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Model output discussion - Winter approaches


Paul

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Posted
  • Location: Scouthead Oldham 295mASL
  • Location: Scouthead Oldham 295mASL
17 minutes ago, Steve Murr said:

So then here woukd be my forecast for the day 5-9 area based on the model variation at the moment.

This is based on what 'normally' happens when we get a fairly robust high over Scandi & a fairly decently alligned upper air cold pool on its southern flank.

I have earmarked the GFS 12z Control run to be the closest as possible, this is unusually over & above the favoured UKMO since its presentations have been very flat compared with the following runs & all ENS suites.

7C5EA143-DF71-4182-BA13-0C23CE1B3961.thumb.png.83a60c2615d9c3848019bca3cb14f0c9.png

- You will see on the GFS control we have a higher lattitude high 

- Also a stronger flow if isolines across Europe compared with the 12z Operational, this is based on the assumption that the models generally underestimate the energy returning SE through Scandi.

* At some point the high pressures try to merge > maybe day 7 however due to the scandi high & westward forcing we often see the jet amplify quickly again. 

NB the GEM tries this on the 12z

DF78B49C-AE8D-49DB-98EE-4216290B822A.thumb.png.81eff5a0ce97a89f2119b8247e8e433c.png

I expect there to be amplification west of what the GEM has -but not east, this then paves the way for a Northerly or a reinforced continental flow depending on where the troughing drops > modelling usually gets corrected west...

Even though the zonal wind is very strong st the moment it appears a quick return to zonality doesnt look on the cards..

Last sentence relates to easterlies occupying the lower strat Steve...

Keeping things de coupled...

Thats my reading of things ...

Obviously last year saw a pretty rapid coupling as we hit Dec ...but did we have the East QBO in the upper trop /lower strat ?

Edited by northwestsnow
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Posted
  • Location: North West Leeds 124m
  • Location: North West Leeds 124m

Lots of chilly weather on offer on the GFS 12Z including a fair few frosts. Certainly a big improvement on what we've seen so far this Autumn. The Atlantic comes back in but it remains cool and unsettled rather than horrible mild muck. 

Frosts then wind, rain and feeling cold. Sounds good to me. 

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Posted
  • Location: STEVENAGE, HERTS (100M ASL)
  • Location: STEVENAGE, HERTS (100M ASL)
14 minutes ago, BLAST FROM THE PAST said:

Forget the GEM...it’s rarely anywhere near.  Not liking the 12z GFS

BFTP

 

 

Outperformed GFS (according to official stats) last winter and was mentioned by Met forecaster (Ian F) as a model they take note of..unlike GFS. Has its performance taken a dip recently as I’ve not seen stats for a while?

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Posted
  • Location: sheffield
  • Weather Preferences: cold ,snow
  • Location: sheffield
11 minutes ago, northwestsnow said:

Last sentence relates to easterlies occupying the lower strat Steve...

Keeping things de coupled...

Thats my reading of things ...

Obviously last year saw a pretty rapid coupling as we hit Dec ...but did we have the East QBO in the upper trop /lower strat ?

I think it was muted nw. The timing and lag don't always fall in line with the winter months. I think the current atrempt at an East qbo may not have a huge effect on the coming 3 month period

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Posted
  • Location: st albans
  • Location: st albans
14 minutes ago, Tim Bland said:

Outperformed GFS (according to official stats) last winter and was mentioned by Met forecaster (Ian F) as a model they take note of..unlike GFS. Has its performance taken a dip recently as I’ve not seen stats for a while?

it had a recent upgrade and imo, is more worthy of analysis than gfs (gfs para seems to be doing ok on x model continuity)

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Posted
  • Location: Tyrone
  • Location: Tyrone
25 minutes ago, BLAST FROM THE PAST said:

Forget the GEM...it’s rarely anywhere near.  Not liking the 12z GFS

BFTP

 

 

As long as the ECM backs it later like this morning run then it has merit gfs control having a go to.

gensnh-0-1-240 (1).png

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Posted
  • Location: Midlothian
  • Location: Midlothian
3 minutes ago, bluearmy said:

it had a recent upgrade and imo, is more worthy of analysis than gfs (gfs para seems to be doing ok on x model continuity)

i hope when people say ‘this model is better than that one’ it’s because they have analysed what they predict, then check what the actual weather was on the day.........instead of the ‘best’ model being the one that shows cold...

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Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.
16 minutes ago, bluearmy said:

it had a recent upgrade and imo, is more worthy of analysis than gfs (gfs para seems to be doing ok on x model continuity)

Not being funny Nick, but why don't you reference it more in your analysis than the GFS then?

EDIT : FWIW - my thoughts are that i don't bother with JMA and GEM at all, GFS is what it is, 3rd best behind ECM & UKMO upto about 96-120, probably about equal with ECM at 240 during winter, and ECM is  level with UKMO at 144.

Edited by feb1991blizzard
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Posted
  • Location: Orpington Kent.
  • Location: Orpington Kent.
6 minutes ago, dragan said:

i hope when people say ‘this model is better than that one’ it’s because they have analysed what they predict, then check what the actual weather was on the day.........instead of the ‘best’ model being the one that shows cold...

How very dare you!

Icon being wheeled out as the 1st of 12z is a good indicator that something might be afoot for coldies..

By the same token a gfs esesemble member at 300 odd hours shown in isolation is a pretty good indicator that more work is required from the models if you're a coldie 

Currently things are broadly looking fair to middling and we are seeing healthy debate on all the big hitting 12z runs. 

 

 

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Posted
  • Location: North East Cotswolds, 232m, 761feet ASL
  • Location: North East Cotswolds, 232m, 761feet ASL

The day 10 ENS have all sorts of charts going on, but not one of them screams Zonal. This isn’t the usual situation in Early Dec so lots to be positive about!!

Canada is PV “less” on many ENS, Why is that happening, and what’s driving that set up ??‍♂️ The mean has most of canada as exceptionally warm for the time of year, the cold needs to head somewhere!! 

466E8AAB-560F-4C73-B897-4D4FFDB70293.png

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403C3D1F-B258-483A-9AB7-DF940C021914.png

B5D59621-9D18-492B-897F-83C8148C2E8F.png
 

Day 10 mean 850s, Canada is notably warm.

5DCFC75A-F16C-43AD-BF3C-C8DA2EF701D3.png

Edited by Ali1977
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Posted
  • Location: Wath upon Dearne, Rotherham
  • Weather Preferences: Snow, severe frost, freezing fog and summer sunshine
  • Location: Wath upon Dearne, Rotherham
8 minutes ago, feb1991blizzard said:

Not being funny Nick, but why don't you reference it more in your analysis than the GFS then?

EDIT : FWIW - my thoughts are that i don't bother with JMA and GEM at all, GFS is what it is, 3rd best behind ECM & UKMO upto about 96-120, probably about equal with ECM at 240 during winter, and ECM is  level with UKMO at 144.

That's a shame. JMA seasonal going for northern blocking right through winter.

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Posted
  • Location: North East Cotswolds, 232m, 761feet ASL
  • Location: North East Cotswolds, 232m, 761feet ASL

NASA and the CMA are both looking good I’ll see what my 4 year old can draw and throw that out there

 

To be fair that CMA is quite like the ECM !! 

 

317626AA-FD8A-43A2-968D-F50F07FEEE9F.png

306BCE38-C0F5-40B3-A5AC-E377C4EFD263.png

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Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.
6 minutes ago, Premier Neige said:

That's a shame. JMA seasonal going for northern blocking right through winter.

JMA seasonal one of the better ones IMO - JMA regular short - med range model is too inconsistent IMO, i find it tends to over amplify but only on some occasions, so at least with the ECM & GFS, if you get a situation where the GFS is too progressive, barrelling the Atlantic through and the ECM as a big convective Easterly with the -12c isotherm slamming into Ireland, you can bet its going to be a Battleground or col. But with JMA i just cannot put my finger on how to read it.

Edited by feb1991blizzard
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Posted
  • Location: st albans
  • Location: st albans
8 minutes ago, feb1991blizzard said:

Not being funny Nick, but why don't you reference it more in your analysis than the GFS then?

EDIT : FWIW - my thoughts are that i don't bother with JMA and GEM at all, GFS is what it is, 3rd best behind ECM & UKMO upto about 96-120, probably about equal with ECM at 240 during winter, and ECM is  level with UKMO at 144.

i rarely ref the gfs unless i'm talking later week 2 where it fits the general ens guidance 

i generally use ecm unless i feel it is off on one and ops are unreliable post day 6/7 in any case

my comment on GEM is simply based on observations - before its upgrade, GEM was useful for spotting a pattern change away from the general guidance in fi. that meant it was often v unreliable in this respect. and it usually ran alongside the gfs in its output. since the upgrade it is less often on the same page as gfs

 

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Posted
  • Location: Solihull, Midlands. (Formerly DRL)
  • Weather Preferences: Sunshine, thunder, hail & heavy snow
  • Location: Solihull, Midlands. (Formerly DRL)
4 minutes ago, Ali1977 said:

NASA and the CMA are both looking good I’ll see what my 4 year old can draw and throw that out there

Hopefully your little one doesn’t use the orange and red crayons over Southern and South-Eastern UK, and the blue and purple ones over Greenland and Canada.

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Posted
  • Location: st albans
  • Location: st albans

the GEFS are struggling for consistency across the members- irrespective of what ecm, eps and other models may show for the 9-14 day period at the moment, id be waiting for the gefs to settle down - any persistent atlantic height rise looks difficult top pin down re likely locale 

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Posted
  • Location: Liphook
  • Location: Liphook
14 minutes ago, bluearmy said:

the GEFS are struggling for consistency across the members- irrespective of what ecm, eps and other models may show for the 9-14 day period at the moment, id be waiting for the gefs to settle down - any persistent atlantic height rise looks difficult top pin down re likely locale 

To be honest the ECM ensembles from 00z also showed large variations, most however were on the somewhat cooler side, though only a handful were really all that interesting.

No point getting too hung up on FI yet given quite a wide range of option on the table

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Posted
  • Location: NR Worthing SE Coast
  • Location: NR Worthing SE Coast

poor run lol,are you joking,considering we are using staring at raging zonality as we head into December which lasts most the winter.At least we have a chance of something more seasonal.Maybe big outbreak from the North at end of this run.

Edited by SLEETY
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