Model Output Discussion - Into Winter

[Harveyslugger]

4 minutes ago, bluearmy said:

Dp’s aren’t great for snowfall south of the north midlands. Nw england marginal 

What are the dewpoints

[Drifter]

Far too far ahead to take notice of, but this must be the most dangerous storm I’ve seen modelled on nwp charts before. 
That would cause carnage!  

[MATTWOLVES 3]

I'm coming at you from a little different angle today.

Mogreps 6z ens I would say are a good 80% in favour of the trend to less cold...How mild I'm not certain! For how long I'm even less certain! 

But I've put in the Oslo ens to see if the cold back aways from the NE...And it remains cold out towards day 8. Let's see how long we can keep that cold in place towards the NE. That would only benefit us further down the line.

Silly season begins on Friday. Yay its officially meteorological Winter...so try and enjoy yourselves and spend a little money if you can. If you can't then don't be coming to me for any,as I'm as free from money as a frog is from feathers.

The next chase awaits.

Edited November 30, 2023 by MATTWOLVES 3

[Huntforsnow]

4 minutes ago, Drifter said:

Far too far ahead to take notice of, but this must be the most dangerous storm I’ve seen modelled on nwp charts before. 
That would cause carnage!  

The day after tomorrow chart that

[minus10]

3 minutes ago, Drifter said:

Far too far ahead to take notice of, but this must be the most dangerous storm I’ve seen modelled on nwp charts before. 
That would cause carnage!  

Yes.... well....

 

 

[sheikhy]

4 minutes ago, MATTWOLVES 3 said:

I'm coming at you from a little different angle today.

Mogreps 6z ens I would say are a good 80% in favour of the trend to less cold...How mild I'm not certain! For how long I'm even less certain! 

But I've put in the Oslo ens to see if the cold back aways from the NE...And it remains cold out towards day 8. Let's see how long we can keep that cold in place towards the NE. That would only benefit us further down the line.

Silly season begins on Friday. Yay its officially meteorological Winter...so try and enjoy yourselves and spend a little money if you can. If you can't then don't be coming to me for any,as I'm as free from money as a frog is from feathers.

The next chase awaits.

Woah woah hold on that blue line for leicester and birmingham was near 0 between the 3rd and 6th december!!leicester now has close -5 850temps till the 6th!!something is stirring in time for the 12zs!!!!!

[James Maidstone]

1 hour ago, johncam said:

Models seem to be agreeing.To be honest would prefer our cold in the next 6 weeks or so when sun is low and longer nights. Once these patterns get established they are hard to shift. 

In 6 weeks time the sun will be at the same angle and the nights will be the same as today

Edited November 30, 2023 by James Maidstone

[MattStoke]

4 minutes ago, James Maidstone said:

In 6 weeks time the sun will be at the same angle and the nights will be the same as today

And SSTs lower.

[A Face like Thunder]

7 minutes ago, minus10 said:

Yes.... well....

 

 

So, two weeks tomorrow, and you heard it here first.

[Dignity]

That GFS hurricane looks so bad it might just come up.

With the whole set up just now not making much sense (figuratively) then something as insane as that might just happen.

Would be more wet and wild than snow though no? Well on one side of it anyways.

 

Imagine if it does verify though

[Lord Grogon]

8 minutes ago, A Face like Thunder said:

So, two weeks tomorrow, and you heard it here first.

Nah. It just looks like a roided up version of Storm Ciaran. Just avoid the Channel and coasts and you'll be fine.

Now, the one a couple of days later however....

[andy989]

1 hour ago, Duane S. said:

I posted this 10 days ago and looks about right so far, that relaxation of favourable ridging/retrogression...

"I posted a couple of weeks ago about the likelyhood of a displaced Azores high becoming a real feature around our neck of the weeks (good & bad?). The good being plenty of Atlantic ridging and retrogression POTENTIAL. IMO this could be a bit of a feature this winter, even in early winter. Pretty much what we are seeing so far. The Jet seems to be displaced more southerly than usual, that could be no pain no gain scenario (An October/November washout being the pain!?). Albeit I wouldn't be surprised to see a relaxation of this just before Mid-December and we endure another short stormy spell, before we go again around Xmas.

I've seen a lot of posts questioning where the amplification signal is coming from recently. Well there will always be a lag effect from the MJO and corresponding Pacific activity. Obviously its influence on a small Island situated on the other side of the globe will massively vary on each occasion, for a whole host of reasons, but we would normally expect to have to wait usually around 7 - 10 days. Looks about right to me. Of course lag alone is only a part of the story, accuracy of the plots and coupling will impact effect massively. Same really for the recent +EAMT as Rossby waves help amplify ridging around the Western Canada region."

That 'relaxation' and potentially a more Atlantic-dominated period now coming into view. I am liking the idea of diving SE jet at the end of the GFS again. This I think will be a pre-cursor to our next window of opportunity, as we go through the festive period.

Snowing in Weymouth first thing this morning, virtually unheard of in November. A good sign of things to come this winter hopefully ?

 

Hopefully the “next window of opportunity” will also be aided by the Canadian warming. 

[andy989]

16 minutes ago, Lord Grogon said:

Nah. It just looks like a roided up version of Storm Ciaran. Just avoid the Channel and coasts and you'll be fine.

Now, the one a couple of days later however....

Storm Ciaran set the new lowest pressure record for England and Wales at 953.3mb at sea level. That chart shows 938mb at 500hpa. I wonder what that would be at sea level 

Edited November 30, 2023 by andy989

[warrenb]

Has anyone ever seen an ENS spread like the short ECM 6z.

Wetterzentrale.de - Diagrams

WWW.WETTERZENTRALE.DE

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Forecasted 850 hPa Temp. from ECMWF, 06Z

 

[IanT]

24 minutes ago, Lord Grogon said:

Nah. It just looks like a roided up version of Storm Ciaran. Just avoid the Channel and coasts and you'll be fine.

Now, the one a couple of days later however....

That would make for an interesting period of weather…

[sheikhy]

2 minutes ago, warrenb said:

Has anyone ever seen an ENS spread like the short ECM 6z.

Wetterzentrale.de - Diagrams

WWW.WETTERZENTRALE.DE

---

Forecasted 850 hPa Temp. from ECMWF, 06Z

 

Its ridiculous!!if ecm fails again at just 72 hours this evening then questions must be asked about the model!thats gona be 3 times in the last 10 days it has failed then!!!ecm has always been my go to model but its performance recently has been woeful!!!the spread is crazy at just 4 or 5 daya out!!!

[Battleground Snow]

5 minutes ago, warrenb said:

Has anyone ever seen an ENS spread like the short ECM 6z.

Wetterzentrale.de - Diagrams

WWW.WETTERZENTRALE.DE

---

Forecasted 850 hPa Temp. from ECMWF, 06Z

 

Tell tale sign that there is extreme model uncertainty at this juncture, calling anything past 96 hours is quite brave I would say.

[knocker]

14 minutes ago, sheikhy said:

Its ridiculous!!if ecm fails again at just 72 hours this evening then questions must be asked about the model!thats gona be 3 times in the last 10 days it has failed then!!!ecm has always been my go to model but its performance recently has been woeful!!!the spread is crazy at just 4 or 5 daya out!!!

I take it you do appreciate that currently the analysis has a warm front edging slowly north on Sunday into the cold air so the ens not too surprising

[Paul]

21 minutes ago, Battleground Snow said:

Tell tale sign that there is extreme model uncertainty at this juncture, calling anything past 96 hours is quite brave I would say.

The multi-model ensembles are certainly quite widely spread.

 

Clearing out the clutter and removing the more extreme ends of the scale, the 90th percentile is still a wide spread, but there is a direction of travel toward something at least a bit less cold in the medium term. 

[sheikhy]

5 minutes ago, knocker said:

I take it you do appreciate that currently the analysis has a warm front edging slowly north on Sunday into the cold air so the ens not too surprising

Yes and you could see that on the pressure charts on ecm with that slight bend to the isobars near the m4 corridor but still the ecm has not been great lately!lets see what the 12z brings!!!!icon about to roll out....

[Downburst]

Yes, further north is more behaved, Dublin for instance. I'd be looking at the mean here. And thanks @knocker for the reminder of looking at the expected conditions when looking at ensembles for a location to put the scatter into context, obvious but easily overlooked.

[Battleground Snow]

6 minutes ago, knocker said:

I take it you do appreciate that currently the analysis has a warm front edging slowly north on Sunday into the cold air so the ens not too surprising

That's true, and obviously magnified because of the potential impact of heavy snow to various areas, and possible  extension of the cold, but to illustrate the variation, look at the range of options on the table at a relatively short lead time.

[Notty]

1 hour ago, Day_9 said:

Crazy member wants -20 850’s so much scatter.  I think we can safely say even at the short range we are probably in one of the most unpredictable winters for some time

 

Agreed. The spaghetti starts in just four days. Uncertainty rules.

[knocker]

10 minutes ago, sheikhy said:

Yes and you could see that on the pressure charts on ecm with that slight bend to the isobars near the m4 corridor but still the ecm has not been great lately!lets see what the 12z brings!!!!icon about to roll out....

Surface chart

[knocker]

14 minutes ago, Downburst said:

Yes, further north is more behaved, Dublin for instance. I'd be looking at the mean here. And thanks @knocker for the reminder of looking at the expected conditions when looking at ensembles for a location to put the scatter into context, obvious but easily overlooked.

Yes when something looks odd the first question should be why?