model discussion Model output discussion 11th July onwards

[carinthian]

On 23/10/2021 at 09:06, carinthian said:

The trend still there for a gradual transition to colder conditions during the first week of November. The overview picture from the latest GFS op run has the colder air . looking at the thickness values moving into NW Europe generally. An area of snow moving into Northern Scotland. The snow models still picking this up , although the % value still low that far out, but encouraging still showing. In the Alpine region we need to see this picture develop also to produce some much needed snow as some of the resorts are due to open  on 27th November. Enjoy your warmth for the rest of the month as a change is a coming !

C

Morning all, further on from the above post, most of the main models now showing some agreement almost in the reliable time span  of a gradual transition  to lower temperatures into NW Europe during the first week of November, especially the British Isles.  Longer term charts from the GFS model also showing a Mid North Atlantic block pattern to show its hand with a diving jet into NW Europe. Obviously the strength of the block will dictate how long any developing cold spell will last. However, a rather unusually set of  charts being shown out past 10 days. The block neither classic diffluent or Omega in positioning, so it will be with interest how the models will evolve going forward more into November. 

C

 

Edited October 24, 2021 by carinthian

[Methuselah]

If today's GFS 06Z is right, things could well be about to change. Even a little freezing fog might turn up too. Not that I miss all those early 1960s pea-soupers:

    

    

    

Edited October 24, 2021 by Ed Stone

[damianslaw]

Signal for a notable shift in the base state now moving into the reliable.. we exchange the predominantly mild pattern which has been locked in for weeks for something colder, the UK moves to the north side of the polar front as the jet takes a nosedive south. The coming weekend now looking quite chilly in the north with the base of the Atlantic trough lying over southern Britain.

Heights forecast to build strongly through mid Atlantic held in by warm air advection west side of Greenland.

End result a chilly NW airstream, troughs and fronts aligned on a NW-SE trajectory. Nothing particularly cold but will feel notably cold compared to recent weeks. Wintry precipitation for higher ground in the north and conditions ripe for fog and frost in any clear breaks.

We are not there yet but the models have held form on this evolution for days now and I can't see  the direction changing.

November looks like starting on a chilly note. Just as the clocks go back, many will be reaching for winter wardrobe.

[Frosty.]

The GEFS 6z mean looks fantastic in my eyes ? ?  from a coldies perspective longer term.   ..it may not to the met office blah blah but it does to me!!!!…nuff said, there is cold potential in early November!  

 

Edited October 24, 2021 by jon snow

[Frosty.]

Holy carp..maybe winter will come early this year?.. …fingers crossed ..and all that!  

Edited October 24, 2021 by jon snow

[Frosty.]

For sure the ECMWF 0z ensemble mean longer term is getting itself into a good position for coldies with the trough transferring further to the NE enabling colder air to spill south in its wake?!..broad brush but it’s what’s showing currently..nobody on here wants an early blast of proper cold more than me? …    

 

 

[Daniel*]

2 hours ago, damianslaw said:

Signal for a notable shift in the base state now moving into the reliable..

November looks like starting on a chilly note. Just as the clocks go back, many will be reaching for winter wardrobe.

EPS seems a lot more bullish with cooler than average theme and developing earlier than initially projected, following exceptionally mild weather will feel more pronounced. 

Edited October 24, 2021 by Daniel*

[Frosty.]

Do I even look like I care that my pathetic team, Tottering Hotspur  lost yet again?.. ..anyway, as long as we have perturbations like this, I will be happy.. I’m oozing sauce!!..any sad Spurs fan familiar with YouTube will know what I mean blud..fam..etc..etc..ps.. why does nuno always have his arms folded? .. … !  

 

 

Edited October 24, 2021 by jon snow

[Frosty.]

Although there’s plenty of rainfall indicated at times for the W / NW on the latest models, and a suggestion of much colder in the longer term GEFS / ECM mean early NOVEMBER..typically there’s nothing wintery indicated from the bods..  at Exeter whatsoever apart from long term frog..I mean fog   ? and frost!   

Edited October 24, 2021 by jon snow

[heath]

The 12z GFS operational looks a lot flatter for the Atlantic. To me at least. Maybe just to flatten a few high spirits. 

[Frosty.]

9 minutes ago, heath said:

The 12z GFS operational looks a lot flatter for the Atlantic. To me at least. Maybe just to flatten a few high spirits. 

For sure it is flatter than the 6z but it’s probably not game over for a colder early November based on this run and in any case, this run isn’t completed yet which is one of the reasons I don’t  usually comment on runs until they are completed!  

[Mike Poole]

GEM T240, pretty much a jackpot run for establishing a northerly, and blocking in the right places.

Other solutions in the mix of course at this stage, but it is nice to see this on an op run.

[Ali1977]

43 minutes ago, Mike Poole said:

GEM T240, pretty much a jackpot run for establishing a northerly, and blocking in the right places.

Other solutions in the mix of course at this stage, but it is nice to see this on an op run.

Yep, that’s a great chart and the GEFS Mean for the same timeframe is still very good. Hopefully the ECM follows that GEM.

It’s all early days, little in the way of snow possible outside the higher hills of the North but it still makes nice viewing.

Edited October 24, 2021 by Ali1977

[Frosty.]

1 hour ago, Mike Poole said:

GEM T240, pretty much a jackpot run for establishing a northerly, and blocking in the right places.

Other solutions in the mix of course at this stage, but it is nice to see this on an op run.

Yep, if all the other models look carp, the gem to the rescue although T+240 isn’t cold as such but once the hypothetical trough tracks further east..it would be.. there’s something fishy about this run?! …    

Edited October 24, 2021 by jon snow

[Mike Poole]

ECM slightly messier than GEM on the NH as a whole, variations on a theme, maybe, and isn’t a mild one, but brings the northerly more as a direct hit for the UK, T240:

Heights into Greenland nowhere on this one though, so I much prefer the GEM.

Edited October 24, 2021 by Mike Poole

[Anthony Burden]

Evening all,ECM and GEM still looking positive for a cold shot from the north,GFS lost the plot but

will probably return to the fold as GEFS ensembles still on the downward trend from beginning of

November.

[Ali1977]

54 minutes ago, Mike Poole said:

ECM slightly messier than GEM on the NH as a whole, variations on a theme, maybe, and isn’t a mild one, but brings the northerly more as a direct hit for the UK, T240:

Heights into Greenland nowhere on this one though, so I much prefer the GEM.

The mean still has heights into Southern Greenland at 240, so there must be some more akin to the GEM within the ENS. 

Edited October 24, 2021 by Ali1977

[Frosty.]

Yep the ECM 12z operational gets there in the end although it’s one of those typically British blink and you miss it topplers but beggars can’t be choosers…actually the mean does seem more robust…in any case, it’s still autumn for another 5 weeks.. still, it’s good to see a chance of arctic incursions before winter!!  

 

 

 

Edited October 24, 2021 by jon snow

[Mike Poole]

GFS pub run at T240:

And just to repeat GEM 12z at T240:

Regardless of detail, we seem to be seeing the kind of 4 wave pattern that can lock in now, into November.  Both the above charts show it, I have refrained for once for getting the pen out!  I think it is case of waiting out the next week or so, but with a promising NH setup possibly in the offing, the interest is most definitely there.  

[Ali1977]

The GFS Op still looking flatter at day 12 after a 4/5 day colder spell, however the ENS have plenty of blocking options .

All to play for, we need this blocking to hang around a few more weeks so these Northerly incursions have a little more punch.

 

 

 

Edited October 25, 2021 by Ali1977

[Ali1977]

Best chart of the morning is the JMA, this would unleash some proper early cold moving forward a few days - obviously JFF at this stage.

[Methuselah]

So, what to make of this morning's GFS 0Z run? Well, it sure looks bog-standard November fayre to me?

    

    

    

Yep. I'd say that looks about right: nothing much worth worrying over!

   

 

[Eagle Eye]

Looks like the slow decrease in temperature will continue this week, slow slide into Winter but a little earlier than usual (I think, I'm only going off last year and that wasn't great for an early Winter) 

[carinthian]

Morning all, latest GFS op run handles the developing wave along the polar front on Sunday rather differently to the other main models. Deeper and more progressive across Southern Britain on Sunday with potential for some possible stormy conditions on its southern flank. Where as UKMO absorbs the potential wave with-in a rather slower moving complex low. ECM somewhere in between. Best sit on the fence with this one and see where we go ! Longer term , the main models still heading for a colder spell as we head towards Guy Faulkes night but hinting that any blocking could be short term with an increased zonal flow in the latest operational runs but the ensemble means still showing  a slower pattern towards displacing the trough over Western Europe.

C

[Cambrian]

The 6z GFS control run supports the idea that has been discussed of a persistent diving trough becoming established over the UK and Ireland from day 4 to day 12 and beyond, reinvigorated by rinse and repeat low pressure systems moving down from the northwest wrapping cold air around them with a possibility even of some wintryness at times.

Every 2 days - 96h / 144h / 192h / 240h / 288h

    

 

Daytime maxima are in single figures from day 5, and struggle to break 5 degrees from day 9 with a few night frosts thrown in.

 

There is showery precipitation too, with the potential for some light snowfalls from a few of the ensemble members, as a result the mean has two or three dustings. 

 

 

P20 is a cracker at 360h.

Bit of a scrunch possible on the 9th November if that setup transpires. 

 

Edited October 25, 2021 by Cambrian