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 

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.

Originally Posted by: Gusty 

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 

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. 

Originally Posted by: Downpour 

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 

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 

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.

Originally Posted by: doctormog 

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 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 

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 

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 

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 

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 

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