Model Output Discussion - Into Winter

[Jacob]

Looks like the PV stopped existing yet we are still getting westerly winds and mild-ish weather lol

[BartyHater]

6 minutes ago, Catacol said:

Enemy? No. It is aiding a significant attack on the strat vortex. And then - as it fades - the pattern shifts east to west. Clear on both ensemble means today. So far the trend for this month, after a cold spell that I think has generally over delivered, is sticking to the script.

I very much hope you're right...but I'm yet to be won over by this argument, having seen this kind of thing a few times over the years. I'll reserve judgement until midweek, by which time I hope GFS has brought the change forward into at least the semi reliable timeframe and isn't still toying with it in deep FI. 

[Chesil View]

37 minutes ago, swfc said:

Tbh Nws was making a point about going forward, not really picking any bones.

Yes I was agreeing with him.

[Rob 79812010]

26 minutes ago, Jacob said:

Looks like the PV stopped existing yet we are still getting westerly winds and mild-ish weather lol

For now anyway 

[TSNWK]

11 minutes ago, BartyHater said:

I very much hope you're right...but I'm yet to be won over by this argument, having seen this kind of thing a few times over the years. I'll reserve judgement until midweek, by which time I hope GFS has brought the change forward into at least the semi reliable timeframe and isn't still toying with it in deep FI. 

I'm with you.  Lots of theory but for most coldies it's about impact on the ground. For example a Canadian warming is much lorded however on this occasion I'm not convinced on its  merit. Yes the vortex has been kicked aside but we are still effected by the jetstream and westerlys 

Edited December 3, 2023 by TSNWK

[ANYWEATHER]

Too many people despondent about the current Synoptics. A lot of people have already seen snow , many weeks before we get to the real meaty part of winter! There is lots of potential in the weeks ahead, but for now our first cold snap has delivered for many , where as some years people never see a snowflake, but have to accept a brief milder period which even happened in all the iconic winters past!

[phil nw.]

2 hours ago, Liam Burge said:

A fairly significant cluster of ECMWF ensemble members are going for an SSW during the 1st-2nd week of January. This has been shown for some time, and every day more members are joining this cluster.

FWIW, I do believe that by mid Jan we'll be seeing an SSW.

Yes looking good.What is also noticable is the dramatic drop off in the mean zonal winds leading up to Christmas.

A much weaker and preturbed tropospheric vortex looks likely in a couple of weeks or so.All in line with the expectation of Arctic heights building later in the month.

[sheikhy]

Well thats the end of the cold spell here!!got snow falling twice this week and last night got a good 2 or 3cms!i will take that all day long especially very early on in the season!!!its been a fantastic last 10 to 14 days but boredom is about to take hold for me lol as we are back to wind and rain from here on in!!!what looks like at least 2 weeks of your bog standard weather now before maybe theres an uptick in snowy charts again!!!so thats me done for a week or 2 and i see my peeps for the next saga!!if it turns up lol!!i can take this time actually to have a break from this as much as i dont wana!!!i am more accustomed to such activity on here late winter early spring so it just goes to show how lucky we have been to get snow and cold this early on!!!catch you later man but as always i shall still have my on this forum!!!ciao!!!!!!!

[NewEra21]

This really does remind me of last December, a very promising start with plenty of very cold frosty weather with snow for a lucky few.

Then when it broke down we all thought the Atlantic wouldn’t be in control for long, but it took an age for the next real cold chase that ended in a whimper in March.

Once the Atlantic gets in, it can take an age to get back to something cold for the UK even without a strong PV as we’re seeing now. Background signals look somewhat promising, but we’ve all fallen into that trap before chasing the never ending carrot

Let’s just hope this winter is a little different!

[Vikos]

12 minutes ago, TSNWK said:

I'm with you.  Lots of theory but for most coldies it's about impact on the ground. For example a Canadian warming is much lorded however on this occasion I'm not convinced on its  merit. Yes the vortex has been kicked aside but we are still effected by the jetstream and westerlys 

Can you point out wich jet you mean? I only see fragments of it… as posted earlier by me

[Chesil View]

8 minutes ago, NewEra21 said:

This really does remind me of last December, a very promising start with plenty of very cold frosty weather with snow for a lucky few.

Then when it broke down we all thought the Atlantic wouldn’t be in control for long, but it took an age for the next real cold chase that ended in a whimper in March.

Once the Atlantic gets in, it can take an age to get back to something cold for the UK even without a strong PV as we’re seeing now. Background signals look somewhat promising, but we’ve all fallen into that trap before chasing the never ending carrot

Let’s just hope this winter is a little different!

Last year the background drivers were not helpful in stopping the Atlantic once it came back in. La nina and westerly qbo.

This year's global set up is much more conducive to making the Atlantic incursion  a relatively brief affair as the likes of Catacol. MattH and Blue army amongst others have articulated so well..

 

 

 

[Methuselah]

So, the GFS 06Z is complete, and it looks as if (for the time being at least) the cold air is on the retreat:

   

   

   

But at least the 15C 850s to our south look interesting! 

[Tamara]

3 hours ago, MattH said:

So, yeah, coming full circle, that is certainly possible and if you link that into the GWO as well then you end up with the following for higher phases 5-6-7 which I think could be achievable this time around

My expectations follow this. You are correct again, to perm the tropical & extra tropical signals together c/o the Global Wind Oscillation to get the complete picture of the macro scale wind-flow budget & not the MJO in isolation.

The evolution to stronger sub tropical flow against burgeoning blocking over NE Europe, discussed in previous posts, has been panning out on the longer timescale as anticipated - but it is coming. Very classic Nino-esque Pacific>Atlantic wave train 

[TSNWK]

10 minutes ago, Vikos said:

Can you point out wich jet you mean? I only see fragments of it… as posted earlier by me

Jets in bits or not  we still have low pressures to introduce atlantic 

[bluearmy]

 More than happy with the start to winter and the momentum that exists in the ens modelling for mid dec onwards 

we have lots of uncertainties before then 

how far east does the Atlantic get against the Russian block ?

how far south does the Atlantic dig into europe and does this lead to a mean trough or is it just weak disruptions?

how far north and east does the Azores high get and does it become a euro high? 

the gfs op theme of Atlantic ridging and west based -NAO against a building euro ridge looks reasonably consistent for that model.

the AI models are hinting that the trough could get stuck up against the Russian ridge a little to our east which means we could end up on the cold side and I’d assume that the trough would then gradually sink as the ridge retrogresses. 

the eps clusters in the extended are more than promising 

 

[bluearmy]

7 minutes ago, TSNWK said:

Jets in bits or not  we still have low pressures to introduce atlantic 

We need some jet and associated low systems from the west to prop up the heights and avoid a general sceuro ridge where we can’t advect any proper cold from the east. As Matt mentioned earlier, avoiding high euro heights is pretty much essential for a proper cold spell across the southern half of the U.K. 

[LRD]

19 minutes ago, TSNWK said:

Jets in bits or not  we still have low pressures to introduce atlantic 

I get your frustration but it's a matter of looking at the bigger/longer-term picture. Accept the next 10-14 days of westerlies and keep an eye on what the output, teleconnections and the likes of MattyH, Catacol, bluearmy, Tamara, etc say about the 2nd half of the month. I'd suggest there is no point agonising over this next period

Besides we need some jet energy going into Europe

Edited December 3, 2023 by LRD

[minus10]

Ec 0z control (op) looking to find winter again in later stages...with a few cold ens in support..wide spread though reflective of mean hugging LT mean..

 

..will hopefully see this downward modelling in 850s ens increase in the extendeds in line with the drivers becoming more favourable as outlined in the informative posts of MattH , Catacol and others above...no guarantees of course but hopefully in a better position re drivers than last year...

[TSNWK]

Love this forum.. a safe place to question / Challenge and learn..  thanks gang..

[MP-R]

2 hours ago, northwestsnow said:

Bloody azores high trying to ruin things 

Just you wait, Azores high upgrades will be few and far between come the summer…

[bluearmy]

Very late in the run and of course very much fi but that gfs op almost splits the spv at 10hpa. It certainly does a bit further down 

[offerman]

1 hour ago, Jacob said:

Looks like the PV stopped existing yet we are still getting westerly winds and mild-ish weather lol

Unfortunately, that is the result of a Hadley cell, which these days do seem to be larger and more influential and at times stubborn to shift. You can have a Mobile train of weather systems, but that doesn’t always involve the high-pressure and the systems just ride over the top of it dragging in the moulder south Westerly or Southerly winds. 
 

[Vikos]

2 minutes ago, bluearmy said:

Very late in the run and of course very much fi but that gfs op almost splits the spv at 10hpa. It certainly does a bit further down 

And then the gates to narnia opens… patience is needed by a few here, outcome can be epic around xmas…

[offerman]

5 minutes ago, MP-R said:

Just you wait, Azores high upgrades will be few and far between come the summer…

That can sometimes be the case that it seems like it just influences at the wrong time which we all wish for. in other words bugger off in winter and please come home to the UK in summer. Beggars certainly can’t be choosers with our weather on this island.

[offerman]

20 minutes ago, LRD said:

I get your frustration but it's a matter of looking at the bigger/longer-term picture. Accept the next 10-14 days of westerlies and keep an eye on what the output, teleconnections and the likes of MattyH, Catacol, bluearmy, Tamara, etc say about the 2nd half of the month. I'd suggest there is no point agonising over this next period

Besides we need some jet energy going into Europe

Agree with you to a point, but there have been occasions where the Teleconnections don’t apply to our local at times stubborn weather patterns.