Model Output Discussion - Autumn arrives

[Scorcher]

I'm not having the 06Z- it looks better for early next week but flattens the high way too hastily when you look at the ensembles from earlier. Pretty sure it will be an outlier.

[mb018538]

Looks pretty warm again…

30c showing on the 6z from Sunday out to Wednesday. Nothing extreme - but 30c for 4 days in a row is still pretty noteworthy for the UK.

[Singularity]

The 06z does feel a bit 'out there' in terms of flattening the high, but has some educational value: A flatter outcome positions the high further south, which is a location more conducive to sending the very hot airmass over Iberia northward.

I sense the charts for 15th are going to be as extreme as any we've seen so far.

Edit: Well, they nearly were. The NE movement of the formerly cut-off low was surprisingly rapid (then again, this is GFS, should I be surprised?).

...but here's the thing - we're seeing a lot of different pathways that lead to temps hitting at least the mid-30s on at least one day. 

Edited July 5, 2022 by Singularity

[kold weather]

10 minutes ago, Scorcher said:

I'm not having the 06Z- it looks better for early next week but flattens the high way too hastily when you look at the ensembles from earlier. Pretty sure it will be an outlier.

Still develops a very hot looking pattern over Fri-Sat next week, though probably not very long lasting. This run is certainly less extreme than some runs we've seen lately, but its still a very warm run out to 240hrs and the slightly flatter pattern only pulls the temps down to 25-26c, so still plenty nice.

 

Edited July 5, 2022 by kold weather

[Bristawl Si]

25-26c in the UK? Perfect temps. Should, hopefully, mean the nightime temps arent too oppressive.

[summer blizzard]

For the second consecutive run (though even more aggressive), the third shortwave picks up the trough east of the Azores. We get a quick plume and Atlantic victory.

[mb018538]

It’s appeared again….can’t remember seeing 38c plus so often in the output!!

Edited July 5, 2022 by mb018538

[mb018538]

Just a casual 27c at 850hpa…

[kold weather]

Very rapid evolution on the 06z its got to be said, we have an outrageous plume event and a LP that undergoes near RI in the middle of July as a result of the plume being so extreme.

Note the 06z would be a record breaker with regards to 850hpa, by some considerable distance as well. Would expect a 40c out of that, possibly even 41-42c.

Anyway I think it looks like a very extreme solution in all respects and whilst I do think there is an increasing chance of a very strong plume event, I'm highly doubting this particular evolution of it.

EDIT - VERY dry air as well, dew points as low as 4c, so it would feel pretty much like continental heat rather than our normal heat.

Edited July 5, 2022 by kold weather

[I remember Atlantic 252]

like the plume of 31st July/01 Aug 2020, hot Friday and much cooler Saturday

 

[Scorcher]

9 minutes ago, kold weather said:

Still develops a very hot looking pattern over Fri-Sat next week, though probably not very long lasting. This run is certainly less extreme than some runs we've seen lately, but its still a very warm run out to 240hrs and the slightly flatter pattern only pulls the temps down to 25-26c, so still plenty nice.

 

Doubt it will be 25-26C here in the west though once the pattern flattens- yes still good for the SE but further west we'd be limited to the low 20s.

[MattStoke]

‘Only’ 39’C from that plume. Damn downgrades

[northwestsnow]

7 minutes ago, summer blizzard said:

For the second consecutive run (though even more aggressive), the third shortwave picks up the trough east of the Azores. We get a quick plume and Atlantic victory.

LOL.

 

 

[Scorcher]

Not sure I've ever seen a chart like that before with the extreme heat so widespread- I can't recall ever seeing 37C for Manchester on one of these charts before. Extraordinary.

[kold weather]

2 minutes ago, Scorcher said:

Not sure I've ever seen a chart like that before with the extreme heat so widespread- I can't recall ever seeing 37C for Manchester on one of these charts before. Extraordinary.

Some of the ensembles in recent days have gone ever more extreme than that, as mad as that may sound.

For example P14 on todays 00z run decides to throw out 3 days at 37-38c followed by a fairly widespread 42C, nuts.

Has to be said looking at all the GFS ensembles from the 00z (my guess is the 06z suite will be cooler given how more mobile the OP is this time) there are MANY hot runs, pretty much all get to at least 30c at some point (even the very progressive runs) and a good number go to 34-35c at least.

 

[Frosty.]

I’ve seen enough of the GEFS 6z to convince me it’s an increasingly FANTASTIC outlook for the majority of the u k with the only probable exception being the far north of Scotland / isles! ️  

[Scorcher]

5 minutes ago, kold weather said:

Some of the ensembles in recent days have gone ever more extreme than that, as mad as that may sound.

For example P14 on todays 00z run decides to throw out 3 days at 37-38c followed by a fairly widespread 42C, nuts.

Has to be said looking at all the GFS ensembles from the 00z (my guess is the 06z suite will be cooler given how more mobile the OP is this time) there are MANY hot runs, pretty much all get to at least 30c at some point (even the very progressive runs) and a good number go to 34-35c at least.

 

Remarkable- there are some really extreme possibilities then. I guess the issue with that is what comes after it though. Do we want the brief extreme heat and then average conditions to follow, or do we want the more prolonged, more moderate heat? An extreme plume like the GFS is showing for Friday 15th is not going to last long.

Edited July 5, 2022 by Scorcher

[Guest]

06Z has 40C on the HD images. 

[kold weather]

2 minutes ago, Scorcher said:

Remarkable- there are some really extreme possibilities then. I guess the issue with that is what comes after it though. Do we want the brief extreme heat and then average conditions to follow, or do we want the more prolonged, more moderate heat? An extreme plume like the GFS is showing for Friday 15th is not going to last long.

Also worth noting that the ECM ensembles also are overall pretty decent, whilst perhaps not quite as extreme (though still a few going to 35-37C), a great many above 30c at some point. Given these are the ensembles and they won't be picking up localised heating effects, etc I think the odds of going 32c+ are increasing.

The 06z GFS IF it came off would have an atmospheric set-up conducive to reach somewhere around the 43C mark in theory, however I guess there would be increasing cloud which probably caps the rise to an extent.

Anyway no point in dwelling on that, even a toned down version of that would easily put it in the top 3 hottest ever blasts along with July 19 and Aug 03.

For now we have a strong warming trend, especially the further south and east you go. Plenty to suggest a 30c by early next week.

[mb018538]

This is going to be an interesting week model watching that’s for sure. All of these extreme charts are now only 10 days away….which is still a mile off, but inching ever closer. By the end of the week we will probably have a reasonable idea if it’s going to be something as ridiculous as that, just staying very warm or a complete breakdown. 

[Don]

49 minutes ago, Singularity said:

I sense the charts for 15th are going to be as extreme as any we've seen so far.

Edit: Well, they nearly were. The NE movement of the formerly cut-off low was surprisingly rapid (then again, this is GFS, should I be surprised?).

When one describes charts showing widespread 37 and 38C's across the south as 'less' extreme than other runs says it all!  Different territory to where we were 20 years ago for sure!

[Methuselah]

Even this, at T+378, would likely see temps still in the 30s, as there might be a lot of residual very hot air close to the surface? But, anyway, the next two weeks will be chock full of fun and games:

    

That said, I'll welcome 42C as I would the Arsenal at White Hart Lane!

[MP-R]

2 minutes ago, Don said:

When one describes charts showing widespread 37 and 38C's across the south as 'less' extreme than other runs says it all!  Different territory to where we were 20 years ago for sure!

Would’ve loved to have seen the models with modern day detail in the run up to the August 2003 heatwave to see whether they would have shown 40 degrees plus, which toned down slightly nearer the time, or underestimated ahead of time.

We will need near perfect conditions to get that level of heat here. Certainly possible, but absolutely everything has to go to plan - no cloud, no strong breeze, drier air, no cool undercut like 2019 etc.

[richie3846]

1 minute ago, MP-R said:

Would’ve loved to have seen the models with modern day detail in the run up to the August 2003 heatwave to see whether they would have shown 40 degrees plus, which toned down slightly nearer the time, or underestimated ahead of time.

We will need near perfect conditions to get that level of heat here. Certainly possible, but absolutely everything has to go to plan - no cloud, no strong breeze, drier air, no cool undercut like 2019 etc.

I've mentioned this recently, the parched ground over some of Europe and the UK may add that extra lift needed for a plume to reach records temperatures. I'm not sure the models even take this into account.

[kold weather]

As expected from the GFS 06z suite generally a *little* cooler than the 00z suite by 240hrs, though the 00z suite was pretty bonkers and extreme. Somewhat flatter pattern on some of the runs, though most are still HP dominated so any such flow would probably soon shift back SW again as the ridge moves back in, and most remain plenty warm enough, if not quite as extreme.

Despite saying it is cooler than the 00z suite, still very warm on a great number of runs, and plenty that still go very hot as well.