Winter Season: Forecast and Model Discussion Commentary

[Mike Poole]

 Met4Cast I think it might be due to the trop vortex now being off to one side:

So the plot of zonal mean zonal winds also includes the highs around which the circulation is the other way.  You can see this on the Stratobserve plot too, if you look where the bottom of the thing is on the map.  But the structure above this looks very much like one vortex.

Edited December 7, 2024 by Mike Poole

[northwestsnow]

 mountain shadow

I wouldn't personally write off 6 weeks myself but it's looking really grim,again.

We can't discount changes the longer the lead time but it all feels very familiar right now...

[Mcconnor8]

ICON 18z blows up the low coming out of Canada quite a lot by Day 5, also has a stronger polar high.

[Severe Siberian icy blast]

 mountain shadow 6 wks im afraid is a hideous, misleading post, its misinformation, rooted in you're own frustration!

None of us have a clue whats going to happen and every year the weather makes fools of us all, 

Its 7th of December and reading comments like that is entertaining, but that's about it,

The models over react to new signals, as they did with every amplification attempt, most storms, and everything else with it, on the wed, we read how interesting the models are, with a very disturbed and weak PV, and on Saturday we read how all of that is a bust, & know background drivers are relevant anymore, but one thing we do know is that the next 6 wks, the writings on the wall!!! 

Come on a tad of realism is needed.

 

[Penrith Snow]

TBH I would much prefer cold zonality than a dull, cloudy uk high.

As least with cold zonality the days are bright, breezy with wintry showers which can be widespread.

Not ideal I agree but better than some of the alternatives and if nothing else it's a decent holding pattern.

If the EC46 is correct then what we won't have is the winter killing Iberia High so something may pop up at short notice.

Andy

[gman144]

Is a computer fed with all information of every synoptic plus historical information going to mark clearly what forecast can be or close to a generalised weather forecast?

With modern day AI would you not think there would at least a clear thought generally by all models on forecasting?  

What information can be inputted in a different way that would/could be thought of as different to a forecasting model?

Lastly, what model do you focus on as reliable  or is it after many years reading this thread ( thank you all contributors) it’s a guessing game.

Call me inquisitive 

Seriously thank you all, this thread come October is a must read for me

 

[Blessed Weather]

 Mike Poole

 Met4Cast

I wonder if we should be using Polar Cap Geopotential Heights to determine whether sPV and tPV are coupled or not? Dr Amy Butler and Dr Judah Cohen both use that measure. Looking at the latest NOAA/CPC GPH 65-90N anomaly from 1000hPa up to 10hPa they don't appear to be coupled?

Source: https://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/hgt.shtml

Here's two blogs from Amy with a useful illustration and description:
https://www.climate.gov/news-features/blogs/polar-vortex/polar-vortex-double-header
https://www.climate.gov/news-features/blogs/polar-vortex/stratosphere-talking-down-troposphere-will-it-listen

And the latest weekly blog from Judah - skip down to Fig. 11 with his latest forecast out to 17th Dec:
https://www.aer.com/science-research/climate-weather/arctic-oscillation/

 

[Coldie24]

Looks like a North vs South situation come Xmas time with northern regions favoured for a white Xmas yet again.

[E17boy]

Hi peeps,

Hope everyone is safe and well a lot of storm stories throughout the UK today and we still got tonight to go.
 

Looking at the models and reading the above posts  makes me think. First are we really doomed here in the Uk seems every year for the past several we seem to have the up head that yes the general. Pattern will be there for a cold start, but then as December arrives the whole windows of opportunities seem to evaporate in front of our eyes. This time round we had that first cold snap in November and the first snow and a week ago it looked good for mid December. Today we are sitting here trying to find crumbs of comfort.  

Secondly a lot of Talk about the MJO and our expectations that if that goes into phase six we have a better chance of cold. However that also seems to have a big question mark now even if it does go to phase 6.  I am no expert but I am trying to understand all this, I ask the question that surely it is a whole load of various factors that influence our weather and not just the MJO.

Thirdly every winter I always keep an eye as to what the temperature are in Europe for cold . At the present moment I am not seeing any significant areas of cold pooling , why cold pooling  ?we need that if our air has any. Chance to come from there the colder the continent the better chance for colder temperatures to reach here. However at the moment this scenario seems a long distance away. 
 

Lastly we are no weather gods the models might give us indications as to what kind of pattern we can expect however the weather will always be a mystery in our part of the world. Here is me now hoping that the coming weeks start to show some light for us coldies. We want to see Europe cooling down considerably and we want to see less energy where it is not needed. As some have said from todays posts and on what the models are showing currently seems doom and gloomy. However it is only the 7th December today a long time still for winter to unfold its mysteries. 
 

take care all

regards

THE SEARCH FOR WINTER GOES ON

[mountain shadow]

 Severe Siberian icy blast It's not rooted in frustration,  it's routed in 30 odd years of model watching.

The PV has been subdued so far this Winter but is now on the move.

This does mean no snow and cold at times, indeed, I'm still hopeful for a white Christmas, but in terms of a favourable high latitude block, I think the probability is low.

[Mike Poole]

 Blessed Weather I don’t know - as @Met4Cast says it is difficult to tell, but it certainly seems in the model forecasts to be behaving like it is one vortex, which until now this winter it hasn’t with the trop vortex looking all over the place.  And you could extrapolate that plot from NOAA 2-3 days to be so, as one way of looking at it.

[northwestsnow]

 Coldie24

I still think christmas is a bit far out to have confidence in what conditions will be like on the ground.

If i were to bet id say some kind of westerly orientated pattern but that could be a mild south wester or a cold north wester..

Obviously Exeter favour Greg Lake but that could change abruptly, you can never be 100% at a two week lead time..

 

[Mike Poole]

 northwestsnow What is Greg Lake?  Is it a swear filter thing?

[northwestsnow]

 Mike Poole

It was a Christmas song from the 70's Mike.. 

it was a classic...

The relevant lyric-

" instead it just kept on raining "..

Edited December 7, 2024 by northwestsnow

[Blessed Weather]

 Mike Poole It would be good if one of our resident strat experts popped into the thread and enlightened us with their opinion Mike.

Paging @chionomaniac and @lorenzo .........

[E17boy]

 mountain shadow I understand your frustration but I do not agree with writing the next 6 to 8 weeks off. We don’t know what position we will be in a week from now . In 6 to 8 weeks the weather can change several times dramatically, even a season can change in 6 weeks. I do understand that what we are seeing at the moment gives little hope for coldies in the coming week but it no way dictates that this is how the weather is going to stay for the next 6 weeks, We live on a small island here and all it needs is subtle changes to shift a pattern. However where we are at the moment I do accept that we need something more than a small nudge to get us out of what is being indicated for the coming days. Things can change suddenly and our weather here does not hold back on surprises. 
 

regards

[blizzard81]

I sense passions rising - always happens at this particular time of year which is understandable of course. Much can happen and indeed much can change between now and Christmas. My powder is dry still. Next week looks more or less nailed on - Cold and blocked. That will do just nicely for mid December thank you. Thereafter? Anybody's guess, nobody knows. It's all up in the air, quite literally. 

[Severe Siberian icy blast]

 mountain shadow for 6 wks? Get a grip mate

[blizzard81]

 northwestsnow I'm guessing Mike must be much younger than us

Edited December 7, 2024 by blizzard81

[northwestsnow]

 blizzard81

you've lost me mate

[blizzard81]

 northwestsnow He didn't know about Greg Lake's Xmas song lol 

[northwestsnow]

 blizzard81 loved that song when I was a nipper ,absolute classic ...

I know, 52 next year ,eeeek!

Edited December 7, 2024 by northwestsnow

[blizzard81]

 northwestsnow It's a brilliant song isn't it? Unique. 51 next year!

[Dennis]

love the ec today

it could make that lobe-split .... still time to see the change (MJO moving and a sudden change in zonal winds in the lower latitudes) some is seen 

[Dennis]

GFS18z is for sure trying something