Model Output Discussions 12z 03/05/2016

[Frosty.]

As man with beard said there are some fascinating possibilities which show the hot spell extended next week towards friday or even further.. the Gefs 12z perturbations are hotter than the 6z and there are more of them...this could yet be longer than a 48 hour event, it could be 72/96 hours of hot continental weather next week...and thats after an increasingly warm anticyclonic weekend and start to next week! P3, P12 & P15 are magnificent!

[Man With Beard]

ECM for Tuesday - now at T168 - this day has been consistently a scorcher on the models and no change tonight - a max somewhere between 32C and 35C on this I'd think

[SMU]

so heatwave cancel to be replaced by 2-4 days of nice weather depending on where you live

max temps shaved again down to 30-31c in the SE tues

more bearable for most - disapointing for the extremists !

Edited August 9, 2016 by Steve Murr

[Frosty.]

It's not a done deal just because the Ecm 12z is more progressive, it's a very complex set up next week and the heat could last through midweek towards later next week..it's not over yet!..we still have the gem and some cracking gefs 12z perturbations..

This is all a bonus anyway isn't it? 2 plumes a month apart is jolly good.

[William of Walworth]

48 minutes ago, Karl. said:

 

 

I'd bank the above two (NOTE DATES!), even if they came with with much reduced temperatures.

 

I wonder whether some observers are concentrating too much on the likelihood (or not!) of a hotter than hot plume for a day or three early to mid next week, and not focussing enough on whether HP-influenced conditions will last longer. Or not.

Edited August 9, 2016 by William of Walworth

[Man With Beard]

The ECM op finishes, like the GFS op, in a pretty ordinary way, with the 90F plus heat gone by Wednesday daybreak. 

Are the ops leading the way? Possibly. But having said that, they've gone from being the hottest runs on their ensembles to perhaps now the coolest. The journey continues towards the truth...

[mb018538]

From the looks of tonight we will probably nudge over 32c/90f somewhere in the SE on Tuesday, but not the 35c of last month - Synoptics aren't quite right to deliver that level of heat I feel. It's still ebbing and flowing though, it all depends on how this low interacts and moves in. Keep those eyes peeled!

[Frosty.]

7 minutes ago, William of Walworth said:

 and not focussing enough on whether HP-influenced conditions will last longer. Or not.

P15 Gefs 12z is what I was hoping the outlook would be with a scandi high or an Azores / scandi high link up, that is what the gefs was showing last week for next week but now its changed to another short-lived plume event but there is still enough time for changes to occur and bring a summery second half of August..The fat lady isn't singing yet..she's not even in the building!

[ANYWEATHER]

Good Evening All! The last summer month and a new plume beckons! It really looks like a brief affair and southeast England looks as always to benefit from any long lasting heat. The Big Question is ....Will we get a dramatic thundery breakdown Just look at that very cold air flirting with NorthEast  Scotland , could well be some record lows for Britain

Edited August 9, 2016 by ANYWEATHER

[Man With Beard]

ECM ensembles, like GEFS, much hotter for the Wednesday. 14C at 850s for the SE, 12C for many - spreads indicate there will still be a fair number of hotter runs too. So a good 4C warmer than the op run, potentially. Probably not lasting to Thursday but still early days.

[Frosty.]

The Ecm 12z ensemble mean shows an increasingly warm anticyclonic weekend and an increasingly hot and humid first half of next week as winds become sly / sely and we draw continental heat north from France with hot hazy sunshine and a growing risk of thunderstorms with temps as high as the low 30's celsius. Beyond the plume it becomes fresher but stays warm with temps comfortably into the 20's c with sunshine and a few showers but the good news is our second plume of the summer is firming up and another spell of summery weather is on the way!

[joggs]

2 hours ago, Karl. said:

P15 Gefs 12z is what I was hoping the outlook would be with a scandi high or an Azores / scandi high link up, that is what the gefs was showing last week for next week but now its changed to another short-lived plume event but there is still enough time for changes to occur and bring a summery second half of August..The fat lady isn't singing yet..she's not even in the building!

That'slike a total winter beasterly ,only as good in summer.Come around once a decade or two.

Edited August 9, 2016 by joggs

[bradymk]

Much better from GFS 18z. Slightly slower breakdown of the hot weather next week with warmer uppers and these also lasting longer than on earliers ECM run. Hopefully a trend in this direction from 00z ECM. Think the heat will probably last from Monday until late Wednesday for most. 

Keep an eye out for high pressure possibly building in again from the south west/south late next week after the breakdown mid-week too

[Man With Beard]

5 hours ago, bradythemole said:

Much better from GFS 18z. Slightly slower breakdown of the hot weather next week with warmer uppers and these also lasting longer than on earliers ECM run. Hopefully a trend in this direction from 00z ECM. Think the heat will probably last from Monday until late Wednesday for most. 

Keep an eye out for high pressure possibly building in again from the south west/south late next week after the breakdown mid-week too

And the 00z carries in the same way, potential for a tasty thundery breakdown too, perhaps. Interestingly, slightly more progression is actually helping the heat stick around as a slightly more progressive trough to the NW prevents heights escaping north so quickly (not the case on UKMO). Well supported by GEFS.

Of course the heat gets going much sooner for southern areas - 27C a likely maximum mark from Friday onwards - charts are similar to last weekend's and that's the values we got. The heat goes nationwide by Monday, 29C ish a possibility somewhere. Tuesday 32-33C, a perfect hit could bring 35C. Wednesday might touch 30C-32C again before the breakdown sets in.

Edited August 10, 2016 by Man With Beard

[mb018538]

ECM forecasts the big heat to start arriving through Tuesday, with Wednesday holding on to the warmth in most areas (especially the SE), and possibly the SE squeaking one more warm to hot day in before the breakdown from the west. Looking like 32c+ is on the cards folks.

[knocker]

The ECM det. this morning has max temps at 18z Tuesday 28C, possibly 30C in places in central, southern and SE England. Same time Weds generally much cooler generally around 20C -22C with the hot spot around Lincolnshire 24C and maybe 26C. Thursday quite chilly.

The general synoptic situation. At 18z on Monday the HP is centred in the North Sea with the frontal systems 300Km west of Ireland thus a nice SE flow over the UK. In the next 24 hours the HP drifts NE and the fronts east but the UK remains in the SE flow bringing some very warm temps. But by 06z Weds the fronts are already into the SW and by 18z rain is in to most of England.

 

[joggs]

Well I just hope it goes out with a bang,unlike the last plume.

[coldcomfort]

Well what was originally a warm/very warm weekend for may now looks set to be another rather indifferent affair, as does Monday, with temps close to normal for many across England/Wales and pretty cool for Scotland/N Ireland. Tues/Weds see temps lifting into the very warm, locally hot categories for inland parts of England and Wales, but any warm up across Scotland and N Ireland still looks fairly muted, especially north of the central lowlands. 

Yes nice to see, but to my eyes we are still only looking at a localised heatwave Tues/Weds across much of England and Wales, with those north of the border and across the water in NI possibly being able to go down to only 1 jumper for 24hrs early next week.... 

[Man With Beard]

43 minutes ago, knocker said:

The ECM det. this morning has max temps at 18z Tuesday 28C, possibly 30C in places in central, southern and SE England. Same time Weds generally much cooler generally around 20C -22C with the hot spot around Lincolnshire 24C and maybe 26C. Thursday quite chilly.

Good to have you back Knocker.

Well this morning's ECM sees trough disruption throwing a spanner into modelling. A mini-low appears over SW England, splitting in between heights to the north and south.

    

Now normally this would just be a case of who gets the rain - SW, central, east or north - the type of situation where those forecasted to be wet at T48 might end up dry by T0, and vice versa. But when this much heat is around -

- there is the potential for some incredible contrasts in weather that may not be fully forecast-able until very very near T0. The difference in modelling between 22C and 32C will be very small.

I think we're pretty well set now until Tuesday. But Wednesday onwards may end up a forecasters nightmare if the tendency to split a trough near our SW continues. 

Coldcomfort - I wouldn't be so pessimistic - I think Manchester will get lows 20s over the weekend (Saturday a little dodgy but might be ok) and high 20s are possible any day from Monday to Wednesday, even Thursday if that low is a little further south. You'd settle for that wouldn't you?

Edited August 10, 2016 by Man With Beard

[coldcomfort]

2 minutes ago, Man With Beard said:

Good to have you back Knocker.

Well this morning's ECM sees trough disruption throwing a spanner into modelling. A mini-low appears over SW England, splitting in between heights to the north and south.

    

Now normally this would just be a case of who gets the rain - SW, central, east or north - the type of situation where those forecasted to be wet at T48 might end up dry by T0, and vice versa. But when this much heat is around -

- there is the potential for some incredible contrasts in weather that may not be fully forecast-able until very very near T0. The difference in modelling between 22C and 32C will be very small.

I think we're pretty well set now until Tuesday. But Wednesday onwards may end up a forecasters nightmare if the tendency to split a trough near our SW continues. 

Coldcomfort - I wouldn't be so pessimistic - I think Manchester will get lows 20s over the weekend (Saturday a little dodgy but might be ok) and high 20s are possible any day from Monday to Wednesday, even Thursday if that low is a little further south. You'd settle for that wouldn't you?

Not being pessimistic at all given the charts in front of me. Low 20's is pretty much ave for Manchester in mid Aug, but upper teens perhaps 20c looks about the mark on Sat, maybe a degree higher on Sun...ergo average. Clearly a warm up early next week, which I think I covered fairly well, we just need to see if ECM is onto anything regarding the trough disruption the SW (a genuine possibility imo), so as ever more runs needed. 

[Scorcher]

25 minutes ago, coldcomfort said:

Well what was originally a warm/very warm weekend for may now looks set to be another rather indifferent affair, as does Monday, with temps close to normal for many across England/Wales and pretty cool for Scotland/N Ireland. Tues/Weds see temps lifting into the very warm, locally hot categories for inland parts of England and Wales, but any warm up across Scotland and N Ireland still looks fairly muted, especially north of the central lowlands. 

Yes nice to see, but to my eyes we are still only looking at a localised heatwave Tues/Weds across much of England and Wales, with those north of the border and across the water in NI possibly being able to go down to only 1 jumper for 24hrs early next week.... 

A slightly misleading post from a poster with a very appropriate name

Going by GFS which has more precise timings (rather than just the ECM which has only one chart per day, albeit the best performing model overall), we can see the warm uppers arriving during the early hours of Monday, which will allow temperatures to reach comfortably above average values for most- even the BBC are suggesting this on the website already despite their usual caution until a couple of days before.

The warm spell has actually been extended this morning by all of the major models- yesterday evening it looked like the heat would be swept away by Wednesday, but it's now looking like there could be another hot day for most of the UK. Perhaps it could be extended even further. There does seem to be some denial from those wanting it to stay cooler- as I said the other day, most of us who want warmer conditions would have bitten someone's hand off for these charts a week or so ago.

It doesn't like there will be much 'cold comfort' on Tuesday night into Wednesday, that's for sure 

[Scorcher]

By the way, here is the 850 hPa chart for Monday afternoon. If you go by the ECM 00Z you only see the charts for the middle of the night for that particular date- the warmer uppers are moving in overnight. Mid 20s is nailed on if that comes off for the north of England and higher further south.

[Frosty.]

I agree with coldcomfort, he's not being pessimistic he's being realistic about the weekend which now looks ordinary with temps only reaching 23c in the south / southeast on sunday. There looks like being a lot of cloud and even a few showers around.

[A.J]

16 minutes ago, Karl. said:

I agree with coldcomfort, he's not being pessimistic he's being realistic about the weekend which now looks ordinary with temps only reaching 23c in the south / southeast on sunday. There looks like being a lot of cloud and even a few showers around.

whilst the NMM medium resolution progs temps of 25C plus for friday/sat/sunday in the south/south east with not too much in the way of cloud and no ppn....quite a contrast of just goes to show that one model output's brings disappointment to some.....other model output's bring nirvana 

Edited August 10, 2016 by ajpoolshark

[coldcomfort]

17 minutes ago, Karl. said:

I agree with coldcomfort, he's not being pessimistic he's being realistic about the weekend which now looks ordinary with temps only reaching 23c in the south / southeast on sunday. There looks like being a lot of cloud and even a few showers around.

Indeed, I think we all have to be mindful when posting that this might be a relatively small island but it is often very meteorologically diverse, with much of the northern half of the country only seeing temps somewhere between 13-18c during the rest of this week and right across the weekend.