Model Output Discussion - Autumn arrives

[stodge]

Evening all

We're now down to the fine detail.

Arpege keeps the hottest conditions on Monday to the north of London and on Tuesday a narrow but long strip from south east England to South Yorkshire looks the place to be for those wanting 40c or perhaps higher. The speed at which the heat is displaced on Tuesday is variable but I think all have the 20c 850 line clear of the east coast before midnight.

It's that pace of displacement which will be the key factor on Tuesday - if the cooler air arrives quicker, the opportunity to approach the highest maximum values will be limited - it does seem east and north east England will keep the heat the longest with the encroaching of cooler conditions from the south west and west reaching London, for example, by late afternoon/early evening.

Down now to the higher resolution "now casting" models to follow the detail,

 

[kold weather]

Looking at the UKV 850hpa profile it looks about the same as the other 12z suite of models.

Thought I'd also post the overnight lows for Monday night, which are pretty unreal truthfully:

Most of the country is above average....the daytime max average!

[tight isobar]

Ec.. impressions!!.. still I’m cautious of the outermost drift!!..  pushing the values out to quick.needs  close eye. 

Edited July 15, 2022 by tight isobar

[MattStoke]

ECM about the same as other models with timing of the heat clearing on Tuesday. Seem to be getting to a good consensus on that.

Edited July 15, 2022 by MattStoke

[Snowy L]

Out of the big 3, the ECM has the 1010mb isobar furthest west at Tuesday 12pm, but then also somehow has the 20C 850 line furthest east.

Edited July 15, 2022 by Snowy L

[mb018538]

15 minutes ago, MattStoke said:

41’C Tuesday.

The furnace zone is getting slimmer. Looking like it’s Lincs or maybe East Yorkshire for the record Tuesday!

[sheikhy]

When looking at the pressure charts i thought the higher 850s would be further west like the gfs but they are further east on the ecm!weird

[kold weather]

ECM generally cooler on both Monday and Tuesday than most other models, IMO too much so. It also only just breaks the min record vs most other models which beat it pretty handily. Indeed only one small area of Wales is above the record, compared with large parts of the country on other models.

36c on Monday and then 37c on Tuesday, but after a less impressive night than most models, so I'm not sure I will give too much weight to its forecasted maxes, they are likely 1-2c undercooked.

Edited July 15, 2022 by kold weather

[nick sussex]

Tuesday looks a lot more uncertain . Any further push ne of the hottest uppers and it will be all down to Monday to get the record .

It’s not just the uppers but how much cloud might spill ne ahead of the front .

Somewhat frustrating that the hottest uppers come in overnight Monday into Tuesday morning .

 

[minus10]

Gfs 12z 850s for herts...

 

A small number peaking at or above 25 deg, although pretty dramatic fall after. Of note also is an uptick again for following weekend with a couple of ens heading towards 20 deg again, however only a ' whiff' of a signal really presently....

Edited July 15, 2022 by minus10

[MattStoke]

MOGREPS clears the heat from London pretty late on Tuesday. Imagine if the peak uppers shown there occurred in the day time instead of Monday night/early Tuesday….

[Mark Smithy]

GFS ensembles are rock solid and consistent with the heat at 40C+.

I'll be very interested to see the ECM ensembles. The ECM is definitely showing slightly less intense surface temps (36C Monday and 37C Tuesday), although I think it usually does?

[Geordiesnow]

3 minutes ago, Mark Smithy said:

GFS ensembles are rock solid and consistent with the heat at 40C+.

I'll be very interested to see the ECM ensembles. The ECM is definitely showing slightly less intense surface temps (36C Monday and 37C Tuesday), although I think it usually does?

Are the ECM temperatures not the mean temperature for that area hence they always show slightly lower temps? 

[kold weather]

21 minutes ago, Snowy L said:

Out of the big 3, the ECM has the 1010mb isobar furthest west at Tuesday 12pm, but then also somehow has the 20C 850 line furthest east.

I think the ECM simply has a less intense thrust of heat that cools quicker than the other models. For example ECM at 06z Tues has 21-22c at 850hpa vs:

ICON -23

GEM -23

GFS - 23-24

UKV - 23-24

So you can clearly ECM is the odd one out here.

Basically the ECM is likely too cool, but we kinda know that anyway as its been running a little too cool lately over the UK anyways.

 

[I remember Atlantic 252]

Aye, maybe signs on 12Z's of a less hot Tues? looks like it on these with the front quite far East, certainly on UKMO chart looks like Atlantic air arrived in the west around 2pm

[MKN]

29 minutes ago, mb018538 said:

The furnace zone is getting slimmer. Looking like it’s Lincs or maybe East Yorkshire for the record Tuesday!

I think the trend is to push it Eastwards. The chances of the UK missing the highest 850s Tuesday and thus the 40+c is increasing.

[tight isobar]

It’s seriously odd.. how lightening could strike twice @ mirror templates!!.. sinking lower air sources getting into wide Iberian position!!.. @ press the button again!!

[I remember Atlantic 252]

And certainly blow the cobwebs away on Wed with a NW facing window, should be goodbye heat

[sheikhy]

2 minutes ago, I remember Atlantic 252 said:

Aye, maybe signs on 12Z's of a less hot Tues? looks like it on these with the front quite far East, certainly on UKMO chart looks like Atlantic air arrived in the west around 2pm

Funny thing is ecm looks further west than ukmo so u think ecm would be hotter!somethings not right!its still gives me a raw 35 or 36 monday and a 37 on tuesday so still record breaking as you can easily add 2 or 3 degrees to these ecm temps!!

[pages]

5 minutes ago, kold weather said:

I think the ECM simply has a less intense thrust of heat that cools quicker than the other models. For example ECM at 06z Tues has 21-22c at 850hpa vs:

ICON -23

GEM -23

GFS - 23-24

UKV - 23-24

So you can clearly ECM is the odd one out here.

Basically the ECM is likely too cool, but we kinda know that anyway as its been running a little too cool lately over the UK anyways.

 

Thing with ECM that I can't fathom is how it is best performing model statistically at day 7 when at closer ranges (inside 48hours) it is often nowhere near as accurate as GFS/icon. How does it go on from starting  with less accurate picture to be the most accurate in the longer range.

It's not really worth looking at any of the medium term models now for Monday and Tuesday, as UKV should be the most accurate being a short term model with higher resolution.

[Mapantz]

Is the record going to get scuppered?

 

 

[Paul]

3 minutes ago, Mapantz said:

Is the record going to get scuppered?

 

A lot of that is high cloud. 

  

[Jason M]

49 minutes ago, kold weather said:

Looking at the UKV 850hpa profile it looks about the same as the other 12z suite of models.

Thought I'd also post the overnight lows for Monday night, which are pretty unreal truthfully:

Most of the country is above average....the daytime max average!

No point in driving up a big hill to get any relief either because the higher you go the higher the temp with that warm air aloft. Snowdonia is a bit toasty!!!

[mb018538]

5 minutes ago, Mapantz said:

Is the record going to get scuppered?

 

 

Certainly looking more cloud on Tuesday than Monday. Whether it’s just high cloud or something thicker remains to be seen. Still don’t think it’ll make too much difference.

[kold weather]

2 minutes ago, mb018538 said:

Certainly looking more cloud on Tuesday than Monday. Whether it’s just high cloud or something thicker remains to be seen. Still don’t think it’ll make too much difference.

It's basically all high cloud until the evening. It might limit the chances of going super extreme with temps but it's not going to have a huge impact given how hot the day starts anyway.