Model Output Discussion - Autumn arrives

[bluearmy]

Ec 12z picks up the cape sat afternoon and evening across s england (hants, Sussex, Surrey , Kent ) 

still looking at an inch plus across that swathe s wales and ne through Birmingham and towards notts/lincs

Edited June 16, 2022 by bluearmy

[Portsmouth Sun]

26 minutes ago, Liam Burge said:

I'm not sure why the Met hasn't issued an amber excessive heat warning for tomorrow yet?

Because it's not that exceptional.  33c is a decent temperature, but it's only lasting for a day.   The models are struggling next week, but can see a glimmer of hope the south will see some respectable temperatures midweek, with mid 20's and good spells of sun. A good enough start to actual summer proper, but could be better.

[Frosty.]

I think the Gfs is up to its old tricks again in underestimating the maxima tomorrow afternoon!, shows 31c 88f for the SE but I think favoured spots will hit 34 / 35c around 94f..say Kew Gardens or Heathrow Airport as two examples.. cloud amounts will decide it but whatever happens, it’s one for the books when you consider the bigger picture with what’s happening in France.. 40c and Spain..even hotter! ? ️  

 

[MATTWOLVES 3]

25 minutes ago, mountain shadow said:

A poor UKMO and GFS with Northerly winds and low pressure possible into late June.

Eternal Autumn continues. 

Are you basing that poor prognosis on your own area or on a wider scale? Ukmo only runs 7 days and GFS longer range just loves to show a different outcome several times a day especially at that range!

Personally I think gfs is overblowing that scenario next week and the models have seemed very keen on N/W blocking so many times the last few weeks. Gem again looks a more prosperous picture. 

Quite a difference between the 2....all be it a long way off.

Edited June 16, 2022 by MATTWOLVES

[Mapantz]

20 minutes ago, bluearmy said:

Ec 12z picks up the cape sat afternoon and evening across s england (hants, Sussex, Surrey , Kent ) 

still looking at an inch plus across that swathe s wales and ne through Birmingham and towards notts/lincs

Yes. Strongest instability ahead of the cold front. The only problem, there's likely to be a strong cap, and with limited sunshine, not much will happen.

Saturday 15Z

 

Edited June 16, 2022 by Mapantz

[minus10]

19 minutes ago, Mapantz said:

Yes. Strongest instability ahead of the cold front. The only problem, there's likely to be a strong cap, and with limited sunshine, not much will happen.

Saturday 15Z

 

Apologies if this is in the wrong thread and should be in the storm thread but just interested...why is there a strong cap and what is causing it given the difference in temp and humidity and instability?

[Cambrian]

25 degrees here in the hills today and yes, warmer than modelled. So how very odd to be looking at 0 degree isotherm height charts!

But heck, these are fascinating ones, from today’s 12z GFS operational run, the 4000m line over Northern England at noon tomorrow, being pushed south to be replaced by a much cooler airmass into Scotland and most of Ireland by noon Saturday, with the freezing level as low as 1500m immediately behind the front.

24h, 36h, 48h

 

It’s a very brief incursion of cooler air though, that never gets through the country -  the freezing level always 3500m or higher in the south and interesting that by noon Sunday, it has risen again over most of the UK and Ireland. 

60h, 72h

 

Another big contrast being set up for day 6, the fresher air perhaps winning through for a while this time, with a cooler air mass in place for all by day 9. and a midday frost for the tops of the Scottish mountains, with some snow possible. 

  

Maybe not likely in the event, but after looking for several days at these extraordinary temperature charts for tomorrow, I thought we might all need something to cool us down  You godda try. Enjoy the heat tomorrow if it’s your thing and comes your way, drink plenty of water  

[bluearmy]

37 minutes ago, Mapantz said:

Yes. Strongest instability ahead of the cold front. The only problem, there's likely to be a strong cap, and with limited sunshine, not much will happen.

Saturday 15Z

 

Good points

my comment made because previous runs were missing any cape ahead of the frontal zone. 

 

 

[Iceman2606]

A hot and sultry day to come tomorrow for many parts of England. Temperatures widely in the high twenties/low thirties especially so for eastern areas where 33-34°C looks possible in a few spots.☀?

[swilliam]

52 minutes ago, Mapantz said:

Yes. Strongest instability ahead of the cold front. The only problem, there's likely to be a strong cap, and with limited sunshine, not much will happen.

Saturday 15Z

 

Plenty of rain by the end of Saturday for some none the less.

 

[Roadrunner]

GFS 12z not making much of the rain Saturday daytime at all. Been quite consistent in this over the last few runs. 

Think some places will be lucky and some unlucky. Sunday looking a lot dryer for many than a few days ago. 

[MattStoke]

3 hours ago, MattStoke said:

29.2’C today at Heathrow. The very top end of the model predictions for today.

Edit: Now 29.3’C at Heathrow and Kew Gardens.

29.5’C was the highest in the end, in Northolt.

[Methuselah]

2 minutes ago, MattStoke said:

29.5’C was the highest in the end, in Northolt.

Exhaust gases from SpaceX rockets at the ready!

[Man With Beard]

Interesting to see ECM ensembles now 80% in favour of Saturday being almost as hot as Friday SE of a line from Dorset to London, a few runs push that further towards the midlands.

[clark3r]

23 minutes ago, Man With Beard said:

Interesting to see ECM ensembles now 80% in favour of Saturday being almost as hot as Friday SE of a line from Dorset to London, a few runs push that further towards the midlands.

Will be amazing if that happens, sitting in the garden having a beer love this weather 

[minus10]

Still amazing temp differences between north and south on ukv 18z. North scotland 7 degrees ( highlands) while just south of the wash 34 degrees at 3pm Friday

Then on Saturday 41 degrees in parts of northern France at 2pm not far from the channel coast...

If not here then surely some big storms in France with that heat and encroaching cold front??...

[sheikhy]

This is astonishing!!gfs 18z no rain for nearly the whole of england and wales all weekend!!what is going on!!!who is gona be correct!!!mad differences only 36 hours out!!!amazing!!

[clark3r]

Saturday maybe now forecast, if clear skys and with all the heat in France, I can imagine temps will rocket in the south east. I’m thinking 30 will be reached 

[sheikhy]

To put into perspective ecm gives me 25 mm of rain by sunday 12pm!!gfs gives me 0 mm by 12pm sunday!!

[sheikhy]

The amount of high cloud tonight is quite excessive!!will it clear in time for the hot temps tomorrow?!!

[Singularity]

Studying the ensembles, the main question for the rest of June and into early July is: Will the AO remain positive enough that troughs tend to stay more toward Scandinavia than further south in Europe, such that the hot air over western and central parts of Europe is largely left in place, with the UK peripheral, often warmer than average in the south, near or a bit below in the north? Or will we transition to a more typical low AAM pattern of cool NW/N flows with mainly showers, sometimes longer spells of rain, by next Thursday?

The runs are almost 50/50 on which way it goes. That the persistence possibility exists at all seems to be down to some heat dome characteristics coupled with a sort of MJO-Monsoon interaction over the western Indian Ocean which shows historical correlation with anomalous ridges centred over both the North Atlantic and Central Europe.

For early July, extended modelling has long suggested that the MJO will set off eastward and drive a big AAM increase. As Tamara noted, this would give us a more clear cut warm/hot & dry weather pattern. There’s yet to be much sign of it in the outer reaches of the mid-range guidance, though.

Edited June 16, 2022 by Singularity

[Captain Shortwave]

Fair to say that if the UKMO/GFS are right, then next week looks very decent indeed.

 

The UKMO is largely the same. Probably the chance of a few showers at times, but also good sunny spells and temperatures would be steadily rising through the week. Mid to high twenties on the GFS.

Yet again the main culprit is the continued presence of below normal heights to the west of Iberia that prop any ridge extension from the west up, whilst continuing to push hot air into a fair chunk of mainland Europe.

Edited June 17, 2022 by Captain Shortwave

[snowblizzard]

+20c isotherm doesn't get anywhere near as far North as initially modelled.

So, temperatures Friday should not be as high as forecast a few days ago!

34c/35c surely much less likely.

Details on breakdown, ie. rain & thunder, still very uncertain.

[clark3r]

32/33 looks likely today, 28/29 in the south east tomorrow, cooler Sunday but pleasant 21/22 gfs this morning is looking lovely next week warming up mid to high 20s, next Friday could be hot again 30 plus one to watch in the coming days 

[sheikhy]

Dry weather continues apart from a bit of rain tomorrow!!ecm seems to have downgraded the amounts by half of what it was showing!!suns out and its heating up here!!