Model Output Discussion - Winter arrives

[Battleground Snow]

11 minutes ago, northwestsnow said:

Wedges appearing in the mean...

There is definitely time for changes for better or worse, look at the area circled to be weaker on the 06z

 

[weathercold]

MOGREPS never supported the easterly, looks like it’s called this v well. On to the next chase…

[bluearmy]

1 minute ago, weathercold said:

MOGREPS never supported the easterly, looks like it’s called this v well. On to the next chase…

Apart from gfs op, did any ?????

[TSNWK]

On 29/11/2021 at 08:27, weathercold said:

MOGREPS never supported the easterly, looks like it’s called this v well. On to the next chase…

I recall a post on this yesterday and mogreps not buying the Easterly.. but confess I got drawn in by several GFS runs.. even after 12 years on the models I never learn. 

[IDO]

The D7 onwards, looks now about the wedge(s) as it does appear that the "new" GFS can overdo heights at that range, corrected on the 0z run. The ECM is an improvement but depends, again, on the modelling of the wedges:

Placed nicely on this run to deflect the flow NW to SE. At this range I would have low confidence in any wedge solution, but definitely a possibility.

All-in-all just the trop in motion with little sense of any forcing from the strat, MJO or other suspects. As with last year, the tPV primed for blocking, by the underlying state is seemingly still docile. Wedges and favourable Atlantic-height pushes remain our best routes to colder shots.

Edited November 29, 2021 by IDO

[weathercold]

7 minutes ago, bluearmy said:

Apart from gfs op, did any ?????

UKMO looked promising at one point…for sure GFS went off on one here - sadly a false signal 

[Yarmy]

2 minutes ago, TSNWK said:

I recall a post on this yesterday and mogreps not buying the Easterly.. but confess I got drawn in by several GFS runs.. even after 12 years on the models I never learn. 

Ha, confirmation bias, isn't it. Had the ECM been showing Scandi heights while the GFS wasn't, nobody would've given the latter the time of day. 

Anyway, carpe diem. Absolutely beautiful out there this morning, walking the dog at 7am.

[Ali1977]

It’s just a hiccup, easterly will be back on the cards in 90 mins 

[Dave Kightley]

ECm has showed an Easterly the cold air moving westwards... it does on this chart for like a day but the low to the west is not behaving that’s it..

Yesterday it had a easterly in by Wednesday just delayed compared to GFS..

 

every model changing every 6 hours... I would not bank on it yet

[TSNWK]

On 29/11/2021 at 08:40, Ali1977 said:

It’s just a hiccup, easterly will be back on the cards in 90 mins 

You been on the sauce already...  

[Eagle Eye]

On 29/11/2021 at 08:40, Ali1977 said:

It’s just a hiccup, easterly will be back on the cards in 90 mins 

I really hope so

[Staffmoorlands]

Just now, Ali1977 said:

It’s just a hiccup, easterly will be back on the cards in 90 mins 

Unlikely.

I quite like the charts this morning especially the ECM. Cold north west winds are the best for surprise snowfalls for many away from the south as these last few days have shown.

 

 

[northwestsnow]

Just now, Staffmoorlands said:

Unlikely.

I quite like the charts this morning especially the ECM. Cold north west winds are the best for surprise snowfalls for many away from the south as these last few days have shown.

 

 

Agreed,  certainly,as it stands the further North the better,i can see Scotland being frozen and south of Birmingham struggling for cold ( that line could be further north or south at times)...

[damianslaw]

Lots of volatility in the models at present. All uncertain how much energy the Atlantic has.. I would not discount some form of height rise over Scandi - the wedge as some are calling it.. deep pool of cold developing and ripe for blocking.. the key feature all models agree on is low pressure dropping into central/SE Europe and as long as this stays the case the azores high will struggle to ridge east or north east hence we maintain a more amplified flow.

[Snowman.]

Just like that, Scandi heights dream shattered. Once again proving that unless it is literally at your doorstep and every model supports it, it has the chance to vanish from sight. 
 

ECM is okay needs a lite nudge SW of those disrupting troughs to upgrade it in my mind. 
 

Still plenty of time for changes. 

[northwestsnow]

As an aside,  there are literally thousands of kids up and down the country beginning the same journey as many of us  started ,in some cases like mine ,nearly 50 years ago,ie,lampost watching!! my 8 year old nephew was glued to the window yesterday, (wonder where he got that from ).

There is of course something magical about Christmas fair/ lights  and snowy weather at this time of year..

Anyway , coldies need to see 

•Retaining euro low

•Jet into Europe ( NW - SE axis,above will help ,moths to a flame  idea)

•Wedges 

It's finely poised , and it could of course go horribly wrong, but if we avoid the heights to our west / south west ridging into Europe then sliders remain an option, north of the jet =cold, probably slack )

6z I suspect will see GFS move towards ECM 0Z ,we will see shortly...

 

Edited November 29, 2021 by northwestsnow

[LRD]

I did think when I called a 40% chance of Scandi Heights, yesterday, I was being a bit optimistic!

ECM 850s ensembles do not indicate any deep cold but they are not mild either. This is for London

Clusters might be of interest. When Mike P posted them yesterday there were plenty of NW'ly options. Not many W'ly or SW'ly options and even the odd E'ly thrown in

Could be looking at one of those frustrating winter months where the cold is never far away but never really establishes in the UK. But a line from B'ham to the Wash northwards may have chances at times

[northwestsnow]

2 minutes ago, LRD said:

I did think when I called a 40% chance of Scandi Heights, yesterday, I was being a bit optimistic!

ECM 850s ensembles do not indicate any deep cold but they are not mild either. This is for London

Clusters might be of interest. When Mike P posted them yesterday there were plenty of NW'ly options. Not many W'ly or SW'ly options and even the odd E'ly thrown in

Could be looking at one of those frustrating winter months where the cold is never far away but never really establishes in the UK. But a line from B'ham to the Wash northwards may have chances at times

They are cold for London,below the average...

Operation ' wedge watch ' incoming...

 

[Premiere Neige]

Is it the gfs that has the habit of picking up a signal, then dropping it only to return to it later or am I thinking of a different model?

[Frigid]

GFS literally did that with a 18z run not long ago 

[Methuselah]

I suspect we need to pay less attention to 'stonking' operational runs having little or no support from their respective ensembles? IMO, the GFS Operational run (sometimes the control too) have had insufficient support. And, there has been no support from the anomaly charts, either. 

But none of that takes away the fact that parts of Siberia and Scandinavia are now in the 'deep freeze'! Today's GEFS 00Z ensembles:

    

And now for the GFS 06Z!

[Updated_Weather]

It seems the EPS has support of some kind of easterly flow from 7th dec

[fromey]

Make of these what you will

Dam someone beat me to it!

Edited November 29, 2021 by fromey

[Beanz]

20 minutes ago, Premier Neige said:

Is it the gfs that has the habit of picking up a signal, then dropping it only to return to it later or am I thinking of a different model?

Yes, very much so - but we shouldn't hang our hats on that fact.  

Not aimed at you (at all) but it makes me chuckle that every year, people forget the fundamentals.

We all know that an easterly from a Scandi high isn't nailed on and should be taken with a MASSIVE pinch of salt until around 96hrs, anything beyond that is just hints even with cross model agreement.  

Claims of a snowfest from charts at 264hrs should be ignored

We all know the MetO will not 'fall in to line' on these kind of set-ups until they are certain, and the last 24hrs demonstrates exactly why - they have resolve and experience and more resource than we do.  

I am a snow lover as much as anybody here, but one thing I've learnt from many years of this is that watching, waiting and playing the odds on FI signals is far better for my blood pressure and general well being. 

Edited November 29, 2021 by Beanz

[TSNWK]

On 29/11/2021 at 09:36, Beanz said:

Yes, very much so - but we shouldn't hang our hats on that fact.  

Not aimed at you (at all) but it makes me chuckle that every year, people forget the fundamentals.

We all know that an easterly from a Scandi high isn't nailed on and should be taken with a MASSIVE pinch of salt until around 96hrs, anything beyond that is just hints even with cross model agreement.  

Claims of a snowfest from charts at 264hrs should be ignored

We all know the MetO will not 'fall in to line' on these kind of set-ups until they are certain, and the last 24hrs demonstrates exactly why - they have resolve and experience and more resource than we do.  

I am a snow lover as much as anybody here, but one thing I've learnt from many years of this is that watching, waiting and playing the odds on FI signals is far better for my blood pressure and general well being. 

If only I had such self control...