Model Output Discussion - Autumn arrives

[Methuselah]

9 minutes ago, ShinyDave said:

...and, of course, "GFS goes too high" was the prevailing assumption for their long-range forecasts last month right up until they actually happened...

When the poster wants super-hot and sunny weather, the GFS always underestimates maxes; when the poster is a Climate Change Denier, the GFS always overestimates maxes? I'm not casting any aspersions here -- I'm merely pointing out that, as we're all human, we all have our personal biases?

[MattStoke]

9 minutes ago, Ed Stone said:

When the poster wants super-hot and sunny weather, the GFS always underestimates maxes; when the poster is a Climate Change Denier, the GFS always overestimates maxes? I'm not casting any aspersions here -- I'm merely pointing out that, as we're all human, we all have our personal biases?

To be fair, the GFS did used to underestimate temperatures by a few degrees but is a lot more accurate since it’s upgrade.

Some still insist it estimates too high because the ECM and UKMO show lower. Models that have a known fault for underestimating temperatures under clear skies.

[MattStoke]

34.2°C in Wiggonholt is today’s high. Another win for the GFS.

[Mike Poole]

ECM nosing the high pressure back in as soon as T192, stronger than on the 0z run:

And with a partial backtrack from the GFS too, I definitely think the ECM looks the form horse here.

Edited August 11, 2022 by Mike Poole

[MATTWOLVES 3]

You know what I think gang? GFS being too aggressive with that Low towards the NW...ECM seems keen to rebuild Heights from the SW...this unsettled spell I feel is in the slow process of backtracking...and that's not me being Summer bias.. I do appreciate we need rain for many areas!

But I really do feel Summer by and large will go on for several more weeks! And I feel the climate change situation is accelerating quicker than some think!

It's definitely heading that way for sure.

 

Edited August 11, 2022 by MATTWOLVES

[I remember Atlantic 252]

6 minutes ago, Mike Poole said:

ECM nosing the high pressure back in as soon as T192, stronger than on the 0z run:

And with a partial backtrack from the GFS, I think the ECM looks the form horse here.

Good chart, rid of the filthy heat

[Methuselah]

2 minutes ago, MATTWOLVES said:

You know what I think gang? GFS being too aggressive with that Low towards the NW...ECM seems keen to rebuild Heights from the SW...this unsettled spell I feel is in the slow process of backtracking...and that's not me being Summer bias.. I do appreciate we need rain for many areas!

But I really do feel Summer by and large will go on for several more weeks! And I feel the climate change situation is accelerating quicker than some think!

It's definitely heading that way for sure.

Hasn't this sort of thing been happening ever since the predicted 'coldest April for many a year' spectacularly failed to materialise? And, FWIW, I'd rate the chances of a warmer-than-usual September well above average. The old adage about basing one's guess as to what tomorrow's weather will be like on what it's like today is, I believe, well founded!

[MATTWOLVES 3]

1 minute ago, Ed Stone said:

Hasn't this sort of thing been happening ever since the predicted 'coldest April for many a year' spectacularly failed to materialise? And, FWIW, I'd rate the chances of a warmer-than-usual September well above average. The old adage about basing one's guess as to what tomorrow's weather will be like on what it's like today is, I believe, well founded!

Worrying times Pete...throw up cold sypnotics and you can guarantee there will be a 1,000 flies in the ointment....but with Heat you just know its gonna come off with no questions asked. My thoughts are now how long before we breach 45C and then 50C! 

But tonight we have the signs from ECM of not much in the way of any meaningful breakdown..and signs of a recovery come later next week! 

 

[ShinyDave]

1 hour ago, MattStoke said:

To be fair, the GFS did used to underestimate temperatures by a few degrees but is a lot more accurate since it’s upgrade.

Some still insist it estimates too high because the ECM and UKMO show lower. Models that have a known fault for underestimating temperatures under clear skies.

That's really interesting - could it be particularly evident at the moment because the drought conditions over most of England reduce how much heat the ground absorbs? That feels like the sort of thing that models could plausibly miss as a variable even if it has a material effect.

[MattStoke]

18 minutes ago, Mike Poole said:

ECM nosing the high pressure back in as soon as T192, stronger than on the 0z run:

And with a partial backtrack from the GFS, I think the ECM looks the form horse here.

Ends with the Azores high in across the south and heat re-building but fronts likely bringing rain to northern areas.

Edited August 11, 2022 by MattStoke

[mb018538]

11 minutes ago, MattStoke said:

Ends with the Azores high in across the south and heat re-building but fronts likely bringing rain to northern areas.

Charts like this have shown why many aren’t 100% convinced of a full on breakdown - yet. Late Sunday through the week looks more unsettled than of late for sure, but when you see 10 day accumulated ppn charts like this from tonight’s 12z ecm still showing large swathes at 0-10mm, then you need to be wary!

[AWD]

One of the models I'm following for next week more closely than others now is the high res UKV model, as this is normally one of the better models when trying to decipher any convective weather potential, for which seems to be the main weather for both Monday and Tuesday.

The latest 15z UKV model continues to evolve into what can only be described as a convective weather enthusiasts orgasm.  Both Monday afternoon and Tuesday afternoon are shown to have a fairly widespread potential for showers and/or storms, some very notable;

Obviously, as ever with convective weather it's hit and miss.  Some places will get nothing and others could get frequent storms.  What the above does demonstrate is a high level of instability in the upper levels, producing a wide amount of storm activity over the country, most notably the Midlands and South.  Tuesday looks pure class, although obviously at this range, detail is irrelevant.  It's also worth noting that this sort of rainfall won't show up well (if at all) on PPN accumulation charts due to the nature of the beast.  You cannot, at this range forecast where storms will happen and to what severity, hence models cannot forecast accumulated PPN from convective activity, which is why I'm personally not looking at these charts.  I do agree that frontal rainfall looks minimilistic for large parts of the south and east though, but that's generally always been the case.

For those who like their temperatures, the 15z UKV run keeps things warm for large parts of England and Wales well into next week.  Obviously not as hot as currently, but warm still nevertheless;

Still very respectable.  So, for England and Wales next week things look like turning more changeable and unstable.  Not full on unsettled, no, that was never really on the agenda, but equally not the solely current settled conditions we have either.  Some interest for convective weather fans, which has been lacking this summer, is there which is something I'm looking forward too.

It is worth a shout out for Scotland too.  This is the model thread for the country, not just south east UK.  For our Scottish friends, who haven't enjoyed as hot or as settled conditions that us English/Welsh folk have, things don't look too bad into next week.  Not much in the way of convective activity, not much in the way of heavy rain either.  Worth noting for you people is the prospect of some chilly night and chilly mornings starting to emerge;

Temperatures probably lower than what's shown in the glens.  First signs of some Autumn nights showing their hand here?

Remember folks, no need to get worked up, the weather will do what the weather wants to do at the end of the day, regardless of what any one person wants or thinks it will do.  

Edited August 11, 2022 by AWD

[MATTWOLVES 3]

The mean kind of backing up the op thus evening..definitely signs of a quick improvement...those further N/NE could have a little influence from that Low as it appears to be clearing NE. Further South may be wondering what all the fuss was about with Higher pressure gaining traction again.

Anyway that's all from me I'm gonna probably set fire to the fence when I light the barbecue seriously guys if only you new how hot it was in this back bedroom....I need to get out before I melt! 

Edited August 11, 2022 by MATTWOLVES

[Singularity]

A note of caution on the UKV model - as far as I'm aware it uses the UKM as a basis, which had the most unstable outcome for Mon-Tue out of it, GFS, and ECM.

Those last two have produced less unstable outcomes compared to their preceding 00z and 12z runs, with a bit of a lottery for the south for between 0 & 10 mm rainfall during Mon-Wed.

UKM has been persistent with its more unstable outcome, though, so who knows, it might be onto something. Would certainly be interesting, albeit dangerous in places owing to intense rainfall hitting hard-baked terrain. I'd not want to be living in reach of a typically fast-responding waterway!

Nice of ECM to demonstrate my point regarding feedbacks and climate trend potentially placing the low even further north for next weekend. Normally I'd welcome such an outcome... but these are not normal times.

[minus10]

12 minutes ago, AWD said:

One of the models I'm following for next week more closely than others now is the high res UKV model, as this is normally one of the better models when trying to decipher any convective weather potential, for which seems to be the main weather for both Monday and Tuesday.

The latest 15z UKV model continues to evolve into what can only be described as a convective weather enthusiasts orgasm.  Both Monday afternoon and Tuesday afternoon are shown to have a fairly widespread potential for showers and/or storms, some very notable;

Obviously, as ever with convective weather it's hit and miss.  Some places will get nothing and others could get frequent storms.  What the above does demonstrate is a high level of instability in the upper levels, producing a wide amount of storm activity over the country, most notably the Midlands and South.  Tuesday looks pure class, although obviously at this range, detail is irrelevant.  It's also worth noting that this sort of rainfall won't show up well (if at all) on PPN accumulation charts due to the nature of the beast.  You cannot, at this range forecast where storms will happen and to what severity, hence models cannot forecast accumulated PPN from convective activity, which is why I'm personally not looking at these charts.  I do agree that frontal rainfall looks minimilistic for large parts of the south and east though, but that's generally always been the case.

For those who like their temperatures, the 15z UKV run keeps things warm for large parts of England and Wales well into next week.  Obviously not as hot as currently, but warm still nevertheless;

Still very respectable.  So, for England and Wales next week things look like turning more changeable and unstable.  Not full on unsettled, no, that was never really on the agenda, but equally not the solely current settled conditions we have either.  Some interest for convective weather fans, which has been lacking this summer, is there which is something I'm looking forward too.

It is worth a shout out for Scotland too.  This is the model thread for the country, not just south east UK.  For our Scottish friends, who haven't enjoyed as hot or as settled conditions that us English/Welsh folk have, things don't look too bad into next week.  Not much in the way of convective activity, not much in the way of heavy rain either.  Worth noting for you people is the prospect of some chilly night and chilly mornings starting to emerge;

Temperatures probably lower than what's shown in the glens.  First signs of some Autumn nights showing their hand here?

Remember folks, no need to get worked up, the weather will do what the weather wants to do at the end of the day, regardless of what any one person wants or thinks it will do.  

Thanks AWD...great post. As a storm fan i shall definately be keeping a check on ukv for late Sunday/ Monday/ Tuesday. Lets hope most areas that are suffering from the drought at least get some rain from this even though it is not always the best re flash flooding etc...still better than nothing. Also if the ecm 12z is to be believed we could have Azores 3 or is it 4...dont know, lost count..

 

[I remember Atlantic 252]

Most important thing though on UKV is the temps! settle for 24 Monday and 18 Tues, way down on GFS, down slightly on bbc too

[mb018538]

Highest recorded max today so far is 34.2c at Wiggonholt. Looks like the models did well to me on this one. Perhaps somewhere else may add a few points on later…

[sheikhy]

13 minutes ago, mb018538 said:

Highest recorded max today so far is 34.2c at Wiggonholt. Looks like the models did well to me on this one. Perhaps somewhere else may add a few points on later…

Gfs spot on mate!!gfs gives me 30+ degrees all the way till tuesday!!ecm till monday!!

[Man With Beard]

18 minutes ago, mb018538 said:

Highest recorded max today so far is 34.2c at Wiggonholt. Looks like the models did well to me on this one. Perhaps somewhere else may add a few points on later…

It looks like I will have to eat humble pie - I said at the weekend this is not a 35C plus set-up, and yet we've hit 34C two days before the supposed peak, meaning 35/36C definitely seems realistic now.

But all the same, many years ago 36C surely would have been unthinkable on this pattern? I always saw that as reserved for set-ups with a straight-line injection from Iberia which would itself need to be 42-45C? You could argue the dry hot summer has made higher temps more possible across the whole of Europe this year. I don't think that's the full explanation though. The heat parameters have simply changed. A simple heatwave in the UK is now likely to reach 34C rather than 32C. A significant heatwave gets to 36C rather than 34C. Rare heat means 37C or more rather than 35C. To even declare a heatwave means 30C these days, whereas ten years ago I would have argued 27C. It's just all changed.

Back to the present, how many consecutive 30C plus will this spell bring us? Monday/Tuesday still seem fiddly but still potential 30C days, which would bring us to 9 consecutive days. Still too early to call Wednesday too, though chances of the heat holding that long surely slim.

[MattStoke]

28 minutes ago, Man With Beard said:

It looks like I will have to eat humble pie - I said at the weekend this is not a 35C plus set-up, and yet we've hit 34C two days before the supposed peak, meaning 35/36C definitely seems realistic now.

But all the same, many years ago 36C surely would have been unthinkable on this pattern? I always saw that as reserved for set-ups with a straight-line injection from Iberia which would itself need to be 42-45C? You could argue the dry hot summer has made higher temps more possible across the whole of Europe this year. I don't think that's the full explanation though. The heat parameters have simply changed. A simple heatwave in the UK is now likely to reach 34C rather than 32C. A significant heatwave gets to 36C rather than 34C. Rare heat means 37C or more rather than 35C. To even declare a heatwave means 30C these days, whereas ten years ago I would have argued 27C. It's just all changed.

Back to the present, how many consecutive 30C plus will this spell bring us? Monday/Tuesday still seem fiddly but still potential 30C days, which would bring us to 9 consecutive days. Still too early to call Wednesday too, though chances of the heat holding that long surely slim.

I was thinking this earlier. We’re reaching temperatures that normally require an import of a lot of continental heat without much continental heat this time. Although the upper air temperatures will rise a little over the weekend. Makes one wonder how hot a plume like July’s could be if it followed a prolonged and quite intense building of ‘home grown’ heat like this and if the peak of the imported heat occurred during day time (The peak of July’s hot airmass affected the U.K. on the Monday night). Makes me think we’re yet to see the limit of what’s possible in our climate.

[FetchCB]

1 hour ago, Singularity said:

A note of caution on the UKV model - as far as I'm aware it uses the UKM as a basis, which had the most unstable outcome for Mon-Tue out of it, GFS, and ECM.

 

UKV is part of the Met Offices unified model. Its not based on the UKM its part of it. 

Unified Model

WWW.METOFFICE.GOV.UK

---

The Unified Model (UM) is a numerical model of the atmosphere used for both weather and climate applications.

Numerical weather prediction models

WWW.METOFFICE.GOV.UK

---

The Unified Model is run operationally in a number of configurations for weather forecasting at the Met Office.

 

[damianslaw]

3 hours ago, MattStoke said:

Ends with the Azores high in across the south and heat re-building but fronts likely bringing rain to northern areas.

Look at the cold air bedding to the NW though..  not so certain azores high will have its way going forward.. that cold air should fuel the jet somewhat.

Edited August 11, 2022 by damianslaw

[Ben Sainsbury]

44 minutes ago, FetchCB said:

UKV is part of the Met Offices unified model. Its not based on the UKM its part of it. 

Unified Model

WWW.METOFFICE.GOV.UK

---

The Unified Model (UM) is a numerical model of the atmosphere used for both weather and climate applications.

Numerical weather prediction models

WWW.METOFFICE.GOV.UK

---

The Unified Model is run operationally in a number of configurations for weather forecasting at the Met Office.

 

It's not always that easy to understand, but the UKV is linked to the UKMO. The UKV utilizes the boundary conditions from the UKMO, so effectively the UKV will use the bigger picture (outside the map boundaries of the model) from the UKMO and then runs its own forecast based on the boundary conditions at that time (I think that's how it works).

Edited August 11, 2022 by Ben Sainsbury

[Geordiesnow]

17 minutes ago, damianslaw said:

Look at the cold air bedding to the NW though..  not so certain azores high will have its way going forward.. that cold air should fuel the jet somewhat.

Could also angle the jet in such a way it becomes more wavey and we are still on the warmer side of the jet stream? September's can often be warm and dry despite increasing colder air at the polar regions, we shall find out if this September will be similar. 

[Don]

3 hours ago, MATTWOLVES said:

Worrying times Pete...throw up cold sypnotics and you can guarantee there will be a 1,000 flies in the ointment....but with Heat you just know its gonna come off with no questions asked. My thoughts are now how long before we breach 45C and then 50C! 

But tonight we have the signs from ECM of not much in the way of any meaningful breakdown..and signs of a recovery come later next week! 

 

Hopefully after I've departed the planet Matt!!  However, unfortunately I'm not convinced that will be the case!  As for September, whilst I suspect it will be above average, I'm hoping for not way above average but climate change has beaten us and is here to stay, so had better accept it!! 

Edited August 11, 2022 by Don