Model Output Discussion - Early Summer and Beyond

[chapmanslade]

I think some are completely missing the point about this weekend. It is NOT going to be a damp, cold, wet, grey day! Events are being driven by a considerable convective event over France this weekend and what happens there will largely determine the weather we get as it spills north. Left over MCS, maybe. Convective weather, very likely. Models are not yet clear on how far this convective plume will spread north, which means uncertainty on the local weather, and it will be local with some places in the low 20's in the south and some much depressed in heavy outbursts of rain. 

In fact this very event is being discussed in the convective thread!

Edited June 2, 2022 by chapmanslade

[kold weather]

30 minutes ago, chapmanslade said:

I think some are completely missing the point about this weekend. It is NOT going to be a damp, cold, wet, grey day! 

I don't see how looking at the models Sunday can be described as anything but that?

Perhaps the far north will be good, the far south MAY get into some warm sunshine for a time in the afternoon that could possibly trigger convection as well should it clear enough, but either side it really does look quite poor.

Pretty much every model has quite a wide zone of maxes between 10-14c at most, which for the time of year is very suppressed indeed. Even should the front move northwards enough for the south to dry out away from perhaps the coastal area it looks very cloudy. Finally, yes the rain may well start convective but it starts to lose that convective look and increasingly look more frontal as it heads northwards, particularly in the afternoon.

Anyway today is looking good, tomorrow looks good away from the convective showers (doesn't look super active though) Saturday is kinda 50-50 at this point, nothing to suggest a total write off though. Sunday by far looking the most dodgy day BUT timing of the frontal system is key as to whether its just a cloudy and coolish day, or whether its a real shocker of a day. Really want that front to make good northward progress, even if it means the south sacrificing Saturday evening.

As I've said all along, its a classic mixed bank holiday, no write off with good spells, but equally not perfect either.

Edited June 2, 2022 by kold weather

[chapmanslade]

29 minutes ago, kold weather said:

I don't see how looking at the models Sunday can be described as anything but that?

Perhaps the far north will be good, the far south MAY get into some warm sunshine for a time in the afternoon that could possibly trigger convection as well should it clear enough, but either side it really does look quite poor.

Pretty much every model has quite a wide zone of maxes between 10-14c at most, which for the time of year is very suppressed indeed. Even should the front move northwards enough for the south to dry out away from perhaps the coastal area it looks very cloudy. Finally, yes the rain may well start convective but it starts to lose that convective look and increasingly look more frontal as it heads northwards, particularly in the afternoon.

Anyway today is looking good, tomorrow looks good away from the convective showers (doesn't look super active though) Saturday is kinda 50-50 at this point, nothing to suggest a total write off though. Sunday by far looking the most dodgy day BUT timing of the frontal system is key as to whether its just a cloudy and coolish day, or whether its a real shocker of a day. Really want that front to make good northward progress, even if it means the south sacrificing Saturday evening.

As I've said all along, its a classic mixed bank holiday, no write off with good spells, but equally not perfect either.

I don't doubt that at some point on Sunday some people will see some heavy rain, but many will not. Look at what ECM thinks for Sunday, many parts with plenty of warmth.

[MP-R]

18 minutes ago, chapmanslade said:

I don't doubt that at some point on Sunday some people will see some heavy rain, but many will not. Look at what ECM thinks for Sunday, many parts with plenty of warmth.

Hate the shading on those maps. Makes it look cold in north and south and warm in the middle

[Cambrian]

24h precipitation totals through to the end of Sunday on the 6z GFS, 0z GFS and ECM operational runs. The higher totals move around from run to run but looking quite solidly now like a wet day for parts of southern and central Britain. 

 =  =  =  =  = 

Ah, don’t worry, she’s well used to it. 

[mb018538]

23 minutes ago, chapmanslade said:

I don't doubt that at some point on Sunday some people will see some heavy rain, but many will not. Look at what ECM thinks for Sunday, many parts with plenty of warmth.

The only place you could call ‘warm’ (and even that’s pushing it) is western Scotland at 18c - relative to average.

16-20c isn’t really warm for June - It’s average to slightly below in the SE.

[Mike Poole]

So now that the holiday is here, here is the UKMO 0z pressure chart for the UK at T22, T46 and T84:

The shallow low over Ireland brings some showers to the NW today into tomorrow, otherwise largely dry.  By T46 most of the UK fine and settled.  Sunday looks wet for some in the SW and SE as pressure falls with lows to our SW and SE.  So after all the model mayhem in the run up to this, this is probably now not going to be that wide of the mark, and it is no disaster as suggested by some earlier, but Sunday does look wet for some.  Interestingly, NE of England and Scotland look fine, rarely commented on in here.

A fair few posts showing precipitation or cumulative precipitation charts from the global models in the run up to this.  These should in my opinion be taken with a pinch of salt - one because of uncertainty at the range shown, but also especially in summer, much of the precipitation will be convective and these models just aren’t intended to resolve this.  The situation will be more nuanced, and maybe the high res models will help with under 48 hours to go for Sunday, some places may be soaked, others less so, we will see…

[kold weather]

52 minutes ago, mb018538 said:

The only place you could call ‘warm’ (and even that’s pushing it) is western Scotland at 18c - relative to average.

16-20c isn’t really warm for June - It’s average to slightly below in the SE.

I think generally Scotland is going to do ok out of this extended weekend, nothing too impressive but 18c in June sunshine will still feel good enough. As you say its pretty much uniformally below average to some extent. The far south/SE might well get some sunshine at some point on Sunday and should that happen temperatures should respond pretty rapidly and 20c in June sunshine again will feel perfectly good enough.

With that being said most models do have a zone of very low maxes, some of those maxes may well come close to daily records should they end up being that low, though my guess is those lowest temperatures are modelled too low and that in the rain 12-14c is more realistic.

06z GFS has sped up the system again in line with the more progressive runs and now breaks out convection as early as Saturday morning, making Saturday a more classic sunshine and showers type day, but nothing too extreme. Convection moves up overnight and sits in the north of England for Sunday, very cool day up there from the looks of things. Dries up but cloudy further south before more convection kicks off and back into a showery cloudy flow, perhaps alot like we saw this previous Monday (though perhaps not quite so many).

[Mapantz]

A lot of chopping and changing still to come, but some areas will be unfortunate, while others won't.

UKV days 2 to 5:

   

[Cambrian]

The 06z GFS op hinting at a fascinating tussle ahead for next week. Frontal rain coming in from the west on day 6 weakens on approach by day 7 but reinvigorates and pushes through to eastern parts by day 8. 

  

To push it through, the belt of rain relies on the formation of a secondary low west of the Brest peninsula around day 7, swinging through to lie over Northern England by day 8. The models are struggling with this potential secondary low formation providing the “second push”. 

 

The tussle continues to day 10, pressure remaining higher over the continent throughout with some widely different air masses in the mix too - T850s ranging from +4 over northern Scotland to +24 over southern France, with secondary lows continuing to form in the southwest approaches and running up over the UK and Ireland along the contours between the air masses. 
 

[Earthshine]

Toasty

[Frosty.]

I will let these GEFS 6z charts speak for themselves! … …is it nirvana.. perhaps Shangri la?… perhaps not… …but there’s support there for at least a decent very early summer!    

Edited June 2, 2022 by jon snow

[Frosty.]

I’m really late to the party today! ..but I did like the end of the ECMWF 0z operational..for sure! ..better than last evenings 12z op absolute dross!!!!!!

 

[Frosty.]

England are 100-7..perhaps even 100-8.. …but fear not..at least the Gfs 12z op shows a plume..let’s have a street party? ! ⛈  

 

 

[StormChaseUK]

12z is better for next weekend yes, plume appears (sort of) then again during following week fi. 

 

 

[Frosty.]

Where is everyone..?…haven’t you seen the ECMWF 12z operational?…ah, yes, I see…. As you were.. almost as bad as the cricket!   

Edited June 2, 2022 by jon snow

[Methuselah]

25 minutes ago, jon snow said:

Where is everyone..?…haven’t you seen the ECMWF 12z operational?…ah, yes, I see…. As you were.. almost as bad as the cricket!   

Seventy years on the throne?

[Frosty.]

Has anyone mentioned the icon 12z longer term?…come on guys, do I have to be the first… jeez..pfffft! …it’s only the weather! … ..

 

[Methuselah]

[StormChaseUK]

20 minutes ago, jon snow said:

Has anyone mentioned the icon 12z longer term?…come on guys, do I have to be the first… jeez..pfffft! …it’s only the weather! … ..

Edited June 2, 2022 by StormChaseUK

[Cambrian]

A lovely “easy” summery day here today, with the holiday it felt more like a Saturday. The 12z ECM operational run looks changeable from a week today, which is actually a Thursday, and decidedly so by a week Sunday, which might well feel like tomorrow won’t. 

  

It will no doubt all come back right in the end - in the meantime, maybe another glass of wine  Oh, go on then

[Frosty.]

The GEFS 12z has a few highlights!.. …and they all lived happily ever after…I do love a story with a happy ending!  

Are you havin a laff!  

 

Edited June 2, 2022 by jon snow

[Frosty.]

All joking aside, the longer term ECMWF 12z ensemble man doesn’t look so good… ….. …come to think of it, the shorter term doesn’t look so good either! …chin up summer fans, there’s still 3 months until autumn!..

 

[summer blizzard]

A shift in the models tonight with the Euro (GFS18z largely backs it) never really rebuilding pressure after this weekend and if anything getting progressively worse out to day 10.

Should be noted that for the first two thirds we only need to go back to 2019 for a start to summer that can be described as poor to horrific.

[Cambrian]

Beautiful morning. The North American and UK models steadily becoming more set on something less settled for the end of next week- 0z GEM, GFS and UKMO ops for day 7 all showing the UK and Ireland under the influence of an Atlantic low to our northwest, UKMO the most reticent, 

  

- supported by the GEM and GFS means too.

 

- the depression is often modelled as a complex low with secondary developments in the mix, bringing more general rain at times.

 

This might please many growers as the showery setups of late can be quite hit and miss.