Model output discussion - August hot spell - how hot, how long?

[Climate Man]

2 hours ago, 38.7°C said:

Ewwww for those who dont like heatwaves..........

Hate them and now know how others feel in winter when coldies like me are ramping 

[johnholmes]

3 hours ago, sawan said:

What sort of temperature would you expect in the coming days John? In the Westmidlands, we have hardly seen much sun over the past few days with subdued temperatures, we have seen consistnlty lower temperatures compared to the forecast. Not sure if we will get to 30C tomorrow. Would like to see some sun even if the temperature is low 20C 

I suspect many parts will see less cloud tomorrow, other than the ST variety on some southern coasts, not sure about that as I have not really been watching how the very low level is being modelled.

The reason I suggest generally less cloud is that the overall wind flow will back so that the flow comes more off the continent than it has been over the past couple of days. So predictions of 30+C in the Midlands generally seem quite attainable, possibly 32 C or so.

[Mandrake]

21 minutes ago, bluearmy said:

Can’t see a 30c today looking at the current T2m’s  ???

Might just miss it...floating around 30C

 

[Frosty.]

For those of us hoping the sunshine / heat / humidity /  thunderstorms / warm / very warm sunny anticyclonic conditions just goes on..and on..and on into late August, the GEFS 6z certainly shows potential for that to happen..and let’s face it, I’m sure most of us do since autumn starts next month..let’s make hay while sun shines!!!

Edited August 6, 2020 by JON SNOW

[Ben Sainsbury]

Oh my... NetWx NMM for next Wednesday! Wouldn't be surprised if we saw record breaking temperatures based on that 12z run.

[MattStoke]

GFS 12z ups the heat for the southern half of the UK on Sunday.

[sheikhy]

4 minutes ago, MattStoke said:

GFS 12z ups the heat for the southern half of the UK on Sunday.

Saturday still same as 06z or even warmer?

[Guest]

1 minute ago, sheikhy said:

Saturday still same as 06z or even warmer?

Very similar as you'd expect. Slightly wider coverage of 30+ for the SE. 34C tops. Widely mid to high 20s elsewhere...

[MattStoke]

2 minutes ago, sheikhy said:

Saturday still same as 06z or even warmer?

Bit hotter.

[johnholmes]

4 minutes ago, sheikhy said:

Saturday still same as 06z or even warmer?

Do you not have access to the model outputs?

[Guest]

GFS is brutally hot through to at least Tuesday, add on the usual couple of C and we could see 35-37C for at least 5days. Also the night minima could start to get a bit of problem. I can see temps not dropping below 23-25C in London and parts of the south coast not just for one night but maybe 3 or 4. 

[mb018538]

GFS absolutely roasting in the south until at least Wednesday next week, with low to mid 30s every day. This is shaping up to be some heatwave.

Edited August 6, 2020 by mb018538

[Fourty Point Three Degrees]

10 minutes ago, Alderc said:

GFS is brutally hot through to at least Tuesday, add on the usual couple of C and we could see 35-37C for at least 5days. Also the night minima could start to get a bit of problem. I can see temps not dropping below 23-25C in London and parts of the south coast not just for one night but maybe 3 or 4. 

Met Office weather app for Heathrow showing:

Friday  36C/21C

Sat   36C/18C

Sun  35C/19C

Mon  35C/20C

Tue   35C/19C

Wed   33c/19C

 

 

Which is SIX days of 33C or above

Edited August 6, 2020 by 38.7°C

[Captain Shortwave]

To day 6

GFS - hot

UKMO - Even hotter

In seriousness the entire UKMO has the risk of 35c being reached or exceeded on every day. 18c isotherm still over the east on Wednesday. That is six days. The GFS slowly mixes out the heat a little and introduces more instability but not really a return to westerlies.

Edited August 6, 2020 by Captain Shortwave

[Mark wheeler]

Ukmo is special , I know uppers are not everything but oh boy .

Edited August 6, 2020 by Mark wheeler

[East_England_Stormchaser91]

Absolutely bonkers stuff yet again being churned out. 

I’m pretty sure that this would warrant the top level of a heatwave emergency? 4 consecutive days of maximums above 32 and not dropping below perhaps 22-23c. Awesome to look at on the face of it. But a nightmare for the vulnerable I’m afraid. You’d like to think that the government will be keeping a close eye on this situation.. heat related incidents and exhaustion would be inevitable given the humidity to factor in, and hospitals really should be preparing for this, with water and ice availability at a minimum.  

[matt111]

UKV slightly lower for Saturday than earlier but now showing much more widespread temperatures well into the 30’s. 

[kold weather]

10 minutes ago, mb018538 said:

GFS absolutely roasting in the south until at least Wednesday next week, with low to mid 30s every day. This is shaping up to be some heatwave.

Yes it is certainly another exceptional run. Both Friday and Saturday now look increasingly similar in terms of temperatures, and its quite possible that Sunday may end up going a similar route, though the atmosphere does look that little bit more unstable so cloud cover may put a slight lid on just how high things go from Sunday onwards.

Still, if the convection stays away then nothing really to stop Mon-Weds getting upto that 33-36c range that is looking like on Fri-Sun.

Crazy runs!

Edited August 6, 2020 by kold weather

[kold weather]

5 minutes ago, matt111 said:

UKV slightly lower for Saturday than earlier but now showing much more widespread temperatures well into the 30’s. 

That is still an utterly insane run and a pretty decent area above 30c now.

34c even to the south coast is a pretty exceptional temperature, the beaches are going to be heaving I suspect. 35-36c seems increasingly possible now on Saturday as well as Friday. 

UKMO is also really quite crazy as well!

ARPEGE has a fairly decent area of 35c as well on its 12z run on Friday, you'd expect a decent chance of a 36-37c within those areas.

Edited August 6, 2020 by kold weather

[cheese]

5 minutes ago, East_England_Stormchaser91 said:

Absolutely bonkers stuff yet again being churned out. 

I’m pretty sure that this would warrant the top level of a heatwave emergency? 4 consecutive days of maximums above 32 and not dropping below perhaps 22-23c. Awesome to look at on the face of it. But a nightmare for the vulnerable I’m afraid. You’d like to think that the government will be keeping a close eye on this situation.. heat related incidents and exhaustion would be inevitable given the humidity to factor in, and hospitals really should be preparing for this, with water and ice availability at a minimum.  

Just send all the old people up here for the next week!

[danm]

6 minutes ago, 38.7°C said:

Met Office weather app for Heathrow showing:

Friday  36C/21C

Sat   36C/18C

Sun  35C/19C

Mon  35C/20C

Tue   35C/19C

Wed   33c/19C

 

 

Which is SIX days of 33C or above

Crazy. Yet if you type in "London" it shows the following:

Friday  34C

Sat   33C

Sun  30C

Mon  31C

Tue   31C

Wed   30c

 

I find it hard to believe that the centre of London will be five degrees cooler than Heathrow, which is just a few miles to the west, on Sunday. 

[mb018538]

22 minutes ago, danm said:

Crazy. Yet if you type in "London" it shows the following:

Friday  34C

Sat   33C

Sun  30C

Mon  31C

Tue   31C

Wed   30c

 

I find it hard to believe that the centre of London will be five degrees cooler than Heathrow, which is just a few miles to the west, on Sunday. 

I mentioned this earlier - the met office now manually input data into some stations that have lots of data/stations/obs. Heathrow is one of those, so may be that it’s adjusted higher than a surrounding one with just raw data fed in.

[Djdazzle]

24 minutes ago, danm said:

Crazy. Yet if you type in "London" it shows the following:

Friday  34C

Sat   33C

Sun  30C

Mon  31C

Tue   31C

Wed   30c

 

I find it hard to believe that the centre of London will be five degrees cooler than Heathrow, which is just a few miles to the west, on Sunday. 

The apps are rubbish, except where they are manually tweaked. Heathrow has human input.

[bluearmy]

Something that could be missed by most on here is the unlikely event that we see cloudless skies next week 

even with high uppers and slack flow, I can’t see sustained hour after hour of unbroken sunshine that would be required to break our T2M record.  Hot - yes but with the predicted set up, I see too much cloud to achieve the temps some of you are hoping to see. 

[Captain Shortwave]

Arpege maxima

Tomorrow - 35c but widespread from London up through central parts of east Anglia.

Saturday - 36c south of London (possibly somewhere like Guildford).

Sunday - 36c similar spread of temperatures to Saturday.

Monday - 37c the heat is much more widespread across the south east and East Anglia.

Just a note - Looks like todays maxima was 29c across parts of London, looks like the temperatures were a little higher than expected. Cloud amounts looks variable after tomorrow as well, so some places could get lucky in areas where the heat is forecast to be highest. Thunderstorms are increasingly likely as time goes on and of course short waves could appear to increase this risk at short notice.

Edited August 6, 2020 by Captain Shortwave