Model output discussion - late November

[SMU]

18 minutes ago, kushty snows best said:

Surely the air not cold enough at day 7 that the low comes into ? I'm sorry to my eye the ECM is poor going forward !

Depends on how much cold gets across the UK in the 120-144 window-

GFS spread is still 8 degrees for London

Post 192 > Its a developing scenario where  the expectation is that the high topples - however the fact thats been pushed back on the ECM & elements of the GFS indicates its not as clear cut as you may think-

 

[knocker]

Despite some differences. the east Pacific ridge being one, the ext EPS in the same ball park as the GEFS so the charts should suffice

[BLAST FROM THE PAST]

With the changes in detail that have been happening why are some folk going on about toppling post 7 days?  I actually think the runs are good, below average which thus is cold and no 1000 mile SW’lies and a lovely cooling near continent.....not bad going forward.

 

BFTP

[carinthian]

2 hours ago, Steve Murr said:

Morning- I hate to be the one to keep opposing the posts but this morning is very nice-

Prospects of milder atlantic weather keep getting pushed back to day 10.

Also on the latest ECM the block at 192>216 gets propped up more by low pressure moving south out of the pole-

Prospects of snow around day 7>8 with the sliding low 

Some record breaking SSWs in the overnight as well ( in terms of negative numbers )

Morning all, yes that sliding low for next weekend was being flagged by our team over here yesterday. Possibly could be even further south. If that is the case , a cold wedge of air would be then established over much of the British Isles with an increasing threat of snow for Southern Britain next weekend. Will get an up date from the team later this morning to see if this possible development is on-going. Longer term at day 10 many models go to cut off the cold supply by toppling the Mid- Atlantic ridge although it is noted GFS this morning holds it a bit longer as @Steve Murr has indicted in his post.

C

Edited November 23, 2019 by Paul

[ItNeverSnowsInWindsor]

1 hour ago, kushty snows best said:

I think we know from past that it will probably will !!

Will it though ? October and November have been below average.

[IDO]

The dynamics of the long-wave NH pattern suggests the Ridge toppling is within the standard deviation of the most likely probability. I suspect we will need a few tweaks with the major players to avoid. 

We can see on the ECM D10 chart the train of HP cells filing east to west, so in all essence a mobile pattern though not aligned to the usual zonal charts we expect at this time:

With the tPV open to persuasion, a wave pattern does ensue in the next 10-days but appears to be overloaded by the magnitude of HP cells, so ATM a static Rossby Wave train fails, as each ridge topples.  

No doubt this forcing can be explained by experts and to whether the models have the momentum correct, as any slow-down could allow more time for WAA, allowing wedges to go to higher latitudes, and get that cold flow redirected. The topple of the Atlantic ridge remains in the 8-10 day window of model volatility so by the end of the weekend, clarity.

[jules216]

this morning EPS are trending milder for my location in Slovakia, mean bottoms out at -4.4C T850 in the 4th December, few days later is back up to around 0C T850. This to me suggests more of a toppler scenario then sustained blocking, for now it appears we will descend in to normal December conditions for about a week and then perhaps scenario where Azores high topples in to continent with westerly winds.

[Jonathan Rhodri Roberts]

A fine spell of weather still on the cards for early December as high pressure builds in for a short time, but after what's been the case during Oct & Nov with frequent and often persistent rain, even that is better than nothing ️

[snowray]

I think we may see a few more surprises today, sorry cant post charts but ICON 06z shows more of an undercut at T120, pitty it don't go out to T144, be interesting to see if 06z follows suite.

[Methuselah]

7 minutes ago, snowray said:

I think we may see a few more surprises today, sorry cant post charts but ICON 06z shows more of an undercut at T120, pitty it don't go out to T144, be interesting to see if 06z follows suite.

I hope so, snowray...'cause there's little in the GEFS 00Z temperature-ensembles that sparks much, in the way of euphoria...?

    

And now for the GFS 06Z: feted or slated?

[Frosty.]

Looking into early December the Ecm 0z ensemble mean suggests the azores high / ridge gradually building / nosing in with tropical maritime air feeding around the top of it and into the uk so becoming milder following a period of cooler weather.

[shaky]

Changes early on low deeper across the uk which is what we dont want cos it just drags in milder air with it and also less amplification around eastern states!!but like steve says its the 06z so expect it!

Edited November 23, 2019 by shaky

[Met4Cast]

Any cold spell at the end of the month is most likely to be short lived, I think a spell of Atlantic driven +NAO is likely during the first half of December.

Pretty strong signal from the EPS there. 

[coldwinter]

11 minutes ago, shaky said:

Changes early on low deeper across the uk which is what we dont want cos it just drags in milder air with it and also less amplification around eastern states!!but like steve says its the 06z so expect it!

It's still better than the UKMO, or has that now been binned as it doesnt show what we want? 

 

[Weathizard]

2 minutes ago, coldwinter said:

It's still better than the UKMO, or has that now been binned as it doesnt show what we want? 

 

It’s a real shame because Greenland is absolutely ripe for blocking between day 4-7 but we just can’t catch a break with these phasing lows flattening any ridges, so any attempt at a proper block or even a ridge keeps getting squished.

Remember people saying the 6z yesterday should be binned, we’ve ended up somewhere in between the 0z ECM and yesterday’s 6Z, with both being over progressive in different ways. 

 

[blizzard81]

6 minutes ago, Met4Cast said:

Any cold spell at the end of the month is most likely to be short lived, I think a spell of Atlantic driven +NAO is likely during the first half of December.

Pretty strong signal from the EPS there. 

That makes for very grim viewing indeed and ties in with ecm and ukmo seasonals.

[Met4Cast]

5 minutes ago, coldwinter said:

It's still better than the UKMO, or has that now been binned as it doesnt show what we want? 

 

ECM isn't the best either, a transient northerly followed by a toppling high 

But, that's the 00z ECM which probably doesn't verify very well, unless it's showing cold of course  

[coldwinter]

Very poor GFS, Still time for things to go back the other way and give us at least a shot of some 'proper' cold, but squeaky bum time is fast approaching, fingers crossed! 

[Danielvn]

13 minutes ago, coldwinter said:

It's still better than the UKMO, or has that now been binned as it doesnt show what we want? 

 

Probably more runs required 

I stupidly come back every winter hoping to see something different, but every winter I read the same posts which hype up something off in FI, disregard models that don’t show cold and use their crayons on model charts to show what they want the weather to do.

Edited November 23, 2019 by Danielvn

[Danielvn]

7 minutes ago, Met4Cast said:

ECM isn't the best either, a transient northerly followed by a toppling high 

But, that's the 00z ECM which probably doesn't verify very well, unless it's showing cold of course  

<something about the ECM not handling these situations well with no evidence whatsoever attached>

[Tim Bland]

1 minute ago, coldwinter said:

Very poor GFS, Still time for things to go back the other way and give us at least a shot of some 'proper' cold, but squeaky bum time is fast approaching, fingers crossed! 

24hrs ago this forum wasn’t ecstatic with the output...just shows how quickly things can change and they can easily flip back the other way. “Squeaky bum time” is end of March when the last chance of a cold spell is on the rocks! ....it’s not even winter for another week!...

[SMU]

Wheres that gif with the bloke smashing his computer up- thats how I feel about the posts on here some days

Not sure why everyone is worried about day 12-13 when the GFS still cant get day 7 correct.

& still people are fretting about the 06z past 144>  Hello its s*ite

As reference to the discussion yesterday with the inference of the GFS 06z going to be wrong at day 7-

Look at how much the model has changed * in favour of cold * in just 24 hours from day 7 now to day 6.

That shows the 06z bias in all its glory - 

* To far East & to fast with the atlantic & pacific jet.

* To quick to eliminate heights over Greenland

* Poor at energy separation between 2 systems

* Heights to high in NE flows.

As a result of this the 850s change over 24 hours- Thats a 6 degree swing for most & at some points like NI as much as 8 degrees.

Wheres the head bang smiley.

Edited November 23, 2019 by Steve Murr

[MATTWOLVES 3]

Weekend gloom is here!! Not the forum guys.... The poxy weather. Most definitely a bit of a roller-coaster ride with the models just now. The pattern beyond next week is most definitely not nailed down just yet!! Some interesting ensembles again from the 0Z. Some cold shot, and still the persistent signs of a build of significant cold to the NE/E. This is a strange set up this coming winter folks, the Atlantic remains sluggish!! Just what as happened to the named storms this Autumn! I don't even think Exeter are as confident of a mild dominated spell moving forward. Jon hammond had pointed out there was very mixed signals and contradictory situations with the output moving forward. At the very least l, this coming winter will be keeping us guessing to the very last minute. And I'm pretty sure, that's the way we like it. Have a great weekend if you can.... Not sure about me, I'm stuck under another ruddy rain cloud..

[Danielvn]

1 minute ago, Steve Murr said:

Wheres that gif with the bloke smashing his computer up- thats how I feel about the posts on here some days

Not sure why everyone is worried about day 12-13 when the GFS still cant get day 7 correct.

& still people are fretting about the 06z past 144>  Hello its s*ite

As reference to the discussion yesterday with the inference of the GFS 06z going to be wrong at day 7-

Look at how much the model has changed * in favour of cold * in just 24 hours from day 7 now to day 6.

That shows the 06z bias in all its glory - 

* To far East & to fast with the atlantic & pacific jet.

* To quick to eliminate heights over Greenland

* Poor at energy separation between 2 systems

* Heights to high in NE flows.

As a result of this the 850s change over 24 hours- Thats a 6 degree swing for most & at some points like NI as much as 8 degrees.

Wheres the head bang smiley.

That’s exactly how people feel reading the ramping and pseudo science posted on here sometimes. When it’s showing what people want in FI model X is great at sniffing out these situations, when it all changes then people talking about how it’s still all to play for and anything could change. We all know that when the models move away from a cold solution it’s far far more likely to verify than the eye candy charts that get posted on here all the time.

[SMU]

4 minutes ago, Danielvn said:

That’s exactly how people feel reading the ramping and pseudo science posted on here sometimes. When it’s showing what people want in FI model X is great at sniffing out these situations, when it all changes then people talking about how it’s still all to play for and anything could change. We all know that when the models move away from a cold solution it’s far far more likely to verify than the eye candy charts that get posted on here all the time.

1) Define ramping when someone is explaining to you how a model works

2) How are we moving away from cold when the above images show the model is getting colder.

Don't confuse me & or include me in the above statement if someone is laying out exactly model flaws & when & where its broken. 

Edited November 23, 2019 by Steve Murr