Onwards...

The return of the jet that Dew mentioned earlier is reflected in the 6z GFS Op, and allows an elongated low to intensify and slip SE towards us by 18th then over us by 19th. Sub 5C uppers and tightened isobars have the potential for huge contrast to current conditions over many parts of the country.

Add - by 22nd cool northerlies bring sub 10C surface temps to the Highlands and only perhaps 15 in the S.

Regarding your post on the previous thread, I'd not encountered the Tropical Night thing before – saw it on the Beeb forecast today. Is it a new term?

It's new to me too. 

It's been around for a couple of years, but (understandably) has been used a lot of late. The Met Office use it to mean a night where the low is 20C or higher.

https://en.wikipedia.org/wiki/Tropical_night

Not that unusual in London I wouldn't of thought. Most if not all recent summers (since 2000 say) have at least one night where the temp fails to get below 20c. They are certainly becoming more common due to GW for sure.

A new type of forecast chart for me - based on the ECM ensembles, I think. From the Met Office Tweet earlier, about the next 10 days. The signal for low pressure next week is strong and they emphasised how much cooler and fresher it'll feel by this time next week. Hurrah!

https://twitter.com/metoffice/status/1293585537429889028

will come as a massive relief to many. 

Boo, Hiss, 

Seen them use this type of chart quite a few times. Quite handy for a quick glance. Shows how in previous runs, the low pressure signal wasnt really there and how quickly it appears to have picked up on the more unsettled outlook.

Looking at the ensembles it will be struggling to reach 20c next week, back to dull cool garbage sadly, unless the ensembles are wrong!

and downwards 

It's been "interesting" - but interesting can get wearisome very quickly.

Agreed. This “interesting” heatwave got wearisome after two days.

It looks as though we are about to be reminded of why the now-defunct Spanish package holiday industry developed after so many people got entirely fed up with looking out of the B&B or tent at the pouring rain in the 1950s and 60s, when experiencing the traditional British summer.

Certainly doesn't look cool to me next week. Looks average at worst with a hint of a stalling low that may shovel up more warmth, if briefly

I'd be keeping an eye on the possibility of heatwave conditions returning next week. Not suggesting it's the favoured outcome yet but things look finally balanced to me.

Sounds like perfect weather to me

indeed!

Well as long as London's dry and not too cool... 

Actually, we are not that far from another heatwave in the SE next week.

https://www.theweatheroutlook.com/twoforecasts/will-it-rain.aspx

10 day Rain prediction Looks wet in the South, dryer North East and Aberdeen