Model Output Discussion - Autumn arrives

[ANYWEATHER]

31 minutes ago, Ed Stone said:

Good morning, all. Nothing to worry anyone if today's GFS 00Z run is anywhere near correct:

    

    

    

PS: Did I imagine it or did someone really claim that UK temperatures exceeded 40C back in the 1930s?!

Yes it was me, but you probably were not around back then...

[mb018538]

ECM mean still looks good from about Friday onwards once the last of that upper disturbance moves away. Increasingly warm and sunny for more of the UK:


   

[Methuselah]

2 minutes ago, ANYWEATHER said:

Yes it was me, but you probably were not around back then...

Nor, it seems, were those responsible for authenticating those 'records'?

[ANYWEATHER]

It takes a while to get here ,but by this time neXT week most of us will be benefiting from some classic British summer weather from our good old friend the Azores high. It does build strongly right across the nation into the following week. But how long will it last??? Perhaps not so long as many would hope for

[Weather26]

Well the last few images, it appears it may not quite be time to break out the BBQ's just yet.

[JayAlmeida]

Is it just me or is the ECM 00z an upgrade on the positioning of the high compared to yesterday's 12z?.

The GFS 00z brings in that useful Atlantic low to give a decent boost to maxima due to the influx of hot air. The low then starts to influence our weather a bit more but doesn't really gain a foothold by the end of the run.

Hardly a massive cause for concern (until the next set of runs )

So from next weekend its either going to be a 3-5 day scorcher followed by dross or the beginning of a longer period of decent summer weather.

There are two very differing schools of thought developing on the forum it would seem. The gap of opinion widens even further on the background drivers and long range stuff.

I think we all foster a head vs heart approach when it comes to predicting the UK weather. Some on here are more head (bad choice of words) some on here more heart. I find myself more conflicted between the two when looking at 10+ day charts.

 

Edited July 1, 2022 by JayAlmeida

[JayAlmeida]

A quick few questions on AAM from a n00b.

What is the typical timeframe for our weather to respond to changes in AAM?

What happens when there is a slower rise to the point of almost being a plateu as seen here?

 

[mb018538]

21 minutes ago, JayAlmeida said:

A quick few questions on AAM from a n00b.

What is the typical timeframe for our weather to respond to changes in AAM?

What happens when there is a slower rise to the point of almost being a plateu as seen here?

 

There is usually a lag between momentum rising and patterns changing - as the 'deck of cards need to be shuffled' as it were. It can be a quick change, or even a 7-14 day lag. No hard and fast answer to that one.

When AAM starts to plateau, you can get patterns that tend to stick. For the UK, a positive AAM pattern against a La Nina background (MJO driven) should usually mean higher pressure for NW Europe. The momentum added shifts the ridge/trough patterns along. If it holds in positive territory, high pressure more likely to stcik around for longer.

The 6z charts below shows today and next Sunday - you can see the ridge/trough/ridge pattern we currently have today with a NW Europe trough has been forced east, so that in 10 days time the trough is now over the Atlantic and eastern Europe, with the ridge in-between covering the UK.

 

Once momentum starts to fall, everything wants to regress....the high will likely start to move away from NW Europe and the troughing will likely return. Perhaps something like this chart from last nights ECM for w/c 25th July

[MATTWOLVES 3]

Cracking icon run...almost iconic!

Things do tend to improve through next week and it gradually warms up. The North still looks prone to some less settled conditions at times in the nearer term.

A very nice Exeter update...Basically saying alot of summery conditions through the month and very warm even hot spells possible...these conditions could become more extensive with time!

You Northerners deserve a break,and hopefully you will get something too cheer about before much longer. Worth noting a blip is possible mid month...but expected at this stage to be short lived!

So very slowly we should see the improvements further South and hopefully with time these will become more extensive.

A very fine Weekend to you all.

[northwestsnow]

Just my sense of humour ..

Not far off sleet in NW Scotland ,sun loungers in Kent.

Edited July 1, 2022 by northwestsnow

[minus10]

37 minutes ago, northwestsnow said:

Just my sense of humour ..

Not far off sleet in NW Scotland ,sun loungers in Kent.

Sums up the uk for you...

[Methuselah]

1 hour ago, MATTWOLVES said:

Cracking icon run...almost iconic!

Things do tend to improve through next week and it gradually warms up. The North still looks prone to some less settled conditions at times in the nearer term.

A very nice Exeter update...Basically saying alot of summery conditions through the month and very warm even hot spells possible...these conditions could become more extensive with time!

You Northerners deserve a break,and hopefully you will get something too cheer about before much longer. Worth noting a blip is possible mid month...but expected at this stage to be short lived!

So very slowly we should see the improvements further South and hopefully with time these will become more extensive.

A very fine Weekend to you all.

It's just a matter of holding one's nerve, Matt, and playing the long game. Or, in the case of waiting for winter snow -- the VERY long game!

[JayAlmeida]

1 hour ago, MATTWOLVES said:

Cracking icon run...almost iconic!

Things do tend to improve through next week and it gradually warms up. The North still looks prone to some less settled conditions at times in the nearer term.

A very nice Exeter update...Basically saying alot of summery conditions through the month and very warm even hot spells possible...these conditions could become more extensive with time!

You Northerners deserve a break,and hopefully you will get something too cheer about before much longer. Worth noting a blip is possible mid month...but expected at this stage to be short lived!

So very slowly we should see the improvements further South and hopefully with time these will become more extensive.

A very fine Weekend to you all.

Massive North West/South East split on the GFS before the blip with any warmth being localised exclusively to the far SE. Only about 4 out of the next 15 days are over 20c for us up in NW England (The NE fairs better).

Just hope the warmth is more widespread past next Friday than it is being shown on the 12z run. Gona av a little break from weather watching for a few days whilst the details are worked out properly.

The models tend to spin their wheels past the 7 day timeframe.

You'd expect the west the fair better temperature wise with an azores high centred to the west of the UK.

Edited July 1, 2022 by JayAlmeida

[MATTWOLVES 3]

Ring a ling a ding if High pressure is your thing,then we are all gonna sing! 

The mean out towards day 10 looks rather nice tbh....im not gonna worry over temperatures at this stage its the fact we are settling down very nicely that floats my boat...granted its gonna take a while for the NW to get there,but for those further South and East the prognosis from mid next week onwards looks very favourable and increasingly warmer.

Now all of you have a drink on me or toast me for all my hard work. Just kidding!

[Allseasons-Si]

The UKMO ext ends nice,...not too hot but in slack winds it should feel pleasant enough

168...

just to add to that,...the GEM has found the too

but ends with a warm and humid thundery breakdown from the SW at day ten but that's a long way off...

 

[Singularity]

7 hours ago, JayAlmeida said:

A quick few questions on AAM from a n00b.

What is the typical timeframe for our weather to respond to changes in AAM?

What happens when there is a slower rise to the point of almost being a plateu as seen here?

 

If it pans out like that, there won’t be a lot of forcing to move the pattern on again once high pressure is located over NW Europe. Only once AAM begins to fall and reaches back into the negative values can we expect the high to shift back west again.

I currently view any model runs that do that before late July - E.g. GFS 12z - as being too quick to proceed.

[Summer Sun]

An historic P20 on tonight's GFS with 40c in the UK

[MattStoke]

35 minutes ago, Summer Sun said:

An historic P20 on tonight's GFS with 40c in the UK

Fewer 40s than yesterday. Damn downgrades!

[tight isobar]

2 hours ago, Allseasons-si said:

The UKMO ext ends nice,...not too hot but in slack winds it should feel pleasant enough

168...

just to add to that,...the GEM has found the too

but ends with a warm and humid thundery breakdown from the SW at day ten but that's a long way off...

 

@Ed stone, sums it in overview. Texas hold ‘em.. But typically when you’ve got heat sourcing from the AZHP, or African/Iberian plume/mid- atmosphere temperature dynamics.. and you have almost suite support (via all raws) it’s quite interesting to watch the unfolding possibilities via heat transfer/ and pepping!!.. my guts are going strong with overlapping sourcing of very- notable heat getting into, And around uk regions... I personally don’t deal with heat/ nor a massive fan.. but if you do... Then I’m sure you’ll be in your element pretty soon, but may even have to tread water with fruition of what may drop 

Edited July 1, 2022 by tight isobar

[Cambrian]

A good spell of dry weather for most parts of the UK and Ireland once we get past day 3. The ECM operational run has had good consistency over its last few runs. On the 12z run, it takes to day 4 for the high pressure to really start imposing itself from the southwest and the air over us still has a cool profile going by the T850 anomaly chart, there’s quite a lot of cool air to shift. 

 

By day 6, the high is already at its peak barometric pressure of 1040mb, with 1035mb into the west of Ireland, 1030mb into the west of Britain and ithe T850’s are warming up to above average.
 

By day 10, the high has elongated west-east across the Atlantic and the central pressure has declined to a little above 1025mb, just as things are beginning to get warm in terms of T850 and at the surface. During this period, many parts do very well for some lovely warm days like here on day 9, low to mid twenties widely. 

  

The high is being squeezed from the south and north by a combination of lower heights near the Azores and a quite vigorous little low to its north. This develops just off the eastern seaboard on day 9 and looks like it’s going to run east between Iceland and Scotland. This could bring something more changeable into the north at least for a while, but all this is a long way off and after at least a solid week of dry and very pleasant weather for most.

Bring it on!

[Don]

3 hours ago, Summer Sun said:

An historic P20 on tonight's GFS with 40c in the UK

40C in Bristol, hotter than London!  Jokes aside, just goes to show how the climate has changed that model ensembles now show the possibilities of 40C possible in the UK now!  Going to happen sooner or later.....

[Iceman2606]

Very far out and is the pub run but what an absolute corker of a run!

 

Edited July 2, 2022 by Iceman2606

[weathermadbarnsleylad]

11 minutes ago, Iceman2606 said:

Very far out but GFS 18z is an absolute corker!

 

Hi mate. Your not joking. I think to be fair it's the best gfs run I have seen for warm/very warm then hot weather in the uk since been following the charts. This could turn out to be a exceptional spell of summer weather.

[Weather-history]

That's a plume

[clark3r]

Right so gfs has some very warm days on this mornings run prob maxing at 30, I am off on holiday for 2 weeks where it’s going to be high 30s most days, will be interesting to see how this develops back home and if I will come back to a heatwave