Model Output Discussion - Autumn arrives

[bluearmy]

The 06z gfs op has an eps cluster around 20% for support. Note the other three eps clusters are fairly evenly spread on percentages but are generally all with the ridge across the top suppressing the surface temps with the North Sea flow 

[Paul_1978]

18 minutes ago, mushymanrob said:

Well this post wont be popular, except perhaps on the heathaters thread! lol..

These charts suggest that after the heat event, next week returns to pretty much average. A moderate Westerly upper flow with only a slight anomaly over Southern areas. This suggests a mobile pattern, and not one with a lengthy spell of high pressure (or low) domination.

 

Bring it on. Not all of us want it to be hot. A steady 20-24C would do most of us just fine.

[seb]

9 minutes ago, Mark Smithy said:

!

Please don't treat GFS precip charts as gospel, especially not snapshot ones. Of course, the <1.5mm shown for the extreme SE (I include parts of Essex in this) are most likely going to do what has happened for the past 12 weeks... disappear to nothing. Even if 1.5mm would fall, it would evaporate before it does any good for anything. The ground is dry down to around 35cm.

[Mark Smithy]

12 minutes ago, mushymanrob said:

And?...... that will run off, it wont penetrate that hard dry ground, for that you need sustained precipitation and that isnt likely.

You're being a bit silly to be frank for some reason.

I'm not here to defend the GFS, nor to suggest the 6z is right, but it obviously shows a thundery breakdown on Tuesday 19th which, for some, would do more than just "moisten the ground" which was your original post before you decided to move your goalposts around: "There wont be much rain IF that Anomaly chart is accurate, i doubt itll be enough to moisten the ground."

Otherwise what you've written is a truism: summer rains rarely penetrate far or fill up reservoirs, for all sorts of reasons including vegetation.

Will this come to pass? No idea, but it's what is shown and, for some, could be fairly intense. To suggest otherwise is to allow obstinacy to get the better of you.

Edited July 11, 2022 by Mark Smithy

[pages]

Going out on a limb here but we haven't seen the actual record that will happen on any model out put yet.. 

What we saw on 6gfs was with a slower evolution there was reload of 28+ plus uppers into Spain before being pushed our way. 

Just a hunch but over next few runs we will see slightly slower evolution and even warmer upper pumped into Spain then onto us on more direct route through France rather than around high over Biscay.

Wednesday too be the hottest once we get down to t-0

 

[Mark Smithy]

The BBC forecast are now talking about the possibility of the temperature record being broken:

[Djdazzle]

2 minutes ago, pages said:

Going out on a limb here but we haven't seen the actual record that will happen on any model out put yet.. 

What we saw on 6gfs was with a slower evolution there was reload of 28+ plus uppers into Spain before being pushed our way. 

Just a hunch but over next few runs we will see slightly slower evolution and even warmer upper pumped into Spain then onto us on more direct route through France rather than around high over Biscay.

Wednesday too be the hottest once we get down to t-0

 

I think we need to see the 12z runs first.

[Guest]

After a cooler couple of days next Wed/Thurs GFS again brings the heat back. 31C next Friday, 35C Saturday the 23rd.....

[Mark Smithy]

Just now, Djdazzle said:

I think we need to see the 12z runs first.

Yes, might need to revise my competition temp forecast which I've pegged at 37.2C. That might be a bit low. 

The fact that the BBC are now talking it up makes me think it might happen. Which, frankly, is very grim news as far as I'm concerned.

[Djdazzle]

Just now, Mark Smithy said:

Yes, might need to revise my competition temp forecast which I've pegged at 37.2C. That might be a bit low. 

The fact that the BBC are now talking it up makes me think it might happen. Which, frankly, is very grim news as far as I'm concerned.

Don't forget though - the BBC will be using old data for their forecasts. This time yesterday, the record looked more likely to be broken. However, if the trend on the GFS 6z continues on the 12z runs, we may well be back in business.

[Singularity]

14 minutes ago, mushymanrob said:

But with quite a moderate Westerly upper flow... that suggests mobility, theres no sustained high pressure over the UK, nor low. Im not going to argue about temps which should be average or above, .

You can get a lengthy extension of the Azores High across southern UK with a mean westerly flow aloft - a 'flat' pattern isn't necessarily changeable. That's where anomalies can help with diagnosis. The 8-14 day indicates a north-shifted polar jet which translates to an increased frequency of high pressure across much of the UK. How many interruptions are likely to occur and how widespread they are (the south could be left high and dry) is better assessed using analysis of ensemble clusters... or at least they are when those clusters exist to begin with - the 00z EPS is lacking in that regard  - too much spread!

[mb018538]

11 minutes ago, Djdazzle said:

Don't forget though - the BBC will be using old data for their forecasts. This time yesterday, the record looked more likely to be broken. However, if the trend on the GFS 6z continues on the 12z runs, we may well be back in business.

We probably won't really know for sure until midweek. It's still 6 days off, which is ages away for something that needs to be so precise. Forecast accuracy drops markedly after 5 days.

[Djdazzle]

1 minute ago, mb018538 said:

We probably won't really know for sure until midweek. It's still 6 days off, which is ages away for something that needs to be so precise. Forecast accuracy drops markedly after 5 days.

Agreed. Small adjustments in this setup can make big differences down the line.

What I would like to see expunged is the trend to bring in an easterly flow. The 6z seems to have bucked that.

[Geordiesnow]

As usual it's the Atlantic air that will try and deflect any heat back into Europe and the ECM shows this nicely but a small adjustment could mean this deflection takes place further northwards and the heat is further northwards again.

Ironically a larger ridge of high pressure off the Atlantic is what reducing Sundays chances of a record so instead of a Spanish plume, we got high pressure over us giving a large part of the UK hot weather but not record breaking(which in probably every other time would be ramped about). As others say, it's the Iberian low that will have a major factor if the plume happens or not and then it's the Atlantic jet that will decide how far north and west that heat will get. 

 

[qwertyK]

BBC forecast for me has gone from 35C on Sunday to 33C. I'm in southern Essex, so right in the firing line for the heatwave. More places talking about 40C being reached but they're over a day late. If the GFS continues how it has been it's less and less likely we'll break the temp record never mind get to 40C. 

[Djdazzle]

2 minutes ago, qwertyK said:

BBC forecast for me has gone from 35C on Sunday to 33C. I'm in southern Essex, so right in the firing line for the heatwave. More places talking about 40C being reached but they're over a day late. If the GFS continues how it has been it's less and less likely we'll break the temp record never mind get to 40C. 

The 6z has actually gone back more to the high temps.

[mb018538]

6z is a bit of an outlier as you'd expect - especially for how long the hotter air lasts.

[WheresTheSnow]

The last 2 or 3 GFS runs seem to have decreased this Fridays temperatures to around 23c from around 29/30c yesterday morning. I don’t have access to UKMO and ECM surface temps, does anyone know what they’re predicting for Friday? 

[bluearmy]

8 minutes ago, WheresTheSnow said:

The last 2 or 3 GFS runs seem to have decreased this Fridays temperatures to around 23c from around 29/30c yesterday morning. I don’t have access to UKMO and ECM surface temps, does anyone know what they’re predicting for Friday? 

You can if you want to 

https://www.meteociel.fr/modeles/ukmohd.php?ech=114&mode=31&map=10

https://www.meteociel.fr/modeles/ecmwf_hres.php?&ech=108&mode=9&carte=6

 

Edited July 11, 2022 by bluearmy

[mushymanrob]

1 hour ago, Mark Smithy said:

You're being a bit silly to be frank for some reason.

I'm not here to defend the GFS, nor to suggest the 6z is right, but it obviously shows a thundery breakdown on Tuesday 19th which, for some, would do more than just "moisten the ground" which was your original post before you decided to move your goalposts around: "There wont be much rain IF that Anomaly chart is accurate, i doubt itll be enough to moisten the ground."

Otherwise what you've written is a truism: summer rains rarely penetrate far or fill up reservoirs, for all sorts of reasons including vegetation.

Will this come to pass? No idea, but it's what is shown and, for some, could be fairly intense. To suggest otherwise is to allow obstinacy to get the better of you.

M8, ive worked outside (  as a gardener) for 49 years, through the summers of 75, 76, 83, 95 etc... When the ground is dry and usually hard, a thunderstorms rain will just wash off, it wont penetrate and moisten the ground below a couple of mm ... For any useful rain to relieve the drought situation many places are in... we need more that one cherry picked predicted spell of rain - and IMHO the anomaly charts do not support that. For the 8 days that mean chart covers, suggesting that "There wont be much rain IF that Anomaly chart is accurate," is a perfectly reasonable statement to make.... whether it becomes reality or not is yet to be determined and cannot be disproven with one predicted cherry picked chart that covers only a few hours.

Now that is my reasoned opinion on what the Anomaly chart i posted suggests to me.... whether its accurate/im accurate or not remains to be seen, some might agree with me, some might not, but its pointless bickering about predictive charts in that timeframe.

 

[minus10]

5 minutes ago, mb018538 said:

6z is a bit of an outlier as you'd expect - especially for how long the hotter air lasts.

Pretty good agreement on the heat up though from the 16th with op and mean together until 18th and fair number of ens topping 20 deg

[Kentspur]

41 minutes ago, qwertyK said:

BBC forecast for me has gone from 35C on Sunday to 33C. I'm in southern Essex, so right in the firing line for the heatwave. More places talking about 40C being reached but they're over a day late. If the GFS continues how it has been it's less and less likely we'll break the temp record never mind get to 40C. 

Brentwoods one of those funny places whenever I drive there my car temp drops by 2c compared to say thames side Thurrock and here in NW Kent whenever u get wet snow there in winter we get sleet or rain your more rural and elevated. Nice place but I find it very "Towie" Never seen so many people touching their hair on the same visit  

[MattStoke]

1 minute ago, bluearmy said:

You can if you want to 

WWW.METEOCIEL.FR

---

Meteociel propose le modèle deterministe de ECMWF CEP en Open-Data avec une résolution de 0.4°

 

Wouldn’t pay any attention to UKMO temperature projections. They’re very poor.

ECM is usually a few degrees too low.

[qwertyK]

1 minute ago, Kentspur said:

Brentwoods one of those funny places whenever I drive there my car temp drops by 2c compared to say thames side Thurrock and here in NW Kent whenever u get wet snow there in winter we get sleet or rain your more rural and elevated. Nice place but I find it very "Towie" Never seen so many people touching their hair on the same visit  

Most likely because it's on a hill and you clearly haven't been in years lol towie isn't even a thing round here. I'm not actually in Brentwood I'm in the town next door, Shenfield, it's usually a degree warmer here despite barely being a mile away. Think having the worst air quality in Essex after Thurrock has something to do with it 

[bluearmy]

2 minutes ago, MattStoke said:

Wouldn’t pay any attention to UKMO temperature projections. They’re very poor.

ECM is usually a few degrees too low.

Yes - just answering the poster who asked.