Model Output Discussion - Autumn arrives

[Captain Shortwave]

The ECM a little further south next week, the jet looks rather flat so it is up to the Azores low to create the plume set up by interacting with an incoming Atlantic trough (Essentially what happens at day 10).

The dividing line will shift over the coming model runs, and it will be the difference between seeing the heat only up to Tuesday and something lengthier. The ECM probably on the pessimistic side on that front in terms of the output.

[SizzlingHeat]

5 minutes ago, sheikhy said:

And once again at day 10 serious heat incoming!!we need to see it in inch closer which it just aint doing!!!before that though we gona see very warm temps regardless!friday to monday looking very warm!!

And the rest... Tuesday into the 30s widely. Wednesday still 30c likely in the south then mid twenties briefly before hot again. Many parts of the south wont see temps below high 20s from tomorrow through another 7 days minimum

[Man With Beard]

So another day's runs ... and the balance of odds still favours a plume of some sorts next weekend, between Friday 15th and Monday 18th. Intensity, timing and duration to be resolved. But the 20C uppers line likely to be close to or over us. It'll be hot! Somewhere between 30C and 42C in the SE

[kold weather]

18 minutes ago, Staffmoorlands said:

ECM 120-168hrs introduces cloud and cooler conditions for the North and west from Tuesday.

I think we have seen the end of posts suggesting 35c+ now

Just FWIW 11 out of 31 GFS ensemble members reach 35c+ somewhere. If we expand that to 34c you can add another 7 runs into the mix. 33C and nearly all ensemble runs are in.

35C VERY much still in play. The really extreme temperatures are still also synoptically possible in most of the 12z model runs bar perhaps the GFS op run, which is way too progressive by the looks of things.

[MattStoke]

16 minutes ago, sheikhy said:

And once again at day 10 serious heat incoming!!we need to see it in inch closer which it just aint doing!!!before that though we gona see very warm temps regardless!friday to monday looking very warm!!

ECM ensembles have always had a plume around the 17th whilst the GFS has had it earlier but is now pushing it back.

Edited July 7, 2022 by MattStoke

[Paul]

If you fancy a stab at forecasting (guessing!) the top temperature later next week, enter our competition

 

 

[Uncertainty]

1 hour ago, Staffmoorlands said:

ECM 120-168hrs introduces cloud and cooler conditions for the North and west from Tuesday.

I think we have seen the end of posts suggesting 35c+ now

The two statements you make do not follow on from one another. Why would a brief Atlantic incursion in the NW preclude the temperature you have selected from verifying later in the forecast period, especially in the S? 

Your reading of the present modelling is that 35+ is now off the cards?

ECM op

GFS control

 

JMA

UKMO 168 is headed that way

You don’t even need the big plume for 35c in the south. That HP sticking around for a few days in mid July and some subsiding air will suffice. The plumes suggested above and consistently over the past few days suggest that record temperatures are possible. Longer range modelling including the EC46 are indicating above average temps will be possible well into August. The latest GEFS for day 10 has an anomaly almost tailor made for heatwave conditions.

Yet your brief summation, devoid of evidential underpinning, would suggest to our thousands of readers that such a threat has now receded. 

Weather forecasting is deeply nuanced and even nailed on ‘spells’ of extreme weather sometimes vanish or collapse within 72 hours. There is no convincing evidence for the U.K. record to fall at present but my use of the word ‘possible’ earlier reflected the fact that the parameter space of the present pattern in the euro - Atl sector and evolving climactic changes  do allow for such a possibility to actualise. Regardless, 35 degrees in SE England in July is neither extreme nor unusual. On the basis of current modelling I’d say it’s  probably likely over the coming weeks. 

 

 

Edited July 7, 2022 by Uncertainy

[Guest]

ECM 12z ensembles for Sheffield. Checked Cambridge and London, too.

A hot set with the control giving a big peak in 850s on the 17th... the operational was primed to follow suit, too. P18 is frankly ridiculous with 25C 850s as far north as Sheffield. Madness.

 

[SizzlingHeat]

8 minutes ago, Staffmoorlands said:

https://weather.us/model-charts/euro/staffordshire/temperature-f/20220713-1800z.html

ECM Shows the much cooler weather next week - Wednesday is back to mid 20's (also shown on BBC & Met Office forecasts)

The temps showing for Wednesday afternoon according to the ECM are mid to high twenties still widely across most of the country. Given the op was at the lower of the ensembles I would suggest that 30c+ would still be very likely for many on Wednesday as well.

[Frosty.]

Tonight’s longer term ECMWF 12z ensemble mean screams hot potential, especially across the s / se…and there’s some very warm / summery weather before that too!…i think the best of this summer is still ahead of us… 

 

 

[Guest]

8 minutes ago, SizzlingHeat said:

The temps showing for Wednesday afternoon according to the ECM are mid to high twenties still widely across most of the country. Given the op was at the lower of the ensembles I would suggest that 30c+ would still be very likely for many on Wednesday as well.

It's Codge, he's only talking about his own back yard. I've never found his views at all representative of the UK as a whole.

The rest of us can see the charts for what they are. Very warm to hot for many away from the far north and west on occasion, with a double-peak heatwave likely for the southern half of the UK especially.

[summer blizzard]

Euro maintains the recently advertised pattern of a plume rebuilding, GFS has job done by day 9.

[tight isobar]

Again- once the bolt on heat establishment intails “ watch the op/ ens summary’s “!! Moreso mid/ England down- the 2m temperature plots will start going into heat overdrive.. ina already wet/ vapour starved placeing. That’s when you’ll likely note plume uping = hammering, As the drag effect finds ground/ mid- then upper level responses!!.. records will likely go into the bin ?.. for mentioned geographical plots/ place... this could get quite conceivable- concerning... its making for some worrying prognosis. .. @ thermo overload!!

Edited July 7, 2022 by tight isobar

[damianslaw]

Models continue to suggest a 'plume' event so to speak of sorts as we end next week, with the heat peaking weekend 16/17th, but we are not there yet, and things could still be shunted further east should the shallow trough/low feature develop more strongly to the SW and phase with the jetstream. Not saying this will happen, but we must remember the last plume event that was a blink and miss it affair and only really affected the far SE.

 

[East_England_Stormchaser91]

These runs are frankly beyond ridiculous for heat. Absolutely staggering to be seeing the 24-25c isotherm entering these shores on some runs. 
40c would definitely be challenged on some runs. I personally would not want to feel what that would be like here. I was in Peterborough when RAF Wittering was recording 38c and it was unbearable on a monumental scale. Not to mention the night time minima could be like being in Greece with 23-24c! No thanks here!! 

[cobby]

5 hours ago, A Face like Thunder said:

Daily Mirror: 'One model from The Weather Outlook forecast astonishing highs of 40C in Bristol on July 14 and a blistering 41C in London two days later'.

Mirror own Daily Express these days

[Paul]

Quick look at the hires ECM ensembles. Max they're showing tonight for London is 38.5c.

[Captain Shortwave]

The pub run coming out now, Monday and Tuesday still looking very good.

   
 

At this moment I suspect we might hit 31c on Monday and possibly 33c on Tuesday. Wednesday still up in the air due to uncertainty regarding the progress of a cold front. Fair to say the GFS is slower than the ECM and has the south as hot, if not hotter on Wednesday.

The heat restricted to the south east corner thanks to a weather front through central/northern England, still very warm though and of course the cooler air can be clearly seen across Ireland and Scotland.

[Allseasons-Si]

Evening all,...just checked in and i am keeping an eye on the 18z gfs,... i know it's not the most reliable suit of the four runs but this is settiing up nicely and better than the 12z...

...more downstream troughing will bolster the high ahead of it and is more amplified than the 12z,also more seperation of the Iberian low(the less this interacts with the downstream trough/northern arm of the jet the better of which will result in a slower transition to unsettled weather and a better plume from the south,...lets see how this goes,...it could be a hot run.

 

[Man With Beard]

28 minutes ago, Captain Shortwave said:

The pub run coming out now, Monday and Tuesday still looking very good.

   
 

At this moment I suspect we might hit 31c on Monday and possibly 33c on Tuesday. Wednesday still up in the air due to uncertainty regarding the progress of a cold front. Fair to say the GFS is slower than the ECM and has the south as hot, if not hotter on Wednesday.

The heat restricted to the south east corner thanks to a weather front through central/northern England, still very warm though and of course the cooler air can be clearly seen across Ireland and Scotland.

CS - I think the GFS has fixed its long standing issue with under-predicting maximums? All the modelled maximums look pretty reasonable tonight - in fact 35C for Wednesday looks a tad over optimistic if anything?

[snowfall09]

GFS 18z ends up broadly similar to the 12z around 264 hours with high pressure building back in from the west.

Il take that!

Edited July 7, 2022 by snowfall09

[Fourty Point Three Degrees]

looks like a rinse and repeat on gfs 18z with the azores sending another ridge our way keeping things hot all in FI

[Captain Shortwave]

6 hours ago, Man With Beard said:

CS - I think the GFS has fixed its long standing issue with under-predicting maximums? All the modelled maximums look pretty reasonable tonight - in fact 35C for Wednesday looks a tad over optimistic if anything?

From looking at the charts for a while, the GFS tends to be around a degree or so off now, which is fine given the maxima will always be in localised locations.

The 18z appeared to be on the optimistic side for Wednesday by holding the hot air over the south for longer (as such allowing the 16c isotherm to establish across the south), this mornings run appears to be more in line with the other output. Still very warm in the south.

 

still time for the heat to hold properly in the south. Beyond that, still question marks regarding a return of the heat and there still isn’t agreement on the track of the low forming near the Azores. The GEM will probably be an eyebrow raiser given the low stalls west of Portugal and is essentially pumping heat across north west Europe.

 

I would say this would be a very concerning chart to verify, purely because that low isn’t moving particularly quickly and is likely to lift northwards. Personally I would take a solution that keeps temperatures in the high 20s/low 30s and then throws a last hurrah (possibly towards 100f) with a quick breakdown afterwards. That low stalling closer to Europe would bring a new definition to the term “heatwave”.

Edited July 8, 2022 by Captain Shortwave

[Cheshire Freeze]

Chances of exceptional heat seem to be receding IMO.

The GEM throws out a different scenario every 12 hours, so I’m not too concerned about that.

[carinthian]

Happy Monday . Looks like UKMO has come up with the best chart of the summer so far for you guys. Should be minimum cloud cover, especially for England and Wales.

C