model discussion Model output discussion - the final third of Autumn

[Mike Poole]

49 minutes ago, Cambrian said:

In addition to the big fellas, I tend to check out the GEM and JMA too. I’ve been impressed with the GEM. The Canadian model was one of the first to see the northerly at day 10 that we’re now looking at for day 7,  held its nerve a couple of days ago at day 9 when the others wobbled (I posted the charts).

Again of potential relevance down the line, on the 0z run today, the GEM operational develops a small low - a shortwave I guess - over Norway at 174h. It brings us into a meatier looking northerly than the 6z GFS does for the same time, which means we have colder air trapped under the high as it topples over us. This is also important more widely as the northerly stab is an important precursor to any pattern change in the offing for down the line.

 

It pushes the high further west, as @nick sussex was alluding to earlier, here at 186h, compared to 180h on the 6z GFS op.

 

The GEM sure isn’t perfect - none of them are - and it can lose the scent as quickly as it has found it, but it looks to me in certain situations to be up there with the best of them, particularly in the day 7-10 period. 

In this case, it might be because it has better local inputs regarding Canada grown WAA over into Greenland etc., relevant upstream connections in this situation, though I admit I don’t know enough to boast further on it’s behalf. In any case, in terms of the performance over the last week or so, it’s clearly a model well worth keeping an eye on - let’s hear it for the GEM !!

GEM currently verifying in third place at T144 (as it often does) - it had a significant upgrade a couple of years ago I think and is now very much one of the big four, similar to GFS and a little behind UKMO and ECM.   

[Bradley in Kent]

On 14/11/2021 at 12:36, Ed Stone said:

I know posting post-Day 12 charts without an estimate of their respective chances of verification is not the done thing. So, my guess is: anywhere between nought and zero!

    

    

Anyway, be that as it may, I now declare the Silly Season fully open!

If I could design the weather I'd make charts like those, slider low and NE winds over the North Sea. 

As you say, there's no way this'll verify even if it does end up cold. Even at 24 hours, there would be so many questions such as the exact track of the low and of course 850s. 

However, FI or not, it's encouraging to see!

[SqueakheartLW]

No wonder charts like these are starting to show up more. The La Nina is switching more to Eastern Pacific based now if you look at the latest 7 day change charts from both NOAA and Tropical Tidbits

00z Coldest 850hpa Temp Chart Pick - P30

06z Coldest 850hpa Temp Chart Pick - P14

A late November and December 2010 redux perhaps

If you want to see a late November and December 2010 redux, just check out P23 on the GFS Extended run on Wetterzentrale

850hpa temps                                          2m temps                                               New snow depth

I know these charts are for Scunthorpe but the 850hpa temps and 2m temps charts would very likely be equally cold for other areas of the UK.

[Methuselah]

Right then, here are the GEFS 06Z ensembles for snowy Suffolk. So, having taken only one look, I'll be putting by 'snowtastic' ramping on hold.  For now! But, having said all that, I do feel more optimistic about Winter than I have for some time. Since last year, in fact!

    

[Kirkcaldy Weather]

On 08/11/2021 at 15:37, Kirkcaldy Weather said:

MJO has had phases 3 and 4 and a double check revealed there was a day of phase 3 in October which links well with quite a few of the posts in here recently  would agree with those runs that have shown a Scandinavian high and lower pressure heading south through UK (phase 3 November also with that Scandinavian high signal), should any lower pressure get far enough south and decent aligning of the scandi high that would be a potential route to some cooler conditions via an easterly. Phase 4 looks like the high doing some retrogressing over UK and toward Greenland I'd say frosty would be the most likely weather from that    

 

2 hours ago, northwestsnow said:

6z is glorious for coldies.

The block holds the Atlantic off and the Arctic air sweeps South....

 

1 hour ago, minus10 said:

Whatever happens, is this not a chart of beauty for cold fans...

Perfect channel low moving east.

We can dream......

Hopefully minus10 and NWS don't mind me referencing their posts , they are useful in matching quite well for the patterns in my post above, in minus10's we see what I was meaning with lows being far enough south getting the east flow in and on NWS post you can begin to see the phase 4 high between uk and Greenland. I'd say by next weekend we'll have those patterns starting to be in the short term if indeed they do set up. 

Edited November 14, 2021 by Kirkcaldy Weather

[MATTWOLVES 3]

Its Sunday and it's grim...the 6z serves up some excitement

There could be a channel runner coming to you southerners in time for silly season...no I don't mean mo Farrow...but some of the crazy stuff could be landing....Big word of caution...precipitation charts this far out are only for the dreamers amongst us...I for one live in a complete dreamworld...a parallel universe if you like...

But good lord ain't it just great to see! Me love it long time.

Hopefully changes are a foot come months end...we really do need a shakeup of this mundane pattern we have right now!

Ps...I only hope the papers don't get hold of these charts

Have a fab Sunday roast!

Ps...please come back jon snow.. Feb blizzard and Mr Steve M.

 

 

 

 

Edited November 14, 2021 by MATTWOLVES

[SLEETY]

Seen it before in late Autumn, very mild then switch to very cold,could be happening this time too, with a little luck. 

[Staffmoorlands]

12 minutes ago, SLEETY said:

Seen it before in late Autumn, very mild then switch to very cold,could be happening this time too, with a little luck. 

Last time was November 2009

[UKSupercell]

Afternoon all - so I've been watching this thread intensely for the last two weeks. I initially posed the question a week or so ago, and now will do so again.....given I've now decided to take nearly two weeks off and go camping/hiking in Scotland, from Friday 19th onwards, do you think there is a fair chance I will see some of the white stuff up there in that time?!?! 

I plan to spend most of my time on the west highland coast, but I will probably pass through the Cairngorms and Loch Lomond/Trossachs National Park too, so will travel about quite a bit alternating camp sites, B&Bs and may even do the odd wild camp! 

 

[tight isobar]

Let’s hope we get a Bryony.. @frost . Like a yala enki ride ..@£50 @ 3-1 .. sorry but had ta post

[Sceptical]

17 minutes ago, UKSupercell said:

Afternoon all - so I've been watching this thread intensely for the last two weeks. I initially posed the question a week or so ago, and now will do so again.....given I've now decided to take nearly two weeks off and go camping/hiking in Scotland, from Friday 19th onwards, do you think there is a fair chance I will see some of the white stuff up there in that time?!?! 

I plan to spend most of my time on the west highland coast, but I will probably pass through the Cairngorms and Loch Lomond/Trossachs National Park too, so will travel about quite a bit alternating camp sites, B&Bs and may even do the odd wild camp! 

 

Hit up the Cairngorms, snow is forecast for this week. Enjoy  

[Ali1977]

Looking good coldies

[MATTWOLVES 3]

As above at Ali...things looking much better today...some cracking ens also...just a little taster from me...

I'm not in anyway advertising tyres here,but make sure your Winter tyre ready or at least have them checked...sounds more like an Health and safety post tbh

Edited November 14, 2021 by MATTWOLVES

[January Snowstorm]

Well the 12s are just about to roll!!

First out is the often trend setting ICON. Not great with the high remaining in situ

[Ali1977]

A little flatter at day 6, hopefully it moves in the same direction as the 06z moving out to day 10

[Methuselah]

57 minutes ago, MATTWOLVES said:

As above at Ali...things looking much better today...some cracking ens also...just a little taster from me...

I'm not in anyway advertising tyres here,but make sure your Winter tyre ready or at least have them checked...sounds more like an Health and safety post tbh

I think it's going to be a Goodyear for snow, Matt. I'll get my coat!

[January Snowstorm]

The gfs goes same way as ICON

Not enough ridging towards Greenland , YET!

Potential is huge going forward

[Mike Poole]

Never one to shy away from a dubious prediction, but the WAA looks better aligned on the GFS 12z T180 than same time on the 6z, so if it is a bit behind it could catch up.

[Ali1977]

1 minute ago, Mike Poole said:

Never one to shy away from a dubious prediction, but the WAA looks better aligned on the GFS 12z T180 than same time on the 6z, so if it is a bit behind it could catch up.

I think you’re right, and this could mean the deeper cold is better aligned to hit the U.K. quicker than the 06z 

[Ali1977]

Slower start but better medium turn - I just wonder if this could become something notable and not just a fleeting  cold spell

[Mike Poole]

GFS 12z T204, and this is the sort of setup that absolutely will bring a Greenland high, getting excited now:

Follow the contours for the WAA, it couldn’t really be better.  Will make a more detailed post between GFS and ECM.

Edited November 14, 2021 by Mike Poole

[Ali1977]

Getting a bit complicated by day 10 near Greenland but all still looks good, maybe a good time to keep checking ENS suites rather than Ops - we need to see mean 850s of around -6 to -8 before we start thinking big freeze and snow, but means around -4/5c would feel nice with wintery showers possible on highly ground!! 
I feel pretty confident with this one !! 

[January Snowstorm]

And up she goes but it's deep FI!

The trend is certainly good from gfs

[Ali1977]

Ignore my last post, day 11 onwards could be epic heights getting pulled north out the Med 

[Mike Poole]

Wowsers! GFS 12z T282:

I think it is fair to say that the front loaded winter idea has gathered some support today!