Model Output Discussion - Autumn arrives

[Aqbadger]

2 hours 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.

All really good points and yes MWB think it's safe to say the bar has been well and truly raised now. Where does it end....GFS I think its fair to say has done very well this year

[MattStoke]

Just had a look at the ECM 12z control which followed the op up to day 10 but runs out further on Meteociel.

It ended with another heatwave developing. Wonder if we’ll see this become a trend. Fits in with the seasonal model outlooks.

Edited August 12, 2022 by MattStoke

[clark3r]

Monday is still looking hot for most of the south east 30 to 32, still very warm Tuesday 28 but back down to average by Wednesday 

[MattStoke]

39 minutes ago, MattStoke said:

Just had a look at the ECM 12z control which followed the op up to day 10 but runs out further on Meteociel.

It ended with another heatwave developing. Wonder if we’ll see this become a trend. Fits in with the seasonal model outlooks.

GFS 0z going down a similar route, although less strongly. This may be gaining some traction. 

 

UKMO also showing more influence from the Azores high after mid week.

Edited August 12, 2022 by MattStoke

[seb]

GFS does it again. The “monsoon” front it showed for several runs, pushing in from the West next Saturday evening… has been entirely removed. Instead it is now showing a dry weekend across the large majority of the country. 

As with any frontal rain modelled by it at T+10, first it shows up with large amounts of rain, each run weakens it and then it vanishes. This has been the case pretty much since last November with less than a handful exceptions.

00z generally warm, closer to average after Monday, but what would normally be considered perfect summer weather - mid 20s with some areas getting to 27. Rain amounts obviously not to be taken literally but significantly drier compared to the previous few runs.

As per other posters this morning… there’s some model consensus appearing.

[clark3r]

12 minutes ago, seb said:

GFS does it again. The “monsoon” front it showed for several runs, pushing in from the West next Saturday evening… has been entirely removed. Instead it is now showing a dry weekend across the large majority of the country. 

As with any frontal rain modelled by it at T+10, first it shows up with large amounts of rain, each run weakens it and then it vanishes. This has been the case pretty much since last November with less than a handful exceptions.

00z generally warm, closer to average after Monday, but what would normally be considered perfect summer weather - mid 20s with some areas getting to 27. Rain amounts obviously not to be taken literally but significantly drier compared to the previous few runs.

As per other posters this morning… there’s some model consensus appearing.

I think a lot of pleasant summer weather on offer after this heatwave, I would prob give it a high chance of another heatwave before mid September but not as hot as what we have seen

[Row w]

gfs 00z hinting towards another warm day for Monday but given any storm activity I suppose will depend on sunshine amounts, it's also looking pleasant again from the 23rd looks like a brief plume of heat into the high twenties but looks to be a one day affair until we return to normal, all in FI of course so remains to be seen

[KTtom]

The only certainty is that temperatures will be back to the 'norm' by Tuesday, GFS ens paint a pretty average picture there on. Next step is to try and get some useful rain, as others have said, this is a constant issue with the medels and the Met App, constant downgrades as we near T0. 

 

[AWD]

A quick glance at this morning's UKV run from me, before I take the kids on a weekend break down to Bognor Regis to enjoy the last few days of this hot, settled spell.

Isolated showers breaking out on Sunday afternoon over parts of England.  Some heavier rainfall forecast for highland Scotland;

This convective activity then increases as we head into the new working week, with storms/showers breaking out more widely over Wales and western England on Monday as well as parts of Scotland, although less intense here;

Then overnight Monday and into Tuesday things ramp up, convective wise again, for much more of the UK, with heavy downpours possible pretty much anywhere;

Tuesday continues to look awesome on this model, with perhaps the hint of storms clustering together to form a more organised band of thundery rain or even a homegrown MCS;

All very uncertain with detail, as you would expect, chopping and changing between each model run, but the theme of instability remains.  As ever with convective weather, it's hit and miss, so I'm not promising storms for everyone, some folk will no doubt stay dry and sunny, if not quite as hot as currently.  Monday is shown to be warm widely across England still;

Tuesday sees the warmth restricted more towards the SE corner, with more typical temperatures elsewhere and as shown above, some rain;

Scotland maintains the theme of some rather chilly nights starting to appear.

Anyway, enjoy your weekend folks.  I'll probably be skirting of towards the convective thread more now, leaving you all to search for what comes next after the upcoming changeable period.  Mixed signals currently but long range forecasting isn't my speciality.  

Edited August 12, 2022 by AWD

[mushymanrob]

14 hours ago, Mapantz said:

You're only comparing the GFS temps against a small amount of official weather stations? Have a look at the hundreds of unofficial stations, plenty have made 34 - 35°C.

Hes right to do so...... records are written at official stations, unofficial ones simply dont count as they dont meet the criteria needed for "officialdom".

[Captain Shortwave]

Monday looks like a case of scattered afternoon showers, still a fair amount of sunshine and a good chance that 30c could be reach or exceeded in some spots.

Tuesday sees quite a convergence develop through central parts with warm air still in place with a cool northerly starting to affect areas further north and west. This allows showers to organise with potentially some intense downpours that could be widespread.

ECM

 

Fits well with the other models that all develop quite an organised areas of showers Tuesday afternoon.

Edited August 12, 2022 by Captain Shortwave

[mb018538]

3 hours ago, MattStoke said:

GFS 0z going down a similar route, although less strongly. This may be gaining some traction. 

 

UKMO also showing more influence from the Azores high after mid week.

That ukmo day 7 chart just looks close to average rather than screaming full on unsettled. If the main trough stays out to the NW/Iceland then SE areas still won’t see a lot of rainfall.

[sheikhy]

Last real hot day is monday of this current spell!!and once again like yesterdays 00zs this mornings runs are showing quite a bit of rainfall again tuesday and wednesday!!wouldnt surprise me if it downgraded again but so far so good for my peeps who want the rain!!ukmo extremely wet like the ukv!!

[Lincs Observation]

Morning all

As I alluded to way back in May the rinse and repeat scenario has played out relatively consistently, what started the summer as showery then warm turned to shower then heat, now as the summer is coming to it conclusion the theme is heat back to shower. I don’t envisage a dramatic change in transition from summer to autumn but a gentle transition from heat to shower, warm to rain.

it’s been an unprecedented and wonderful summer no one can deny, and to be honest I’m quite looking forward to a gentle autumn like back when I was a kid nothing dramatic nothing serious.

what’s is everyone else’s take ?

LO

[Cambrian]

The best effort from the 0z GFS at getting some frontal rain into southern parts in the next ten days is at day 8, but the troughing is too far north, the low forming over Iceland, with only dribs and drabs getting into the south of the UK. 

  

Getting rain into that swathe between the Suffolk, Surrey and Sussex Savannahs and the Kent Kalahari will need proper energy in the jet stream and far enough south - something like at day 10 on the 0z ECM operational run, though cutting against the grain of the ensemble, so possibly a bit of a “day tenner”; 

    

a handsome looking low pressure, 990mb to the north of Scotland, driven by some proper Atlantic energy in the jet stream, heading southeast into southern Britain and Ireland, with a nice little flick at its northern edge to help the troughing over Scotland - otherwise it’s just having a giraffe. 

[Paul]

A few ensemble members from both the GFS and ECM going for temperatures into the mid-high thirties into the final week of August this morning. 

But, they're outliers at the moment. Taking them out of the equation with the 90th percentile (top of the greyed out area), the mid-high twenties looks more likely. Long way out though...

[feb1991blizzard]

gfs 6z is a snorter! - up to 240

[minus10]

Well gfs 6z shows that although more changeable with cooler weather at times the heat is never really that far away and makes the occasional return. Some rain from this run however remain very skeptical about any gfs precip forecasts beyond a few days...so we shall see..

Op dancing about the mean so scope within that for warmer and cooler spells ..

[damianslaw]

4 hours ago, Captain Shortwave said:

Monday looks like a case of scattered afternoon showers, still a fair amount of sunshine and a good chance that 30c could be reach or exceeded in some spots.

Tuesday sees quite a convergence develop through central parts with warm air still in place with a cool northerly starting to affect areas further north and west. This allows showers to organise with potentially some intense downpours that could be widespread.

ECM

 

Fits well with the other models that all develop quite an organised areas of showers Tuesday afternoon.

Clash of airstreams a much cooler northerly mixing with the lingering tropical continental airstream is a recipe for convection..

[MATTWOLVES 3]

Absolutely stunning today...nearly 7 whole days of blue skies here now...who needs the Costa del sol!

Right folks this weekend stays hot with 36 perhaps 37C possible. Good grief! The risk of storms is obviously there early next week and you convection guys could be getting your just deserts...A hit and miss situation as always but I'm sure some could see some hum dingers! Fingers crossed.

Does this spell then end? I don't think it does tbh there is a trend emerging of a warm up again within some of the ensembles and  the 6z mean again rebuilds pressure towards the South as we enter the final 3rd.

Hand on heart I've loved this...but I'm also aware some of you have hated it for numerous reasons....but there's never much we can do about mother nature...I've spoken to the fire officers over on my trail walk just now over here,and they've been rushed off there feet with fires all over the place...and several over here! I told them they don't get payed enough whatever it is...brilliant service they provide.

I provide the mean showing that improvement again...and a couple of pics today...one of how bad the ground is right now,and a picture of what runners around here call the Death steps...Great once you've reached the top but a killer getting up em.

Enjoy the weekend each and everyone of ya  

Edited August 12, 2022 by MATTWOLVES

[minus10]

9 minutes ago, MATTWOLVES said:

Absolutely stunning today...nearly 7 whole days of blue skies here now...who needs the Costa del sol!

Right folks this weekend stays hot with 36 perhaps 37C possible. Good grief! The risk of storms is obviously there early next week and you convection guys could be getting your just deserts...A hit and miss situation as always but I'm sure some could see some hum dingers! Fingers crossed.

Does this spell the end? I don't think it does tbh there is a trend emerging of a warm up again within some of the ensembles and  the 6z mean again rebuilds pressure towards the South as we enter the final 3rd.

Hand on heart I've loved this...but I'm also aware some of you have hated it for numerous reasons....but there's never much we can do about mother nature...I've spoken to the fire officers over on my trail walk just now over here,and they've been rushed off there feet with fires all over the place...and several over here! I told them they don't get payed enough whatever it is...brilliant service they provide.

I provide the mean showing that improvement again...and a couple of pics today...one of how bad the ground is right now,and a picture of what runners around here call the Death steps...Great once you've reached the top but a killer getting up em.

Enjoy the weekend each and everyone of ya  

Thanks Matt...tbh take my hat off to you mate (if i was wearing one) ...running up hills in this heat and up those 'death steps'...i'm finding it hard enough just to keeps the plants watered

Yes as you say the gfes pressure mean does look on the rise with the ens all heading in that direction (think the op's on the cider or something)...just need some good rain mate down here and where you are by the looks of it first...

[Earthshine]

Hmm, GEFS not looking as cool as it was before.  In fact looking pretty warm (although not as warm as recent).

[Dangerous55019]

Hello everyone. 

Its been about a week since I last did one of these, so here's a look at the CFS v2 for the next four weeks.

Week 1 - 12th to the 18th August: High pressure over Scandinavia and parts of central Europe is extending its influence over us here the UK. It also appears to be joining up with a ridge from the Azores high! So yet more of the current heatwave conditions that we are experiencing at the moment. But it you look closely, you can see the low pressure brewing off the coast of Portugal, and towards the Bay of Biscay. Hopefully this will give us the breakdown of this current weather pattern and bring us all some much needed rain.

Week 2 - 19th to the 25th August: All change! The high pressure that has influenced our weather for the past week slips south wards into main land Europe and towards the Mediterranean. Low pressure centered between Iceland and the north of Scotland would put us in a much more westerly driven air flow. At a guess I would say showers and longer spells of rain... But I'm certainly not seeing a total washout.

Week 3 - 26th August to the 1st September: High pressure across main land Europe and towards Scandinavia, and then up towards Greenland, Iceland and the North Pole! Meanwhile over us in the UK, there is nothing really showing, but I'm gonna hazard a guess that there could well be a shallow trough of low(er) pressure over us. It could be nothing too wet, or it could a low(er) pressure area that gets stuck over us bringing us some more much needed rain? A bit hard to tell really... And what's more only time will tell! 

Week 4 - 2nd to the 8th September: The high pressure has fully scuttled up towards the North Pole and towards the eastern sea board of the USA, Plus a spot of high pressure off the North western tip of Africa! Neither will do anything for us! But we have got a trough of low pressure over us here in the UK, and its extending out towards Scandinavia. Hopefully bringing us some much needed rain for the start of autumn.


So there you go! Make of that what you will! Hopefully this will help others in trying to decipher what some of the shorter range models are trying to forecast. 

[damianslaw]

Two main players as we approach latter stages of August.

1. Atlantic trough anchored to the jetstream, initially it will be a weak affair but signs the jet will be invigorated somewhat in time aided by colder polar air.. GFS shows the trough digging further south.. 

2. Azores high- omnipresent to the SW it drifts west for a time then looks like ridging NE again but coming unstuck somewhat against the stronger jet.

End product most likely a north- south divide.. northern parts cool, wet with a westerly feed, southern parts drier and warmer but not totally dry. However any frontal activity unlikely to produce much rain.

Edited August 12, 2022 by damianslaw

[mb018538]

 

GFS 12z…..breakdown? Not for long…