I am very grateful to have a nice cool 19c sea to swim in for 30 minutes each evening after a day of 30+ temperatures. 

That sounds like heaven right about now.

GFS 18Z has maxima of 33, 35, 35, 32, 27 for Monday to Friday. 

I agree. Last year’s relatively short lived record heatwave seems to have triggered 900 excess deaths. All those elderly people who’ve been kept in their rooms in care homes for weeks for fear of infection, and haven’t seen family and friends, are going to be pretty vulnerable.

Jeez. What is wrong with you people? This is a horror show.

My house is like an oven. But when your chasing a record, you have the grin and bare it 🤣🤣

FWIW, it returned last night. It does, however, mix out faster today.

http://meteocentre.com/numerical-weather-prediction/vertical-profile-skew-t.php?lang=en&map=UK&run=18&mod=gfs&stn=London&hh=012

It lessens by 9z, is almost gone by 12z and by 15z there's only a tiny remnant - not enough to impact things.

This heatwave is really rubbish and not proper one due to too much clouds.  No sun here yet and they going for 30C so to order a 30C here need sunny weather from dawn to achieve it.  Was only 26C yesterday as the clouds cleared by 2 pm so lost of 8 hours of warming up from 6am to 2pm.  To see 37C there need to be direct sun rise to the peak point.

Indeed and also most models show the surface flow turning more SSE during the afternoon, which will help. Still some cloud around, but London should get at least 36C today.

Models generally only going for 34C today, lower than tomorrow, so I would be surprised. But I remain hopeful. 

If 34 was achieved yesterday, everything today suggests that temps should be higher - unless it’s cloud which has been factored in?

The cool lower layer is definitely affecting these parts. 850HPA temps of 16-17c this afternoon, but highs 25-27c max. Always been forecast that way though, so no expectation of a heatwave here, just some nice warm weather and perhaps thunderstorms.

Yes there is definitely cloud on the models as they show a much less even temp distribution over the coming days, blobs of 30C or below scattered among the 33s to 34s. 

Met Office have gone from 37/37/37 for Heathrow to 36/36/37 and I would expect them to knock another degree or two of those as time goes on. It’s been the pattern every day of this spell so far, with the temps 2-3C below the original estimate. 

I’m hoping we can just scrape 34C every day till Wednesday because AFAIK six consecutive 34C+ days would be a record. 

It would be a mighty shame if we don’t get a good record during this spell. I don’t know, but I have a feeling about today and Wednesday. 

Actually I may be wrong but I think 5 consecutive 34C days would be a record too. Previous best as far as I can see is four (1-4 July 1976)?

Current watch level: Level 3 - Heatwave Action

Issued at: 08:35 on Mon 10 Aug 2020

There is a 90 % probability of Heat-Health criteria being met between 0900 on Monday and 0900 on Friday in parts of England.

This alert updates that issued at 08:47 Thursday 06 August. The alert has been extended in time for all previously affected regions of England, now extending to Friday 14 August, although this is a more definite end time than in previous issues, as less hot weather looks to become established more generally across England before the weekend. The alert level has increased for West Midlands, as confidence in hot weather and warm nights affecting at least the south of the region has now increased. The alert level in all other regions remains unchanged. This forecast is under daily review, with the most likely change being a possible upgrade in probability for both Midlands regions around midweek, and perhaps a progressive downgrade in probability from the west late in the week.

An update will be issued when the alert level changes in any region. Alerts are issued once a day by 0900 if required and are not subject to amendment in between standard issue times. Note that the details of the forecast weather are valid at the time of issue but may change over the period that an alert remains in force. These details will not be updated here unless the alert level also changes, the latest forecast details can be obtained at the following link: http://www.metoffice.gov.uk/public/weather/forecast/#?tab=map

https://www.metoffice.gov.uk/public/weather/heat-health/?tab=heatHealth&season=normal#?tab=heatHealth

In terms of diurnal temperature ranges you are competing with something like -20C on a cold winter night and +13C on the SW side of a warm front.

So maybe a degree or so shy of the record if I had to guess?

I can't imagine a diurnal range much above 33C though.