Model Output Discussion - Autumn arrives

[minus10]

Last one from me as have to get to work...but hey bbc look what bbc now ssying for sunday..

Edit...Mark just beat me to it...

Edited June 16, 2022 by minus10

[mb018538]

22 minutes ago, Mark Smithy said:

Interesting BBC / MeteoGroup forecast just out. They are very much sticking with heat in the south-east, amazing temperature gradients and lively thundery breakdown with heavy rain Saturday / Sunday.

Saturday:

Sunday:

Sorry - but I think this is going to go down as one of the worst forecasts of all time. 33c Saturday and Sunday? There isn’t one model showing anything close to this! UKV and ARPEGE showing around 20-21c maxima on Sunday.

Fax chart for Sunday shows the 564 line and frontal boundary separating the cooler and hotter air is the wrong side of the UK. 33c? Yeah ok then…

[Mark Smithy]

33 minutes ago, minus10 said:

Last one from me as have to get to work...but hey bbc look what bbc now ssying for sunday..

Edit...Mark just beat me to it...

Yes and in my opinion, others may disagree, they rarely get things like this spectacularly wrong at such close range. They did say that there was 'some uncertainty over the position of the rain band' Saturday but they seem pretty convinced of the essentials: heat in the south east ('up to 33C in the far south-east Sunday'), steep temperature gradients, and plenty of rain.

Bet against at your peril!

Edited June 16, 2022 by Mark Smithy

[Paul]

The BBC use the ECMWF, to bring this back to model discussion. It's out on its own to an extent currently when it comes to Saturday, with most other models pushing the front through more quickly.

[Mike Poole]

40 minutes ago, Mark Smithy said:

Yes and in my opinion, others may disagree, they rarely get things like this spectacularly wrong at such close range. They did say that there was 'some uncertainty over the position of the rain band' Saturday but they seem pretty convinced of the essentials: heat in the south east ('up to 33C in the far south-east Sunday'), steep temperature gradients, and plenty of rain.

Bet against at your peril!

Looks like they are majoring on the ECM 0z to me, here T72:

ECM isn’t the best for short range stuff, so I’m sceptical given other model output.

Edit: @Paul beat me to it!

Edited June 16, 2022 by Mike Poole

[StormChaseUK]

1 hour ago, minus10 said:

Last one from me as have to get to work...but hey bbc look what bbc now ssying for sunday..

Edit...Mark just beat me to it...

Looks like Saturday chart error, it certainly won't be 33C Sunday 

[MATTWOLVES 3]

1 hour ago, minus10 said:

Last one from me as have to get to work...but hey bbc look what bbc now ssying for sunday..

Edit...Mark just beat me to it...

I pointed out the other week that I felt the met and Beeb had been pretty poor with their forecasts over the last few weeks,especially regarding the surface details over a few days. And these long range forecasts have been changing on a daily basis to include every weather type imaginable!

For instance there thoughts last week on a NW/SW Split is now clearly indicated on the gfs 6z mean...Heights to the SW and a trough too our NE. But the bigboys appear to have dropped that option now!

Moving forward its the Gem that looks the most settled so I'm hoping that is closer to the mark. The ECM looks pretty poor further ahead and its not really that big an outlier.

Enjoy the heat if you've got it and it's your thing...a band of rain sinks south this weekend and marks the boundary line ofmuch cooler conditions....How much rain and where is not yet nailed down...as very often in these set ups,somewhere as a deluge and just a few miles down the road gets nothing.

So if its precipitation or perspiration that's your thing your bound to get one or the other this Weekend

 

[Methuselah]

57 minutes ago, mb018538 said:

Sorry - but I think this is going to go down as one of the worst forecasts of all time. 33c Saturday and Sunday? There isn’t one model showing anything close to this! UKV and ARPEGE showing around 20-21c maxima on Sunday.

Fax chart for Sunday shows the 564 line and frontal boundary separating the cooler and hotter air is the wrong side of the UK. 33c? Yeah ok then…

But not as bad as all those 'summer is doomed' posts -- from only a week or so back, eh?

[knocker]

31 minutes ago, Mike Poole said:

Looks like they are majoring on the ECM 0z to me, here T72:

ECM isn’t the best for short range stuff, so I’m sceptical given other model output.

Edit: @Paul beat me to it!

I am not sure that I'm following much of this as the ecm is pusihng the front through early Saturday afternnon

Edited June 16, 2022 by knocker

[sheikhy]

Ecm out on its own for now with how far north the front gets!!

[Paul]

On 16/06/2022 at 10:27, knocker said:

I am not sure that I'm following much of this as the ecm is pusihng the front through early Saturday afternnon

It keeps it further north a bit longer though, which keeps a bit of heat in the south for longer that in turn triggers more precip / possibly storms than the other models currently. Most of which have the front far enough south to suppress temperatures further and limit convective development. 

[bluearmy]

The beeb forecast shown above for 33c in the se on Sunday has no basis on either ec op 18z or ec 00z.  

[MKN]

4 minutes ago, bluearmy said:

The beeb forecast shown above for 33c in the se on Sunday has no basis on either ec op 18z or ec 00z.  

Their latest forecast showed 26c in London on Saturday and 20c on Sunday so nothing like the 33c for Sunday shown earlier. 

[Paul]

It's a pretty subtle difference between the ECM and MetOffice models looking at it more closely. The ECM has the 10c line maybe 50 miles further north and the 15c line not even that. It does have a sharper gradient than the Met Office though, which I assume is what peps up the rain a bit more and a bit further north. 

Don't have a UK only ECM view, but these are for the same time ECM on the left, Meto on the right. 

 

Prec differences - again apples and oranges a bit here, as it's a total to that point on the ecm, but all of the prec from the midlands south is from Friday night onwards. It's further north on the ECM with probably 50% higher totals in places than the UKV.  (ECM on the left)

 

[sheikhy]

4 minutes ago, bluearmy said:

The beeb forecast shown above for 33c in the se on Sunday has no basis on either ec op 18z or ec 00z.  

Also gfs continues on from the 00z!!hardly any rain for most places!!gfs is actually looking very nice up to 96 hours so far!!we might have just got away with what would have been a heck of a lot of rainfall!!ukv 06z tops me out at 33 degrees tomorrow!looks like there has defo been a shift west and north of the heat compared to the ukv runs from yesterday!

[mb018538]

1 hour ago, Ed Stone said:

But not as bad as all those 'summer is doomed' posts -- from only a week or so back, eh?

Who said summer was doomed?

[Djdazzle]

7 minutes ago, Paul said:

It's a pretty subtle difference between the ECM and MetOffice models looking at it more closely. The ECM has the 10c line maybe 50 miles further north and the 15c line not even that. It does have a sharper gradient than the Met Office though, which I assume is what peps up the rain a bit more and a bit further north. 

Don't have a UK only ECM view, but these are for the same time ECM on the left, Meto on the right. 

 

Prec differences - again apples and oranges a bit here, as it's a total to that point on the ecm, but all of the prec from the midlands south is from Friday night onwards. It's further north on the ECM with probably 50% higher totals in places than the UKV.  (ECM on the left)

 

As much as I don't rate the BBC forecasts, it shows what difference a small shift can make.

Although unlikely, I wouldn't want to bet too much money against Saturday being very hot in the SE.

[knocker]

22 minutes ago, Paul said:

It keeps it further north a bit longer though, which keeps a bit of heat in the south for longer that in turn triggers more precip / possibly storms than the other models currently. Most of which have the front far enough south to suppress temperatures further and limit convective development. 

It has it in the same position as the METO and yes it becomes a tad more active

But I would have thought the more convective activity down to the upper trough engaging with the cut off low and the extreme temp gradient to the east which could bring some heavy rain to the south west

 

 

Edited June 16, 2022 by knocker

[Paul]

On 16/06/2022 at 11:22, knocker said:

It has it in the same position as the METO and yes it becomes a tad more active

 

I posted a few charts above to illustrate what I was getting at. But yes, very little in it position wise - albeit on the meto global charts there is one. I didn't look at the fax to compare. 

[minus10]

Yes...a correction now by the bbc...

Still stressing the uncertainty...

[Supacell]

BBC latest forecast more sensible now with 27⁰c max on Saturday in the SE and then 20⁰c max on Sunday.

Edit: Minus10 beat me to it.

BBC still showing thundery downpours over the weekend though. But as we know, this will be based on the ECM 0z output. So uncertainty remains.

Edited June 16, 2022 by Supacell

[Guest]

17 minutes ago, minus10 said:

Yes...a correction now by the bbc...

Still stressing the uncertainty...

Bit embarrassing that really.

[Paul]

We need to get back to discussing the models rather than tv forecasts on here please. 

[StormChaseUK]

The 06z does a Jim Bowen "this is what you could have won" if we didnt have that NW front this weekend.

[MattStoke]

1 hour ago, Paul said:

We need to get back to discussing the models rather than tv forecasts on here please. 

To be fair, discussing the BBC forecasts is the same as discussing the ECM output.

Doesn’t matter how many times it’s pointed out that the BBC just mirrors the ECM, people still get hung up on it.