Model Output Discussion - cold spell to end Autumn

[nick sussex]

The wheels have really come off this morning with a spawn of satan shortwave blocking the clean flow from the ridge developing ahead of the eastern moving Pacific troughing over Canada across to Iceland.

Its this which stopped an earlier calamity. The amplification arrives too late by which time the UK is stuck on the wrong side of the jet.

Very disappointing to see yet another sorry episode of a northerly imploding.

The GFS is least worst this morning as it eventually pushes the pattern se, the ECM really finds the worst phasing point and delivers a pile of crud at day 10.

I can't imagine the ECM could plot such vile output again tonight!

 

 

[samalllpop]

Maybe this high might be good guys.... it gives more cold weather to tap into to the north of us and east? It will also bring down ground temps..... and we have so much going for us looking at the models and nothing has been decided! 

[johnholmes]

Just to cheer you all up, at least those who are looking beyond a week ahead the 500 mb anomalies, well ECMWF-GFS this morning, are not good reading if you want deep cold.

For a couple of days all 3 had gone with the idea of some kind of 500 mb ridge from the Azores well into Greenland, NOAA last evening still does even in the 8-14 day mean chart. Not so the other two this morning although whether the charts shown below are a major shift or just a temporary hiccup will not be known for another 24-48 hours.

Why not enjoy the cold now and for the rest of this week. Some down the eastern side, even on low ground, will see the odd passing sleet/snow shower and high ground is likely to see a temporary covering. Frost for many. Just what is expected in late November early December by some of you?

Links below

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

[Summer Sun]

GEM follows on from it's past few runs bringing in less cold air through the weekend and this continues into next week

Temp won't be spectacularly high more like higher single figures and maybe low double figures in the west with Ireland getting into the low teens at the end 

[karlos1983]

Bitterly disappointing output this morning across the board really.

Throughout the past few days one post that really stuck out in my mind was Tamara's post from a few days ago. Worth another read and a bookmark me thinks.

 Things could still change of course. have a good day everyone and enjoy the cold this week, it's only the weather 

Edited November 28, 2017 by karlos1983

[Sky Full]

As far as I can see there is nothing to get depressed about in the charts this morning.  None of the models are proposing to let the Atlantic become the driving force in the foreseeable future, there are several ways to bring colder conditions across the UK in the days ahead, and the jet remains disorganised and relatively weak (at least, according to the GFS):

This appears to be the best start to Winter we have seen for at least a couple of years.

Dont panic, Mr Mannering!   

 

Edited November 28, 2017 by Sky Full
Edit

[Frosty.]

1 hour ago, lassie23 said:

What northerly beast?

It was a joke, you obviously didn't read the meow part!

Anyway, no use crying over spilt milk, the models chop and change in the unreliable timeframe..twas ever thus.

Edited November 28, 2017 by Frosty.

[Seasonality]

1 minute ago, karlos1983 said:

Bitterly disappointing output this morning across the board really.

Throughout the past few days one post that really stuck out in my mind was Tamara's post from a few days ago. Worth another read and a bookmark me thinks.

 Things could still change of course. have a good day everyone and enjoy the cold this week, it's only the weather 

Well said Karlos. The thing about this forum is that there are plenty of enthusiasts, perhaps even a few dramatists if I'm being cheeky , but only a few experts. Tamara is very much one of the few and her posts are always worth paying attention to.

[Daniel*]

ECM 12z looks a tad progressive to me, if things can go wrong... 

No done deal yet, many times I’ve seen the OP & ensembles go the other way, only for them to swing back following the doom merchants in full voice never mind the fat lady. While the trend is not our friend, but it was a very short time ago, see where that got us, it’s wise to not feel it’s been dropped. Getting a decent block of a high enough latitude especially with no help from no tropical forcing from MJO etc, to Greenie is very challenging I don’t think impossible, fraught with landmines, indeed last winter we had the very same challenge. I’ll take a Scandi high please. Uncertainty is still v high despite the appearance the models have come to a consensus. All still up for grabs this morning, although we may be a bit pushed back again with not so much of a quick reload following a less cold weekend and beyond possibly. In D10 we have another wave of amplification it’s being consistently modelled, so it does appear a bit of a reloading pattern of our ridge, let’s see what the day brings, but it can only get better I only hope. Good thing too at D10 on ECM 12z that the vortex has no inclination to rear its ugly heard, compare to 12 months back it was in the start of the process. 

 V 2016 .

[Gavin Hannah]

To cheer everyone up.

 

My two cents. Despite the outputs flip flopping longer term, the consistent feature is the HP to our West.  This fits in with my gut feeling that December is going to be Nrlys, interspersed with 'milder' blips. Compare the current setup to the last few winters and I'm rather pleased with whats on offer. No atlantic steam roller insight. I even waxed my snowboard last night. All ready for Xmas sliding!

 

 

Edited November 28, 2017 by Gavin Hannah

[I remember Atlantic 252]

2 minutes ago, Gavin Hannah said:

To cheer everyone up.

 

My two cents. Despite the outputs flip flopping longer term, the consistent feature is the HP to our West.  This fits in with my gut feeling that December is going to be Nrlys, interspersed with 'milder' blips. Compare the current setup to the last few winters and I'm rather pleased with whats on offer. No atlantic steam roller insight. I even waxed my snowboard last night. All ready for Xmas sliding!

 

 

Having a laugh, that's 384, 240 on ECM is bad enough

[Gavin Hannah]

1 minute ago, I remember Atlantic 252 said:

Having a laugh, that's 384, 240 on ECM is bad enough

Well obv, but it's pretty lol.

[Kentish Snowman in Yorks]

5 minutes ago, I remember Atlantic 252 said:

Having a laugh, that's 384, 240 on ECM is bad enough

It does seem to be a recurring theme in the output though.  That blocking in the Atlantic does not just look like imploding.  The signal is there for it to remain as we head into December and if we get a little luckier with the positioning of those damn shortwaves (hate that word) then a huge northerly may be back on the table at relatively short notice!

I just think the doom and gloom this morning whilst understandable if you are of a cold persuasion seems a little over the top and dramatic if I am being honest.

Eyes down for a frigid 6z?!  

[Had Worse]

Did we not have the models flip a week or two ago . I remember it being shown as mild, even zonal and then....

Eye candy charts were a plenty.

I have the feeling that we are going to repeat this scenario and cold will be delivered.

[feb1991blizzard]

Ironically now the UKMO is the best output wrt the N'ly shot.

[Frosty.]

There were 130 + members on here at 7 am and now there's 7..it's a shame but next week is still an unreliable timeframe so things could still improve upstream on any run and get this place buzzing again!

Edited November 28, 2017 by Frosty.

[Man With Beard]

9 minutes ago, feb1991blizzard said:

Ironically now the UKMO is the best output wrt the N'ly shot.

It is very ironic because the UKMO was the first to spot the fly in the ointment a couple of days ago with the interfering Atlantic low. Perhaps it's got the T144 stage right again now!

I've looked through all 51 EC ensembles between T192 and T240 and, in comparison to yesterday when there were maybe 20% of runs which were not salvageable for cold, today there are as many as 50% or 60% of runs which will not result in a quick return to Arctic influenced weather. Whereas yesterday the mean was being skewed away from a colder scenario by an outlier set of runs with Euro highs, my judgement today is that the mean is actually being skewed away from a milder scenario by a the minority of runs persisting with a strong north Atlantic ridge.

If this run were to verify, next week would be dominated by the Atlantic High sinking into Europe, starting off cool but becoming milder with time. 

But of course developments in the D5-D7 could still trump that, and whilst the UKMO seems as it might keep the high more NW based, it's obvious that there's still room for manoeuvre.

 

[shaky]

You just couldnt make this up!!the gfs is now slightly more amplified at 114 hours!!man this is draining me out?

[Gavin Hannah]

Seems to be stronger HP ridging at t.114 as mentioned. Better link up with the HP in greenland & canada. Hopefully more favorable for a quicker reload.

[I remember Atlantic 252]

13 minutes ago, Frosty. said:

There were 130 + members on here at 7 am and now there's 7..it's a shame but next week is still an unreliable timeframe so things could still improve upstream on any run and get this place buzzing again!

Time of day/week Frosty, schools in, I won't be on after 7 tomorrow

[weirpig]

Right  im not giving up  lets see what the 6z does   wow its like the mary celeste  in here

[tight isobar]

Well i think this run 6z..

Is going to do wonders for the nerves..

Already a mile in front on' ridge alignment..

And much better canada/greenland...

 

[Man With Beard]

Not completely unlike the UKMO at T144 - so will be interesting to see where it goes

  

[Seasonality]

A little pool of positive 850hpa uppers for the UK.

[Gavin Hannah]

Everything is further west too which helps immensely.