Model Output Discussion - Autumn arrives

[Captain Shortwave]

No surprise to see the ECM follow the other models on the 12z suite. Things might swing the other way in the morning, or of course shift further east again.

Still looking for a decent band of frontal rain though, again the precipitation is driven primarily from convection, either surface based or elevated. The ECM doesn’t have a particularly large window for showers as it looks like the Azores high will ridge across us again.

Edited August 10, 2022 by Captain Shortwave

[Singularity]

Interesting that we still have the low dropping well to the southwest - that change seen in the 00z runs has persisted - but a stronger jet stream has provided a counter on the 12z model runs, most of all UKM, least ECM. 

It drives cooler air aloft which allows the heat low to develop more as its own entity during Mon-Tue rather than becoming a mere ‘lobe’ to the south-western low.

So, now we wait to see if that change is held onto.

[Cheshire Freeze]

24 minutes ago, Captain Shortwave said:

No surprise to see the ECM follow the other models on the 12z suite. Things might swing the other way in the morning, or of course shift further east again.

Still looking for a decent band of frontal rain though, again the precipitation is driven primarily from convection, either surface based or elevated. The ECM doesn’t have a particularly large window for showers as it looks like the Azores high will ridge across us again.

Thankfully the Azores HP doesn’t get a foothold past that point and the LP to the NW drives the flow.

By D10 we’re getting towards late August and any HP will begin to struggle to assert as easily as the jet stream slowly begins to awaken from its mid summer slumber. 

[Man With Beard]

17 minutes ago, Singularity said:

Interesting that we still have the low dropping well to the southwest - that change seen in the 00z runs has persisted - but a stronger jet stream has provided a counter on the 12z model runs, most of all UKM, least ECM. 

It drives cooler air aloft which allows the heat low to develop more as its own entity during Mon-Tue rather than becoming a mere ‘lobe’ to the south-western low.

So, now we wait to see if that change is held onto.

Someone said this morning, shades of a typical winter situation where a low tries to breakthrough heights to the east, only to fail and sink SW. In those situations, once the trend to keep the low further SW begins, it almost always trends further in that direction between D6 and D3. Will the same happen here?

Interesting this summer that the GFS and ECM have often moved in tandem - first this morning, now tonight with a slight correction back to yesterday's plan.

[Mark Smithy]

GFS overbaked today's cake by 2C pretty much across the board and with its operational still out of line with almost all of its own members and all the Euro models, it looks like this time it is overstating this week by around 2C for the majority. Some isolated places may reach 35C or 36 but they will be exception.

Looking ahead and there is now good model consensus amongst the Euros and most GFS members for the breakdown to start Sunday evening.

As I have been stating, the devil will be in the detail for precipitation but the omens are excellent for some much needed rain. The ECM is a thing of beauty for those of us who would prefer now to see parched ground revived, rivers filled and wildlife given a chance once more:

 

 

[MattStoke]

6 minutes ago, Mark Smithy said:

GFS overbaked today's cake by 2C pretty much across the board and with its operational still out of line with almost all of its own members and all the Euro models, it looks like this time it is overstating this week by around 2C for the majority. Some isolated places may reach 35C or 36 but they will be exception.

Looking ahead and there is now good model consensus amongst the Euros and most GFS members for the breakdown to start Sunday evening.

As I have been stating, the devil will be in the detail for precipitation but the omens are excellent for some much needed rain. The ECM is a thing of beauty for those of us who would prefer now to see parched ground revived, rivers filled and wildlife given a chance once more:

 

 

GFS had a high of 31°C. The high was 31°C, at 6 different locations.

You really just hope cast a lot.

Edited August 10, 2022 by MattStoke

[Sunny76]

On 09/08/2022 at 06:28, CreweCold said:

Thankfully we’re starting to see the effects of longer nights in the overnight temperature projections. Yep, still low 20s possible to midnight but the GFS min temperatures show a drop off to 16-17c for most towards dawn. Even 3 weeks ago that wouldn’t have happened.

Another tell tale sign we’re headed towards the back end of the season is in the ebb and flow of the 850s. Run the 850s on Meteociel and watch how the highest 850 temperatures retreat overnight then build up again through the day. Again, 3-4 weeks ago that wouldn’t have happened, 850s were unaffected by diurnal cooling.

The last gasps of high summer are coming.

Late summer starts on the 15th of august, so next week will be the starting point for the end of high summer and the late summer feel takes over.

[clark3r]

7 minutes ago, Mark Smithy said:

GFS overbaked today's cake by 2C pretty much across the board and with its operational still out of line with almost all of its own members and all the Euro models, it looks like this time it is overstating this week by around 2C for the majority. Some isolated places may reach 35C or 36 but they will be exception.

Looking ahead and there is now good model consensus amongst the Euros and most GFS members for the breakdown to start Sunday evening.

As I have been stating, the devil will be in the detail for precipitation but the omens are excellent for some much needed rain. The ECM is a thing of beauty for those of us who would prefer now to see parched ground revived, rivers filled and wildlife given a chance once more:

 

 

Have to disagree with you, there is not cross model agreement for a breakdown late Sunday  it is very uncertain at the moment. 

[mb018538]

12 minutes ago, Mark Smithy said:

GFS overbaked today's cake by 2C pretty much across the board and with its operational still out of line with almost all of its own members and all the Euro models, it looks like this time it is overstating this week by around 2C for the majority. Some isolated places may reach 35C or 36 but they will be exception.

Looking ahead and there is now good model consensus amongst the Euros and most GFS members for the breakdown to start Sunday evening.

As I have been stating, the devil will be in the detail for precipitation but the omens are excellent for some much needed rain. The ECM is a thing of beauty for those of us who would prefer now to see parched ground revived, rivers filled and wildlife given a chance once more:

 

 

It didn’t really. A quick check shows a large area of 30-31c, and a couple of 32s. We didn’t reach 32, (31.2c) but it a good representation of what was recorded. Not sure what your agenda is!

[Singularity]

For the far south of the UK the ECM 12z offers some heavy showers and thunderstorms moving north-eastward on Monday with a suggestion of organisation to them.

After that it’s mainly dry and warm for the region, so not a great outcome for tackling the drought.

GFS managed to bring a small disturbance across the far south Tue-Wed with some longer spells of rain, although they mainly miss the very far south and southeast.

Thankfully this is all far enough ahead in time that the details are likely to change, hopefully for the better!

[Scorcher]

11 minutes ago, mb018538 said:

It didn’t really. A quick check shows a large area of 30-31c, and a couple of 32s. We didn’t reach 32, (31.2c) but it a good representation of what was recorded. Not sure what your agenda is!

His agenda is an odd one- seems to be in complete denial.

There is no consensus about a breakdown at all- the models are still chopping and changing for Monday and the heat could still continue into Monday and Tuesday.

I also highly doubt the GFS is overestimating maxima- it's showing 32/33C here for Sunday with uppers around the 18C mark and a favourable wind direction from the SE- it could actually go higher than that.

[NTC]

2 minutes ago, Scorcher said:

His agenda is an odd one- seems to be in complete denial.

There is no consensus about a breakdown at all- the models are still chopping and changing for Monday and the heat could still continue into Monday and Tuesday.

I also highly doubt the GFS is overestimating maxima- it's showing 32/33C here for Sunday with uppers around the 18C mark and a favourable wind direction from the SE- it could actually go higher than that.

BBC, Met Office. most people on here say there is a breakdown Monday why are you the only one still insisting it isn't happening  Scorcher there IS a breakdown on Monday.

[I remember Atlantic 252]

22 minutes ago, clark3r said:

Have to disagree with you, there is not cross model agreement for a breakdown late Sunday  it is very uncertain at the moment. 

Aye, have to agree, hoping it is the case, but expecting a mega hot GFS 00Z tomorrow, heat 35 degrees lingering into Tues, with a slightly cooler 29 on Wed

[Captain Shortwave]

54 minutes ago, CreweCold said:

Thankfully the Azores HP doesn’t get a foothold past that point and the LP to the NW drives the flow.

By D10 we’re getting towards late August and any HP will begin to struggle to assert as easily as the jet stream slowly begins to awaken from its mid summer slumber. 

Someone needs to tell the jetstream that. It seems to have been in a slumber for months (Be it wet/cold/dry hot), aside from throwing a couple of windstorms like a teenager throwing a strop before going quiet again.

To be honest we are due a few volatile Autumn, I guess it is only fair after having a summer that has delivered some real highs. 

Week 2 seems to shaping up to be pretty average, westerly flow, low pressure centred towards Iceland. Looks okay in the south, not so great in the north.

ECM/GFS Mean

   

 

[Methuselah]

5 minutes ago, NTC said:

BBC, Met Office. most people on here say there is a breakdown Monday why are you the only one still insisting it isn't happening  Scorcher there IS a breakdown on Monday.

Indeed. I sometimes wonder why I bother posting the Met Office's Ten-Day forecast. I know nothing's set in stone, but a breakdown does look likely. And, by the way, there's stonking moon rising just now!

[stodge]

Evening all

Plenty of detail still to be resolved, but looking across the models at T+120, remarkable unanimity:

GFS OP, ECM, JMA and UKMO from the 12Z suite

All have the British Isles under a broad but slack trough of LP which suggests a growing likelihood for showers and thunderstorms though these will obviously vary on local conditions. The heat may indeed take a little more time to leach out than if we were dealing with an Atlantic frontal system moving in from the west but the net effect will be the same as the trough moves up from the south and fills the gap between the two HP centres to east and west.

Hot until Sunday but from then a progressive return to normal temperatures by midweek next week and as others have said some much needed rain but nowhere near enough.

[MattStoke]

Suppose it depends how one defines a breakdown.

A breakdown to the heat? - Not completely. Temperatures falling away but still warm/very warm for a few days at least.

A breakdown to the settled conditions? - For some there may be some rain, mostly in the form of showers or thunderstorms, but it looks far from a washout and may stay dry for some.

Wouldn’t say it’s the sort of rapid breakdown that we normally see. More of a fairly gradual transition to something less hot and less settled but it wouldn’t be a surprise to see hotter and more settled conditions returning before long.

Edited August 10, 2022 by MattStoke

[mb018538]

15 minutes ago, NTC said:

BBC, Met Office. most people on here say there is a breakdown Monday why are you the only one still insisting it isn't happening  Scorcher there IS a breakdown on Monday.

A breakdown is on the cards for sure…

10 day ppn chart looks the wettest it has for a while, but with most of it coming as showers rather than steady frontal rain, it’s hard to pin down. Also seems to have a western bias, so some areas that really need some rain the the E/SE corner may see little to no rain yet again. Really need this firming up.

[Scorcher]

16 minutes ago, NTC said:

BBC, Met Office. most people on here say there is a breakdown Monday why are you the only one still insisting it isn't happening  Scorcher there IS a breakdown on Monday.

The BBC also said we'd be in a northwesterly by Sunday only a couple of days back...not happening is it.

I stand by what I said. I didn't say there definitely wouldn't be a breakdown- I said there is no consensus over it. And I'm certainly not the only one saying this.

[Earthshine]

Warmer than average down south throughout.  ECMWF suggesting warm weather continues well into September (and yes I know we don't have any clue that far ahead but I just put these model runs up for fun!)

[JayAlmeida]

What a mess the model output is this evening 

Details like rain and cloud totals aren't what these models excel in so bear that in mind at this range. To me things look hot, humid and potentially thundery Mon and possibly Tue with a transitional period from Wed. 

Can anybody shed some light on the MJO and AAM projections for the second half of August? 

This evenings NOAA charts look very LP dominated which doesn't bode well for the rest of August. Seems similar to July's pattern of 10 days of exceptional summer weather for most of the UK before returning to usual NW/SE divide. Was hoping for a bit more consistency in August.

Edited August 10, 2022 by JayAlmeida

[Methuselah]

Well, I certainly hope so, Jay. As, thanks to the GFS, I've been able to warn my 88-year-old mother of potential heatwaves approximately 2 weeks before they've happened!

[jam]

48 minutes ago, NTC said:

BBC, Met Office. most people on here say there is a breakdown Monday why are you the only one still insisting it isn't happening  Scorcher there IS a breakdown on Monday.

you do realise it’s Wednesday today ? 

[viking_smb]

14 minutes ago, JayAlmeida said:

What a mess the model output is this evening 

Details like rain and cloud totals aren't what these models excel in so bear that in mind at this range. To me things look hot, humid and potentially thundery Mon and possibly Tue with a transitional period from Wed. 

Can anybody shed some light on the MJO and AAM projections for the second half of August? 

This evenings NOAA charts look very LP dominated which doesn't bode well for the rest of August. Seems similar to July's pattern of 10 days of exceptional summer weather for most of the UK before returning to usual NW/SE divide. Was hoping for a bit more consistency in August.

i cant see the UK on this chart

[I remember Atlantic 252]

2 minutes ago, viking_smb said:

i cant see the UK on this chart

top right of chart