Would the record temperature of 37c at Heathrow yesterday occurred if that area was still open green fields?

Absolutely not, it was clearly UHI induced.

These new records shouldn't stand unless they are recorded in open green areas well away from the urban fabric.

Andy

It doesn`t detract that wherever you were yesterday it was bloody hot!! Lets hope it returns asap and this time stays for several days not just one day!

This is the world we live in now. Of course it should stand!

Malcolm
Wakefield & Gothenburg, SWE

If you read back however many pages before the heat arrived, I predicted it would be Heathrow. Someone posted a photo of the weather station there. You can clearly see the runway in the background. 

[quote=Andy Woodcock;705760]

Would the record temperature of 37c at Heathrow yesterday occurred if that area was still open green fields?

Absolutely not, it was clearly UHI induced.

These new records shouldn't stand unless they are recorded in open green areas well away from the urban fabric.

Andy

I agree, across the way over in Belgium, Holland,  NE France and parts of western Germany the temperature wildly peaked above 35 degrees today.

I agree, across the way over in Belgium, Holland,  NE France and parts of western Germany the temperature wildly peaked above 35 degrees today.

Heathrow is by no means the most urban or built up weather station. It consistently beats City airport and Northolt, both closer to the centre, and for that matter St James's park. 

London has been built up pretty much to the same level it is now for almost 80 years. In recent decades it has greened considerably after losing a lot of its trees in the early part of the 20th C.

Green belt policies mean the environs of Heathrow are as rural as they were in the 1940s. Even the current runway configuration has been here for decades. Are we to forbid all station readings from cities since they were built? What about stations subject to equally disruptive land use changes like deforestation and planting of cereal crops? Discard the record for zero hours of sunlight that December in the 1890s because it was made worse by coal smoke? We might as well ignore any heat record anywhere in the world on the basis it is influenced by CO2 emissions.

Besides, the all time record is held by a fruit tree nursery in the middle of fields in East Kent.

Sorry Andy but that's crap - there is barely any UHI influence at Heathrow - it is on the very edge of the London urban area. You can argue that it might have some influence from the nearby runway but that's still not supported by anything other than silly speculation, given the average highs at Heathrow are identical to Kew Gardens, Greenwich and Gillingham - and the record high for London is actually at Kew Gardens, not Heathrow. Kew Gardens recorded 38.1C in August 2003 compared to 37.9C at Heathrow.

Plus, as the above user mentioned, why don't London City Airport and London Weather Centre top the list since they are actually in central London and surrounded by skyscrapers, tarmac and concrete galore? Simple answer - the UHI doesn't impact maximum temperatures that much.

I think people need to put this whole 'Heathrow is not accurate' thing to bed. It's just silly.

You were comparing this spell to Florida the other day. Now that's silly. 

I can see Andy and others point. Heathrow consistently tops the shop. Even when Kew outdid it by a whopping 0.2c (I didn't realise the gap was so enormous)

I take these Estofex things with a huge dose of salt as they always seem to forecast far worse than rarely happens. However, in this case, unless I'm reading it wrong (possible/probable) they are forecasting a level 1 for southern England. Possible large hail and extreme precipitation. No mention of 'very' large hail or tornados of any sort?

Just to clarify, here's the overview text:

and here's the forecast detail. Standard UK few flashes and bangs fair that your standard US storm chaser wouldn't even get out of bed to look at if it passed over his house, lol

Same to rain showers during poor summers was very boring and extremely lame, no matter what it never matched from what I witness abroad.  Even my wife's brother in Chicago laughed about seeing excited posts about passing rain shower here.  He know UK rain showers are very lame after they used to live in Ireland which get same thing there.

A real rain shower abroad deliver more than 10C temps drop within few minutes, saw that most recently in Chicago last year on the road when we got hit by a storm shower front with outdoor car temps from 32C to 20C in few minutes.  Here only a degree or 2 drop after seeing 18-20C maxes then drop to 16-18C and often come late at the day for no reason leaving a wet nights.  So far touch wood not seeing this stupid set-up this summer so far and hope we see more heat until September.  August had been poor for many years so we are well overdue for a decent one.

Nice cool breeze today, if I didn't have work I'd be sitting in the garden enjoying it, anyone that wants/needs it warmer in the SE park yourself up against a South Facing fence or wall and you can add a few extra degrees to the temp 

..... I wonder what tonight will bring, I'll be the pub watching whatever's thrown at us 

Tomorrow afternoon doesn't look too bad to me either, can't complain it's been a decent spell down this way 

Indeed, and if this morning's runs are anything to go by, it looks like continuing for the foreseeable future here. Barely a blip in this area before temperatures start to climb again 

usually a "level 1" can be see to translate roughly, in terms of actual outcome, to "some clouds"

Seem so slightly and with uppers up to 17-18C would give us low 30's around midday if conditions are right before slowly cooling off with decent mid 20's on Sunday as it been predicted firmly for a week now. 

Not all UK showers are lame. I'm not sure Marigold would agree with that after having her window smashed by one. 

Our text temperature forecast on the MetO website was majorly downgraded overnight. The update around 3:30pm yesterday had a max of 29c for today. When it was updated in the early hours it's now a max of 23c

Regarding tonight's expected thunderstorms, 'ere's my own take on it all, where I've included this as part of my own Cloud Master forecast for Kent - which I'm sure made for interesting tea time reading.  

According to the models, all the values for storm developments (Theta, Li, Cape, Dewpoint, etc, etc) are at their highest over Kent in the early hours tonight and yet the heaviest precipitation are shown to be occurring off to the west and north of the country thus keeping us lot here at Kent high and dry.
  My thoughts are storm initiation would tend to occur to the "lee side" of those modelled high values through air motion both at surface level and at the upper 850 hPa level - a bit like a flame coming out of a bunsen burner and being blown to one side in the wind - in this case, more towards Central Southern England and Kent is the bunsen burner itself.
  In this case, the "shear" effect does appear to be quite pronounced so this may be why storms are expected to form on the spot over Central Southern England rather than right over Kent where the "potential" is at its highest and then the lot move towards the north thus missing us here at Kent.
  So for me to pick up anything out of this storm event tonight, I may have to rely on a “back building” effect.  Lots of head scratching over this one, but I think those living at Central Southern England (anywhere between Oxfordshire and Essex) will get to see a good display tonight before the lot trundle northwards to affect the rest of the UK by tomorrow morning.

I'll keep a fully charged up camera close to hand tonight, just in case I do actually strike it lucky tonight. Although I've suggested that there is an 80% chance that I'll get to miss out, there is that "you never know" thing about it.

Not sure I see many places getting into the low 30s at midday, and I've not seen that forecast anywhere either???

Naturally Heathrow is the warmest place at the moment at 21c. Not a chance it'll jump 10c+ in two hours 

Don't hunt the warmest "air" to find the storms. Warm air on it's own means nothing.

I don't see 30*c today, I can see only Mid 20's in this NE/E'ly breeze and cloud due to build this afternoon, happy to be wrong though. More chance of 30's tomorrow (Saturday) in clear afternoon sunshine 

At present humidity here is nice, not a problem at all, going to feel it tonight though I reckon