Model Output Discussion - Autumn arrives

[philglossop]

35 minutes ago, qwertyK said:

Has that ever happened in the UK before, in 76' or in any other heatwave? 

No. The hottest I’ve been through was early August 1990 and we got to low 30s in Devon/Dartmoor and that was bad enough. But these figures here of 36- 38c are unthinkable. That’s as hot as I’ve been in Greece and that was flipping unbearable. 

[mb018538]

2 minutes ago, legion_quest said:

You would hope, but it doesn't take much to see people who are seeing these charts and celebrating, or even hoping it happens every year. Climate Change is downplayed constantly, or seen as something for the far future to worry about. This will be looked at as an outlier and sold as 'a glorious Jubilee Summer!' rather than the wake up call it should be. 

It’s literally no different to 10x more people wanting -10c and snow in winter which happens on here every year

[kold weather]

9 minutes ago, danm said:

Yes it is notable how easily we now reach 35°c+. If we look at the last few years, here in London we’ve hit or exceeded 35°c in 2015, 2018, 2019 and 2020 and look highly likely to again next weekend. 

Prior to 2019, the only times during my lifetime (1986 onwards) where we’ve hit or exceeded 35°c was in 1990, 2003 and 2006. Even the amazing summer of 1995 only reached 34°c as a max. Before 1990, if I’m not mistaken the last time we hit 35°c was in 1976. 

Even in years we didn't make 35c we weren't all that far away, for example Sept 2016 and July 2017 (Heathrow at 34.5 for the latter). Despite that I feel we've been actually quite lucky in that alot of the heat shots have been brief and not really established (such as 2015, 2019) the only time we've had a more classic build up of heat was Aug 2020 and that probably was the cumulative hottest 7 day spell ever recorded even taking the near 38c from late July aside. Should it bed in even for 48hrs then 40c suddenly feels realistic to me. If it is a shot acorss the bows then probably a 34-37c looks more reasonable.

Anyways the trigger for all this evolving is now moving into the near very reliable range of 72-96hrs, the only thing that may shift things is if the atlantic comes in stronger than expected at 120hrs. Should the models still look good for heat by 12z Monday I'd expect you'll start to see briefings from the met office about possible extreme heat coming soon.

Still we may not get a better chance in the next few years to smash 40c, we've got a hugely dry surface layer now across W.Europe, an embedded hot spell with very high soil temps across France/Iberia and exceptional SST's in the Med, with also high SST's across BoB and channel waters. Get the heat in and it will deliver.

Edited July 10, 2022 by kold weather

[Geordiesnow]

18 minutes ago, kold weather said:

 

I think we can now have good confidence of another hot spell this weekend coming up, with temps at least reaching into the 30s, lesser confidence in just how high it goes.

Yep that is how I see it, I think the major  heatwave across northern France is more or less nailed on, just how much heat does the UK get and you got to say, either Saturday or Sunday or both, southern areas will see temperatures in the thirties. 

The ECM has moved closer to the GFS and this mornings UKMO run may suggest some heat also. I still say temperatures of 40C is a low chance(mostly because of the apparent GFS bias) but its not an impossibility but because its such a slack set up, any minor shifts could have a massive effect. 

[Guest]

1 minute ago, qwertyK said:

The met office forecasts, or certainly the apps, always seem to be way too conservative on temperatures. 

I read some discussion either on here or perhaps TWO that speculated on the apps using the mean maximum when it is at the medium range, rather than the raw maximum. Don't know if it is true but it would explain why in spells similar to this the temperatures rise on app forecasts as the event draws closer.

I noticed it for Sheffield this week and weekend for example.

[legion_quest]

19 minutes ago, *Stormforce~beka* said:

Would they cancel schools in this type of heat?

There is no maximum temperature law, and with concerns over summer holidays already being too long and Covid having hurt children so much, I can't see it being advised as a norm.

[chrisbell-nottheweatherman]

1 minute ago, philglossop said:

No. The hottest I’ve been through was early August 1990 and we got to low 30s in Devon/Dartmoor and that was bad enough. But these figures here of 36- 38c are unthinkable. That’s as hot as I’ve been in Greece and that was flipping unbearable. 

We've had 35 or so here in Norfolk and I was seriously struggling.  41C scares me.  TBQH, anyone cheering 41C is an idiot.

[NO LONGER POSTING]

2 minutes ago, Steel City Skies said:

It never flipped. The 00z ensembles supported the same outcome, it was the operational that went against the grain by sweeping the heat away quicker.

A flip is normally described for when the majority of an ensemble suite changes.

It goes for the hotter option once more as opposed to being the "cooler" run

[MattStoke]

4 minutes ago, legion_quest said:

You would hope, but it doesn't take much to see people who are seeing these charts and celebrating, or even hoping it happens every year. Climate Change is downplayed constantly, or seen as something for the far future to worry about. This will be looked at as an outlier and sold as 'a glorious Jubilee Summer!' rather than the wake up call it should be. 

Summer 2018 had a higher mean temperature than 1976 but the deniers ignore that.

[GSP]

37 minutes ago, Quicksilver1989 said:

Been watching the charts with an element of shock over the last 24 hours. I still think the GFS is off on one but I also do think we will have 1 day with a realistic chance of somewhere surpassing 40C and also breaching the UK temperature record.

Heat of this intensity these days always seems to break down in a plumey manner. The increasing difference between the land temperatures and ocean temperatures in these kind of setups often  gives the Atlantic an extra kick to push it away from the UK after a short time.

The fact though that we are seeing temperatures regularly surpass 40C with model runs is in itself scary, even if they don't come into fruition... as it shows just how much easier it is in this modern age to import intense heat.

Over the past 100 years, only 12 have seen temperatures on a given day surpass 35C, 4 of those since 2015. What was once happening once every 10-15 years is now happening every 2 years or so.

One day though we will get an anticyclone strong enough to withstand a quick breakdown and allow more intense heat to build over us. Will that be next weekend and early into the following week? I back the EC overall, which I still think could break the temperature record if it comes off.

The heat being forecast is alarming but it will serve as a wake up call to the risk of anthropogenic climate change. It'll at least keep the climate change deniers quiet. Imagine if the weather patterns of summer 1976 were replicated now?

Yes as we clean the air, the earth is getting warmer. Is that supposed to happen?

[Paul]

Can we keep it to discussing the model output in here please, there are numerous other threads for discussing the summer or heat more generally, or climate change etc etc 

[Polaris]

34 minutes ago, Mark Smithy said:

Just seen the 06z GFS. This would not be funny.

Dangerous temperatures.

 

7 days away. 
 

8 days ago it had temps hitting 37-38c in the SE for tomorrow. 
 

Reality = 31-32c forecast for tomorrow. 

[MattStoke]

3 minutes ago, Polaris said:

7 days away. 
 

8 days ago it had temps hitting 37-38c in the SE for tomorrow. 
 

Reality = 31-32c forecast for tomorrow. 

I don’t recall any predictions of 37-38’C for tomorrow. Certainly not consistent and persistent cross model ensemble support of such heat, anyway.

Edited July 10, 2022 by MattStoke

[Guest]

4 minutes ago, Polaris said:

7 days away. 
 

8 days ago it had temps hitting 37-38c in the SE for tomorrow. 
 

Reality = 31-32c forecast for tomorrow. 

The major difference is that @Mark Smithy shows in that chart are actually supported by a significant cluster in the ensembles as well as supported by the ECM ensembles and MOGREPS.

Edited July 10, 2022 by Steel City Skies

[qwertyK]

1 minute ago, MattStoke said:

I don’t recall any predictions of 37-38’C for tomorrow. Certainly not consistent and persistent cross model ensemble support of such heat, anyway.

Not even 37-38C. Tommorow it was supposed to be 41C.

Britain to swelter in temperatures of up to 41C in record heatwave - Wales Online

WWW.WALESONLINE.CO.UK

---

Prediction models suggest next Monday (July 11) could see be an 'historic moment' with record temperatures for most of the country, peaking in the south-east of England

In fact, these articles about 40C weather seem to go right back to the start of July. 

[bluearmy]

2 minutes ago, MattStoke said:

I don’t recall any predictions of 37-38’C for tomorrow. Certainly not cross model ensemble support of such heat, anyway.

Neither do I 

[MattStoke]

1 minute ago, qwertyK said:

Not even 37-38C. Tommorow it was supposed to be 41C.

 

Britain to swelter in temperatures of up to 41C in record heatwave - Wales Online

WWW.WALESONLINE.CO.UK

---

Prediction models suggest next Monday (July 11) could see be an 'historic moment' with record temperatures for most of the country, peaking in the south-east of England

In fact, these articles about 40C weather seem to go right back to the start of July. 

That’s a newspaper report, not a computer model. 

[bluearmy]

1 minute ago, qwertyK said:

Not even 37-38C. Tommorow it was supposed to be 41C.

 

Britain to swelter in temperatures of up to 41C in record heatwave - Wales Online

WWW.WALESONLINE.CO.UK

---

Prediction models suggest next Monday (July 11) could see be an 'historic moment' with record temperatures for most of the country, peaking in the south-east of England

In fact, these articles about 40C weather seem to go right back to the start of July. 

Best not to use media articles (apart from met office and bbc) for evidence !

[Derecho]

14 minutes ago, GSP said:

Yes as we clean the air, the earth is getting warmer. Is that supposed to happen?

Ah yes, global cleaning. I forgot about that.

[qwertyK]

1 minute ago, bluearmy said:

Best not to use media articles (apart from met office and bbc) for evidence !

It uses Theweatheroutlook though which is semi reputable. 

[snowsummer]

3 minutes ago, qwertyK said:

Not even 37-38C. Tommorow it was supposed to be 41C.

 

Britain to swelter in temperatures of up to 41C in record heatwave - Wales Online

WWW.WALESONLINE.CO.UK

---

Prediction models suggest next Monday (July 11) could see be an 'historic moment' with record temperatures for most of the country, peaking in the south-east of England

In fact, these articles about 40C weather seem to go right back to the start of July. 

You need to read the charts into of the papers maybe?

[qwertyK]

2 minutes ago, MattStoke said:

That’s a newspaper report, not a computer model. 

It uses a computer model from The Weather Outlook

[MattStoke]

2 minutes ago, MattStoke said:

That’s a newspaper report, not a computer model. 

In fact, that article mentions charts showing 40’C for the 14th (not tomorrow), which would have been the same plume that there is now good agreement in timing on for next weekend but at that far out any timing of any potential plume would always be very uncertain. That though is how long this potential extreme heat has been modelled and is still showing with ever increasing support.

[Captain Shortwave]

On 03/07/2022 at 10:31, minus10 said:

Yes Mike...that cut off low over canaries is key here i think shown on the ecm..whether it gains traction and how it develops or not will be key to plume potential..

 

On a separate note just wondering whether the gfs 18z extreme temps shown last night is some kind of record..

 

Widespread 46 's in France...i have never seen that before and while it is very unlikely to happen the fact that this is being shown at all more than once is raising an eyebrow...incredible..

Apologies to minus10 for this necro-quote, but here is the first evidence of 40c+ from a GFS run from the 2nd, the date projected was…. 16th July (next Saturday).

Current modelling shows that this wasn’t such an outlandish punt, if it happens it would have been just a day out and essentially evolves like the models are currently showing.

Yes temperatures were forecast to be a little higher in places back then, mostly because the Azores high was going to be in full command, ironically the current evolution still keeps the south sunny and warm or hot at times and of course develops the potential once in a lifetime event for next weekend.

Edited July 10, 2022 by Captain Shortwave

[kold weather]

 

7 minutes ago, Steel City Skies said:

The major difference is that @Mark Smithy shows in that chart are actually supported by a significant cluster in the ensembles as well as supported by the ECM ensembles and MOGREPS.

Spot on.

There was the odd 38-40c on the occasional GFS ensemble run, but broadly the models consistently went for 31-33c on Tuesday.  

The big difference now is we've got 22 out of 31 going above 35c on the ensembles compared to 1 out of 31 previously. Suggests huge support for heat.