Model Output Discussion - The Start Of Summer

[Ross Andrew Hemphill]

3 minutes ago, CheesepuffScott said:

Thursday on 18z has raw temps of 34°C in London area, probably 36/37 keeping in mind it’s usually undercooked. Even Scotland sees mid-high 20s..

Uppers up to +24 in the south

 

20C isotherm into the North of Scotland! Surely that’s a record 

[MATTWOLVES 3]

No need to have nightmares tonight folks... 18z still delivering the goods, that should keep you sweet til the 0z runs... Heat well and Truelly in place, if anything some small corrections are likely to be made over the coming few days... Sometimes West, sometimes East... All still looking good though. 

[NorthernRab]

Scotland joining in the fun on the 18hz run - high 20s in the Highlands & Islands and North East Scotland at midnight is pretty unheard of! 

[chapmanslade]

The heat peaks in France on Wednesday transferring north to UK on Thursday which looks like being the hottest day. Very much depends on amounts of cloud about. Note also the onshore breeze keeping the East coast cooler by then.

[Guest]

I can’t tell if its 26 or 28c but at 18z next Thursday the GFS definitely has a 27c dew point in the West Midlands....a dew point, not the 2m temperature.... ?

Edited June 20, 2019 by Alderc

[Derecho]

Yup still very much game on for next week with a more cyclonic influence then the previous run. Some intense thunderstorms more likely if it transpired, especially Friday which looks absolutely primed for them. Look at this for rainfall rates over 3 hours...

Obviously huge uncertainty at this range but it demonstrates just how much moisture is being held in the atmosphere come later next week if such a scenario unfolded. Another very hot run.

 

Edited June 20, 2019 by Quicksilver1989

[Fourty Point Three Degrees]

9 minutes ago, StormChaseUK said:

28c at 9am - incredible 

That's the best part of watching model runs, you know its going to be a scorchio when its showing 28C at 09:00

[Man With Beard]

GFS has been relentless today with this heatwave, but a few give up the ghost early tonight 

[Mike Poole]

Holding firm on the GFS 0z, here's the take at T168:

Homing in on the UK, +25C 850 temperatures into the SE a week from now:

[Weather-history]

Never took these charts at face value but it must be like walking through a nitroglycerin factory with a blowtorch

 

[Cheshire Freeze]

3 minutes ago, Weather-history said:

Never took these charts at face value but it must be like walking through a nitroglycerin factory with a blowtorch

 

I've never seen values that high forecast for the UK, ever.

Any trigger for a storm would see the storm able to utilise scary amounts of energy.

[Mike Poole]

2 minutes ago, Weather-history said:

Never took these charts at face value but it must be like walking through a nitroglycerin factory with a blowtorch

 

Yes, not worth overanalysing this until much nearer the time, but this I have never seen before, GFS 0z MUCAPE at T162:

Off. The. Scale.

[knocker]

Outlook - A much welcome improvement of the weather over the next seven days with it becoming warm, and even hot in some areas in the south, but still rain around and the regional variation of the weather and temp may well be tricky to pin down.

Meanwhile the North Atlantic 500mb and surface profiles for midnight

We are finally losing the attention of the low to the north albeit still frequent showers around over Scotland and N. Ireland today, and a few further south, but elsewhere a dry and sunny day mostly with temps starting to pick up in these regions as high pressure builds from the south

A few showers may well linger over Scotland this evening but generally a fine and clear night and getting quite cool in some areas

Saturday the pattern change is well underway with high pressure over the UK, albeit centred in the North Sea, heralding a fine dry day with plenty of sunshine and temps rising over England and Wales but the usual caveat vis sea breezes applies.

Over Saturday night and through Sunday the new upper low to the south west takes closer order and surface fronts associated with this will track north east bringing some heavy showery rain to many western and northern areas after a fine start to the day. And now temps generally a tad above average

The upper low continues to re-orientate over Sunday night into Tuesday under pressure from the amplifying subtropical high zones which initiates some WAA from the south. Meanwhile the surface fronts continue to track north east with some heavy thundery showers breaking out and longer periods of rain.

The hot and humid weather builds over Tuesday, particularly over England and Wales and some storms could break out in southern and western regions with some hefty downpours

 

Edited June 21, 2019 by knocker

[Chris.R]

Speechless!!

?️️?⛈?

[reef]

Some of the dewpoints shown on this run are extreme to say the least:

I think you would be hard pushed to find many places in the World with dewpoints that high right now. Most of coastal India / Bangladesh are only 24-26C.

Utterly ridiculous if it were to come to fruition.

[SMU]

Surely next week is homing in on one of the most exciting / crazy weeks of weather ever!

- Heat locked in ( extreme )

- Instability & moisture locked in...

Its going to go bang.

Look at this chart- totally stationary air = Boiling.... but with minimum movement flash flooding could also be an issue...

 

[knocker]

To continue for a couple of days with the gfs

The position of the upper low with respect to the amplifying ridges continues to evolve, and the ingress of warm and humid air accelerates. As has been mentioned previously how this precisely pans out, vis the energy flows, is critical

Storms could break out just about anywhere but more likely in the west and south

 

 

Edited June 21, 2019 by knocker

[Guest]

Morning all, so some good news our plume hasn’t gone anywhere overnight and the setup hasn’t really changed with GFS and UKMO holding firm. Warmth starting to build Sunday into Monday, then spreading to most parts of England and Wales by Tuesday. Looks like a couple of rounds of elevated storm activity Monday/Tuesday up the western flank of the county. Core of the heat Wed-Fri, 31C as far north as Inverness...down in the south probably 3 or 4 days above 30c, at this stage looks like one of the best challenges we’ve seen to the June all time record which currently stands at 35.6c, on current modelling there has to a 50/50 chance it’ll go and this is clearly isn’t a London only event, 30c likely right to the west coast of Wales and northern coasts of Devon and Cornwall. 

Onto GFS’s dew points / 2meter temps. There has to be problem, several times through next week GFS is forecasting higher dew points than the air temperature which is not possible during the overnight period to 06z each morning. Given the issue one would assume DPs are generally are at least 2-4c too high, plus I really can’t see the UK having widespread DP’s in the mid possibly high 20s during the daytime going the other way 2meter temps are probably a 1-3c too low.

On to storm activity, it’s actually looks quite limited, accumulated precip south east of a line Bournemouth to the Wash is almost zero out to next Saturday as the whole profile of the atmosphere may not massively promote convection despite many 1000’s of joules of CAPE in place. west of here there does as I mentioned earlier does appear to be a couple of rounds of Elevated action running up the western side of the UK, too early to pin down details but likely some highly electrical active storms Monday and Tuesday evening in the same areas probably Bournemouth / Birmingham west.

 

[Leo97t]

In this point it looks like maxes in London will be as follows:

Monday - 30C

Tuesday - 32C

Wednesday - 33C

Thursday - 34C

Friday - 34C

I wouldn't Be surprised to  see even higher at the end of the week into the high 30s

[Weather-history]

There was one 850hpa ensemble on the 18z GFS run peaking at +19.4C for.....the Orkneys!

[StormChaseUK]

00z upgrades the heat prolong until saturday 

One of the classics for uk weather coming up this week. Historic I think.

[Singularity]

Intriguing that FV3’s suddenly switched to much weaker ridging north of the heat dome Thu-Fri (happened with the 18z and the 00z is consistent).

Speaks volumes that it produces similar UK conditions to ECM despite this; the low to the west is more important. So I wonder what the chance is of it moving north more quickly - likely steering the heat dome away a bit sooner - if it doesn’t stay very weak - another aspect FV3’s suddenly changed since the 12z.

Let’s see if ECM makes these adjustments to our west too.

[Man With Beard]

25 minutes ago, Leo97t said:

In this point it looks like maxes in London will be as follows:

Monday - 30C

Tuesday - 32C

Wednesday - 33C

Thursday - 34C

Friday - 34C

I wouldn't Be surprised to  see even higher at the end of the week into the high 30s

My feeling was that the GFS would produce hotter maximums than this by the end of the week (as you suggest) - more of a SE element in the wind on this run. But these are the small details that will make the difference between records going or not. 

Monday to Wednesday now pretty secure to forecast in general terms I think (except further north/west where the heat boundary is still debatable), Thurs/Friday needs a bit longer to pin down. 

Edited June 21, 2019 by Man With Beard

[Frosty.]

Looking at the GEFS 00z mean it's an increasingly scorching week ahead but then it turns much cooler.

[mb018538]

The 00z is top of the pile again ensemble wise, but what an ensemble that is. Mean touching 20c, above 15c for 4 days straight. Looks quite dry on the more southeastern ensembles, wetter towards the midlands and the west.....but these will be extremely hard to get accurate in this sort of set up. It'll come as quite a shock when this breaks down next weekend! Also a relief to many i'd imagine....but this is going to be epic. Can't wait til the fun and games kick off next week!