Model output discussion - hot spell beckons but then what?

[Derecho]

5 minutes ago, Stonethecrows said:

Baffles me are some people seem to assume that this tiny island of ours should expect temps of 30° every summer and heavy snowfall every winter. Reality is as you say 25° is very warm and  27+ is hot for our neck of planetary woods.

30C is exceeded pretty much every summer now though and yearly maximums of over 33C are pretty much the normal compared to previous decades.

[MattStoke]

6 minutes ago, Stonethecrows said:

Baffles me are some people seem to assume that this tiny island of ours should expect temps of 30° every summer and heavy snowfall every winter. Reality is as you say 25° is very warm and  27+ is hot for our neck of planetary woods.

Well I’m from London originally and 27’C certainly isn’t hot for that part of the UK. It’s a little above the seasonal average but it’s common throughout most summers. 30’C is also recorded numerous times in the South East every summer.

[Summer Sun]

Tomorrow night could be recording breaking with temps potentially not dropping below 24c for some but not only that some torrential showers will break out first tomorrow afternoon in the south-west before spreading further north during the evening and overnight

The storms clear quickly to leave a hot and dry day on Wednesday for the majority but the rain may just peg the temps back a bit for Scotland, northern Ireland & ROI with lower 20s here but widely in England and Wales upper 20s to mid 30s

Edited July 22, 2019 by Summer Sun

[Cheshire Freeze]

52 minutes ago, Singularity said:

Now for another angle on affairs:

That might well be the most extreme cross-polar ridge I've ever seen in July. Extraordinary.

Yes, the underlying base state this spring/summer has been nothing short of extraordinary, and that is a cracking cross polar ridge as you say.

I'm extremely excited about prospects going forward towards autumn and winter. A pretty decent tripole began to emerge towards the back end of May and into June in the N Atlantic too.

[MATTWOLVES 3]

3 minutes ago, MattStoke said:

Well I’m from London originally and 27’C certainly isn’t hot for that part of the UK. It’s a little above the seasonal average but it’s common throughout most summers. 30’C is also recorded numerous times in the South East every summer.

The average is 21c in June... And 23c in July and August... So its a fair bit above average in my eyes. 

[Britneyfan]

It looks like the gfs continues the heat into Friday and Saturday especially for the south east, on Friday London could still reach 30 and Saturday 28

[MattStoke]

1 minute ago, Mattwolves said:

The average is 21c in June... And 23c in July and August... So its a fair bit above average in my eyes. 

24’C is the summer average, but 27’C is common for a few weeks at least each summer. It’s not note worthy in the slightest for the South East. Even 30’C occurs numerous times in the South East each summer. It has a warm climate. Far warmer than the rest of the UK.

[Mark wheeler]

Well , let’s roll out the barrel with a chart from the Navgem as it’s one of my favourites, Surely this is not possible. These uppers coming back at us in the east , I recognise it also has the pattern further east , posted a little in Jest .

[Radiating Dendrite]

Just now, MattStoke said:

24’C is the summer average, but 27’C is common for a few weeks at least each summer. It’s not note worthy in the slightest for the South East. Even 30’C occurs numerous times in the South East each summer. It has a warm climate. Far warmer than the rest of the UK.

Yeah, 27c in Greater London is usually hit a few times at least every month from May to September. I only see it as being hot when we are talking +28c with humidity being high. +33c and above is fairly exceptional though. 

[MATTWOLVES 3]

The mean shows a dip out to day 10 just like what the extended was showing a couple of days ago... Say around 7.5c...which indicates cooler conditions from the NW later next week... The pressure shows a slight increase though, around 1017mb...so all in all not bad 

[feb1991blizzard]

10 minutes ago, CreweCold said:

Yes, the underlying base state this spring/summer has been nothing short of extraordinary, and that is a cracking cross polar ridge as you say.

I'm extremely excited about prospects going forward towards autumn and winter. A pretty decent tripole began to emerge towards the back end of May and into June in the N Atlantic too.

Yes saw that, could have done with the warm water just below Greenland extending a bit further South and then the cold band as a result further South and the bottom warm band obviously in the sub tropics, but did look decent, has Gav done a video on it yet?

[MattStoke]

12 minutes ago, Radiating Dendrite said:

Yeah, 27c in Greater London is usually hit a few times at least every month from May to September. I only see it as being hot when we are talking +28c with humidity being high. +33c and above is fairly exceptional though. 

I’d say 30’c is hot for the South East, even though it’s fairly common most summers. 

Very different to Stoke. 30’C here is rare. I’d say a hot temperature for here is the mid to high twenties. In fact, the July record here is 31.3’C (which London easily beats every July) and the all time record is 32’9’C (which London beats a few times each summer) but the models are showing 32’C here for Thursday. Could be a local record!

I am from Harrow, where the nearest station is Northolt, so probably have a different perception to heat than many

Edit: The summer average of 24’C in London is based on the 1980 to 2010 average. I imagine once the next decade of data is used the average will be somewhat higher. London’s summer climate has been much warmer for years!

Edited July 22, 2019 by MattStoke

[Frosty.]

Gorgeous Ecm 12z ensemble mean chart for thursday!!!..  Hope we see more of this next month!!!!!!!!!!!!!!!...smokin!!

Edited July 22, 2019 by Jon Snow

[NorthernRab]

Is no one else not really a bit concerned by this sort of sustained rain continuously being forecast Scotland, Northern Ireland and parts of England? Looks potentially dangerous to life 

 

[Man With Beard]

Some interesting things to watch out for:

- A couple of attempts at the all-time minimum record of 23.9C

  

- Wednesday's maximum is still up in the air too. There are various potential bands of cloud moving through the SE, and even with rain attached in the the morning. The chart below shows morning rain in the very area that could hold onto the hotter air mass, but will this actually happen?

Doubts over cloud levels and how quickly the heat clears east...

...makes the maximum tricky to forecast in East Anglia. Anything between 32C and 36C possible. Maybe a 10% chance of the UK record going on Wednesday itself?

- And Thursday. Again, we're now looking at the potential impact of afternoon showers:

Will they happen? Will they interfere with the hot spots? I genuinely think there's an envelope of between 35C and 40C for Thursday afternoon, and I wouldn't like to call which end of this range it will be until the day. 

 

[Man With Beard]

3 minutes ago, NorthernRab said:

Is no one else not really a bit concerned by this sort of sustained rain continuously being forecast Scotland, Northern Ireland and parts of England? Looks potentially dangerous to life 

 

Nothing excessive coming on the ARPEGE?

[knocker]

Max temps Synops

http://www.met.reading.ac.uk/~brugge/18.html

 

 

[danm]

28 minutes ago, MattStoke said:

24’C is the summer average, but 27’C is common for a few weeks at least each summer. It’s not note worthy in the slightest for the South East. Even 30’C occurs numerous times in the South East each summer. It has a warm climate. Far warmer than the rest of the UK.

Yes, despite the fact that (up until this week) summer 2019 has not been exceptional, and we had a very cool and wet 2/3rds of June, we’ve recorded 25c or above on 14 days so far in London, including today. About 9 or 10 of those were 27c+. 

Edited July 22, 2019 by danm

[NorthernRab]

2 minutes ago, Man With Beard said:

Nothing excessive coming on the ARPEGE?

It keeps being modeled for early next week between Tuesday and Wednesday, wouldn't normally mention but it keeps showing up on every GFS run. 

[Stonethecrows]

21 minutes ago, Quicksilver1989 said:

30C is exceeded pretty much every summer now though and yearly maximums of over 33C are pretty much the normal compared to previous decades.

Which would only be relevant if it exceeded 30 c multiple times across the summer months and for several days at a time. Only then could 27 be described as merely warm.

Think it's fair to say last year was a cracking summer for lots of us but only a few saw 33 c and certainly not day in day out so i stand by my original point that throughout the majority of the summer months and for the majoity of uk wide postcodes, 27 is hot.

[MattStoke]

6 minutes ago, Stonethecrows said:

Which would only be relevant if it exceeded 30 c multiple times across the summer months and for several days at a time. Only then could 27 be described as merely warm.

Think it's fair to say last year was a cracking summer for lots of us but only a few saw 33 c and certainly not day in day out so i stand by my original point that throughout the majority of the summer months and for the majoity of uk wide postcodes, 27 is hot.

It does that most summers in South East. Honestly, the climate there is more like the med! It’s remarkably dry as well.

I have noticed a huge difference in climate moving to Stoke. Here 25’C is a heatwave and newsworthy. In London is a pretty bog standard, pleasant summers day.

Edited July 22, 2019 by MattStoke

[Derecho]

Just now, Stonethecrows said:

Which would only be relevant if it exceeded 30 c multiple times across the summer months and for several days at a time. Only then could 27 be described as merely warm.

Think it's fair to say last year was a cracking summer for lots of us but only a few saw 33 c and certainly not day in day out so i stand by my original point that throughout the majority of the summer months and for the majoity of uk wide postcodes, 27 is hot.

Fair enough, can't argue with that. A day with temperatures over 30C for a large area of the UK is rare. Absolute maximums over our island of 30C+ though are common annually thanks to these Spanish plumes which often deliver warmth to the SE.

[Mike Poole]

Some probabilistic fun from the ARPEGE ensemble 6z.  Here are the 25%, 50%, 75%, 90% percentiles and maximum peak temperatures Thursday...

The max is insane (edit - apologies that I originally posted a chart 3 hrs later for the max one, now corrected) and what also strikes me is the location of the hot spots, not just the SE corner, and with 20+ uppers affecting a large swathe of the south and east, we might find some new hot spots!

Edited July 22, 2019 by Mike Poole

[nick sussex]

Just now, MattStoke said:

It does that most summers in South East. Honestly, the climate there is more like the med! It’s remarkably dry as well.

There’s been some real horror show summers even in the se . Admittedly it often does get the best of the summer weather .

In terms of the hot debate. I think it depends where you live .

If I was still in the UK I’d go as follows .

23 to 25 warm

26 to 29 very warm 

30 to 32 hot 

33 to 36 very hot 

36 + extremely hot 

[MattStoke]

3 minutes ago, nick sussex said:

There’s been some real horror show summers even in the se . Admittedly it often does get the best of the summer weather .

In terms of the hot debate. I think it depends where you live .

If I was still in the UK I’d go as follows .

23 to 25 warm

26 to 29 very warm 

30 to 32 hot 

33 to 36 very hot 

36 + extremely hot 

I’d agree with that. I think 24’C (The London average) is very pleasant but the locals here would probably consider that to be in the very warm category. Just a big difference in climate and what people are used to. Conversely, an average winter day here is around 4-5’C but a cold winter day in London is around 7’C. Stoke gets a few ice days every winter but they’re rare in the South East.