I thought it worth a quick update as the models are trending towards slightly more extreme solutions, though uncertainty remains over exactly how hot it will get and how the weekend breakdown progresses.
Consider this an addendum to my previous forecast – so everything I said on Monday stands except what I update here.
I’ll now be surprised if the temperature on Friday doesn’t reach 31’C, probably 32’C, but it could be even higher – 35’C wouldn’t be out of the question. There must be an outside chance of the record June temperature, set in 1976, being broken somewhere in England – which was 35.6’C. A warm night is likely too, minimum temperatures between 18’C and 22’C.
Saturday remains highly uncertain, but more likely we keep the heat to an extent, temperatures somewhere between 26’C and 32’C depending on sunshine amounts – there will be cloud around, there may be some showers or even thundery downpours – the breakdown details are very sketchy at the moment. Not impossible that it could rain all day and be 16’C – but the general rain is more likely to be further north.
The chance of some very heavy or torrential rain, possibly thundery, either Saturday night and/or at some point(s?) on Sunday has increased since my last forecast – though remains uncertain. Temperatures more likely to be around 20’C, but anything from 12’C to 26’C is feasible.
The broad picture is there but getting the details right is going to be tricky, as they always are when these plume-like situations degrade.