GFS Op - mostly HP to Tue 25th (though this mainly to the south at the weekend, with W-lies, perhaps less settled for the N); then the HP moves E-wards and LP drifts N from France to become centred 1000mb Wales Fri 28th before drifting to the NE. Then a broad and rather unfocused area of HP for the following week, but with a tendency to stay to the SW with cool-ish NW-ly winds. 

ECM - less positive than GFS. A  deeper trough embedded in the W-lies Sat 22nd, and then the LP arrives from France Wed 26th setting up a more definite centre 995mb Hebrides Fri 28th before moving to the N Sea Sun 30th with an associated cold pool.

GEM - close to ECM but the LP on 26th is deeper (990mb) and near N Ireland before moving to SW England at the weekend

GEFS - in the S, temps rising to warm (ca 6C above norm) Thu 27th with good agreement from ens members, before dropping back to norm for the rest of the period with more variability; not much rain at any time but if anything, more later on. In the N, similar temp profile but some heavy rain from Thu 27th occurring irregularly and not in every run. 

Summer enthusiasts should be cheering on GFS.

Yes charts becoming more and more unsettled.  The charts at one point looked to be heading for a pattern change to HP dominated.  But they have gone back to where we have been for most of Spring.  The end of June is often where the summer pattern starts. Unsettled summer? You wouldn't bet against it.

The models have flipped unsettled,  breakdown likely Wednesday now sadly.

The only one who should be despondent is me, as the outlook sucks. For everyone else, I'd imagine they'd rather enjoy the forecast weather here... here's the MetO raw, showing it to be warm and dry, with temperatures well above average (21C).

https://ukwct.org.uk/weather/warm.jpg 

"On the cloudy side at times over the weekend, perhaps with the odd shower. Some sunny spells developing too, as very warm, increasingly humid conditions establish into the new week."

*if you like hot weather!

UKV only has 28c Monday but 31c Tuesday 

Any reason we can't see all of the hours on Arpege?

That certainly proved to be the case last year, Ally. After a hot start to last summer, the heat faded at the end of June and never really returned for most of the country for the rest of the meteorogical summer. There was the hot first week of September, but that doesn't really count as being part of summer, at least not meteorogically speaking.

St Swithin's Day = 15 July

https://www.meteociel.fr/modeles/arpege.php?ech=78&mode=31&map=300 

https://www.meteociel.fr/modeles/arpege.php?ech=72&mode=16&map=300 

ECM is not too bad. It lets a trough in but by the end of the run it looks like HP will build back in à la GFS.

Possible near or at 30C here on Monday before I travel out on Tue when it break down so early but hope settled and warmer early July.  Need full azure blue skies to deliver those high temps as the chart show.

Outlook for Sunday to Tuesday:

Rather cloudy start Sunday, but this breaking to give some very warm sunshine. Turning fairly hot and quite humid Monday and Tuesday, with sunny spells, once any early mist clears.

Not one of their finest (it can't be "fairly hot", it's either "hot" or "very warm", according to their own guidelines), but I'm sure the prospect of "hot" and "humid" will have the heat-hounds salivating. Unfortunately unlike snow in winter, hot and humid weather is guaranteed every summer!

I'll pin my hopes on the GFS, which shows some heavy rain on Wednesday and fresher, average conditions on Thursday and Friday. However, considering today's torrential downpours (as shown up to a couple of days ago) have poofed, I suspect the same will happen again!

25C is not classed as hot just warm level.  I never read or watch those 3rd world forecasting systems here.  They were top class range of forecasting before they dumb down especially the BBC graphic before. 

Those 25s are from the new automated system, which has been within a degree of reality - it's been superb so far and has completely outclassed the GFS (which has 17/22/22/24/17 instead). Bear in mind too that's 25C with winds from the North Sea, which is presently 16C off the coast of Sheppey!

As you'd expect, if you look inland (e.g. Heathrow), you'll see 27s and 28s. Not scorching, no, and right on the borderline of "hot" (which is 6C or more above average). I would have said "very warm", hence my comments on the MetO text forecast.

It's interesting, as an aside, how sloppy they've become with their terms. It's perhaps unsurprising that the official definitions of "warm", "hot", "cold" etc aren't easy to find on their site...

UKV has 28/29c Monday 29/30c Tuesday 

ARPEGE has 31c Monday 

GFS Op - shallow trough moving E across Britain tomorrow, followed by HP from the SW, its centre slowly moving E-wards. By Wed 26th it's 1020mb Norway with  LP having spread N from France to Britain 1000mb Irish Sea Thu 27th. HP re-establishes as a SW-NE ridge across Scotland which lasts through to Sun 7th but with continental LP never far away from SE England and NE-lies through the Channel.

ECM - like GFS at first but the LP Thu 27th moves first up the N Sea and then settles at 995mb W Scotland Sat 29th having imported cold air from Greenland to create an unseasonably cold trough covering Britain for that weekend.

GEM - close to GFS output (LP 27th over S England but soon replaced by HP)

GEFS - warm to Wed 27th with good ens agreement, then dropping back to norm with the usual spread developing. Rain most likely around 28th (big totals in SW, not so much in NE), mainly dry before 27th, intermittent rain in various runs after. 

As much as I hope the ECM is on the ball this morning, it is sadly every bit as giddy and chaotic as the other models at that range.