Saturday suddenly looking like a washout on some on the models this morning for some areas

Indeed - I'm quite keen to understand this as I'm visiting family this weekend.  Seems to have come from nothing. I thought it was all fizzling...

Even the UKV temperature charts are suggesting a band of 19C on Friday 3pm over Central southern England with 33C still in East Anglia - and 24C behind, suggestive of a band of rain associated with that cold front. 

Won't stop me geeking out about Thursday, but I need to stop looking at Arpege temps and start pondering their rainfall charts I think.

EDIT: Looks as if the stalling eastward progression keeps the main Atlantic weather way out west, but stalls a band of boundary rain trundling up from the south over East Anglia for much of Saturday. Also giving some much needed rain over central France and Paris I notice.

 

Indeed - I'm quite keen to understand this as I'm visiting family this weekend.  Seems to have come from nothing. I thought it was all fizzling...

Even the UKV temperature charts are suggesting a band of 19C on Friday 3pm over Central southern England with 33C still in East Anglia - and 24C behind, suggestive of a band of heavy rain associated with that cold front. 

Won't stop me geeking out about Thursday, but I need to stop looking at Arpege temps and start pondering their rainfall charts I think.

 I have not seen such un-certainty in forecasts before. Met Office video forecast last nigt showing all push button spinning globe thingy still could not produce an outcome of some accuracy beyond Friday.  BBC week ahead very coy about showing much beyond that as well.

WRF - GFS showing rapid developments in the rain late tonight

38.5 not looking under threat unfortunately/ fortunately (depending on your viewpoint).
I’ll be heading back to Sussex from Cornwall on Thursday so it will be interesting to feel the temp rise by about 10 degrees during the journey.

I think there’s a decent chance. Most models are showing 38C somewhere. iPhone app which doesn’t usually overdo things too much now saying 39C for London. 

Mean while Scotland can look forward to endless low pressure, high humidity and Muck for the foreseeable.

J

06z so far

that deep low has gone on this run

Look how far north that blob of 20C uppers goes on the UKMO!

 

Have you reviewed all the data? 

Indeed. I would say its 50/50 for a new UK all comers max temp record on Thursday afternoon.

 

Indeed. I would say its 50/50 for a new UK all comers max temp record on Thursday afternoon.

That's overcooking IMHO but you could of course be right. This morning when I spoke to the media I went with a 25% chance of an all time record and 60% for a new July one.

 

I think there’s a decent chance. Most models are showing 38C somewhere. iPhone app which doesn’t usually overdo things too much now saying 39C for London. 

Exactly.. here is the metoffice for Heathrow 

 

Exactly.. here is the metoffice for Heathrow 

 

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It’s worth noting that in my experience the MetO app tends to underplay maximum temps. Which is a bit scary! 

 

It’s worth noting that in my experience the MetO app tends to underplay maximum temps. Which is a bit scary! 

I agree, and often by several degrees. However that's for my coastal location which when all thing's are considered can be a tricky one. Heathrow is a more inland so perhaps easier for the app to be closer ro the mark? Still i think 39C is real possibility now.

Sounds spot on to me Brian the thing is you can’t pro ratio the exact amount to be added on or taken away it must be a variable.

I have been keeping an eye on the calculations it seems to work with gfs roughly as follows for my location 

of course it’s not that simple as the weather conditions  are the variability factor but having said that history tells me the below is not far out

20c x 1.15 real T 23c

29 x 1.05 real  T #30.5 no approx symbol on my keyboard 

so Thur I’d take 35 taken from opp x 1.05 # real T 37c

 

That's overcooking IMHO but you could of course be right. This morning when I spoke to the media I went with a 25% chance of an all time record and 60% for a new July one.

Sounds spot on to me Brian the thing is you can’t pro ratio the exact amount to be added on or taken away it must be a variable.

I have been keeping an eye on the calculations it seems to work with gfs roughly as follows for my location 

of course it’s not that simple as the weather conditions  are the variability factor but having said that history tells me the below is not far out

20c x 1.15 real T 23c

29 x 1.05 real  T #30.5 no approx symbol on my keyboard 

so Thur I’d take 35 taken from opp x 1.05 # real T 37c

 

 

The forecast low level thicknesses for Thursday PM are the highest ever seen in the far SE. Of course all the ducks need to line up - and the deciding factor will probably be how much upper cloud impacts on incoming solar. Still - it wont be long until we find out. Even one day of those temperatures will take quite a toll on health services.....

Mean while Scotland can look forward to endless low pressure, high humidity and Muck for the foreseeable.

 

J

It’s glorious here today (and was yesterday) with temperatures in the mid 20s which is very pleasant. The rest of the week, barring the occasional thunderstorm, looks pretty decent too. I realise that the east looks more favoured although I’m not sure of your location.

If the models are to be believed things will break down more generally by the weekend but nonetheless it seems like a good spell for most of the U.K. for much of the time.

A really, really good link below - it's a detailed video by the Met Office going into the heatwave and includes all sorts of stuff relating to the upper air charts, physics etc behind it. I would strongly urge everyone to look at at least part of it!

https://twitter.com/metoffice/status/1153636088268722177

At 20 minutes into it, they even go into reanalysis charts from WZ to illustrate the sort of upper ridging required to generate exceptional heat.

A really, really good link below - it's a detailed video by the Met Office going into the heatwave and includes all sorts of stuff relating to the upper air charts, physics etc behind it. I would strongly urge everyone to look at at least part of it!

https://twitter.com/metoffice/status/1153636088268722177

At 20 minutes into it, they even go into reanalysis charts from WZ to illustrate the sort of upper ridging required to generate exceptional heat.

I go on the link and nothing happens, which is a shame.

as the MOD has gone a bit quiet here’s a quick summary of this evening’s output on the lower resolution global models so far:

GFS op: heat maxing at 35C around London Thurs, lingering a bit on Friday, then showery breakdown with retreating Scandinavian high followed by reasonable zonal flow and intermittent ridging.

GEM op max 37C in Norfolk on Thursday, manages a 30 on Friday then similar generalised breakdown and later evolution to GFS

UKMO similar, retreating high takes up station over Greenland. Possibly less good long term

ICON similar long term to UKMO (low pressure lingers longer than GFS and GEM). Short term max 35C in midlands on Thurs and a cheeky 31 on Friday.

as these are lower res models - with the exception of ICON - they will be undercooking maxes a bit. Note GFS has alternated between 34-36C over the last few runs.

ECM has 37c again Kent/Essex for Thursday 

It also keeps the high 850s in the east all the way through to 168h . 12c to 16c 850s for a week in the east.