Putting Into Perspective

[Robbie Garrett]

Can anyone possibly help me?

I was wondering if the UK had this weather when the Sun was at it's most power, say June/July/August time - what sort of temperatures would we be experiencing? Wanted to know if it could be calculated?

Regards,

[Liam J]

I would think that maxes would be around 30-33c in the hot spots like the SE and 25-28c for areas North and West on the mainland.

[AderynCoch]

I would think that maxes would be around 30-33c in the hot spots like the SE and 25-28c for areas North and West on the mainland.

Considering many places away from the southeast have already exceeded 25C, I'd say 30C+ would be quite widespread.

[mushymanrob]

id have thought there was a good possibility of the hottest day record being broken, id expect temps easily to be well over 30c for the bulk of england.

[Terminal Moraine]

With upper air temp's around 15c and a southerly flow I'd expect the hottest places to be around 34-35c if the same situation had occurred in July.

[knocker]

Well why waste the opportunity. Attached is the Nottingham midnight ascent, perfect for forecasting the max temp in Nottingham today. Any advance on 26C?

[johnholmes]

not really although I suppose add 1C for a super adiabatic in the bottom few hundred feet?

[Evening thunder]

But how much warmer would the uppers have been in July/August?

[knocker]

But how much warmer would the uppers have been in July/August?

I was taking the original question to be about the sun not the airmass. I'll edit that because it seems rather stupid. In other words given exactly the same synoptic situation what would the environmental profile of the airmass have been and thus the max surface temps? Who knows but I should think TM wouldn't be far out.

[Evening thunder]

Sorry if that came across aimed at you, I was just replying to the thread in general and didn't intend to aim it at anyone.

Yes with todays uppers etc in July

I pretty much agree with posts from you and others about surface temps today and in summer under the same upper temps.

[Thundery wintry showers]

Average 850hPa temperatures at the end of September are about 2 to 3C down on those of July, so if these synoptics had occurred in July we'd probably be looking at 850hPa values in the region of 16-18C, but not quite reaching the 20C seen in the second week of August 2003.

Thus I think we'd be looking at something similar to the third week of July 2006, with 30C widespread in the north and 33-35C in the south, and perhaps the odd place getting a 36- not much different to what Terminal Moraine suggested really.

[Robbie Garrett]

Thanks guys, very interesting to know. I remember the MetOffice wrote me a very detailed email regarding how the 2003 record could be broken, but just how could it be broken?

[knocker]

not really although I suppose add 1C for a super adiabatic in the bottom few hundred feet?

A true professional. Last I saw was 27.4C.

[Thundery wintry showers]

That's interesting to hear. I don't know the answer, but my guess is that it would require dry ground, an anomalously warm airmass to gather across Spain (25-30C 850hPa), infiltrating up from Africa, and then a pronounced southerly airstream (similar to the one we have now) carrying that airmass to the British Isles.

The August 2003 heatwave managed the first two of those criteria but not the third, as the exceptionally hot Spanish airmass swiftly moved north to cover most of France (850hPa of 22-25C widespread) but only made relatively tentative movements towards the British Isles, with the 20C 850hPa isotherm nudging into the southeast on a couple of occasions.

[Liam J]

Considering many places away from the southeast have already exceeded 25C, I'd say 30C+ would be quite widespread.

Areas to the South and east of England are over 25c in many locations, Look at the locations over NW England and Scotland which are reporting mid to high teens up to the low 20's at best maybe the odd 23c here and there but by no means widesspread.

[Slowpoke]

Areas to the South and east of England are over 25c in many locations, Look at the locations over NW England and Scotland which are reporting mid to high teens up to the low 20's at best maybe the odd 23c here and there but by no means widesspread.

Incorrect. I live in Blackpool. We hit 26C yesterday and 24C today. 26C looks likely tomorrow too.

[Liam J]

Incorrect. I live in Blackpool. We hit 26C yesterday and 24C today. 26C looks likely tomorrow too.

I did say one or two locations are around 23c thats just 1c off you're max today mid 20's were not widepsread today this far north. I was refering to widespread temps above 25c - which they were not apart from further east and south from Cumbria.

Tomorrow is looking warmer than today, much warmer - possibley up to 27c in parts of NW England.

[summer blizzard]

If we take London as the example then the average isotherm in October is 5C and 10C in July. The average lapse rate in October is about 11C and in July about 14C.

The peak isotherm in this spell is near enougth 15C with maxima exluding the urban heat effect of 25-27C. In july we would have seen an isotherm closer to 20C with a lapse rate of 14C, so exclusign the urban heat effect we would have seen 33-35C being widespread, the spell possibly too short to take the record for July, but very close.

[Thundery wintry showers]

The average 850hPa isotherm over London at this time of year is between 6 and 7C:

http://www.wetterzen..._London_ens.png

...and I think in high summer (July/August) it is a little short of 10C, so the difference is more like 2-3C rather than the 5C suggested.

[JASON221]

Yes 30C+ would be quite widespread.

[Optimus Prime]

Also depends on the environment too. If it had rained a lot before than the temperatures wouldn't be so hot. In the 2003 summer it had been warm and dry since February which helped to build the temperatures well over the landmass. I particularly remember the nights being warm that year.

A wet ground will release energy through evaporation. A dry ground will retain the heat better and release heat more slowly resulting in higher temperatures.

[Robbie Garrett]

I can imagine that the 2003 heatwave was a one off, maybe never to be repeated for the UK ever again, but hopefully we can get 4 weeks of what we have now next Summer for once.

[Robbie Garrett]

I didn't want to create another topic, but does anyone have any details as to how the PV got disrupted last year? I can't find the topics on the model forums for November last year, just wondering where I can find it? or something on it?

[Duane S.]

I didn't want to create another topic, but does anyone have any details as to how the PV got disrupted last year? I can't find the topics on the model forums for November last year, just wondering where I can find it? or something on it?

Up for debate but I'd say the main factor was the early warming of the stratosphere made it difficult to get up and going which then meant splitting/displacement was relatively easy. A severe cooldown mid December(ish) meant that that was not the case going into Mid January onwards!