model discussion Model output discussion 11th July onwards

[Newberryone]

I think judging by the latest model output we could be quite possibly reverting back to something less or indeed far less cyclonic than what was being forecast just a couple of days ago. These high pressure cells look far too robust for there to be any significant change right now. Nothing other than mixed conditions from midweek looks to be the form horse with any Atlantic lows having little impact as there being diverted well away to the northwest. 

Edited September 18, 2021 by Newberryone

[Mike Poole]

2 minutes ago, Newberryone said:

I think judging by the latest model output we could be quite possibly reverting back to something less or indeed far less cyclonic than what was being forecast just a couple of days ago. These high pressure cells look far too robust for there to be any significant change right now. Nothing other than mixed conditions from midweek looks to be the form horse with any Atlantic lows having little impact as there being diverted well away to the northwest. 

Yes, I never bought into that idea of a resurgent atlantic which suddenly appeared on the models and ensembles a couple of days ago.  Plenty of blocking on the early 12z runs.  

[Frosty.]

The Gem 12z looks quite changeable with a trough / ridge / trough / ridge flow to it, so, not a washout by any means but certainly not completely settled either!…I actually think a middle ground scenario could be ours? (which I feel would be decent news for the s/se? )… by the way, the trend from the 12z output so far is to make the low later next week into more of a glancing blow..yes, a blow with less than full force that falls off to one side! 

 

 

Edited September 18, 2021 by jon snow

[Cambrian]

Yep, the 12z ECM op has backed off from the northerly for us towards the end of the week, at 144h takes the low further east, troughing down into Poland now rather than the North Sea, deflected comfortably by the resurgent high to the southwest.

[Frosty.]

The GEFS 12z mean currently rolling out on meteociel doesn’t really scream unsettled, for sure there is a more unsettled spell later next week but more so further N / NE, I’ve used the words glancing blow a few times today and the same applies here…so yes, probably a changeable outlook, for sure there are some unsettled members but also some which indicate high pressure could return again in the mid / longer term?..a middle ground between settled / unsettled favouring the s/se?

 

Edited September 18, 2021 by jon snow

[Methuselah]

That's a good GFS 12Z run IMO. I don't mind foggy mornings but cold, wet, windy rubbish? No, not yet; I'd rather be able to enjoy what's left of (dare I say it, summer?). IMO, there'll be plenty of opportunity for cold, cold rain, sleet, drizzle and snow as we approach the Solstice?

Meanwhile:        

                             

                             

 

[Mike Poole]

I know we get stuck in a trough on this run, that’s local stuff and may and probably will change, but the ECM T240 - does not look good for the fledgling vortex at all:

If this pattern persists the vortex will struggle to form.

The // looks even worse for the vortex if honest:

Edited September 18, 2021 by Mike Poole

[Frosty.]

The ECM 12z operational is something of a mixed bag, there’s alternating troughs and ridges, temperatures are up and down which I think indicates typical early autumn weather with the autumnal equinox just around the corner!.changeable then?!! .for sure it could be worse..of course, it could be better too?   ? ️ ?  

Edited September 18, 2021 by jon snow

[Cambrian]

On the 12z ECM op, day 7 and 8, a new low drops out of Greenland and takes a swipe at us, but you do get the feeling it will probably in the event get squeezed out north by either one or a combination of both the areas of high pressure either side. 

ECM 168h / 192h 

 

 

The 12z GEM op has a similar idea at that timeframe, though it develops a deeper low between Scotland and Iceland.

GEM 168h / 192h

 

 

[Cambrian]

The 9 day (day 2-10) panels show how the ECM is being consistently more progressive in dropping troughs down over the UK compared with the GFS.

The 12z ECM brings the trough down over us for a fleeting northerly at day 5 and then again at day 8 / 9. It ends up with a strong looking high in the Atlantic to our southwest. A meridional flow pattern with slow alternations. Day 10 is broadly back to where we were at the start.

 

With the 12z GFS, the trough never gets through the UK once in the 10 days. A shallow low slowly drifts our way from the west towards day 10. Interestingly, there is no impressive looking high in the Atlantic by then. Still in a post-summer slumber, with a weak jetstream at 240h that stalls altogether in the mid-Atlantic, no pronounced troughing and hardly any flow at all. 

 

[Zenarcher]

On Sunday, the best weather will be over Western parts of the country, with some sunshine, although there will still be heavy showers. The Eastern parts of England and Scotland will see a lot of rain. With a ridge of high pressure moving in, Monday and Tuesday will be generally dry with some sunshine, making for a good start to next week. On Tuesday, as low pressure moves near Iceland, exposed parts of Western and Northern Scotland will experience wind gusts of up to 50 mph or more.

  

Wednesday will be a little more unsettled, with rain moving over the country, but the Southern parts of the country will likely stay dry. The models have eased off from really unsettled weather over the past day and pushed the worst to the far North, so most agree with it will be getting colder on Thursday and Friday, with some rain or showers about and a bit windy in Northern regions. The ECM shows a deep area of low pressure on Thursday, bringing very strong winds to the UK, but there isn't much support for it at the moment.

  

Next weekend shows increasing support of low pressure developing to Iceland's South West, which might bring more rainy and windy weather to the UK, particularly in the North. Any low pressure around might lessen off through the start of the following week. However, the weather looks to remain on the unsettled side, with rain or showers expected.

   

This evening's amination, 19th Sept to 28th (average model outlook) 

[Mark Smithy]

Pretty progressive overnight model outputs. The GFS has buckled and given up its recency-bias high pressure cell.

Autumn looks like it is slowly but surely cranking into gear, folks. Batten down the hatches and enjoy!

[Frosty.]

Looking at the GEFS 0z mean, to me it’s a north / south split with most of the unsettled weather across northern parts of the u k whereas the s / se escapes relatively lightly and in any case, longer term the trend is more settled from the south with the north improving too (this is broad brush) but…on balance, early October, especially further south would be more generally settled / benign with overnight mist / fog? ? ? ️  

Edited September 19, 2021 by jon snow

[Scorcher]

1 hour ago, Mark Smithy said:

Pretty progressive overnight model outputs. The GFS has buckled and given up its recency-bias high pressure cell.

Autumn looks like it is slowly but surely cranking into gear, folks. Batten down the hatches and enjoy!

Does it? Still looks like a glancing blow to me. It also looks like the south is going to stay warm into the weekend now- although increasingly breezy, I don't think the low 20s can really be described as 'autumnal'.

If anything, the GFS is actually less unsettled for the coming week than it was yesterday- the core of the low is actually missing Scotland now. A few days ago it looked like it would plough through the UK.

Anything properly autumnal is still way out in FI and with tropical storms in the mix, you can never be certain more than a few days out.

Edited September 19, 2021 by Scorcher

[sheikhy]

27 minutes ago, Scorcher said:

Does it? Still looks like a glancing blow to me. It also looks like the south is going to stay warm into the weekend now- although increasingly breezy, I don't think the low 20s can really be described as 'autumnal'.

If anything, the GFS is actually less unsettled for the coming week than it was yesterday- the core of the low is actually missing Scotland now. A few days ago it looked like it would plough through the UK.

Anything properly autumnal is still way out in FI and with tropical storms in the mix, you can never be certain more than a few days out.

Yup totally agree with u!!!hardly any rain again from both the gfs and ecm!!ecm has defo moved towards the gfs in the earlier timeframe with a more stubborn high for wednesday!!

[Atmogenic]

15 hours ago, Ed Stone said:

That's a good GFS 12Z run IMO. I don't mind foggy mornings but cold, wet, windy rubbish? No, not yet; I'd rather be able to enjoy what's left of (dare I say it, summer?). IMO, there'll be plenty of opportunity for cold, cold rain, sleet, drizzle and snow as we approach the Solstice?

This is exactly what I was thinking, let's hope it's mostly how it is now with it being mostly dry and not so much cloud (like August) until the end of October. That is when it should start with the cold uppers lows with the hope of some snow or ice days as the sun itself doesn't have much warmth at all with it anymore at that period.

[Frosty.]

Just had a look at the ECMWF 0z ensemble mean and to me it’s the north / northwest of the u k which would bear the brunt of the unsettled weather during the second half of the week ahead onwards…further s/se doesn’t look too bad at all with probably quite a lot of fine weather in comparison to the n/nw…this is broad brush and doesn’t mean the south / southeast wouldn’t see occasional rain?…just my opinion!  

[Frosty.]

No comments on the Gfs 6z op?..well, ok, it’s not perfect but there is some warmth and even some high pressure, especially later! ….ok, there’s some low pressure and cooler more unsettled weather too! …come on guys, it’s nearly October, what do you expect..???   ?  

 

Edited September 19, 2021 by jon snow

[Scorcher]

49 minutes ago, jon snow said:

No comments on the Gfs 6z op?..well, ok, it’s not perfect but there is some warmth and even some high pressure, especially later! ….ok, there’s some low pressure and cooler more unsettled weather too! …come on guys, it’s nearly October, what do you expect..???   ?  

 

Not a bad run, especially for the south if it's more warmth you want while we can still get it. We have enough windy, chilly days in the year so that can wait until October or after as far as I'm concerned.

This run will also hold the CET up- a very warm final figure is looking increasingly likely now.

[Methuselah]

The trend is your friend. Or, perhaps, the trends are your friends would be more apt?    

    

[Frosty.]

The GEFS 6z mean is essentially showing a north / south split, best is south, worst is north..but, as with the 0z mean, towards / during early October pressure rises more generally (on balance)..so it could become more widely settled into the new month?

[Frosty.]

 

I spotted some snow blobs on the Gfs 12z operational in FI!  
 

 

Edited September 19, 2021 by jon snow

[Frosty.]

You would almost think it was high summer looking at these ECMWF 12z operational charts wouldn’t you, ignoring the blue bits of course?… ?  ..and that’s all from the Jon snow model output discussion for now…

Edited September 19, 2021 by jon snow

[Don]

48 minutes ago, jon snow said:

You would almost think it was high summer looking at these ECMWF 12z operational charts wouldn’t you, ignoring the blue bits of course?… ?  ..and that’s all from the Jon snow model output discussion for now…

 

September 2021 IS high summer!

[damianslaw]

Marked differences between ECM and GFS/UKMO at the 144hr-168 range.. not sure what ECM is on this evening but it looks wrong. It cleans out the trough and low ish heights over scandi in one swoop replacing with a high pressure..GFS and UKMO dig the trough in and down through scandi. ECM looks wrong at the 96-120 hr range it shows barely any change in the Atlantic profile whilst it is a fluid scene.