Model Output Discussion - Autumn arrives

[Mark Smithy]

1 hour ago, Evening thunder said:

 

It does appear the GFS was a few degrees too high for most of France, as suspected like Kold Weather was saying (since I think some of the reaction to his posts was a bit unfair..)

 

I apologise if I was being a bit unfair to Kold Weather. I had thought the GFS was overstating it and went in with an open mind but it soon seemed that criticism of the GFS's modelling was the thing wasn't entirely fair. Okay, maybe it errs a little bit on the warm side but it hasn't been that far out and was actually under for the UK today. That's all.

It's the ECM which has been really out but maybe tomorrow and Tuesday it will get it right? After all, we're talking record-breaking temperatures.

Generally I've been pretty impressed with the GFS's modelling on this heatwave.

[Paul_1978]

For the record, top temperature recorded in my garden today in Wakefield was 29.1C

Currently 27.2C at 21:27

[Phil Blake]

25 minutes ago, nick sussex said:

I was talking more in relation to that rain in the north yesterday.

The rain we had barely wet the ground in the north east

[terrier]

Well it certainly been a warm one today not looking forward to work tomorrow and Tuesday. Thankfully looking at the models we should be back into normal temps by late Wednesday. Seems like some of the models are lining up a short plume next weekend but a long way off yet. Just hope we don’t end up back in our usual summer after this heatwave. By that I mean wet and unsettled. But until then keep safe everyone and drink plenty of water. 

[nick sussex]

Looking at the Met office radar some of those showers effecting the sw and south look very heavy .

 So some people who were thinking great let’s have an evening barbecue are going to be hacked off to say the least .

A pretty poor effort from the BBC and Met Office who made no mention at all of any showers .

[kold weather]

9 minutes ago, Mark Smithy said:

I apologise if I was being a bit unfair to Kold Weather. I had thought the GFS was overstating it and went in with an open mind but it soon seemed that criticism of the GFS's modelling was the thing wasn't entirely fair. Okay, maybe it errs a little bit on the warm side but it hasn't been that far out and was actually under for the UK today. That's all.

It's the ECM which has been really out but maybe tomorrow and Tuesday it will get it right? After all, we're talking record-breaking temperatures.

Generally I've been pretty impressed with the GFS's modelling on this heatwave.

No need to apologise!

Besides the GFS isn't alone, the other high resolution models (even those that aren't using GFS as a base such as AROME) are broadly on the same page as the GFS. Its clearly a real signal and not just the GFS overdoing it due to model bias/error.

And yes, the GFS has been awesome with this spell, pretty much ran with this hot spell right from the off and never really dropped it even after the models delayed things. Even IF its forecasted temps turn out too high, its still going to be closer than the earlier ECM runs that were sticking with 32-35c range.

[Derecho]

3 minutes ago, nick sussex said:

Looking at the Met office radar some of those showers effecting the sw and south look very heavy .

 So some people who were thinking great let’s have an evening barbecue are going to be hacked off to say the least .

A pretty poor effort from the BBC and Met Office who made no mention at all of any showers .

Poor modelling I think, they only appeared on the 15z UKV from what I can see!

[Captain Shortwave]

Quite a few posts have been moved. Can we please keep to model discussion in here thanks. General comments about the weather are better suited to the regionals or the general summer thread.

[kold weather]

ICON 18z going upto 41c again on Tuesday, though more widely 38-40c. MANY stations will break the current UK all time record on Tuesday, reasonable chance that the all time record also goes tomorrow, though it will be a close call, it'll almost certainly be a 100f day regardless.

[MattStoke]

19 minutes ago, kold weather said:

ICON 18z going upto 41c again on Tuesday, though more widely 38-40c. MANY stations will break the current UK all time record on Tuesday, reasonable chance that the all time record also goes tomorrow, though it will be a close call, it'll almost certainly be a 100f day regardless.

Fairly confident the record will go tomorrow and some places will hit 39’C. Less confident about 40’C than I was.

Tuesday looks ridiculous. Large swathes of the country into the low 40s

[jam]

1 hour ago, nick sussex said:

I was talking more in relation to that rain in the north yesterday.

much further north than Red area 

[JayAlmeida]

All I see on this thread is MOGREPS this and MOGREPS that. This image springs to mind when I hear the words mog reps...

Edited July 17, 2022 by JayAlmeida

[Snowy L]

Don't know what's happened with this update but the area of high 30s is much smaller compared to 12z for Monday.

Not even a 39C. What's happened here then?

[Man With Beard]

1 minute ago, Snowy L said:

Don't know what's happened with this update but the area of high 30s is much smaller compared to 12z for Monday.

Not even a 39C. What's happened here then?

Is it because peak temps are after 3pm?

[Mizzle]

Apologies to mods for being a bit off topic but I just want to say a huge thank you to all the knowledgeable posters who have been giving their insights and sharing their wisdom over the past couple of weeks. I have learned so much and feel I have been part of something very, very special as we approach this historic meteorological event.

Am now in bed, three electric fans on the go and a cold, wet sheet hanging in front of the opened bedroom windows. It's not just the heat keeping me awake though: I feel like a kid at Christmas waiting for this plume to make its presence felt.

So thank you to all contributors, drink plenty of water, keep cool and stay safe.

[kold weather]

1 minute ago, Snowy L said:

Don't know what's happened with this update but the area of high 30s is much smaller compared to 12z for Monday.

Not even a 39C. What's happened here then?

If I I to guess it's the GFS losing its warm bias. From what I've read on average it runs about 1-1.5c too hot until about 24hrs out.

Also suspect as France wasn't as hot as forecasted by GFS that is having the effect of lowering the temps forecasted (since it was on an assumption of much higher maxes which never came off)

It looks totally in line either other models now though around the 38c mark, maybe a 39.

[bluearmy]

4 minutes ago, Snowy L said:

Don't know what's happened with this update but the area of high 30s is much smaller compared to 12z for Monday.

Not even a 39C. What's happened here then?

shown on the run to run change 

 

Edited July 17, 2022 by bluearmy

[Cheshire Freeze]

1 minute ago, kold weather said:

If I I to guess it's the GFS losing its warm bias. From what I've read on average it runs about 1-1.5c too hot until about 24hrs out.

Also suspect as France wasn't as hot as forecasted by GFS that is having the effect of lowering the temps forecasted (since it was on an assumption of much higher maxes which never came off)

It looks totally in line either other models now though around the 38c mark, maybe a 39.

Is it not forecasting more cloud than it was too?

With the largely unforecast showers this evening down south, I’m beginning to think this event may be moister than we’ve been led to believe…a tad more unstable.

Edited July 17, 2022 by CreweCold

[JayAlmeida]

2 minutes ago, CreweCold said:

Is it not forecasting more cloud than it was too?

As others have pointed out previously the GFS is pretty bad when it comes to cloud forecasts even a day out.

[Snowy L]

2 minutes ago, CreweCold said:

Is it not forecasting more cloud than it was too?

With the largely unforecast showers this evening down south, I’m beginning to think this event may be moister than we’ve been led to believe…a tad more unstable.

Yes, looks like more luck has come into the equation now with more high and even medium level cloud in the forecast, somewhere will have to stay mostly sunny for the record to go. It's never a straightforward sunny day with the UK!

[kold weather]

7 minutes ago, CreweCold said:

Is it not forecasting more cloud than it was too?

With the largely unforecast showers this evening down south, I’m beginning to think this event may be moister than we’ve been led to believe…a tad more unstable.

Certainly could be that as well. 

I suspect a similar thing might happen for Tuesday as well fwiw, where we lose maybe 1c from the max current forecast, bit we will see, still leaves us in the 40c ballpark.

Edit - not so much more cloud, but the thin high cloud is somewhat further east compared to the 12z.

Edited July 17, 2022 by kold weather

[Mapantz]

GFS shows high cloud for Monday and Tuesday. Whether that happens, it remains to be seen.

Monday:

Tuesday:

[JayAlmeida]

GFS 18z wants Tuesday as the hottest day whereas the BBC is adamant that the peak is tomorrow. 

Much more widespread heat all the way up the North Sea coast.

 

Edited July 17, 2022 by JayAlmeida

[ChezWeather]

18z UKV has a vast swathe of 39/40 across the country, even a few 42s in Lincs

 

It also shows some areas not dropping below 28c Monday night into Tuesday, completely eclipsing the old night min record

[nick sussex]

Arpege has some early morning cloud tomorrow  , this clears to leave  most areas sunny .