Model output discussion - August hot spell - how hot, how long?

[ICE COLD]

Quite a difference on the ECM tonight 

12z from yesterday at T144

V 12z today at T120 the throughing is closer. 

Yesterday’s T168 

Todays T144 

quite a difference at fairly short range and not so settled . 

[mb018538]

1 minute ago, ICE COLD said:

Quite a difference on the ECM tonight 

12z from yesterday at T144

V 12z today at T120 the throughing is closer. 

Yesterday’s T168 

Todays T144 

quite a difference at fairly short range and not so settled . 

As I’ve been saying for days - expect this with an ex hurricane coming into the mid latitudes and heading our way. Nothing set in stone at all.

ECM tonight is upper 20s at day 9 and over 30c at day 10...

[MP-R]

Definitely a warm up on the cards into the first week of September, just can't decide between a tropical maritime cloudfest, a sunny high (I hope not - I've got a major business event on the Saturday and Sunday indoors), or a brief thundery plume. We've only had the entire second half of August to serve up something interesting...

[stodge]

Evening all

Tentative signals for a warmer spell in the second week of September. I'm not quite sure whether +16 850s would deliver the same values in September as in July but it would still be very pleasant. 

12Z GFS OP quickly pushes any heat any south while ECM's evolution ends with the LP very close - too close I think - to the SW so less settled than some might want or hope.

12Z GEM has a transient push of warmer air through the south as early as the end of next week but it's a "blink and you'll miss it" scenario.

12Z GFS Control is pleasant but never that warm - more average temperatures and I suspect a hint of autumnal conditions with fog and chillier mornings.

As others have said, tropical energy can render a forecast obsolete quickly at this time of year. Yet there's little sign of anything in the near future - over North America, the pattern is one we see sometimes of a large HP over the Pacific and a shallow heat LP over the interior and a further HP over the Great Lakes. Fantastic weather if you're on the California coast - an off-shore wind so plenty of sun and low humidity - perfect.

 

[mb018538]

22 minutes ago, stodge said:

Evening all

Tentative signals for a warmer spell in the second week of September. I'm not quite sure whether +16 850s would deliver the same values in September as in July but it would still be very pleasant. 

12Z GFS OP quickly pushes any heat any south while ECM's evolution ends with the LP very close - too close I think - to the SW so less settled than some might want or hope.

12Z GEM has a transient push of warmer air through the south as early as the end of next week but it's a "blink and you'll miss it" scenario.

12Z GFS Control is pleasant but never that warm - more average temperatures and I suspect a hint of autumnal conditions with fog and chillier mornings.

As others have said, tropical energy can render a forecast obsolete quickly at this time of year. Yet there's little sign of anything in the near future - over North America, the pattern is one we see sometimes of a large HP over the Pacific and a shallow heat LP over the interior and a further HP over the Great Lakes. Fantastic weather if you're on the California coast - an off-shore wind so plenty of sun and low humidity - perfect.

 

Sadly the climate in California is almost too nice for its own good. Everyone loves the sun, but there’s so much of it and so little rain there that the drought and wildfires are just catastrophic, and getting worse. Not sure I’d want to live worrying about an inferno every year...

[Man With Beard]

Great looking op runs in the past 24 hours, at least for next weekend, but personally I'm not convinced - yet! I would like to be, don't get me wrong! But these "hot" runs have not been that common in the ensembles and still aren't tonight - the ECM op is unlike any other ensemble at T216 and that's not good for confidence. A situation to put in the "pending" file!

Edited August 27, 2020 by Man With Beard

[ICE COLD]

13 minutes ago, Man With Beard said:

Great looking op runs in the past 24 hours, at least for next weekend, but personally I'm not convinced - yet! I would like to be, don't get me wrong! But these "hot" runs have not been that common in the ensembles and still aren't tonight - the ECM op is unlike any other ensemble at T216 and that's not good for confidence. A situation to put in the "pending" file!

You can say that again the op leaves the graph on day 9 and doesn’t return lol . Now that is what you call the biggest outlier ever. 

[I remember Atlantic 252]

1 hour ago, stodge said:

Evening all

Tentative signals for a warmer spell in the second week of September. I'm not quite sure whether +16 850s would deliver the same values in September as in July but it would still be very pleasant. 

12Z GFS OP quickly pushes any heat any south while ECM's evolution ends with the LP very close - too close I think - to the SW so less settled than some might want or hope.

12Z GEM has a transient push of warmer air through the south as early as the end of next week but it's a "blink and you'll miss it" scenario.

12Z GFS Control is pleasant but never that warm - more average temperatures and I suspect a hint of autumnal conditions with fog and chillier mornings.

As others have said, tropical energy can render a forecast obsolete quickly at this time of year. Yet there's little sign of anything in the near future - over North America, the pattern is one we see sometimes of a large HP over the Pacific and a shallow heat LP over the interior and a further HP over the Great Lakes. Fantastic weather if you're on the California coast - an off-shore wind so plenty of sun and low humidity - perfect.

 

Aye, saw this and thought summer/shorts f flops, but then looked at temps, looks wrong to me? 13 degrees at 3pm? be warmer off this in Feb

[Mike Poole]

I’m sensing a few more model runs are toying with a settled and warm start to September, and on cue, is the GFS 18z which has this at T180:

I’ve backed this horse for a while now, and maybe the odds are just getting a bit shorter...more runs needed, but I sense a direction of travel towards a decent start to September.

[Sky Full]

A quick look at what the models are predicting for +144h and I’m not really enthused.....

UKMO.      
ECM          

GFS          

GEM         

That almost ever-present ‘Icelandic low pressure’ (is that a thing?)  continues to show its hand which means little chance of high pressure gaining strength over the UK.  I have watched this pattern recur regularly over a couple of weeks now and I don’t have a lot of confidence that a nice, settled September is about to unfold.....

Edited August 28, 2020 by Sky Full

[Methuselah]

Nowt too scintillating on today's GFS 00Z, I'm afraid... But, that said, I do lose a lot of interest in things meteorological at this time of year, as we head into the dank, dreary days of autumn:

    

    

    

    

But, as the GEFS ensembles clearly show, the noise is outshining the signal... whatever that is!

    

    

[GeordieX9v]

We're not a million miles away from a decent spell by day 10 of the ECM

 

[Frosty.]

Looking at the GEFS 0z mean we could be heading towards a north / south split with actually some predominantly very decent early September weather across southern parts of the u k..and finally, the ECM 0z op is still indicating increasing high pressure influence as time goes on...NATIONWIDE!...in the meantime, a ridge of high pressure from the west is going to settle our weather down for a time with pleasant spells of sunshine and lighter winds but with chilly nights where skies clear.

Edited August 28, 2020 by JON SNOW

[mb018538]

As warm as last nights ECM OP run was (big outlier), today's is the opposite! Thursday and Friday could see 25c, but there's certainly no 28-31c like there was last night.


With the ensembles showing anything from 5c to 15c at 6 days away on the 850mb temps, i wouldn't be looking much beyond this at the moment. Day 10-15 can go in the bin.


 

Edited August 28, 2020 by mb018538

[Weather vane]

1 hour ago, Sky Full said:

A quick look at what the models are predicting for +144h and I’m not really enthused.....

UKMO.      
ECM          

GFS          

GEM         

That almost ever-present ‘Icelandic low pressure’ (is that a thing?)  continues to show its hand which means little chance of high pressure gaining strength over the UK.  I have watched this pattern recur regularly over a couple of weeks now and I don’t have a lot of confidence that a nice, settled September is about to unfold.....

Tend to agree. Whilst so.e green shoots of settled weather are appearing, the Atlantic dominance has been very hard to shift for a lot of this summer. Ground is almost fully saturated here, across the entire island of Ireland. Been a long time since I"ve seen it this bad at end August.

[Polar Maritime]

A cold end to Summer 2020, With the first Frosts of the season for parts as we enter Autumn..

[MATTWOLVES 3]

Last night's EC46 on cue for a more settled Bank Holiday, but cloud amounts could be an issue at times. Beyond this we perhaps see an increase in temps later next week, and possibly some decent conditions. Into the following week it does trend more unsettled especially further North, but with these conditions spreading South at times. Towards mid month and beyond is still looking pretty good with High Pressure having more influence. 

Just to mention the 7 Month anomalies, at this stage they are predicting a rather cold November, but a warmer December... This is also true for much of Europe and Scandy... Hope to god its not going to be another 2019 re run... Only time will tell... Enjoy your weekends.. 

[sundog]

39 minutes ago, MATT said:

 

Just to mention the 7 Month anomalies, at this stage they are predicting a rather cold November, but a warmer December... This is also true for much of Europe and Scandy... Hope to god its not going to be another 2019 re run... Only time will tell... Enjoy your weekends.. 

How accurate were they for the last number of months?

[MATTWOLVES 3]

5 minutes ago, sundog said:

How accurate were they for the last number of months?

Hi mate, I've not been following them long enough to bring a true reflection on how they are performing. I would say take with a huge pinch of salt on anything that is so far out.. And just for the record they are quite a bit different to last months anomalies.. But at this kind of range it's to be expected.. They run on the 5th of every month so hopefully I may be able to bring a more stable roundup closer to the time.. If they are showing the same kind of situation come November I may get a little concerned.. But at this stage I won't be getting to concerned.. Namely they show warmer conditions over Scandy and Europe... Come January they have pockets of warmer air over the UK with colder air in place over Southern and Western areas.. They also show colder air over France and Spain..

[mb018538]

Unusual to see this level of agreement at 12 days out. Looks like a big mid-Atlantic high setting up - which usually means troughing/low pressure down its eastern flank like cluster one and two show. More patience needed i think, the good weather will come.....eventually.

[sundog]

3 minutes ago, MATT said:

Hi mate, I've not been following them long enough to bring a true reflection on how they are performing. I would say take with a huge pinch of salt on anything that is so far out.. And just for the record they are quite a bit different to last months anomalies.. But at this kind of range it's to be expected.. They run on the 5th of every month so hopefully I may be able to bring a more stable roundup closer to the time.. If they are showing the same kind of situation come November I may get a little concerned.. But at this stage I won't be getting to concerned.. Namely they show warmer conditions over Scandy and Europe... Come January they have pockets of warmer air over the UK with colder air in place over Southern and Western areas.. They also show colder air over France and Spain..

Cheers

[Man With Beard]

A few clusters now showing plume potential between D8 and D10 - look for the red block to the east and straight lines up from the south. I don't think it's quite the majority, though

 

[summer blizzard]

Euro this morning is relatively settled, warm and dry. 

 

Not convinced how long this will last. We saw a relaxation in the Pacific trades between 10th-30th August but trades are forecast to return with a vengance so would assume we will see a much more unsettled signal towards mid month.

 

[Mike Poole]

Well the ICON 12z showing some interest by next weekend, here T180:

This would be a very noticeable change, some kind of plume has been showing in the ensembles, wonder if this could get firmed up?  

[mb018538]

15 minutes ago, Mike Poole said:

Well the ICON 12z showing some interest by next weekend, here T180:

This would be a very noticeable change, some kind of plume has been showing in the ensembles, wonder if this could get firmed up?  

It’s a possibility - will need a split jet/cut off low like icon is showing though. One to watch!

Edited August 28, 2020 by mb018538