Model Output Discussion - Autumn arrives

[SunnyPlease]

Even if we were to get that cloud and rain ,which is extremely unlikely, with a 20-25c isothern and 576 thickness, it would still be into the low 30's at least. That UKMO is a joke, as it often is in certain runs at longer range.

[mb018538]

3 minutes ago, SunnyPlease said:

Even if we were to get that cloud and rain ,which is extremely unlikely, with a 20-25c isothern and 576 thickness, it would still be into the low 30's at least. That UKMO is a joke, as it often is in certain runs at longer range.

It’s horrific for temps. Look at the 12z run for this afternoon. It has 27c for me (Cambridge) when it was 32c today. Always miles off.

[kold weather]

7 minutes ago, SunnyPlease said:

Even if we were to get that cloud and rain ,which is extremely unlikely, with a 20-25c isothern and 576 thickness, it would still be into the low 30's at least. That UKMO is a joke, as it often is in certain runs at longer range.

What sort of temperatures would you expect from this:

This is the max temps for the day:

Not just always about the 850hpa profile or even the thickness, if there is a frontal zone and lots of cloud it will surpress temperatures.

In the above example there was a ENE surface flow.

Not saying the UKMO is right, but I wouldn't just throw it into the bin because it has a different temperature profile.

FWIW - the flow switched SE the day afterwards and we got to 34c.

[Derecho]

6 minutes ago, SunnyPlease said:

Even if we were to get that cloud and rain ,which is extremely unlikely, with a 20-25c isothern and 576 thickness, it would still be into the low 30's at least. That UKMO is a joke, as it often is in certain runs at longer range.

In terms of broader scale patterns it is up there with EC but for some surface parameters it's not very good. UKV is better for that kind of thing.

Based on the output I think there is an increasing chance the record will go on Sunday and Monday. The 06z MOGREPS were more progressive with the heat. EC 00z was close for intensity but earlier GFS output was less hot believe it or not.

Big EC run coming up.

[Geordiesnow]

I'm not buying into too much in that UKMO run either, I do think the 96 hour chart might be more 'wetter' than meets the eye so I can buy maybe Saturday being cloudier than the chart may suggest but not by Sunday surely, the strong flow will push the cloud northwards. 

One thing with the UKMO though with the stronger flow, it could mean less likely of a record because of more wind mixing the air but any warmth should be more widespread(e.g even into Scotland!). 

[kold weather]

3 minutes ago, Quicksilver1989 said:

In terms of broader scale patterns it is up there with EC but for some surface parameters it's not very good. UKV is better for that kind of thing.

Based on the output I think there is an increasing chance the record will go on Sunday and Monday. The 06z MOGREPS were more progressive with the heat. EC 00z was close for intensity but earlier GFS output was less hot believe it or not.

Big EC run coming up.

MOGREPS was quite abit more progressive, the GFS 12z ensembles also had a few more runs than previously moving things in (and out) faster.

Have you seen the 12z GFS ensembles, they are absolutely mad!

[Geordiesnow]

3 minutes ago, kold weather said:

What sort of temperatures would you expect from this:

This is the max temps for the day:

Not just always about the 850hpa profile or even the thickness, if there is a frontal zone and lots of cloud it will surpress temperatures.

In the above example there was a ENE surface flow.

Not saying the UKMO is right, but I wouldn't just throw it into the bin because it has a different temperature profile.

FWIW - the flow switched SE the day afterwards and we got to 34c.

In fairness, the models were predicting the lower temperatures than one might expect back then, we all doubted the GFS predictions at the time but they proved to be correct. 

At least on the GFS runs, the flow is that slack, what the uppers show will reflect in the actual heat.

 

[Howie]

2 minutes ago, kold weather said:

MOGREPS was quite abit more progressive, the GFS 12z ensembles also had a few more runs than previously moving things in (and out) faster.

Have you seen the 12z GFS ensembles, they are absolutely mad!

Do you have the ensembles chart?

[Derecho]

4 minutes ago, kold weather said:

MOGREPS was quite abit more progressive, the GFS 12z ensembles also had a few more runs than previously moving things in (and out) faster.

Have you seen the 12z GFS ensembles, they are absolutely mad!

Indeed, I think a few days ago I said I expected mid-high 30s to be more realistic (something like 37C)... but if this EC comes in with a real scorcher then the pendulum may swing to something more extreme...

Edited July 11, 2022 by Quicksilver1989

[Sainsbo]

I could be wrong, but I'd think that global models like the UKMO will have some large biases in surface temperature in circumstances where you have a high airmass temperature but some cloud around. Model resolution likely isn't high enough to resolve many of the breaks in the cloud, and you'll end up with a more uniform layer of cloud being modelled than we would see in reality.

 

With 20C+ 850hPa temperatures and strong solar heating, the temperature would respond very quickly in cloud breaks, and this is probably isn't going to be captured in the model.

[mb018538]

13 minutes ago, kold weather said:

What sort of temperatures would you expect from this:

This is the max temps for the day:

Not just always about the 850hpa profile or even the thickness, if there is a frontal zone and lots of cloud it will surpress temperatures.

In the above example there was a ENE surface flow.

Not saying the UKMO is right, but I wouldn't just throw it into the bin because it has a different temperature profile.

FWIW - the flow switched SE the day afterwards and we got to 34c.

The UKMO run is hindered by cloud and rain though on Sunday. Plus as I’ve shown today, it can’t even get a temperature right when it’s a 12z run on the day it’s forecasting (4-5c error here). Don’t buy that rain and cloud at all. 
UKV is much better (probably the best temperature prediction model as it’s hi res and shorter range).

[Methuselah]

3 minutes ago, mb018538 said:

The UKMO run is hindered by cloud and rain though on Sunday. Plus as I’ve shown today, it can’t even get a temperature right when it’s a 12z run on the day it’s forecasting (4-5c error here). Don’t buy that rain and cloud at all. 
UKV is much better (probably the best temperature prediction model as it’s hi res and shorter range).

All things considered, MB, I think we could all do with some rain -- more than triple-digit (Fahrenheit scale) temperatures -- right now?

[mb018538]

1 minute ago, Ed Stone said:

All things considered, MB, I think we could all do with some rain -- more than triple-digit (Fahrenheit scale) temperatures -- right now?

That we could…even that dodgy ukmo run is only spits and spots though. No signs of anything prolonged yet ‍

[minus10]

Gfs ens 12z (wgc)

[bluearmy]

38 minutes ago, kold weather said:

GFS 12z ensembles are INSANE in terms of heat, again the hottest I've ever seen.

Out of 31 ensemble runs, 18 have maxes of *37* or higher at some point in their run.

Over half have at least near record breaking temperatures.

Most of others are now reaching 33-35c, and just a few manage to only reach 28-30c.

Gefs and geps are on the rise

mondays mean max 34 and 33 respectively 

Have we seen the max swing back of the pendulum  which places a baseline of 30/31 at the bottom end and a top line of 38/39 ?  if so, we may now hone in on a solution somewhere between these values

ive asked the question but I think it’s a bit too early to be doing this as we haven’t settled on how the surface low, upper low, upper ridge and surface highs are likely to interact yet. 

 

 

 

[MattStoke]

2 minutes ago, minus10 said:

Gfs ens 12z (wgc)

That looks like a big cluster well above the mean.

[Man With Beard]

30 minutes ago, kold weather said:

What sort of temperatures would you expect from this:

This is the max temps for the day:

Not just always about the 850hpa profile or even the thickness, if there is a frontal zone and lots of cloud it will surpress temperatures.

In the above example there was a ENE surface flow.

Not saying the UKMO is right, but I wouldn't just throw it into the bin because it has a different temperature profile.

FWIW - the flow switched SE the day afterwards and we got to 34c.

It is totally alone though in comparison with all the other charts, ops and ens, and clearly the METO don't buy it either. Probably safe to ignore considering it has zero support.

[Cambrian]

GFS 12z run for next Monday, at only day 7 now - the hottest ensemble member, P13, is diabolical. The op looks challenging too, but if we have to go through that, do you think it’ll be too much to ask for some occasional wafts from P9 ?

  

[Cheshire Freeze]

FWIW there is a precip signal in the GEFS for Sunday

I wouldn't rule out a muggy, hot and unbearable day.

[Guest]

2 minutes ago, CreweCold said:

FWIW there is a precip signal in the GEFS for Sunday

I wouldn't rule out a muggy, hot and unbearable day.

It could well be muggy if we get any cloud cover. In terms of precipitation it looks restricted to the far northwest, with those lighter blues meaningless on such a low res chart.

[bluearmy]

2 minutes ago, CreweCold said:

FWIW there is a precip signal in the GEFS for Sunday

I wouldn't rule out a muggy, hot and unbearable day.

Tbh, there wasn’t much precip on the Ukmo run - just seemed at odds with the pressure chart but as Kold mused, has to be a warm front in there but no way wouldn’t it clear and leave v hot sunshine in the continental flow that follows. 

[CoxR]

 

[Methuselah]

8 minutes ago, CreweCold said:

FWIW there is a precip signal in the GEFS for Sunday

I wouldn't rule out a muggy, hot and unbearable day.

As the Obersturmbahnfuhrer-SS said to the actress: I vill believe zat ven I zee it!

[mb018538]

ECM gearing up to be a hot one…

[kold weather]

Warm front is on the 12z ECM overnight Saturday-Sunday though not nearly as much coverage as on the UKMO and somewhat different orientation, and so its not the biggest issue in terms of pushing temperatures down too much.

Hot on Sunday, but probably setting up very hot on Monday.