Model Output Discussion - the cold has arrived

[LRD]

10 minutes ago, northwestsnow said:

It's out, it's not as bad as I feared 

Already looks wrong in week 1! Unless the shorter term models have got it wrong for next week...?

As frosty ground and Battleground Snow say, doesn't it use starting data from the 0z runs? If it can be so wrong in the short term, it sort of renders it a bit useless

Edited December 15, 2022 by LRD

[Benny123]

That’s a big temperature contrast upstream..

[tight isobar]

20 minutes ago, MATTWOLVES said:

Ok so it's been a poor evening so far,but hey I'm happy as it's nearly Xmas.. my dad's health is failing fast so as long as I can get him smiling come the festive period I will be happy.

A crumb of comfort from the ens is that there's still a fair few colder members.

Onwards and upwards good people.

Sending strength x

[Daniel*]

As we know ECM op was very mild

EPS 0z was keen to turn things colder quite quickly 12z plot will be updating soon. You would think a big flip is unlikely but let’s see…

 

New in: Next week has flipped predominately milder…

 

Edinburgh mild weather brief 

 

Manchester

Edited December 15, 2022 by Daniel*

[blizzard81]

19 minutes ago, MATTWOLVES said:

Ok so it's been a poor evening so far,but hey I'm happy as it's nearly Xmas.. my dad's health is failing fast so as long as I can get him smiling come the festive period I will be happy.

A crumb of comfort from the ens is that there's still a fair few colder members.

Onwards and upwards good people.

I'm sorry to hear that mate. Hope your dad isn't suffering. 

[chris55]

3 minutes ago, Benny123 said:

That’s a big temperature contrast upstream..

Hopefully that’ll drive some WAA into the Artic due to the lack of zonal flow generally  

[Nick F]

12z EPS day 10 h500 mean looks pretty amplified with the upper flow, over the N America and N Atlantic by Xmas Day.

If that -ve height / trough anomaly west of Iberia cuts-off eventually, as would be expected with a highly amped flow as indicated above, it could lead to pressure rises over the top close our N and NW, pretty much what the week 2 progression to week 3 suggests on the updated EC weeklies:

So even though we may endure a mild week in the south next week, could turn cold for all Xmas or Boxing Day onwards ...

[bluearmy]

10 minutes ago, Benny123 said:

That’s a big temperature contrast upstream..

Of course very low anoms across the lower middle states and high anoms across ne Canada could mean that actual temps are pretty similar across both areas 

[swfc]

1 hour ago, MATTWOLVES said:

Thing is to many are basing this on 1 days output! Last night we had a colder trend emerging...fast forward 24hrs and its trended milder! This does not set the future in stone..what happens if all the mornings run go cold again? Do we say yep looking good...cold spell back on..and then come the evening runs they trend mild again. Do we say oh well that's it till after Xmas all over again?

I can't for the life of me work out why so many on here take every op run as some kind of guarantee and get really fed up when they downplay any cold. We all know the models are struggling and there's nothing to suggest that this evening is any different.

Also worth pointing out was the fact the met update points to colder conditions throughout the Xmas period!

You know what I think? If we were on the verge of another 62/63 winter there would still be some saying its not gonna last and the end is in sight everytime they viewed an op run! And I tell you what even back in the day during severe Winter spells the data would make a mess of it all ending with mild in sight!  Fast forward 40 years and not a lot as changed! OK perhaps the accuracy is better for a 5 day period...but that's about it!

If Friday and the Weekend output all goes mild I will perhaps worry a tad! But not for too long,as anything beyond 5 days in the UK is going some. And also if it trends mild all weekend..I think many of us will blame it on a lack of data with Xmas coming up

You know what I mean! 

Your wasting your time Mattbe all good on 18z and EC oz

Have a beer man

[Nick F]

13 minutes ago, Benny123 said:

That’s a big temperature contrast upstream..

They are getting excited over on the eastern US weather forums, while we get a little downbeat over our prospects next week, as that cold there comes with a possible big east coast Nor'easter end of next week, which will probably amp ridging downstream over the far N Atlantic which may benefit us from Xmas Day onwards.

[Drifter]

Can someone tell me what the eps ensembles are? Are these another name for ECM ens?

 

[bluearmy]

2 minutes ago, Drifter said:

Can someone tell me what the eps ensembles are? Are these another name for ECM ens?

 

Yes 

[Paul]

Just a quick reminder that the community crowdsourced model highlights thread is available.

The posts which get copied in there are controlled entirely by the 'insightful' reaction in here. So, please continue giving that reaction to the posts you think are most insightful and interesting, so they can be copied into the highlights thread. The insightful reaction is this one:

And for those who would rather a more concise read of the model discussion, the highlights thread is here:

 

[Frosty.]

I’ve seen worse ECMWF 12z ensemble means for crimbo day!.. just saying! …it’s usually very mild innit!   

Edited December 15, 2022 by Frosty.

[Derecho]

36 minutes ago, Benny123 said:

That’s a big temperature contrast upstream..

Not going to lie, I look at the synoptics just before Christmas over the eastern seaboard and I get very envious. Absolute dream synoptics for them.

We'll be left with the stormy remains probably if that transpires. 

The -5C 850hpa line gets well into Florida on the EC and GFS!

[Mark wheeler]

Well this looks encouraging. However I am by no means an expert at reading these charts . I suppose it depends where any block could it happen to set up.

Edited December 15, 2022 by Mark wheeler

[sheikhy]

Be very surprised if icon is the same as the 12z!!!surely gona jump ship now!!!

[Jake March-Jones]

1 minute ago, sheikhy said:

Be very surprised if icon is the same as the 12z!!!surely gona jump ship now!!!

Just watch the evening runs go cold haha

[Frosty.]

There’s a few GEFS 12z members which could spell Victory for coldies  around Christmas time! … keep the faith! V for Victory!

 

 

[Jake March-Jones]

5 minutes ago, Frosty. said:

There’s a few GEFS 12z members which could spell Victory for coldies  around Christmas time! … keep the faith! V for Victory!

 

 

At what point do we have to say we're clutching at straws??? I mean... As long as there's hope we can hope eh??? 

[cheese]

16 minutes ago, Quicksilver1989 said:

Not going to lie, I look at the synoptics just before Christmas over the eastern seaboard and I get very envious. Absolute dream synoptics for them.

We'll be left with the stormy remains probably if that transpires. 

The -5C 850hpa line gets well into Florida on the EC and GFS!

Florida has seen temperatures as low as -19C before. That’s the ‘benefit’ of being on a huge continental landmass with no mountain range to block cold Arctic air flooding south. 

[Battleground Snow]

Can't believe I'm sharing a 72 icon chart, but that is some difference between ecm at that short timeframe!

Edited December 15, 2022 by Battleground Snow

[Allseasons-Si]

1 hour ago, MATTWOLVES said:

Ok so it's been a poor evening so far,but hey I'm happy as it's nearly Xmas.. my dad's health is failing fast so as long as I can get him smiling come the festive period I will be happy.

A crumb of comfort from the ens is that there's still a fair few colder members.

Onwards and upwards good people.

Sorry to hear this Matt and i know he has been ill for some time and wish him all the comfort in the world and from everyone here on Netweather, and peace to him.

1 hour ago, Nick F said:

12z EPS day 10 h500 mean looks pretty amplified with the upper flow, over the N America and N Atlantic by Xmas Day.

If that -ve height / trough anomaly west of Iberia cuts-off eventually, as would be expected with a highly amped flow as indicated above, it could lead to pressure rises over the top close our N and NW, pretty much what the week 2 progression to week 3 suggests on the updated EC weeklies:

So even though we may endure a mild week in the south next week, could turn cold for all Xmas or Boxing Day onwards ...

Thanks Nick for this,...short term pain for long term gain,...maybe,the latest CPC 6-10 and 8-14 day anomalies back the EPS

and the ext'd shows -ve height's dropping south into Iberia.

 

Edited December 15, 2022 by Allseasons-si
typo

[stodge]

Evening all

To be fair, time was called on the current cold spell earlier in the week and a rapid transition to milder weather will now happen in the second half of the weekend.

As to the lead up to Christmas, there still remains a small window but tonight's runs have trapped most fingers in the window frame with the troughs phasing and keeping the milder airflow.

I didn't think ECM 12Z OP was too bad - the T+240 looks a very good chart in terms of the direction of travel:

A nice disrupting trough and heights to the north west - may not amount to anything but I've seen a lot worse.

No clue as to the New Year - the disconnect between the stratosphere and the troposphere keeps things interesting.

[Singularity]

This weekend, just a couple of days from now, a little low by Iceland will interact with the trough from the Atlantic and either:

- Be absorbed into the circulation of the bigger low as that races past to its southeast, the whole lot then heading to Scandinavia by Wed 

or

- Avoid being absorbed and then develop into an intense low that holds up the trough across the UK for a day or two while maturing to the N or NW of the UK

That 2nd scenario has suddenly become the majority vote of the deterministic runs this evening. It leaves less room for a ridge to our west, allowing the trough to the west of that to cut across and send over a low or two to  visit our shores.

At such short lead time this would usually be final, but that little low looks very borderline to me, its future highly sensitive to fine details. Hence we still see a fair few colder outcomes in the ensemble sets even as the mean has shifted milder. 

So who knows, things might look markedly different yet again tomorrow. Or they might not, in which case I’ll frankly enjoy the reduced heating bills for the 4-5 days or however long the milder interlude lasts (I’m really not convinced by runs that keep it going 7+ days).