Model Output Discussion - Winter arrives

[iceman1991]

23 minutes ago, northwestsnow said:

Please don't be an outlier ,repeat after me

That is the number one model ,yes it can get things wrong ,but if I were to pick one model to face off the rest ...it would be ecm ..

 

Amen  

[East_England_Stormchaser91]

A huge stand off between the ECM and GFS. Crazy rollercoaster scenarios yet again. Big pub run to come. 

[Ali1977]

EC Op vs ENS Mean at 168, I’d say there some support there

 

It all gets a little watered down by day 10, but there’s still LP over Spain etc which mean some ENS must follow the Op!! 

Edited December 1, 2021 by Ali1977

[MATTWOLVES 3]

On 28/11/2021 at 15:11, MATTWOLVES said:

Firstly folks its Sunday...its November,and I'm seeing some great snow pics! Just started trying to again here...pretty fab for so early in the season.

Secondly we have a little model disagreement currently regarding the outlook...GFS and ECM at loggerheads perhaps...but I am noticing with ECM that there's plenty of ensemble support for more colder options on the table...

Now the main part,I've had a chat with our very own Tamara and she most gratefully gave me some insight to where we may be heading with all of this.

The signal for a Scandinavian High has good support diagnostically based on the likely Asian Mountain torque c/o the tropical convergence zone standing wave that is moving West across the tropics.

This has longer term implications also heading into winter in terms of Blocking potential. So the signal for downstream amplification is becoming greater with an increased Tropospheric pathway to the strat.

So we are looking for a signal of occluding fronts grinding to to a halt close to the UK as pressure builds in situ,and the jetstream from upstream fragments and splits,this would allow continental air to come from the East.

So this is a possibility,not a certain outcome,based on the lobe vorticity to the NW,but the signal does support the downstream amplification to enable it to happen.

So we do have some signs for perhaps a little joy moving forward.

Now roll on the 12s.

Just to add a little more thinking towards this...This still looks the case irrespective of the support for Height rises towards the NE,though perhaps too much upstream inertia to back the pattern fully West.

So perhaps the optimum time in the UK revolves around the standing wave edging East through the tropics. There is likely to be some feedback time on this process, so could be a while before felt. So what the hight frequency tropical signal does during December will be off interest regarding attempts to kick start a flip on the pattern.

[Mike Poole]

This on the mean T168, are you serious ECM?

Looks like this is well backed up and we’re going to see more of that bulge of cold in future runs…

Edited December 1, 2021 by Blessed Weather
Word changed out to a less offensive adjective.

[Methuselah]

Looking at today's GEFS 12Z temperature ensembles, I can almost imaging two 'clusters'; one in which the depression moves towards Iceland, whilst the other sends it into Europe and away to the south?I can't see the cluster forecasts, so I have to squint a lot!

   

Edited December 1, 2021 by Ed Stone

[Ali1977]

Does anyone have the EC ENS clusters, to see where the Op lies, and if the support is dwindling or not?

If on the off chance the ECM does have this right , I wonder if the MJO phase can give the heights to our NE the boost it needs to bring on the beast !! 

[Updated_Weather]

Make of this what you will

Edited December 1, 2021 by Updated_Weather

[Cold Winter Night]

EPS clusters at 120h-168h.

Well, what can I say, NAO- and BLO+, the NAO+ clusters at that timeframe from this morning are gone now.
Firm suport for the Op.

 

[tight isobar]

Pretty solid support ecm

[Cold Winter Night]

EPS clusters at 264h, with all that is going on before 144h really just for fun, but the majority (32 members) now in a BLO+ (Scandi High) cluster, That's new.
To be fair, the other 19 are more of a GFS scenario. But the Scandi blocking is gaining support now.

[jules216]

When NE Scandi/E.Europe/W.Russian high in such extent advected in June 2021 it was inevitable the record long hot spell was in the making and IT resulted in warmest June/July combo in central Európe ever, IT was a very wet spell of weather in Belgium and France. Looking at this I have a sense of inevitability again. I know some will praise the pattern as good for stratosphere,not me.

 

 

 

[Mike Poole]

ECM clusters, this might be a long post, but stay tuned, first T72 - T96:

It seems to me that ALL of them are putting up a decent ridge to prevent the Atlantic barrelling in (purple borders = Atlantic ridge).

T120-T168, this is the key timeframe and there are 6 clusters representing the uncertainty:

But here’s the thing, for me, they all end up in exactly the same place as far as it affects us, Scandi block and some ridging over the top (green border), and the last one (red border) just the Scandi block.  

And then, wouldn’t you know it the atlantic rains on our parade quite literally, as the T192-T240 charts show a likelihood of a blue borders (+NAO).  But we’re in FI here, by some margin, so I would disregard these, and wait for more information re day 8+

In the reliable, all looks good, even very good….

Edit -and yes I have missed off the last one T264+ and it does show 2/3 chance of Scandi blocking, but hey, you know at some point you have to draw the line on the amount of uncertainty.   Any road, hope that floats your boat folks!

Edited December 1, 2021 by Mike Poole

[winterof79]

A little colder than the majority but not without support.

Easterly feed signal won't go away

Edited December 1, 2021 by winterof79

[knocker]

The differences between the gfs/ecm become quIte evident early on and  these differences continue to dominate in the medium term with the ecm diverging the upper flow in the eastern Atlantic, courtesy of low pressure in southern Europe and the Urals ridge, whilst the gfs has the tpv ext the main influence. This needs sorting before any confidence can be felt regarding any details. NOAA trending towards the ecm

[Griff]

I haven't checked any charts yet since this morning where I'm pretty sure I said the GEM was worth watching... 

Did I miss anything?

[phil nw.]

Liking the ECM set this evening.It keeps the UK within the battle zone between the Atlantic and the blocking further east,so opportunities continue for more cold and wintry weather over the next week/10 days.

In the short term UKMO also sticking with a rather chilly and unsettled outlook as another low approaches from the north west. 

GFS operational again noticeable quite early for flattening the Atlantic pattern and along with GEM shows weaker wedges of heights to the north as early as day 5 which allows low pressure to phase and track that bit further north.

It really is down to short term modeling as to how much cold is in situ as the lows approach but certainly we are still looking at a unsettled period with an ongoing mild v cold battle as that signal for positive ht anomalies continues to show to the north and east right out to day 10.

Quite an unusual pattern for early December  as we see these lows dropping south east from a strong polar vortex feeding into the European trough.That blocking further east holding back a normal west to east Atlantic jet.

I realise we are not in a classically blocked and cold setup currently but there is enough in the modeling to keep coldies interested i should think.

[Griff]

1 minute ago, phil nw. said:

Liking the ECM set this evening.It keeps the UK within the battle zone between the Atlantic and the blocking further east,so opportunities continue for more cold and wintry weather over the next week/10 days.

In the short term UKMO also sticking with a rather chilly and unsettled outlook as another low approaches from the north west. 

GFS operational again noticeable quite early for flattening the Atlantic pattern and along with GEM shows weaker wedges of heights to the north as early as day 5 which allows low pressure to phase and track that bit further north.

It really is down to short term modeling as to how much cold is in situ as the lows approach but certainly we are still looking at a unsettled period with an ongoing mild v cold battle as that signal for positive ht anomalies continues to show to the north and east right out to day 10.

Quite an unusual pattern for early December  as we see these lows dropping south east from a strong polar vortex feeding into the European trough.That blocking further east holding back a normal west to east Atlantic jet.

I realise we are not in a classically blocked and cold setup currently but there is enough in the modeling to keep coldies interested i should think.

Over the last 24 hours (thanks partly to reading @Met4Cast latest thoughts), I'm getting a sens of deja vu, from about a year ago when there was chat of 'invisible' blocks holding back the Atlantic. 

[Allseasons-Si]

Lol i love the winter is over post's from some on the 1ST DECEMBER

i mean C'mon,...also when the gfs is showing exciting charts then that is the favorite model and now it is showing rubbish charts,...and nobody thinks that it could be right?,now that the ECM and GEM are showing good charts and now these are great models

the gfs has a habbit of blowing the Atlantic westerly +NAO train with it's bowling ball lows,...not going to happen

now rant over and let's have a look at some anomalies etc:-

what i am seeing in the anomalies this evening is a large Scurasian/Urals block forming and this could be a major player in putting the spv on it's ropes later on into Dec>

gefs and ECM mean Geopotential height anomalies for day ten with that said same block, Aleutian low with trough axis NW-SE through the UK 

EPS for same time 500 mb,mslp and 850's

EPS/cpc mean at day ten

EPS postage stamps at 168 and you can see that the majority go for a trough/low to the SW of the UK,...this is what we want to see and only a select few go for this trough/low to our NW

the MJO update from the gefs(ECM not out yet and still shows yesterday's),...go on son,...we are starting to get more amplitude into phase 7 now

that's me for now,...take care all and i will be back for the 18z.

OH!,...and what a great read of that winter forecast from @Nick F. 

 

 

 

 

 

 

Edited December 1, 2021 by Allseasons-si

[phil nw.]

9 minutes ago, Griff said:

Over the last 24 hours (thanks partly to reading @Met4Cast latest thoughts), I'm getting a sens of deja vu, from about a year ago when there was chat of 'invisible' blocks holding back the Atlantic. 

Certainly no sign of those +ve ht anomalies easing to the ne yet Griff.Current pattern ongoing.

[Penrith Snow]

Nice looking Fax chart update for Sunday with one high pressure cell over Finland and another to the East of Iceland, and with low pressure across Northern Europe the UK is in a cold North easterly flow, from here it looks to me like next weeks deep low will go south.

It's worth bearing in mind you don't need 1060mb Scandy Highs to maintain an Easterly, December 1981 saw weak high pressure across Scandinavia ward off many Atlantic assaults which just produced frontal snowfalls.

Just saying  

Andy

[Updated_Weather]

A very wise Ian Fergusson

[Mike Poole]

2 minutes ago, Updated_Weather said:

A very wise Ian Fergusson

Yes, absolutely agree, and tonight’s ECM out to T144 should ring real alarm bells for those advocating an Atlantic rollover…

[Allseasons-Si]

On 01/12/2021 at 20:49, Penrith Snow said:

Nice looking Fax chart update for Sunday with one high pressure cell over Finland and another to the East of Iceland, and with low pressure across Northern Europe the UK is in a cold North easterly flow, from here it looks to me like next weeks deep low will go south.

It's worth bearing in mind you don't need 1060mb Scandy Highs to maintain an Easterly, December 1981 saw weak high pressure across Scandinavia ward off many Atlantic assaults which just produced frontal snowfalls.

Just saying  

Andy

I am not going into the archives of past winters talk but i remember that quite well and i had a snow drift rught up to my bedroom window

this is case in point for folk,...blocking can be hard to shift because of dense cold air under the block,i am not saying that this will happen as there is much to be resolved(ain't it always) over the coming days but if we do get the alignment right then things could turn into our cold favor.

Edited December 1, 2021 by Allseasons-si
typo

[damianslaw]

I know some bemoan the Met Office updates.. and I have many a time.. but generally they go for milder conditions beating colder.. however yesterday there was an about turn and the forecast by them resolutely remains colder rather milder.. milder pushed back, and possibly brief.. winter in the north. The la Nina base state I think is the key driver and this should promote heights to our west for a good while.. NW- SE jet and heights to our NE. No surprise to see ECM in line with this..  GFS as ever sends Atlantic on turbo change it's been doing it all year.. and it has never come to avail..