Remove ads from site

ballamar
07 January 2023 10:39:42

His guess may be right and time will tell as it has done with his previous multi-week guesses over the past year. The point is that the guess is based on current conditions, climate averages and psychology not model output. I would be as misguided to say with confidence that he will be wrong about weeks of zonal conditions as he would be to state with absolute confidence that is what will happen. 

Wintry weather may return this month, at the start of February or not all this season. In early January it is impossible to say which will be the case.

Our planet’s weather is so complicated and our little group of islands’ weather affected by so many factors, many local others global, that it is impossible to say what will happen with any real confidence beyond a week or so. Yes, we get hints and patterns but that’s all they are. We can all use the climate norms or averages or prevailing Atlantic weather to make a guess and most times we would be right but it doesn’t really make it model analysis.

The top researchers in the area with the best equipment and access to data understand the limitations and always caveat the outlook beyond a certain time period and issue probabilistic forecasts. Some could learn from that. With probabilities even less likely scenarios do occurs and hopefully when that happens we all learn a little from it.

Originally Posted by: doctormog 


was hoping you had detected my sarcasm !
Gusty
07 January 2023 10:40:07

Question why we still have raging zonality and PV sitting in wrong place if still mild in Toronto? If mild there we should be looking at cold and snowy by then. 

Originally Posted by: Jiries 



That is because there is a strong zonal (west to east) hemisperical northern jet at the moment with relatively small amplification keeping the very cold air bottled up over the higher latitudes.
Steve - Folkestone, Kent
Current conditions from my Davis Vantage Vue
https://www.wunderground.com/dashboard/pws/IFOLKE11 
Join Kent Weather on Facebook.
https://www.facebook.com/stevewall69/ 



Jiries
07 January 2023 11:03:59

That is because there is a strong zonal (west to east) hemisperical northern jet at the moment with relatively small amplification keeping the very cold air bottled up over the higher latitudes.

Originally Posted by: Gusty 



Yes looking at Canada weather map it show the northern part of the jet are sub -10C temps while southern side of the jet where Toronto sit is mild side.  I remember seeing the USA weather channel showing the jet stream goes straight from west to East at times but mostly in waves more often than straight lines.
Downpour
07 January 2023 11:14:02

Experience tells me that when a Zonal spell sets up in the North Atlantic, it can take weeks, or even months, to shift.

Hence why I felt we were on the cusp of a long Zonal spell.

I've a feeling it may blow itself out by February, but we have a lot of water to go under the bridge before we settle down again.  

Originally Posted by: moomin75 



agreed. And a good shout by you. Credit where it is due. 
Chingford
London E4
147ft
Downpour
07 January 2023 11:17:45

His guess may be right and time will tell as it has done with his previous multi-week guesses over the past year. The point is that the guess is based on current conditions, climate averages and psychology not model output. I would be as misguided to say with confidence that he will be wrong about weeks of zonal conditions as he would be to state with


absolute confidence that is what will happen. 


Wintry weather may return this month, at the start of February or not all this season. In early January it is impossible to say which will be the case.

Our planet’s weather is so complicated and our little group of islands’ weather affected by so many factors, many local others global, that it is impossible to say what will happen with any real confidence beyond a week or so. Yes, we get hints and patterns but that’s all they are. We can all use the climate norms or averages or prevailing Atlantic weather to make a guess and most times we would be right but it doesn’t really make it model analysis.

The top researchers in the area with the best equipment and access to data understand the limitations and always caveat the outlook beyond a certain time period and issue probabilistic forecasts. Some could learn from that. With probabilities even less likely scenarios do occurs and hopefully when that happens we all learn a little from it.

Originally Posted by: doctormog 



Well he made a forecast before Christmas which looks like being spot on. For that he surely deserves some credit, after all, members are quick to attack him when he is proved wrong. 

This wet zonal dross is not what many (any?) of us want to see, but one has to say he looks to have called it correctly. 
Chingford
London E4
147ft
doctormog
07 January 2023 11:23:46

Well he made a forecast before Christmas which looks like being spot on. For that he surely deserves some credit, after all, members are quick to attack him when he is proved wrong. 

This wet zonal dross is not what many (any?) of us want to see, but one has to say he looks to have called it correctly. 

Originally Posted by: Downpour 



The fact that this is what you take as the key message from my post shows you don’t understand what I wrote.

Ok, I can guess the next two months will have above average temperatures and summer will be warmer than the LTA. None of this is model output analysis. 

As we are in the model output thread, what is your take on the last couple of GFS op runs for late January, especially in terms of the jet stream profile over N America and consequently N Europe? It would be helpful to see your analysis in this particular point especially given the meridional nature of the last two consecutive runs.
idj20
07 January 2023 11:31:29

Yes looking at Canada weather map it show the northern part of the jet are sub -10C temps while southern side of the jet where Toronto sit is mild side.  I remember seeing the USA weather channel showing the jet stream goes straight from west to East at times but mostly in waves more often than straight lines.

Originally Posted by: Jiries 



I think I know what you are getting at. I tend to associate strong zonal straight-line jet stream profiles being the result of extensive deep cold digging well south over the USA, that would then lead to regular wet and windy conditions here at the UK via Atlantic low pressure systems one after the other. Currently it doesn't seem to be THAT cold over there (apart from obviously Canada) and yet we're still stuck under this long-fetched maritime-type zonal set up with little change expected for the foreseeable future. I think the wind profile at the stratsopheric level is the main culprit where it is still very westerly zonal-like around the mid-latitude zone. Or perhaps I'm talking out of my backside as usual.
Folkestone Harbour. 
Brian Gaze
07 January 2023 11:31:55

Well he made a forecast before Christmas which looks like being spot on. For that he surely deserves some credit, after all, members are quick to attack him when he is proved wrong. 

This wet zonal dross is not what many (any?) of us want to see, but one has to say he looks to have called it correctly. 

Originally Posted by: Downpour 



Credit should go to those who are consistently doing well at medium range. Therefore, I wouldn't praise Moomin for this specific forecast, but equally I wouldn't admonish him if it was wrong. Look at the Met Office medium term outlooks as an example. They change frequently and illustrate the limit of what is possible. We need to accept those limits and not buy into extravagant claims. For example, I read comments a couple of weeks ago saying that "experts" on another forum were explaining why a cold January was a shoe-in.  
Brian Gaze
Berkhamsted
TWO Buzz - get the latest news and views 
"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan
doctormog
07 January 2023 11:34:10

I think I know what you are getting at. I tend to associate strong zonal straight-line jet stream profiles being the result of extensive deep cold digging well south over the USA, that would then lead to regular wet and windy conditions here at the UK via Atlantic low pressure systems one after the other. Currently it doesn't seem to be THAT cold over there (apart from obviously Canada) and yet we're still stuck under this long-fetched maritime-type zonal set up with little change expected for the foreseeable future. I think the wind profile at the stratsopheric level is the main culprit where it is still very westerly zonal-like around the mid-latitude zone. Or perhaps I'm talking out of my backside as usual.

Originally Posted by: idj20 



Yes it is just now, but there are signs that may change (in some of the recent output GFS and ECM ensemble data). Time will tell.
idj20
07 January 2023 12:00:39

Yes it is just now, but there are signs that may change (in some of the recent output GFS and ECM ensemble data). Time will tell.

Originally Posted by: doctormog 



I notice the stratsopheric polar vortex at the 10 hpa and 30 hpa levels being put under stress later on this month, but the wind profile is still largely westerly over Europe. Like you say, we shall see. 
Folkestone Harbour. 
NMA
  • NMA
  • Advanced Member
07 January 2023 12:04:47
I’m old enough to remember when Berne was seen by at least one TWO member as the Gold Standard for UK cold weather predictions. Is it now Toronto's turn to seize the moment and become the benchmark?

For me reading the arcane, obscure and Runic models such as “When Thor's Ice Hammer melts in Iceland, Freya’s frigid white mantle cometh to Southern England”, is as good as any indicator for cold here. The reason being a winter easterly in Southern England almost always means a long fetch mild southerly for Iceland. The winter up there has been quite snowy and cold in recent weeks. And for now I can’t see much change. But who knows?

My Dad was a professional weather forecaster but could never pin down what in his opinion would lead to long lasting cold weather in the UK. He had a theory though that somewhere in a lava lamp lay part of the answer. The lava lamp was developed from a design for an egg timer using two liquids spotted in a Dorset pub for anyone who still wonders. He would have loved to see how much more accurate medium length weather predictions have become. But he always said it would be a shame if we could predict a year or more in advance as that would take away the daily magic of our lives if we knew exactly how a week, month or year will turn out.
Vale of the Great Dairies
South Dorset
Elevation 60m 197ft
Saint Snow
07 January 2023 13:46:51

The fact that this is what you take as the key message from my post shows you don’t understand what I wrote.

Ok, I can guess the next two months will have above average temperatures and summer will be warmer than the LTA. None of this is model output analysis. 

As we are in the model output thread, what is your take on the last couple of GFS op runs for late January, especially in terms of the jet stream profile over N America and consequently N Europe? It would be helpful to see your analysis in this particular point especially given the meridional nature of the last two consecutive runs.

Originally Posted by: doctormog 



👍

Well put. 

Moomin (and some others) frequently fire out these zonal forecasts. Given that 8/10 winters will have prolonged unsettled spells (not always from a genuine zonal pattern, but that's another discussion) they're going to be right a lot of the time. 

As you say, it's not based on model output - so really should be in the Winter General Discussion thread - and is just firing out a forecast based on what is statistically likely. 

When they're wrong, they stress that they 'hold my hands up, I was wrong' but anyone with an ounce of understanding would ignore any forecast they make, whether right or wrong, because it's based on nothing more, like I say, than statistical probability. 

 

Martin
Home: St Helens (26m asl) Work: Manchester (75m asl)
A TWO addict since 14/12/01
"How can wealth persuade poverty to use its political freedom to keep wealth in power? Here lies the whole art of Conservative politics."
Aneurin Bevan
Gandalf The White
07 January 2023 14:01:00



Well he made a forecast before Christmas which looks like being spot on. For that he surely deserves some credit, after all, members are quick to attack him when he is proved wrong. 

This wet zonal dross is not what many (any?) of us want to see, but one has to say he looks to have called it correctly. 

Originally Posted by: Downpour 



Actually, not wishing to be pedantic here but there is a difference:  he made a prediction not a forecast.  A forecast is based on the available evidence. A forecast is based on data; a prediction is rooted in subjective judgements.
Location: South Cambridgeshire
130 metres ASL
52.0N 0.1E


Jacee
07 January 2023 14:48:04
This is an interesting discussion today 😊 I suppose there are merits to both sides and you could argue there is a significant overlap between the terms 'forecast' and 'prediction' given one can inform the other.

Reading moomin's previous posts it would seem they have turned a forecast into a prediction: a prediction based around the commonality of a zonal pattern in winter for the UK. If you look at the charts for evidence at the time (say, around the early festive period) you could confidently forecast a mild, zonal flow for a week, perhaps two and link to jet stream charts, ensemble data, etc.

Where the prediction then comes in is when you look beyond the model output (> 10 to 14 days in this case) and predict that the zonal pattern would continue. I would assume moomin did this because it is common for a w-e zonal flow to maintain beyond a week or two. The further out you call it, the less live data you have to evidence and IMO the less right you have to call it a forecast. It becomes an educated guess or prediction based on historical evidence and probabilities, rather than explicitly evidencing current model output 🤯



 
Jacee, Hucknall (Notts) 😽 x
fairweather
07 January 2023 15:05:54

This is an interesting discussion today 😊 I suppose there are merits to both sides and you could argue there is a significant overlap between the terms 'forecast' and 'prediction' given one can inform the other.

Reading moomin's previous posts it would seem they have turned a forecast into a prediction: a prediction based around the commonality of a zonal pattern in winter for the UK. If you look at the charts for evidence at the time (say, around the early festive period) you could confidently forecast a mild, zonal flow for a week, perhaps two and link to jet stream charts, ensemble data, etc.

Where the prediction then comes in is when you look beyond the model output (> 10 to 14 days in this case) and predict that the zonal pattern would continue. I would assume moomin did this because it is common for a w-e zonal flow to maintain beyond a week or two. The further out you call it, the less live data you have to evidence and IMO the less right you have to call it a forecast. It becomes an educated guess or prediction based on historical evidence and probabilities, rather than explicitly evidencing current model output 🤯

 

Originally Posted by: Jacee 


A very good and well put post. That's what the evidence was from around Dec 21st (disputed by a few) and sadly the predictive element based on experience and history that it might take some time to shift has also come to fruition.
S.Essex, 42m ASL
The Beast from the East
07 January 2023 16:39:53
Not bad but probably a classic toppler
https://www.meteociel.fr/modeles/gfse_cartes.php?&ech=240&mode=0 
"We have some alternative facts for you"
Kelly-Ann Conway - special adviser to the President
Hippydave
07 January 2023 17:04:17
GFS 12z op continues with the theme of a more amplified pattern in the mid to longer term, allowing colder shots from the North West or North - nothing particularly exciting I guess but brings snow chances for some and less warm rain for others 🤣
Home: Tunbridge Wells
Work: Tonbridge
MStewart
07 January 2023 17:11:40
I’m finding the day to day models are pretty much typical this time of year with a strong jet stream and a strong temperature gradient across our latitude.

What’s interesting me more is watching GEFS and a trend of general lowering of temperatures over time.

The jet stream will weaken and buckle as the temperature gradient begins to flatten, then model watching (hopefully) becomes exciting for wintery fans once again. Two or three weeks time?
Mark
Twickenham
12m ASL
Jiries
07 January 2023 17:40:26

Not bad but probably a classic toppler
https://www.meteociel.fr/modeles/gfse_cartes.php?&ech=240&mode=0 

Originally Posted by: The Beast from the East 



Should get direct heavy snowstorms like in the USA as there kinks on the isobars as it move south.  Cannot be bone dry set-up and topplers are my favourite weather as it bring lot of sunshine for few days afterward, that time I used to get frequent -6 to-10C temps at nights often from topplers back in the time I was living in the SE.  It been absent for several years now in winter and in summer months that started off cool with some sunny spells then warming up to hot and sunny weather as HP move east.
UncleAlbert
07 January 2023 20:54:04
Nice to see lots of intersting discussion on here today, despite the relentless Atlantic onslaught (at least in the medium term).  Forgive me for being off topic, but I was doing a bit of TV schedule scrolling and noticed the the Channel 5 documentary 'The Big Snow of 82' at 9.30 this evening.  Something to feed the passions while we wait for this scrooge of a January to deliver something a little more interesting..... Maybe
doctormog
07 January 2023 21:08:34

Nice to see lots of intersting discussion on here today, despite the relentless Atlantic onslaught (at least in the medium term).  Forgive me for being off topic, but I was doing a bit of TV schedule scrolling and noticed the the Channel 5 documentary 'The Big Snow of 82' at 9.30 this evening.  Something to feed the passions while we wait for this scrooge of a January to deliver something a little more interesting..... Maybe

Originally Posted by: UncleAlbert 



Off topic: Thanks for the reminder, I remember it well and is probably one of those events that sparked a lasting interest in snowy weather (and I didn’t even get a day off school as I could very easily walk there). It may just be because I was quite young but the snow seemed very deep in rural NI. It was also of course a record setting/equalling cold spell with -27.2°C being reached.
 
UncleAlbert
07 January 2023 22:44:10

GFS 12z op continues with the theme of a more amplified pattern in the mid to longer term, allowing colder shots from the North West or North - nothing particularly exciting I guess but brings snow chances for some and less warm rain for others 🤣

Originally Posted by: Hippydave 



Yes, ECM 16 day ens now giving a definite cluster in the second half that is in the -4 to -6 range and that's the first time it has shown anything like this since the beginning of this zonal type spell.  Some support for an increased likelyhood of a period of Polar Maritime bias as suggested by recent GFS ops then. 
https://www.theweatheroutlook.com/charts2/ecmhrens/ecmwfens850london.png 

So something more below average or rather cold for a time?  Over the years its more often than not been a prerequisite to have this type of pattern if we are to see something more potent down the line.  However, more often than not, after a while it goes the other way again, but at least something for starters.
dagspot
07 January 2023 22:50:50
Polar Maritime would suit me and if cold enough NW would provide good snowshowers in my neck of the woods.  Actually been a long time since I can remember the repeated ominous dark clouds bring hefty snow showers
Neilston 600ft ASL
nsrobins
08 January 2023 00:00:19
I’m not seeing anything that suggests a change from the predominantly mobile westerly type weather for the next 10 days.
Brief fleeting wafts of Pm air are typical in this pattern, which in itself is typical of Januaries of recent years. 
Hoping for a change to dryer, cooler weather to get some outdoor jobs done and have a rest from this filthy mild gunk.
Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
Lionel Hutz
08 January 2023 00:22:01

Off topic: Thanks for the reminder, I remember it well and is probably one of those events that sparked a lasting interest in snowy weather (and I didn’t even get a day off school as I could very easily walk there). It may just be because I was quite young but the snow seemed very deep in rural NI. It was also of course a record setting/equalling cold spell with -27.2°C being reached.
 

Originally Posted by: doctormog 


I can't say what '82 was like in NI but I can tell you that it was pretty spectacular in the South East of ROI. The 2nd deepest snowfall of my lifetime, only beaten by February 2018.
Lionel Hutz
Nr.Waterford , S E Ireland
68m ASL



Remove ads from site

Ads