Model Output Discussion - mid Autumn

[Battleground Snow]

The icon/ukmo solution is represented by a fair few ECM EPS members, all we can say at the moment is that post day 8  has a lot of options on the table,

120-168 is good atm

Edited November 25, 2023 by Battleground Snow

[snowking]

1 hour ago, nick sussex said:

ECM hits the buffers by day 8 . Once again the models have overdone the Greenland blocking at longer range .

That’s still a way off but the trend hasn’t been great . 

Absolutely this. I can’t believe that so many years have passed by with so many phantom height rise debacles and yet despite numerous upgrades to all model suites in the intervening years we still don’t seem to have solved this modelling tendency.

I always tend to be sceptical of height rises to the NW beyond day 5 because of this reason. One of these days soon the modelling suites will call one correctly, but it will very much be stopped clock syndrome when they do.

[Blessed Weather]

13 minutes ago, weathercold said:

London 

Why not add your location to your profile? It's always nice for other members to see what part of the country you're from, especially if you're in your Regional thread and post about the snow in your back yard. I've marked a screen grab showing how:

[Ali1977]

People are commenting as if the writing is on the wall long term, where as this actual cold spell kind of appeared from a wrongly modelled northerly at about Day 5 - the cold is coming, and any breakdown being modelled beyond day 6-8 is just as likely to swing colder again!! 

[PiscesStar]

1 hour ago, Big Gally said:

I’m hoping to see a return of the cold weather as we approach Christmas. 
It’s great start to winter considering the dross the uk has endured the last few years.

Many more twists and turns to come.

 

I think anything woukd be an improvement on previous seasons. Tonight's runs will be important to reinforce this. Keep the faith all! 

[Uncertainty]

13 members go for a reversal by early Jan. 

The 8-10 period is a long way off in modelling terms and the ecm hasn’t exactly been prophetic with this spell. If the block does break down days 8-15, which today’s trends have edged towards slightly, we would only be returning to the forecast we thought we were getting for December. The big differences now being:

a) The SPV is far weaker

b) We have seen already the jet is behaving strangely 

The next pacific wave should be coming through in mid December, combined with the weak vortex, that’s a thrilling place to be before winter even actually starts!

FWIW, the NAEFS still look interesting out to the 9th of December 

The eps have 3 clusters in the extended:

- Continued southerly tracking jet under the Greenland wedge

- flat

- Strong high pressure over the top of the country

As a few have said, the rather profound momentum drop / unfavourable cycle of the mjo probably make option 2 increasingly likely with time. But how long the transition takes and, crucially, how long it lasts, are still completely up for grabs. I think the regimes demonstrate this quite neatly!

By early Jan, only around 20% are +nao.

I think we’re here for the long haul. Next week is just the beginning!

 

[Dennis]

EC ENS 8 dec 

[TauntonRoss]

Everything seems fine to me, what happens beyond the end of next week is irrelevant right now as its a week away, let's get the end of week settled and sorted, the outcome of that will go some way to determine what happens afterwards. UKMO is brilliant and so is the GFS at the end or final 3rd but that's not the most reliable...just shows there are many different options available and charts will flip flow for a bit yet.

[northwestsnow]

EC46 has upgraded the cold anomaly 27th to 4th

[Ali1977]

Not sure what model they used, and which version but the bbc just tweeting this weeks weather saying it could stay cold for 2 weeks 

Next Saturday below.

[PiscesStar]

2 minutes ago, northwestsnow said:

EC46 has upgraded the cold anomaly 27th to 4th

The anomalies all remain solid and that should be reflected in the models and what they portray expect twists and turns on this ride folks!!! 

Edited November 25, 2023 by PiscesStar

[bluearmy]

Just now, northwestsnow said:

EC46 has upgraded the cold anomaly 27th to 4th

That’s next week ….. we surely will don’t need the ec46 to know likely  temps Mon 27 for a week 

[northwestsnow]

4th to 11th

ties in with BBC tweet..

[The Enforcer]

30 minutes ago, bluearmy said:

Stockholm?  Stockholm?  It’s not like anyone here would be going there ……

They'd never be able to get there when all the snow next week closes the airports and the North Sea freezes over.

[Bricriu]

1 minute ago, northwestsnow said:

4th to 11th

ties in with BBC tweet..

So  is it milder the following week?  

[TauntonRoss]

2 minutes ago, northwestsnow said:

4th to 11th

ties in with BBC tweet..

Hence why people need to chill, the charts will catch up.

[bluearmy]

The 12z ops have thrown a bit of a curve ball beyond day 8. It may go somewhat flatter beyond that but it’s still likely to be colder than average for days 9/10 even if it does. 
 

we have to wait to see if this breakdown to flatter produces a southerly jet at a latitude to keep an unknown portion of the U.K. in ‘proper winter’.  
 

And more importantly, it simply is far from resolved if we will go flatter as week 2 progresses. Onto the 00z suites !  (The AI models seem to be moving towards flatter too btw) 

[mbrothers]

1 minute ago, Bricriu said:

So  is it milder the following week?  

What in 3 weeks ?

[Derecho]

Next week looks messy, akin to early December 2008 or December 2020. It's a shame we don't look like getting some deeper cold later in on Tuesday... just not enough of an easterly flow.

I can't complain at this early point in the winter though and later next week still looks of interest.

Longer term is the risk of the heights to our NW waning and allowing an Atlantic influence to set in but it wasn't that long ago EC was suggesting mild weather at present with no northerly so it's still all up in the air at this point.

The NOAA 8-14 day outlook is at least still showing anomalous heights to the NW

Edited November 25, 2023 by Derecho

[The Enforcer]

I can't see how the level of blocking Day 8+ can possibly be resolved whilst there is so much variation in the period before that, primarily the position, intensity, amount of phasing, of LWP, which has knock-on implications for the blocking beyond that.

Edited November 25, 2023 by The Enforcer

[Kentspur]

10 minutes ago, northwestsnow said:

EC46 has upgraded the cold anomaly 27th to 4th

Looks great in Stockholm even better for Dennis further west ill need 3 pairs of budgie smugglers to keep me from getting frost bite in unwanted places 

[bluearmy]

Have I walked into a parallel universe?

every model (both ops and ens) are showing a cold week 27th to 4th - and have been for days 

there is no ‘catching up’ and no question on cold. How cold is unknown beyond day 5/6.  What  happens for the 7 day charts 4/11th dec also has cross model agreement on the ens  - staying cold but less clarity across the three suites. 

Edited November 25, 2023 by bluearmy

[Methuselah]

20 minutes ago, Ali1977 said:

Not sure what model they used, and which version but the bbc just tweeting this weeks weather saying it could stay cold for 2 weeks 

Next Saturday below.

And what about that snow-buildup over Russia and Scandinavia? That cannot be a bad thing. 

[iceman1991]

34 minutes ago, Ali1977 said:

People are commenting as if the writing is on the wall long term, where as this actual cold spell kind of appeared from a wrongly modelled northerly at about Day 5 - the cold is coming, and any breakdown being modelled beyond day 6-8 is just as likely to swing colder again!! 

Out of genrel interest why you think that is the case as I really hope your right of course ? 

[DIS1970]

2 hours ago, Daniel said:

Ecm is fine! Learn how to read charts or don't comment 

Yep, best way, been doing for years.