Model Output Discussion - Autumn arrives

[qwertyK]

I haven't paid that much attention to the graphs but if the peak will be Monday/Tuesday that is still a week away, and so I am still very cautious about believing anything exceptional will happen.

It wasn't forecast to rain for weeks yet we have had a few downpours here in south Essex.

2-3 days ago, Sunday here was being forecast for 36C.

It's now being forecast as...28C.

[kold weather]

3 minutes ago, Man With Beard said:

Big increase in ECM ensembles showing a raw 36C or more for next Tuesday - up to 34 out of 51 (was 17 out of 51).

 

*Edit: I see @kold weatherhas come up with a slightly lower figure, I shall do a recount!

and will you stop bickering

Its quite possible I missed a couple to be MiB! I am very tired now and so my counting may not be great!

Regardless we are in the same ballpark, somewhere around the 60% mark, which as you say is a shift upwards for sure.

[Stav]

16 minutes ago, Mark Smithy said:

So what was the point in that reply when I'd already made that very point that he meant Wednesday not Tuesday?

I'm downcast because this is going to be godawful.

I've lived in a place where temps were 40C and that was with aircon inside. It's hideous.

#metoo

[Mark Smithy]

4 minutes ago, seb said:

What was the reason for you picking my post when there are two others saying that same? 
 

His post still says Tuesday. If he meant Wednesday then fair enough although of course he could simply edit his post.

Back to models now please.

Fair enough and sorry.

ECM does show widespread rain for Wednesday though. I admit that would only start 7 days away, which is a long time in forecasting.

p.s. it's a well known fact that hotter temps make people more short tempered so just wait until next week 

[Man With Beard]

6 minutes ago, Man With Beard said:

Big increase in ECM ensembles showing a raw 36C or more for next Tuesday - up to 34 out of 51 (was 17 out of 51).

 

*Edit: I see @kold weatherhas come up with a slightly lower figure, I shall do a recount!

and will you stop bickering

I recounted meticulously, zooming in on areas I wasn't sure about, and this time I found actually 36 out of 51 ECM members had a 36C or higher next Tuesday! A few 38Cs, just one 40C.

Decent odds!

[Maz]

15 minutes ago, hotsummer said:

Frankly, not seeing this. We’ve had 37c/38c more than once since 2003. That wasn’t hideous/dreadful. It was just very hot and that’s all it looks. 

Now this seems to shows below mid 30s in SE so defo no record here on Tues with highest north of. So I think that looks like a UK record maybe just perhaps 39c? 
 

EDIT: What are the local records for those areas further N showing the max? Local records could well be smashed even if overall not so much. 

 

Really interesting with some of the models having the really hot uppers reaching northern England.  Many places could smash their local records.  SSE drift giving a slight drying foen (sp?) effect, could put Vale of York in the sweet spot, with another hotspot in Cheshire/ S Manchester.  Now that would be a turn up,  not areas associated with extreme heat!

[bluearmy]

19 minutes ago, hotsummer said:

Frankly, not seeing this. We’ve had 37c/38c more than once since 2003. That wasn’t hideous/dreadful. It was just very hot and that’s all it looks. 

Now this seems to shows below mid 30s in SE so defo no record here on Tues with highest north of. So I think that looks like a UK record maybe just perhaps 39c? 
 

EDIT: What are the local records for those areas further N showing the max? Local records could well be smashed even if overall not so much. 

 

We can’t be taking any specific runs as gospel from this range 

what is significant from the runs over the last 36 hours is the feasibility that we could set a U.K. temp record in n england ! 

[chrisbell-nottheweatherman]

Can I ask - is there consensus on rain/storms late Tuesday/Wednesday in any part of southern or eastern England, please?  Forecasters on Twitter saying no rain at all out to 22nd on some models.

[bluearmy]

Just a note that relative humidity on mon and Tues in association with the highest temps is in the 25/30% area

[terrier]

So after the heat and storms early next week does anyone more knowledgeable than myself want to take a punt on we’re we then go from here. Do we trend unsettled and wet. Or a rebuild of the heat. 

[bluearmy]

Just now, chrisbell-nottheweatherman said:

Can I ask - is there consensus on rain/storms late Tuesday/Wednesday in any part of southern or eastern England, please?  Forecasters on Twitter saying no rain at all out to 22nd on some models.

No consensus yet

and models are poor at picking up convective thorms at range of more than a few days.  Fwiw, the eps mean precip total by next Thursday is 5mm in your region. 

[Scorcher]

7 minutes ago, Man With Beard said:

I recounted meticulously, zooming in on areas I wasn't sure about, and this time I found actually 36 out of 51 ECM members had a 36C or higher next Tuesday! A few 38Cs, just one 40C.

Decent odds!

That 40C member must be unbelievable- would probably equate to 42C or more in reality?

[bluearmy]

Just now, terrier said:

So after the heat and storms early next week does anyone more knowledgeable than myself want to take a punt on we’re we then go from here. Do we trend unsettled and wet. Or a rebuild of the heat. 

There is only a single eps cluster from day 8 = no one has a scooby ……..

[hotsummer]

12 minutes ago, bluearmy said:

We can’t be taking any specific runs as gospel from this range 

what is significant from the runs over the last 36 hours is the feasibility that we could set a U.K. temp record in n england ! 

Yeah, so it seems for the ‘peak’ the higher temps have edged just that bit north on a few runs I thought. Going further now. Local records defo under threat, national perhaps and that’ll be outside SE. 

It seems that for one of the more ‘extreme’ spells we see the highest outside the SE. Surely that in itself is quite a feat. 

All this aside. We’d likely have been happy with beyond that as so far it seems very good indeed. But I know that things can go ‘wrong’ this far out. 

Edited July 12, 2022 by hotsummer

[damianslaw]

1 hour ago, terrier said:

So the big question for me is once this all breaks down on Tuesday into Wednesday with heavy rain we’re do we go from here. Do we trend unsettled for awhile with near normal temps. Or do we see a rebuild of the warmth and heat. Maybe people more knowledgeable than myself may have a better take on things going forward. 

Suggestion is for the azores high to not go away really and we could end up with a weak atlantic flow, but I suspect we will see a more concerted frontal system push down from the NW and usher in generally much cooler conditions.

[Dbarb]

How is the humidity relative to the temperatures on Monday Tuesday now? Because I remember when the 40 was being shown on the Sunday the humidity was low so actually not that dangerous relative to past records. Remember the heat index is what measures danger especially at night 

[Geordiesnow]

30 minutes ago, qwertyK said:

I haven't paid that much attention to the graphs but if the peak will be Monday/Tuesday that is still a week away, and so I am still very cautious about believing anything exceptional will happen.

It wasn't forecast to rain for weeks yet we have had a few downpours here in south Essex.

2-3 days ago, Sunday here was being forecast for 36C.

It's now being forecast as...28C.

The reason Sunday may be having a lower max is because high pressure is holding firm so not allowing the true hot air in* but I can't see how the hot air does not make it into the UK, seems a matter of when rather than if too me. The only questions are  how far northwards the hot air gets and how hot that air gets. 

* The only exception I could maybe see if the Atlantic trough comes down from the North but model runs have totally backed away from this hence northern Scotland in particular look alot warmer than some earlier runs. 

In general this afternoons runs have trended on the exceptionally hotter side with the GFS perhaps surprisingly not going as hot hpa wise. 

As for the breakdown, if current trends continue, we may start seeing TV forecasts saying Tuesday is going to be very hot and dry and Wednesday is when it will break down but its all still a long way off yet. 

Edited July 12, 2022 by Geordiesnow

[kold weather]

13 minutes ago, hotsummer said:

Yeah, so it seems for the ‘peak’ the higher temps have been edged just that bit north. Going further now. Local records deco under threat, national perhaps and that’ll be outside SE. 

It seems that for one of the more ‘extreme’ spells we see the highest outside the SE. Surely that in itself is quite a feat. 

All this aside. We’d likely have been happy with beyond that as so far it seems very good indeed. But I know that things can go ‘wrong’ this far out. 

Worth noting much depends on timing. If the front is slower on Tuesday then the hottest temperatures will be spread evenly out, and I suspect London with its UHI will probably make the difference up unless the front has already come through.

 

[cheese]

52 minutes ago, hotsummer said:

Frankly, not seeing this. We’ve had 37c/38c more than once since 2003. That wasn’t hideous/dreadful. It was just very hot and that’s all it looks. 

 

Uh, have we? I’m pretty sure the highest temperature in the UK between 2003 & 2019 was 36.7C in July 2015. Temperatures above 37C are incredibly rare in the UK - 3 August 1990, 10 August 2003 and 25 July 2019 are the only days that spring to mind.

Whether the national record goes or not, to potentially have widespread temperatures of 37-38C across England is exceptional. A lot of people in the UK have never experienced heat like that.

Edited July 12, 2022 by cheese

[hotsummer]

Just now, kold weather said:

Worth noting much depends on timing. If the front is slower on Tuesday then the hottest temperatures will be spread evenly out, and I suspect London with its UHI will probably make the difference up unless the front has already come through.

 

This brings me onto another thought. Further pushbacks then meaning higher uppers come at the wrong time and it all falls short? All finely balanced indeed 

[kold weather]

1 minute ago, cheese said:

Uh, have we? I’m pretty sure the highest temperature in the UK between 2003 & 2019 was 36.7C in July 2015. 

We've only had 37+ four times in recorded history.

37.1 Aug 1990, 37.8 July 2020, August 2003 and July 2019.

Indeed even reaching 36 is pretty rare, especially pre 1990s. 

This is why when you've got 60% of models/ensembles going north of 36c it is a pretty major deal, especially because many of them don't have the resolution to feel out the typical local hotspots.

[hotsummer]

3 minutes ago, cheese said:

Uh, have we? I’m pretty sure the highest temperature in the UK between 2003 & 2019 was 36.7C in July 2015. 

37.9c 2019

37.8c 2020 (then three 35c in the same year during that Aug spell)

[damianslaw]

I'm looking beyond the projected intense heat, indications where we may be heading latter part of July. Always good to look at the jetstream profile forecasts for a broad indication of likely direction of travel. Whilst these often fluctuate at long timeframes 7 days plus, they can be a good barometer for general expected conditions, i.e. will we be locked on the warm side of the jet or not, where is energy transferring to, the northern arm, is there a split flow on the way, how zonal may it be etc..

Looking at the immediate future you can see the cut off low feature and weak southern arm languishing off Portugal going nowhere with a weak jet riding to the north of the UK, by mid week next week, the low has moved north into the UK, and a slow transition then takes place with a much more invigorated jet taking a crash course for the UK, and eventually we go on the colder side, indeed looks quite a typical flow, ridge and trough pattern and atlantic dominated. Traditionally the jet moves into gear later July, mind since Dec 2020 it really has been a weak entity. My guess is the azores high will remain a strong feature but much further west, more of a mid atlantic high allowing frontal systems to move in from the NW from time to time, and these will have more gusto about them than recently, ties in with La Nina base state for second half of summer.

Might it be a good time to create a focus on the shorter term - heatwave thread, and allow this one to go back to longer range model watching, I fear it is fast becoming lets show charts showing most intense heat, and broader picture and longer term forecast watching not really being given much attention.

Edited July 12, 2022 by damianslaw

[mushymanrob]

Ok im not courting popularity here... and im a John Holmes convert... but this chart has (since the last post two days ago) suggests that high pressure will diminish, weaken, in a moderate Westerly upper flow. There is slight troughing over the UK with a hint of a possible return of a mid Atlantic ridge.

Now heat haters will welcome this pretty average (not bad) conditions. But these charts are consistent in not supporting a strong high pressure over/near us.

That is my assessment on this chart... it might be accurate, it might not.. lets wait and see eh?..

[damianslaw]

Can we keep to model discussion , not talk of record highest temperatures etc, past heatwaves. Those speculating on how hot temps may become please use the other threads dedicated to that topic, thank you.