly stronger solar cycle than what solar cycle 24.

Although this solar cycle is not expected to be as strong as solar cycle 23, this goes very much against us getting a cold winter on this occasion.

In addition to that, there are a lot of warm SSTs around. The SSTs in the NE Pacific Ocean appears to be very warm just now and when that happens, that never bodes very well for a cold winter here. However, we have an Easterly QBO developing at the moment, and that usually favours a colder winter here.

A lot might well depend on what the models are saying but at the moment, it is really too early to say how this will actually affect things. If was forced to make an early forecast on that, I would go for a fairly average winter in terms of the temperature, but a rather wet winter with possibly, a higher than average amount of snow.
The north of Edinburgh, usually always missing out on snow events which occur not just within the rest of Scotland or the UK, but also within the rest of Edinburgh.
Jiries
05 August 2023 06:09:55
Winter in the UK is the worst place to endure than the rest of N Hemisphere winter climates in other places.  Can't see this winter being cold as all the coldness had been striking hard this summer which seem much colder than 1988 and 2012 as they had few hot days,  Temperatures might likely to be similar by winter with 10's to mid-teens with few days below 10C during a frosty spell.   Main hoping that no SSW to strike in March 2024 which led to no Spring so hope not a repeat next year with normal warm spring days and normal frequent warm to hot summer days.

Heating costs is a priority to think of so best to get mild winter if there no snow on offering.  
speckledjim
05 August 2023 08:14:37
Last El Nino was 2018/19 and the winter of 18/19 was milder than average so that's my guess for this year
Thorner, West Yorkshire


Journalism is organised gossip
Bertwhistle
05 August 2023 09:56:31
Originally Posted by: BJBlake 

Here we are, already past midsummer’s peak, with some unusually autumnal weather for early August, the jet stream seemingly locked into a winter latitude, and delivering weather to match, while other parts of our N hemisphere burn in record heat. The seas are simmering, and the El Niño builds - all beginning to tap the shoulder and nudge the dawning question - just what will all this do to our winter weather here in little old Blighty? My thoughts are that we may see the first effects of a weakened North Atlantic Drift, and of El Niño, which just might create a puzzlingly cold winter here, against the back cloth of global averages reaching record highs. But I am far more interested in hearing all of your thoughts on the matter. So please tell and any evidence would be most welcome.



The NAD has long been understood to keep the NW of Europe milder in winter than it might otherwise be. Decreasing salinity due to Arctic ice melt is expected to disrupt the Drift, upsetting the downwelling end of the cycle by replacing the denser saltier water with fresh. The disaster was excellently explored in Kim Stanley Robinson's 50 below zero. What I haven't been able to locate is a site that updates with live or even continuous data about the state of the current. Any ideas?
Bertie, Itchen Valley.
'We'll never see 40 celsius in this country'.
doctormog
05 August 2023 10:10:30
Originally Posted by: Bertwhistle 

The NAD has long been understood to keep the NW of Europe milder in winter than it might otherwise be. Decreasing salinity due to Arctic ice melt is expected to disrupt the Drift, upsetting the downwelling end of the cycle by replacing the denser saltier water with fresh. The disaster was excellently explored in Kim Stanley Robinson's 50 below zero. What I haven't been able to locate is a site that updates with live or even continuous data about the state of the current. Any ideas?



The Met Office have some data connected to this area but I’m not sure if it will answer too many questions related to our upcoming winter season to be honest!

https://climate.metoffice.cloud/amoc.html#datasets  
Bertwhistle
05 August 2023 10:30:06
Thanks Doc. Interesting articles about AMOC26 and some links to higher latitude observations. I will have a go at the ones I can understand!
Bertie, Itchen Valley.
'We'll never see 40 celsius in this country'.
Spring Sun Winter Dread
05 August 2023 11:58:57
A single cold winter will not be evidence of a "weakened North Atlantic drift" as that would be a long term trend and not something you can conclude off one winter , especially when the long term trend since the late 1980s (with the exception of some winters in 1994-97 and 2008-13 periods) has been for milder and wetter winters with significant Atlantic/westerly component .
Nonetheless if we do get cold and snow for one winter (which if it happens would almost certainly be due to easterly/northerly  dominance) this purely speculative model will no doubt be trotted out in the Guardian, BBC and all the other media unscientifically despite being completely unrelated... In fact a change in the salinity of the water leading to weakened NAD is something that would take decades to change our winter climate and not happen overnight.. and surely evidence of it would be for a westerly winter to be cold and snowy nonetheless, and not a cold/easterly winter like 2009-10 which was cold precisely because the maritime Atlantic influence was absent, not because it was full of freshwater. 

For the record I would say mild and wet is the form horse for the winter ahead 
DEW
  • DEW
  • Advanced Member
05 August 2023 12:05:22
CFS charts (which were totally wrong last winter, but at least they tried)  suggest that England (but not Scotland) will have a cold December along with most of continental Europe, and that the same area will be incredibly mild in February. Otherwise nothing special, for persistent cold weather the favoured spot is the Pacific off W Canada.

https://www.theweatheroutlook.com/twodata/datmdlout.aspx 
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
doctormog
05 August 2023 12:12:46
Originally Posted by: DEW 

CFS charts (which were totally wrong last winter, but at least they tried)  suggest that England (but not Scotland) will have a cold December along with most of continental Europe, and that the same area will be incredibly mild in February. Otherwise nothing special, for persistent cold weather the favoured spot is the Pacific off W Canada.

https://www.theweatheroutlook.com/twodata/datmdlout.aspx 



Really? That’s not what it looks like to me. https://www.theweatheroutlook.com/twodata/chart.aspx?chart=/cfs/12_2023_00z_500.png 

 
Bertwhistle
05 August 2023 12:52:51
Originally Posted by: Spring Sun Winter Dread 

A single cold winter will not be evidence of a "weakened North Atlantic drift" as that would be a long term trend and not something you can conclude off one winter , especially when the long term trend since the late 1980s (with the exception of some winters in 1994-97 and 2008-13 periods) has been for milder and wetter winters with significant Atlantic/westerly component .
Nonetheless if we do get cold and snow for one winter (which if it happens would almost certainly be due to easterly/northerly  dominance) this purely speculative model will no doubt be trotted out in the Guardian, BBC and all the other media unscientifically despite being completely unrelated... In fact a change in the salinity of the water leading to weakened NAD is something that would take decades to change our winter climate and not happen overnight.. and surely evidence of it would be for a westerly winter to be cold and snowy nonetheless, and not a cold/easterly winter like 2009-10 which was cold precisely because the maritime Atlantic influence was absent, not because it was full of freshwater. 

For the record I would say mild and wet is the form horse for the winter ahead 



Thanks, agree with some points here. However, the thinking about the temperature changes as a result of a weakened circulation includes a change in predominant synoptic setups as a result of cyclogenesis and jet patterns changing. One suggestion has been that containment of the PV might be affected, so not so much an instant cooling regardless of the wind direction, but a change in prevalence of the dominant wind direction. With warming oceans, westerly winters are still (possibly more) likely to be mild.
Bertie, Itchen Valley.
'We'll never see 40 celsius in this country'.
DEW
  • DEW
  • Advanced Member
05 August 2023 13:19:14
Originally Posted by: doctormog 

Really? That’s not what it looks like to me. https://www.theweatheroutlook.com/twodata/chart.aspx?chart=/cfs/12_2023_00z_500.png 

 



There's a -9 anomaly along the S coast for the above December chart, and a +3 for Aberdeen - and I did say England but not Scotland!
War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
CreweCold
05 August 2023 16:43:12
The EC seasonal pressure anomalies from Dec-Feb are reminiscent of the CANSIPS prognosis. Higher than average pressure around Greenland and the hint of a Euro trough.

Quite 09/10 ish really

Crewe, Cheshire
55 metres above sea level
Brian Gaze
05 August 2023 16:48:52
30 day tracker has 1993, 1977 and 2007 as the top 3.

https://www.theweatheroutlook.com/premium/weather-analogues.aspx?dt=30days 

The 45 and 60 day trackers still have 1948 and 2022 as the top 2, but they should be excluded for another 25 days or so.
Brian Gaze
Berkhamsted
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doctormog
05 August 2023 16:55:15
Originally Posted by: DEW 

There's a -9 anomaly along the S coast for the above December chart, and a +3 for Aberdeen - and I did say England but not Scotland!



That is the 500hPa height anomaly chart which indicates if anything a higher probability of blocking to the NW. I read your comments properly, I just disagree with the interpretation and would think it it were to prove accurate there would be more winds from a northerly quarter than the long term average for December.

If it was t850hPa or t2m chart then I would agree with your post. It’s all rather hypothetical at this range anyway given the reliability of the CFS long range charts.
pdazz
05 August 2023 17:14:28
Originally Posted by: Bertwhistle 

The NAD has long been understood to keep the NW of Europe milder in winter than it might otherwise be. Decreasing salinity due to Arctic ice melt is expected to disrupt the Drift, upsetting the downwelling end of the cycle by replacing the denser saltier water with fresh. The disaster was excellently explored in Kim Stanley Robinson's 50 below zero. What I haven't been able to locate is a site that updates with live or even continuous data about the state of the current. Any ideas?[/quote

there was an article on Earthsky on 25th July 2023 about this

Is an Atlantic Ocean current collapse imminent? (earthsky.org)

https://www.nature.com/articles/s41467-023-39810-w 



 

Spring Sun Winter Dread
05 August 2023 19:26:19
So we are saying that winters will become more easterly/northerly as a result of the Gulf Stream decline as the decreased salinity will change the dominant circulation pattern away from westerlies?
But of course at the same time the whole world will be warming and the source air from the east or north won't be as cold as it is now so is there not a chance we could meet ourselves in the middle and end up more or less where we are now for winters ? 


I take these theories about NAD with a pinch of salt... If you'll pardon the pun

 
Gavin D
06 August 2023 08:22:13
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Gandalf The White
06 August 2023 08:36:11
Originally Posted by: Spring Sun Winter Dread 

So we are saying that winters will become more easterly/northerly as a result of the Gulf Stream decline as the decreased salinity will change the dominant circulation pattern away from westerlies?
But of course at the same time the whole world will be warming and the source air from the east or north won't be as cold as it is now so is there not a chance we could meet ourselves in the middle and end up more or less where we are now for winters ? 


I take these theories about NAD with a pinch of salt... If you'll pardon the pun

 



The basic point is that the amount of heat transported to northern latitudes reduces, which means cooler conditions. It doesn’t mean more blocking necessarily, just that even winds from a western quadrant will bring much cooler air masses. Cooler sea surface temperatures should also reduce the amount of moisture picked up.  

If you knock 2-3c off average temperatures that changes the amount of snowfall in winter quite significantly.
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


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