Model Output Discussion - Autumn arrives

[danm]

24 minutes ago, Bristle Si said:

Mid to upper 20s for 3 days or more is a heatwave in my book, and plenty hot enough for this country. Despite being a frequent visitor to S Europe, Canaries and beyond, anything past 27c in UK is too hot, as a couple of days past 27c usually results in a rise in humidity.

I love the heat, but personally what makes it harder to bear in the UK when it gets really hot is our homes not being built for it. There’s no escape as UK homes are built to trap the heat and very few people have air conditioning. 

[Ross Andrew Hemphill]

20 minutes ago, Alderc said:

Your right, probably the strongest set of GFS ensembles and mean so far. Lots more of the ensembles going into the hot category. 
 

Op is on the cooler side of things in the second half of the run as well 

[Cheshire Freeze]

1 hour ago, summer blizzard said:

Important to note the context of any heatwave. There is certainly in modelling good agreement that we will see 25C+ temperatures sustained for probably a week (probably 80f+). The idea of a speculative hellfire is very much an ensemble option but still well within FI and still not the favoured option.

For those interested in such a plume or indeed avoiding it like me it’s worth saying that the important feature to watch at day 10 is not the Azores Low (that has a high likelihood of forming) but rather the low near NewFoundland and also the second feature near Iceland.

 

To achieve a proper plume you need two things to happen.

1) The low near Newfoundland needs to stay weak, the less that phases with the Azores Low, the more chance that a plume can occur while trying to push the high east.

2) The Low around Iceland needs to stay slow so that it does not tilt the high as per the chart above given that the core of the high starts west of the U.K.

Looking like a decent chance of a heatwave now. I’m resigned to it. Everything I look at in the models right out to week 2 looks to be setting the foundations.

The good thing for you and I is that in 6 weeks time it’ll be mid August and hot spells will begin to lose their punch.

 

[kold weather]

The set-up looks somewhat primed to allow a hot shot at some point to come up, however I wouldn't think that is the most likely situation. This is looking more like a steady and sustained warm spell with the core of the HP cell being to our west more often than not.

What is becoming increasingly concerning is just how dry it is looking, especially given we've had a pretty dry first half of the year, particularly the further SE you go. Combined with a sustained spell of 25-30c maxes will quickly deplete reserves at this time of year.

[Lukesluckybunch]

the ICON is looking absolutley great,hints of the high moving southeastwards..looks a hot run to me

[ANYWEATHER]

3 hours ago, tight isobar said:

Tip of the day.. why bother coming onto a “meteorology forum “ and commenting on model formats.. when some clearly cannot decipher  them  !! Shocking commentary from some.. Anyway enjoy the upcoming HEATWAVE

Do you work for the Sensationalist Media,

[Kentspur]

2 hours ago, danm said:

I love the heat, but personally what makes it harder to bear in the UK when it gets really hot is our homes not being built for it. There’s no escape as UK homes are built to trap the heat and very few people have air conditioning. 

This literally was almost a carbon copy of what i posted on my Facebook story earlier. I live in a new build its even worse than most people that have houses over insulated to the max i.never even need the heating on winter if only I could afford a house! My sisters mums and dads all much bettere than these apartments sandwiches together its awful here even today my place is currently 28c! Imagine if we get to high 30s/40c!

Edited July 3, 2022 by Kentspur

[Ross Andrew Hemphill]

High is centred a good bit closer to the UK by next weekend on the GFS 

edit: BIG upgrade in the positioning of the high by T177!!

Edited July 3, 2022 by Ross Andrew Hemphill

[Scorcher]

Fantastic GFS so far- particularly after Friday. It looks like for us in the west that it's going to take a while for it to properly warm up- looking pretty cool and cloudy until midweek at least here. This is the issue with the Azores high- it can be a slow process to get the high where you want it, with cloud and weather fronts often filtering in around the top of the high.

By Friday though it looks to be moving far enough east for more of the country to get the warmth and sunshine and looks very robust from the weekend on for most of the country- very promising indeed.

[mb018538]

Looking like a warm run once the high finally arrives at the end of the week. Temps into the mid to upper 20s, then depending on where the high goes, also some potential for scorching heat beyond.

[Snowy L]

Sorry but 27C is not a heatwave it's like 2 degrees above average for London. We don't even notice temperatures 5c above average in winter so I'd say the absolute minimum for a heatwave in London should be 30c, elsewhere like the Midlands 28C.

 

Looking to next week unfortunately looks like a lot of cloud to shift with fronts moving over the top of the high, affecting much of the UK. Hopefully by Saturday next weekend we finally get proper summer weather.

[Guest]

4 minutes ago, Snowy L said:

Sorry but 27C is not a heatwave it's like 2 degrees above average for London. We don't even notice temperatures 5c above average in winter so I'd say the absolute minimum for a heatwave in London should be 30c, elsewhere like the Midlands 28C.

27C - across 3 or more consecutive days - would certainly be a heatwave for us here in Sheffield. As it would also for nearly all of England, Wales, N. Ireland and Scotland. 28C is required for the London area, granted.

25C is most certainly not the average for London either. I really am not sure why some of you want to split hairs on this. You're disagreeing with official guidance and while that may be suitable for a summer chat thread, it's not suitable for the model thread where anything other than facts and supporting evidence will just muddy the thread.

Edited July 3, 2022 by Steel City Skies

[mb018538]

UKMO shows yet another disturbance in the high next Sunday. We’d be absolutely cursed if it pans out like this. Just not strong enough 500mb heights to really make this a nice sunny high. I reckon we’re going to be seeing a lot of cloud.

[kieranweatherfan]

14 minutes ago, Snowy L said:

Sorry but 27C is not a heatwave it's like 2 degrees above average for London. We don't even notice temperatures 5c above average in winter so I'd say the absolute minimum for a heatwave in London should be 30c, elsewhere like the Midlands 28C.

 

Looking to next week unfortunately looks like a lot of cloud to shift with fronts moving over the top of the high, affecting much of the UK. Hopefully by Saturday next weekend we finally get proper summer weather.

25 is not the London average, Heathrow has an average of 23.89° as per the met office, central London is more 23° average, so having 27 or 28° is a good 4 or 5 degrees above average 

[Guest]

8 minutes ago, mb018538 said:

UKMO shows yet another disturbance in the high next Sunday. We’d be absolutely cursed if it pans out like this. Just not strong enough 500mb heights to really make this a nice sunny high. I reckon we’re going to be seeing a lot of cloud.

it is at odds with the GFS which maintains and then builds on stronger 500mb heights through the weekend into the following week. At the same time the UKMO starts from a strong position but those stronger heights ebb away a touch on the Sunday. Hopefully that'll change as next week progresses  

[danm]

23 minutes ago, Steel City Skies said:

27C - across 3 or more consecutive days - would certainly be a heatwave for us here in Sheffield. As it would also for nearly all of England, Wales, N. Ireland and Scotland. 28C is required for the London area, granted.

25C is most certainly not the average for London either. I really am not sure why some of you want to split hairs on this. You're disagreeing with official guidance and while that may be suitable for a summer chat thread, it's not suitable for the model thread where anything other than facts and supporting evidence will just muddy the thread.

The average for London in mid to late July is about 24°c. 27°c is therefore about 3°c above average. Warm, but not exceptional. 

[Frosty.]

This is a better Ukmo run than recently, the high looks better positioned regarding next weekend, on previous runs it was under more pressure from lower heights to the NW but this looks more like I’m hoping for regarding the mid range which will hopefully have the knock-on effect of making the longer range better too! ️  

Edited July 3, 2022 by jon snow

[minus10]

Gfs 12z showing from Friday 8th July onwards temps of 25 deg or above for the rest of the run in many parts of the uk... definately feeling summery if that happens but also mostly dry...

[Guest]

19 minutes ago, danm said:

The average for London in mid to late July is about 24°c. 27°c is therefore about 3°c above average. Warm, but not exceptional. 

That's why 28C is required to hit the heatwave threshold. I said that in my original post  

[danm]

1 minute ago, Steel City Skies said:

That's why 28C is required to hit the heatwave threshold. I said that in my original post  

Ok, but even 28°c is hardly a heatwave. I get why they have that particular threshold of 28c for 3 consecutive days. However, reaching 28°c is a not uncommon occurrence here. Depends how we define “heatwave” I suppose. 

Edited July 3, 2022 by danm

[Scorcher]

45 minutes ago, mb018538 said:

UKMO shows yet another disturbance in the high next Sunday. We’d be absolutely cursed if it pans out like this. Just not strong enough 500mb heights to really make this a nice sunny high. I reckon we’re going to be seeing a lot of cloud.

Very early to be examining those precipitation charts, which are notoriously inaccurate anyway.

[mb018538]

1 minute ago, Scorcher said:

Very early to be examining those precipitation charts, which are notoriously inaccurate anyway.

Wasnt so much the ppn….but was looking like the high would properly build in by the weekend and kill off the drizzly stuff and hopefully increase sunshine. If it’s like that then it’s going to stay very cloudy, especially in the west. One to watch.

[Methuselah]

6 minutes ago, danm said:

Ok, but even 28°c is hardly a heatwave. I get why they have that particular threshold of 28c for 3 consecutive days. However, reaching 28°c is a not uncommon occurrence here. Depends how we define “heatwave” I suppose. 

I thought it needs 3 or more days at or above 5C above the long-term average? But, whatever the Met Office's definition of a heatwave is, that's what we have to go by?

[Frosty.]

Here’s a few nice GEFS 12z perts that keep the summery weather firing on all cylinders until mid July and beyond which I’m pretty sure the majority on here want.. well, I do anyway!!! ️  

[Guest]

Unremarkable mean driven by a massive spread on ensembles. Anything possible from record breaking heatwave to troughy  mctrough with the high way out west.