Model Output Discussion - Autumn arrives

[mb018538]

Those sick of the heat...let's have a look at a potential saviour from last nights ECM update. We have troughing over the UK showing by the 25th July. The MJO is shown to perhaps cycle out to phase 2/3 around that time - which tends to correspond well to what the ECM is showing on the RMM plots for 2/3 around the last week in July.

Edited July 12, 2022 by mb018538

[SunnyPlease]

I remember that my birthday (21st July) was showing as pretty much green on both the GFS and ECM on a previous run suggesting lower pressure and cool. Thankfully that's absent now and both show continuation of a warm flow to that date and beyond.

I don't expect a constant 30c+ as that's unrealistic, but just wanted a continuation of settled and warm conditions ala 2018, rather than an atypical short plume followed by muck. Thankfully the former is looking a good possibility.

[Guest]

GFS is pretty insane this morning, has 30C achievable everyday from Saturday until the end of the run and barely any breakdown in the south. 

[mb018538]

ECM slightly less hot than the other runs this morning, with not as much of a southerly component, and the heat a tad slower to build in.
As such 30c is the high on Sunday, and around 34c on Monday (slight easterly setting in later on Monday which shows in EA, but it's still bloody hot):


 

Edited July 12, 2022 by mb018538

[Mark Smithy]

30 minutes ago, SunnyPlease said:

I mean the most recent run of the ECM and GFS. Both were showing lower pressure and a big absence of warm isotherm on their previous runs. Both have backtracked on that now and high pressure/warm flow is shown on both suites right through the run.

I guess the point being made was that you wrote: 'Thankfully the ECM and GFS have rather backtracked from the breakdown they showed yesterday'. But the ECM chart to which you were referring was yesterday's 12z. It's not a big deal

Anyway, the 0z ECM is up to T144 as I type and the hottest of the 850hPa plume is slower to arrive. Here's 12h00 Monday:

On yesterday's 12z:

On today's 0z:

 

But boy oh boy, when it does arrive! This is Tuesday and it looks to me seriously hot:

[ChannelThunder]

7 hours ago, danm said:

Heat Low - isn’t that what forms annually over the Indian subcontinent during their hot season, which then drives the onshore winds which result in the SW Monsoon? 

When did we last have a heat low form over the UK?

7 hours ago, Don said:

Possibly never?  Times are changing.....

We had one in August 2020. What a mad, tropical week that was.

[Mark Smithy]

That 0z ECM makes Tuesday the furnace day.

Scorchio.

[bluearmy]

Looking a tad complicated 

how much of a e/se surface wind component will we  have with the highest uppers? 
Ukmo and now ec how this with consequential suppressed maxes. 

 

 

[bluearmy]

3 minutes ago, Mark Smithy said:

That 0z ECM makes Tuesday the furnace day.

Scorchio.

Fronts headed in from the sw will likely cap Tuesday on this run (35 c in Yorks) 

[MattStoke]

5 minutes ago, Mark Smithy said:

I guess the point being made was that you wrote: 'Thankfully the ECM and GFS have rather backtracked from the breakdown they showed yesterday'. But the ECM chart to which you were referring was yesterday's 12z. It's not a big deal

Anyway, the 0z ECM is up to T144 as I type and the hottest of the 850hPa plume is slower to arrive. Here's 12h00 Monday:

On yesterday's 12z:

On today's 0z:

 

But boy oh boy, when it does arrive! This is Tuesday and it looks to me seriously hot:

2nd chart is 2am, so 10 hours earlier than the first chart. Hard to tell then if it is slower to arrive. Have to see what the higher resolution version shows.

[Mark Smithy]

Interesting comments above about monsoon pattern low pressure heat. Is that what happens in Thailand during March / April? Heat and humidity builds under sunny hazy skies with temps often widely 40C or higher. It gets staggering, unbearably, hot and humid. Then the SW monsoon comes and gradually cools things down through May onwards.

[mb018538]

Just now, bluearmy said:

Fronts headed in from the sw will likely cap Tuesday on this run (35 c in Yorks) 

Tuesday on the ECM is battle between the hot air and rapidly approaching cooler air on the developing low. 

[Man With Beard]

2 hours ago, Porto said:

From a very quick look at the 00z GFS members, it almost looks like more of the members now believe Tuesday could end up being the hottest day, although the entire period of Sunday-Tuesday is quite hot on all of them.

 

The split between the members purely just seems to be a disagreement of how quickly that low moves in over everything.

I'm not sure all these pushbacks are good for confidence in the event, and make me wonder if the Met Office have gone slightly early on this (even if they are eventually proved right). 

Extreme weather events tend to have a window in which to happen, and if they don't happen within that window, then they often don't happen at all.

The models are progressively removing extreme heat from Sunday (could still change back), which means we remain at T144 and beyond for the heat. In a cut off low situation, that's miles away.

One very plausible way the main heat could miss entirely is by the cut-off low being slower and the heat all goes out past the Isles of Scilly into the Atlantic.

Don't get me wrong, I still very much think the plume is the main solution on offer, but I just see that it is not without potential to miss, just yet. It needs to get consistently within T120 first.

[Staffmoorlands]

ECM and UKMO not showing any record heat this morning. In fact the UKMO suggests a cloudy weekend whilst the ECM has rain pushing in on Tuesday.

 

[mb018538]

6 minutes ago, Man With Beard said:

I'm not sure all these pushbacks are good for confidence in the event, and make me wonder if the Met Office have gone slightly early on this (even if they are eventually proved right). 

Extreme weather events tend to have a window in which to happen, and if they don't happen within that window, then they often don't happen at all.

The models are progressively removing extreme heat from Sunday (could still change back), which means we remain at T144 and beyond for the heat. In a cut off low situation, that's miles away.

One very plausible way the main heat could miss entirely is by the cut-off low being slower and the heat all goes out past the Isles of Scilly into the Atlantic.

Don't get me wrong, I still very much think the plume is the main solution on offer, but I just see that it is not without potential to miss, just yet. It needs to get consistently within T120 first.

I mentioned this yesterday - the extreme warning for Sunday could be a tad early. If you look at the GFS ensembles the 850 mean for the start of Sunday is around 12c, rising through the day (which is lower than it is now). It's the only model showing 33c for Sunday - ECM, MetO and GEM are much lower. Is it going to be worthy of that extreme heat warning? 

[JayAlmeida]

GFS now struggling to hit 40 now in the south but steadfast in bringing more widespread heat to England. In the NW the GFS 00z is showing 37c possible next Monday and 38c possible next Tuesday. 

The likelihood of those temperatures is still pretty low but interesting nonetheless (especially with today's wobbles). Those temps would smash the current records for Liverpool (34.5 in 1990) and Manchester (33.7 in 1976).

All the amazing hot spells we've had over the years and those temperatures have stood for 32 and 46 years respectively.

Edited July 12, 2022 by JayAlmeida

[Singularity]

ECM 00z shows what may happen if an Atlantic low merges with the heat low over the UK. However, most modelling has other ideas, so it’s best viewed with a pinch of salt.

[mushymanrob]

56 minutes ago, mb018538 said:

Those sick of the heat...let's have a look at a potential saviour from last nights ECM update. We have troughing over the UK showing by the 25th July. The MJO is shown to perhaps cycle out to phase 2/3 around that time - which tends to correspond well to what the ECM is showing on the RMM plots for 2/3 around the last week in July.

And this chart is in the same ball park...
 

[MattStoke]

Too be fair, the ECM ens have always had the peak plume around the 18th/19th whilst the ops and GFS have been more progressive.

[bluearmy]

12 minutes ago, Man With Beard said:

I'm not sure all these pushbacks are good for confidence in the event, and make me wonder if the Met Office have gone slightly early on this (even if they are eventually proved right). 

Extreme weather events tend to have a window in which to happen, and if they don't happen within that window, then they often don't happen at all.

The models are progressively removing extreme heat from Sunday (could still change back), which means we remain at T144 and beyond for the heat. In a cut off low situation, that's miles away.

One very plausible way the main heat could miss entirely is by the cut-off low being slower and the heat all goes out past the Isles of Scilly into the Atlantic.

Don't get me wrong, I still very much think the plume is the main solution on offer, but I just see that it is not without potential to miss, just yet. It needs to get consistently within T120 first.

I think they’re as concerned about the overnight temps as they are the daytime. Many people live in flats which just don’t cool down. In addition, areas in the n of England look like they will be reaching levels they simply never have. 
 

I guess their confidence that we won’t miss the plume completely is behind going early - better to get it into peoples minds and then push it back a day 

[Derecho]

23 minutes ago, Man With Beard said:

I'm not sure all these pushbacks are good for confidence in the event, and make me wonder if the Met Office have gone slightly early on this (even if they are eventually proved right). 

Extreme weather events tend to have a window in which to happen, and if they don't happen within that window, then they often don't happen at all.

The models are progressively removing extreme heat from Sunday (could still change back), which means we remain at T144 and beyond for the heat. In a cut off low situation, that's miles away.

One very plausible way the main heat could miss entirely is by the cut-off low being slower and the heat all goes out past the Isles of Scilly into the Atlantic.

Don't get me wrong, I still very much think the plume is the main solution on offer, but I just see that it is not without potential to miss, just yet. It needs to get consistently within T120 first.

Agreed, this is the first day I could really say those mentioning the word downgrade have a point. Monday is the perfect day for the record to go if that plume pushes up from the south but the high pressure is too slow to relax its grip. We now have to wait yet another 24 hours for the peak of the plume and with a SE wind on Tuesday the risk of a spanner in the works is notably higher.

Firstly a breeze off the North Sea could come into play. Second we could end up with loads of cloud pushing up from the south on Monday night and 3rd a SE wind and low pressure pushing up tends to be conductive for thunderstorm development which the models won't have a grip on yet.

If the models are showing the same on Thursday I don't believe the record will go. GFS ens have also come in a bit cooler this morning.

14 minutes ago, Staffmoorlands said:

ECM and UKMO not showing any record heat this morning. In fact the UKMO suggests a cloudy weekend whilst the ECM has rain pushing in on Tuesday.

 

GFS and UKMO cloud parameters are garbage, there is no way this weekend will be cloudy!

Edited July 12, 2022 by Quicksilver1989

[Mark Smithy]

9 minutes ago, Staffmoorlands said:

ECM and UKMO not showing any record heat this morning. In fact the UKMO suggests a cloudy weekend whilst the ECM has rain pushing in on Tuesday.

 

Yes ECM does show some decent rain potential for Tuesday: HALLELUJAH!! We badly need rain and I love a torrential tropical downpour.

 

BUT the ECM then shows the Azores high rebuilding over the UK. Anyone hoping for a pattern change had better look away now:

 

Edited July 12, 2022 by Mark Smithy

[mb018538]

3 minutes ago, Mark Smithy said:

Yes ECM does show some decent rain potential for Tuesday: HALLELUJAH!! We badly need rain and I love a torrential tropical downpour.

 

BUT the ECM then shows the Azores high rebuilding over the UK. Anyone hoping for a pattern change had better look away now:

 

Nothing more than a splash across most of central and E/SE England that really need it though....and after a few days in the 30s, a couple of mm of rain will evaporate in minutes.

[MattStoke]

All 3 of the main models have the heat well across the U.K. during Monday, as they did yesterday so not not sure where this talk of it being pushed back is coming from.

[bluearmy]

9 minutes ago, MattStoke said:

All 3 of the main models have the heat well across the U.K. during Monday, as they did yesterday so not not sure where this talk of it being pushed back is coming from.

The 20c isotherm is arriving overnight into Monday morning whereas yesterdays runs had it here later on Sunday.  This is a continuation of push backs of its arrival - originally it was supposed to be here on Saturday!