Model Output Discussion - Autumn arrives

[emmett garland]

Its getting HOT in here

[bluearmy]

Still no strong indication that a mid month heatwave of notable proportions is going to happen.  The odd gefs member and now gfs op on that page. The geps were sniffing an Iberian upper low a few days ago but have dropped that now 

I guess we have to wait to see how persistent the upper ridge is in sticking to our west and how the troughing to our east evolves. If we raise that whole pattern north then we do bring the southern half of the U.K. into the w European mainland temp profile under a slack pattern which would raise the heatwave stakes. 

[ANYWEATHER]

2 hours ago, MattStoke said:

An incredibly hot end to the GFS. Temperatures reaching 38’C on the 18th (39-41’C with the usual caveat of how it underestimates maximums), and that’s before hotter 850hpa temperatures (as high as 26’C) move in on the 19th. It doesn’t quite run far enough to see what temperatures it gives for the 19th but it would surely be 40’C+ in some places.

 

Yes, but you're talking like that's set in stone, we are talking the last frame of the Gfs, unreliable even at short to medium time frames,

[MattStoke]

5 minutes ago, ANYWEATHER said:

Yes, but you're talking like that's set in stone, we are talking the last frame of the Gfs, unreliable even at short to medium time frames,

No I wasn’t. I was merely commenting on some model output in the model output forum. I made no suggestion that it will happen.

Edited July 3, 2022 by MattStoke

[Lukesluckybunch]

Just now, MattStoke said:

No I wasn’t. 

Very unlikely to happen,but what's more likely is it getting warmer then potentially hotter! First half of July looking decent!

[Mike Poole]

The evolution to settled and warm weather over the next 10 days seems clear on all models and it is what happens after that is up for grabs.  

The ECM T240 seems to reflect that position in 10 days well.  A large area of high pressure with the UK at the eastern end, extending some distance out west.

UK comfortably with +12C uppers with home grown heat, before any kind of plume scenario takes place.  

Beyond that, the plume scenario is entirely plausible, and if any of the 4 GFS op runs was going to be the first to show 40C in the UK, it is no surprise that it was the 18z pub run!  But there are many runs that don’t show anything so extreme as well, so at the moment it is one to watch, certainly within the envelope of possibilities in the 10-20 day range, but how likely is difficult to pin down.  We will see…

[Frosty.]

If the ECMWF 0z ensemble mean was a piece of fruit… …it would be a PEACH…for sure, that’s a peachy run for summer fans!!! ️ ? ?  

 

Edited July 3, 2022 by jon snow

[Captain Shortwave]

 

Ten day rainfall prediction. Probably the most notable thing about the outlook. The 10-16 day trend basically offers little either.

So the next few days should be mostly fine and pleasant, still potentially turning warmer from Wednesday onwards as a warm front draws warmer air over the whole country. 
 

 

Looking good overall.

Edited July 3, 2022 by Captain Shortwave

[Sweatyman]

Lol! Anyone got the Navgem? used to be the extreme temps model

[MattStoke]

1 minute ago, Sweatyman said:

Lol! Anyone got the Navgem? used to be the extreme temps model

It’s not showing such a plume as the GFS. If it did, it’d probably have the sea on fire Massively overdoes surface temperatures compared to the 850hpa profile.

[Lukesluckybunch]

54 minutes ago, MattStoke said:

No I wasn’t. 

Very unlikely to happen,but what's more likely is it getting warmer then potentially hotter! First half of July looking decent!

[Mark wheeler]

5 minutes ago, Sweatyman said:

Lol! Anyone got the Navgem? used to be the extreme temps model

Last frame of the Navgem 

[minus10]

52 minutes ago, Mike Poole said:

The evolution to settled and warm weather over the next 10 days seems clear on all models and it is what happens after that is up for grabs.  

The ECM T240 seems to reflect that position in 10 days well.  A large area of high pressure with the UK at the eastern end, extending some distance out west.

UK comfortably with +12C uppers with home grown heat, before any kind of plume scenario takes place.  

Beyond that, the plume scenario is entirely plausible, and if any of the 4 GFS op runs was going to be the first to show 40C in the UK, it is no surprise that it was the 18z pub run!  But there are many runs that don’t show anything so extreme as well, so at the moment it is one to watch, certainly within the envelope of possibilities in the 10-20 day range, but how likely is difficult to pin down.  We will see…

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..

Edited July 3, 2022 by minus10

[Supacell]

7 minutes ago, 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..

They are the highest temperatures I personally have ever seen on the GFS model, in 18 years of looking.

[MattStoke]

6 minutes ago, Supacell said:

They are the highest temperatures I personally have ever seen on the GFS model, in 18 years of looking.

I think the surface temperatures for the 19th on the 00z would have been even higher as the plume looked more intense, but it didn’t run out far enough to see them.

[MKN]

6 minutes ago, Supacell said:

They are the highest temperatures I personally have ever seen on the GFS model, in 18 years of looking.

Likewise I haven't seen a gfs op run show 41c before and also as mentioned in the original post widespread 45 or 46 across France is scary I can see them hitting close to 50c in the next 20 years at this rate. In the more immediate term next week looks like a gradual increase in temps for those in the south to the mid to high twenties at least once again. 

[Bristawl Si]

25 minutes ago, 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 

That low is nowhere near the Canaries. It's near to Maderia and Sao Miguel.

Edited July 3, 2022 by Bristle Si

[Cambrian]

Any exceptional heat heading our way mid to late July is far too early to take a proper punt at yet. It’s all quite plausible but then so are many other outcomes. Some of the more strident operational runs are very interesting, they appear like they’re seeing a trigger setup and then getting themselves into a bit of an algorithmic positive feedback loop towards the end of the run.

For now, it’s the broad pattern that strikes me already as exceptional, especially with the mid-summer timing. 

The 0z GEFS and ECM means show the high pressure to our west continue building and encroaching towards Ireland and the UK, It reaches its peak on day 5, next Friday, with 596+ dam heights into the southwest of Ireland and England, 1030-1035mb pressure typically. Hardly a precipitation signal anywhere in the UK or Ireland.

  
  

Lovely summer high pressure, impressive for the extent of its west-east elongation, the 1020mb isobar extending from just off the United States all the way to Eastern Europe. 

By day 10, the high pressure is declining somewhat, but only very slowly, its centre pulling west into the Atlantic. We’ve lost the exceptional heights and the pressure is 1020-1025 typically, allowing for some weak signals for occasional precipitation to creep into the GEFS mean, but the high still extends over the breadth of the Atlantic to Austria.

  
 

The sheer west-east extent of this high and its consistent orientation, with waves of heights building out of North Africa into the mid-Atlantic and bubbling up to our west, is clearly going to be a hard pattern to shift, a long spell of largely dry weather in the offing for all of Western Europe. 

Edited July 3, 2022 by Cambrian

[Captain Shortwave]

The GFS 06z cuts a cold pool down the east of the UK, which settles towards Spain later on.

 

This will allow any heat to the south to push a little further north. We will see how the low resolution handles things. 
Yes the 00z was actually at the point of creating an even more extreme solution than the 18z by the end of the run

[minus10]

44 minutes ago, Bristle Si said:

That low is nowhere near the Canaries. It's near to Maderia and Sao Miguel.

My bad...maybe north of Madeira and east of the Azores....?

[Derecho]

58 minutes ago, Supacell said:

They are the highest temperatures I personally have ever seen on the GFS model, in 18 years of looking.

The output of the GFS 18z is actually scary, UK records would be smashed to pieces if that came off and to see a 47C in northern France on the GFS (which tends to underestimate max temps by 1-2C) is utterly bonkers. Nuclear power stations would have to shut over France and there would be blackouts and heat related casualties there as well.

Thankfully however, something like that is very unlikely  but in this day and age... never say never, records these days tend to get smashed by large margins. We had close calls in July 2015, August 2018 and July 2019 but those plumes got cut short. Some day in the future, with further warmth to tap into, the dice will unfortunately roll that way.

Most likely scenario, high pressure remains over the UK with heat building if it crosses eastwards, followed by a brief plume and a thundery breakdown.

Edited July 3, 2022 by Quicksilver1989

[Don]

22 minutes ago, Captain Shortwave said:

This will allow any heat to the south to push a little further north. We will see how the low resolution handles things. 
Yes the 00z was actually at the point of creating an even more extreme solution than the 18z by the end of the run

All the time the GFS is showing these extreme solutions it remains a concern, even if unlikely at this stage!

[Cloud 10]

"That" 18z GFS has nearly +30 uppers for Paris.

 

[Weather26]

I see the downgrades have well and truly arrived-One thing's for sure, the 2nd week of July still looks all to play for to me?

[mb018538]

25 minutes ago, Quicksilver1989 said:

The output of the GFS 18z is actually scary, UK records would be smashed to pieces if that came off and to see a 47C in northern France on the GFS (which tends to underestimate max temps by 1-2C) is utterly bonkers. Nuclear power stations would have to shut over France and there would be blackouts and heat related casualties there as well.

Thankfully however, something like that is very unlikely  but in this day and age... never say never, records these days tend to get smashed by large margins. We had close calls in July 2015, August 2018 and July 2019 but those plumes got cut short. Some day in the future, with further warmth to tap into, the dice will unfortunately roll that way.

Most likely scenario, high pressure remains over the UK with heat building if it crosses eastwards, followed by a brief plume and a thundery breakdown.

Very unlikely as you say….but what about last summer? It was 49.6c in Lytton (Canada) last summer….resulting wildfire destroyed the place. That’s at 50N. In recent times we’ve had to reconsider what Is possible at the higher latitudes!