Model Output Discussion - Autumn arrives

[Lukesluckybunch]

i think this extreme heat is not likely at all...even the less hot ECM op was a warm outlier

[Guest]

16 minutes ago, Polaris said:

Bump on the head for the folk that need a reality check for 40c + ‘Crying how awful it would be’ but secretly hoping it happens!! 

Mid 30’s - 35-37c a possibility on current charts with the realistic timeframe in play. 

Models and posters were going for 37/38c 7 days ago for this coming Monday. - 32c reality. 

fridge/freezer’s safe for now

We can only post about what the models currently show. If those temperatures were to downgrade by 5C + it'll be because the plume doesn't engage as far north as models like the GFS currently show. Not because of a downgrade in temperatures/850s nearer the time.

The situation 7 days ago for the coming Monday were different and therefore not comparable to this. Models never showed historic heat potential for that time period over a number of days, did they?

No reality check needed. The reality is the potential for record breaking heat is there, however unlikely it may be. Today's output has been nothing short of incredible.

 

Edited July 9, 2022 by Steel City Skies

[Guest]

ECM 12z ensembles for London show the early arrival of the plume, and subsequent quicker breakdown isn't particularly well supported by the rest of the suite.

[mb018538]

9 minutes ago, Lukesluckybunch said:

i think this extreme heat is not likely at all...even the less hot ECM op was a warm outlier

ECM is hotter at a different time to the mean though. Still up around 16c at day 8.

[Dunstable Snow]

Met office temperatures for Fulham, West London, don’t get above 30c between now and next Friday. Not sure anything beyond that is in the reliable.

For Dunstable the top temperature is 28c for the same period.

if anyone can see a met office prediction above 35c between now and the end of next week please post with screen shot. I will be surprised.

[TSNWK]

1 hour ago, ResonantChannelThunder said:

So, a quick furnace and return to westerlies on that ECM, which now shows some thunderstorms into the south east early on Sunday morning. That run certainly looks realistic when compared to past events 

Bank... 40  

Is just not healthy for us

[Guest]

14 minutes ago, Lukesluckybunch said:

i think this extreme heat is not likely at all...even the less hot ECM op was a warm outlier

As @mb018538 alludes to, the ECM op is just hotter at a different time, peaking the heat on Saturday and swatting away the very hot uppers quickly east on Sunday. The ECM ensembles don't support the latter particularly, but continue to be supportive of hot conditions 16-19th peaking during the middle two days. Worth noting the ECM mean is only a degree down on the GFS mean for the same time period  

[Lukesluckybunch]

6 minutes ago, Steel City Skies said:

As @mb018538 alludes to, the ECM op is just hotter at a different time, peaking the heat on Saturday and swatting away the very hot uppers quickly east on Sunday. The ECM ensembles don't support the latter particularly, but continue to be supportive of hot conditions 16-19th peaking during the middle two days. Worth noting the ECM mean is only a degree down on the GFS mean for the same time period  

ok i just cant see anything like 40-42c appearing,..i think its looking more likely 33/34c

[bluearmy]

The ec op is in one of smaller clusters 

onto the 00z suites ….

[Guest]

1 minute ago, Lukesluckybunch said:

ok i just cant see anything like 40-42c appearing,..i think its looking more likely 33/34c

That's never been the likely outcome though. It remains a possibility, however. I believe your 33/34C though is a tad pessimistic going by the mean of much of the model output this evening, though. Perhaps a couple higher  

[Man With Beard]

Quick reaction to the ECM ensembles for next weekend:

Approx 75% of runs exceed 30C raw at some point (so given the model's underestimate bias, real max probably 32C)

Approx 60% exceed 32C (so probably 34/35C)

Approx 40-50% exceed 35C (so probably 37/38C)

Approx 20% might reach or exceed 40C after adjusting for underestimate bias.

We'll get the charts to confirm this shortly I guess.

A long, long way to go!! Monday/Tuesday before we really firm up!

[mushymanrob]

in my 17 years here, theres never been so much interest in summer ... and quite rightly too so, if the GFS is anything near correct then its an unprecidented spell of weather..

[wimblettben]

2 hours ago, Josh Rubio said:

Not often anyone wishes for this but roll on the downgrades!! 
 

This has gone beyond ‘just for fun’ territory now. I advise anyone ‘wanting’ these temperatures to come into fruition to have another think. 

Yes.

Lower the heat but increase the humidity so we can have temps in the 20s or 30s celcius instead but have a much higher chance of thunderstorms.

At least that way it won't be too extreme with the heat to cause infrastructure problems, wildlife and human deaths but we can have the fun of thunder and lightning along with the much needed rain that a lot of places could do with now.

Thats my wish at the moment as we have had a poor year for thunderstorms so far and this projected dry intense heat won't do anyone any favors.  

[JayAlmeida]

Nothing particularly inspiring for those North of Birmingham over the next 5 days looking at the GFS and ECM today.

This supposed heatwave is now beginning to look like brief spike of heat on Monday which breaks down to become slightly warmer than normal on Tuesday then it's as you where until next weekend.

The cloud cover being shown on the GFS is a nuisance aswell.

I'm pretty sure we got a more sustained spell of decent weather during the heat spikes in June.

 

 

Edited July 9, 2022 by JayAlmeida

[Cambrian]

The GFS ensemble of the 12z run for surface temperatures for the quaint little riverside town of London again displaying an accumulation effect from the 14th through to the 18th in its deviation from the mean, with successively higher daytime maxima following successively higher nighttime minima. The difference gets bigger and bigger, a full 12 degrees difference between op and mean by the 18th, the op clearly building in an accumulative effect, probably including an urban heat island effect.
 

The beginning of the heat build is coincident with modelling of the arrival of some very dry air resulting in very low dew points, down to 1 degree above freezing on the 15th.

Further west for the bustling metropolis of Tregaron, the pattern is different. There is a much smaller deviation between op and mean, around 5 degrees. There are also no conspicuously low dew points in the run up to the warm spell. 

 

A few mathematical multiplier effects clearly at play with the op in order to get the 40+ degree temperatures for London, it only takes one of the factors not to align to scupper those very highest outputs, hence the GFS mean, ECM and others not being so high. 

It’s looking more and more likely that it will get notably hot though, a 4 day hot spell for the southeast from the GFS. A comparison of the 12z run today with that from last Saturday shows the mean a full 7 degrees higher for the 17th, a marked firming up of an already very warm signal. Interestingly, there was a similar difference between op and mean even a week ago.

 

[Man With Beard]

It's not just next weekend which could be hot of course - based upon usual adjustments to raw values, this is what I expect the ECM op would mean for London this coming week:

Sunday 30-32C

Monday 31-33C

Tuesday 30-32C

Wednesday 30-32C

Thursday 27-29C

Friday 30-32C

Saturday 36-38C

Sunday 30-32C

 

[MATTWOLVES 3]

20 minutes ago, mushymanrob said:

in my 17 years here, theres never been so much interest in summer ... and quite rightly too so, if the GFS is anything near correct then its an unprecidented spell of weather..

Yeh Rob your showing ya age now mate

Just a quick glance at those 12z gfs ens showing many bringing the heat back later next week... can't help but notice how on so many of em we have major Heat loitering to the South like a bad smell...hang around any longer and it will be getting an ASBO

My thoughts this evening are we have 2 bites at the cherry coming up during the next 7 or 8 days...and I'm confident there will be others to follow on from that.

Putting my credentials on the line here folks (what credentials I hear you yell) I'm thinking this August could finally buck the trend of recent poor ones...not saying 2003 but stay tuned  

A very pleasant evening to each and everyone of ya...if your lucky enough to have air con...crank it up...if not have an argument with the missus so you get kicked out for a night on the patio...or if your very lucky the shed!

Edited July 9, 2022 by MATTWOLVES

[Arrows1986]

Interesting lol

Edited July 9, 2022 by Arrows1986
Edited pic

[Man With Beard]

26 minutes ago, MATTWOLVES said:

Yeh Rob your showing ya age now mate

Just a quick glance at those 12z gfs ens showing many bringing the heat back later next week... can't help but notice how on so many of em we have major Heat loitering to the South like a bad smell...hang around any longer and it will be getting an ASBO

My thoughts this evening are we have 2 bites at the cherry coming up during the next 7 or 8 days...and I'm confident there will be others to follow on from that.

Putting my credentials on the line here folks (what credentials I hear you yell) I'm thinking this August could finally buck the trend of recent poor ones...not saying 2003 but stay tuned  

A very pleasant evening to each and everyone of ya...if your lucky enough to have air con...crank it up...if not have an argument with the missus so you get kicked out for a night on the patio...or if your very lucky the shed!

I know some people won't want to hear this, but yes, I've seen some signs in the ensembles there might be a round 2 frythe plume between D11-D14.

What I haven't seen on any run, but slightly expected to, was a run that doesn't push the Biscay low through but instead builds high pressure over the top, trapping the heat below it (i.e. southern England). This is how some recent hot spells carried on e.g. June 2018, it was supposed to be a one week heatwave with a breakdown from a Biscay low but the low never made it to us, and week 2 ended up hotter than week 1.

[The Northern Ramper]

More runs needed

 

I didn’t expect to be viewing this thread in July

[Singularity]

42 minutes ago, Man With Beard said:

I know some people won't want to hear this, but yes, I've seen some signs in the ensembles there might be a round 2 frythe plume between D11-D14.

What I haven't seen on any run, but slightly expected to, was a run that doesn't push the Biscay low through but instead builds high pressure over the top, trapping the heat below it (i.e. southern England). This is how some recent hot spells carried on e.g. June 2018, it was supposed to be a one week heatwave with a breakdown from a Biscay low but the low never made it to us, and week 2 ended up hotter than week 1.

Tamara’s earlier post regarding the potential for pattern re-sets springs to mind. In this way, high summer patterns do tend to be more persistent with internal feedbacks self-sustaining, so it would not be surprising if the GFS 00z proved closer to the mark than the subsequent det. runs of today.

Such did occur in 2018, as an exceptionally positive summer NAO pushed ridge after ridge toward Scandinavia even as AAM fell a long way negative during 2nd half July. The -AAM forcing eventually gained the upper hand in the final third of August.

Not saying there will be so much lag this time, but recent extended EC runs have showed considerable interest.

[ANYWEATHER]

It's amazing how meny newbies are on here ,You are all going to be dissapointed by computer models 

[Snowman.]

18z somehow ups the heat and brings them faster. However may be a more fleeting afair like the ECM.

 

[Guest]

Another record breaking run in the offing from GFS. The 18z looks likely to breach 40C again on the Sunday rather than waft away the heat east. 38C widely in the SE on the Saturday.

 

[Mark wheeler]

Boring GFS coming up then . Here we go ..

ahhh Bisto

Edited July 9, 2022 by Mark wheeler