In fact the latest GFS keeps the the heat going and going

I will eat my hat if that comes off! 

I am sorry to say that this is a dodgy/lazy forecast for tomorrow. Today and tomorrow the air near the surface over the London area is being modified by the N.Sea, so it's impossible to get to 37C. If you add more cloud and the risk of showers tomorrow, it makes it a pretty silly forecast.

This modification will stop on Tue and Wed, so then yes.

Into the 28s now almost guaranteed that today will be hotter than yesterday.

Oh dear. Shall I get the hat ready? Another poster who feels like he knows more than the pro's. It's not silly at all. It's a forecast based on current parameters available.

I wouldn't say impossible (as that's a recipe for a red face!) but perhaps unlikely, granted.

GFS shows the lower layer modification vanishing this afternoon, FWIW, as heating overrides it.

https://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=modtemps&MODELLTYP=4&BASE=-&VAR=modtemps&HH=3&ZOOM=0&ARCHIV=0&RES=0&WMO=03772&PERIOD=

(Forecast soundings from GFS - compare T+3 with T+12, for example, you can see the low-level modification vanishes during the afternoon. It returns overnight but again is mixed out by the afternoon).

Does this mean that we will see dramatic increases in temperature in some places. 

Well they were too high by 3C yesterday, going for 36C at Heathrow (later modified down to 35 then 34), and in the end the Heathrow max was 33.4. 

Many of us on here were saying they had gone too high, and so it turned out. 

There is some mixing, otherwise we'd have peaked in the mid 20s (like June last year when the air mass was even warmer than the current one). But the near surface fetch off the N.Sea never really stops completely.

It's a wrong and unprofessional forecast based on the parameters available.

Herstmonceux was the leader of the official stations at 11am again.

Beautiful day here with warm sun but a cooling northerly breeze. Hard to reconcile with the 30C+ forecasts, let alone 35C+ for just up the road.

Midday temp here is 22.9C while 19 miles away at Heathrow it is 26.9! Herstmonceux up to 27.2. 

Are you familiar with all the parameters and tools they have available?

Did you check the forecast soundings? Here's a better link:

http://meteocentre.com/numerical-weather-prediction/vertical-profile-skew-t.php?stn=London&mod=gfs&run=00&lang=en&map=UK&hh=015

Compare Dover with London. Dover has a marked "nose" even at 15z today, showing the modificatoin of the boundary layer.

London doesn't. London did, however, have a "nose" at 9z and by 12z it was being straightened out. By 15z it's gone - the modification is overriden by mid-late afternoon, in other words.

The "nose" reappears for London tonight, but straightens out a bit earlier tomorrow - less modification to be gotten rid of.

Even Dover loses most of its "nose" during the afternoon tomorrow.

("nose" of course referring to colder lower layers, with warmer layers higher up).

Yes.

As luck would have it, it's one of the few places that sends a balloon up each day.

The 12z sounding will be available here:

http://weather.uwyo.edu/cgi-bin/sounding?region=europe&TYPE=GIF%3ASKEWT&YEAR=2020&MONTH=08&FROM=0912&TO=0912&STNM=03882

And the 0z one is here:

http://weather.uwyo.edu/cgi-bin/sounding?region=europe&TYPE=GIF%3ASKEWT&YEAR=2020&MONTH=08&FROM=0900&TO=0900&STNM=03882

There was quite an inversion (the "nose" in my previous post) at 0z, I suspect that'll have mostly gone on the 12z.

What are they quoting at the moment?

I have had a go at listing all the days where 35C has been reached in the UK. I am sure there may be one or two missing but hopefully it is fairly comprehensive. So far I have identified 35 days. If anyone has any thoughts on additional days to add to the list please let me know.

Table

Nice list. Cheltenham 3 July 1976 is on there twice though at 13=?

Yes didn't spot that. Now amended.

Well, North Norfolk coasts are not going to threaten anyone’s record! Struggling to reach above 19°, and the sea fret is making it look like October. Just been out, car headlights came on, and I’ve put sleeves on. Beach is almost empty though