Model Output Discussions 12z 03/05/2016

[Frosty.]

The GEFS 6z mean paints a very summery picture from this weekend and throughout next week and even further ahead with continued azores high influence. We are on course for an increasingly anticyclonic weekend with rising temps and more prolonged sunshine with temps into the mid 20's c further south but as the high drifts further east early next week it opens the door to hot and humid continental air to drift north across the uk with temps going up into the 80's and even into the 90's F with hazy sunshine but a growing chance of thunderstorms, even by next thursday the temps are still in the mid to high 20's c in the southeast and low 20's c elsewhere.. still looks very good to me!

 

Edited August 9, 2016 by Karl.

[Nigelapplewhit4]

The GFS 06Z run is a disaster for fans of heat ! Very negative but inline with Met Office predictions of a very brief hot spell, to be swept away by active Atlantic lows very quickly.

 

Only one day over 30 for Manchester then the temperatures plunge. Not as much sunshine and a lot more cloud than was predicted on the 12Z yesterday. 

 

Im pinning my hopes that the GEFZ is more accurate. ! Fingers crossed that GFS 12Z returns to the heat forecast from yesterday! 

[cheese]

11 minutes ago, Nigelapplewhit4 said:

The GFS 06Z run is a disaster for fans of heat ! Very negative but inline with Met Office predictions of a very brief hot spell, to be swept away by active Atlantic lows very quickly.

 

Only one day over 30 for Manchester then the temperatures plunge. Not as much sunshine and a lot more cloud than was predicted on the 12Z yesterday. 

 

Im pinning my hopes that the GEFZ is more accurate. ! Fingers crossed that GFS 12Z returns to the heat forecast from yesterday! 

That's one more than Manchester usually gets.

GFS looks good to me though - even when the heat disappears things remain pleasant and settled. No complaints.

Edited August 9, 2016 by cheese

[mountain shadow]

49 minutes ago, Scorcher said:

What about beforehand though? Number 1, it's the 6z, number 2 it's well in FI. Funny how whenever there's something positive showing people immediately play it down, whereas when something horrid is showing deep in FI it's definitely going to happen. The warm spell could yet be extended.

Interesting you mention the start of September as well- the end of deepest FI is still a week away from September!

Because I balance my comments along with what the Met Office are saying. Their 16-30 day forecast talks of unsettled, therefore I have more confidence in the 6z input than I normally would.

[A.J]

It's a jolly good thing that the model output doesn't dictate the weather isn't it?.............The outputs are ebbing and flowing as usual when one considers all the variables that have to go into place for each data set especially when one takes into account how the verification percentages drop off rapidly the further the algorithms predict  future timescales. With that in mind, I do find it a touch ironic that some are looking at a breakdown of any warmth/decent weather before the warm/decent weather is actually showing its hand in the here and now!

[Man With Beard]

GEFS ensembles for the 06Z - looking at next Wednesday, this is clearly the most popular cut-off point for the heat, with a pretty even split between the runs that maintain the heat throughout Wednesday for most and those that have already chased the heat away the previous night. The number of ensemble runs that maintain a Scandi High that maintain a continental flow over is UK by the Friday (T240) is just 4. So the idea of keeping the heat going throughout the week not particularly strong on this ensemble set. But so much water to go under the bridge yet. We're probably well set until Monday now - generally fine with increasing warmth apart from a weak front Saturday/Sunday that may not amount to much, Monday/Tuesday very likely to be hot (but how hot??), then Wednesday onwards is the interesting bit where, I still feel, a twist could come if a Scandi High is close enough to the UK.

Interestingly, the extended GEFS (T250-T300) maintains some heights to the east, and the trough generally too far to our north-west to cause too much bother, so a half-decent period between D9 and D13 with warmth and sunny spells could transpire, though clustering not really strong enough to provide much confidence there.

ECM ensembles for London show strong clustering for heat on Tuesday/Wednesday next week (again, around the 30C mark for maxes more likely than 35C I guess), and then a drop back to normal or slightly above normal for the rest of the week.

This is probably a massive amount of over-analysis at such a long way out (fair point AJP!!), but I think it's interesting to follow trends - and I'd say the model trend so far today is to be a little more definite about whatever heat there may be probably being over by Thursday next week - but personally I'm still not so sure because of past experiences of an Atlantic failing to break down blocks to the east at the first attempt!

Edited August 9, 2016 by Man With Beard

[SMU]

41 minutes ago, Man With Beard said:

GEFS ensembles for the 06Z - looking at next Wednesday, this is clearly the most popular cut-off point for the heat, with a pretty even split between the runs that maintain the heat throughout Wednesday for most and those that have already chased the heat away the previous night. The number of ensemble runs that maintain a Scandi High that maintain a continental flow over is UK by the Friday (T240) is just 4. So the idea of keeping the heat going throughout the week not particularly strong on this ensemble set. But so much water to go under the bridge yet. We're probably well set until Monday now - generally fine with increasing warmth apart from a weak front Saturday/Sunday that may not amount to much, Monday/Tuesday very likely to be hot (but how hot??), then Wednesday onwards is the interesting bit where, I still feel, a twist could come if a Scandi High is close enough to the UK.

Interestingly, the extended GEFS (T250-T300) maintains some heights to the east, and the trough generally too far to our north-west to cause too much bother, so a half-decent period between D9 and D13 with warmth and sunny spells could transpire, though clustering not really strong enough to provide much confidence there.

ECM ensembles for London show strong clustering for heat on Tuesday/Wednesday next week (again, around the 30C mark for maxes more likely than 35C I guess), and then a drop back to normal or slightly above normal for the rest of the week.

This is probably a massive amount of over-analysis at such a long way out (fair point AJP!!), but I think it's interesting to follow trends - and I'd say the model trend so far today is to be a little more definite about whatever heat there may be probably being over by Thursday next week - but personally I'm still not so sure because of past experiences of an Atlantic failing to break down blocks to the east at the first attempt!

I cant see any ECM clustering around 30c & as it stands that means 35c is unlikely

The mean is nearer 25c - so reality if the clustering is 25-27 - the maxes are expected to peak 31-32c

Thats a notch down on yesterdays expectations - as the mornings runs are yet more progressive than yesterday....

 

Edited August 9, 2016 by Steve Murr

[coldcomfort]

40 minutes ago, ajpoolshark said:

It's a jolly good thing that the model output doesn't dictate the weather isn't it?.............The outputs are ebbing and flowing as usual when one considers all the variables that have to go into place for each data set especially when one takes into account how the verification percentages drop off rapidly the further the algorithms predict  future timescales. With that in mind, I do find it a touch ironic that some are looking at a breakdown of any warmth/decent weather before the warm/decent weather is actually showing its hand in the here and now!

It's a model discussion thread is it not? Therefore if people wish to talk about a breakdown which is supported by charts from said models, does it really matter what the current weather setup is?

[Man With Beard]

6 minutes ago, Steve Murr said:

I cant see any ECM clustering around 30c & as it stands that means 35c is unlikely

The mean is nearer 25c - so reality if the clustering is 25-27 - the maxes are expected to peak 31-32c

Thats a notch down on yesterdays expectations - as the mornings runs are yet more progressive than yesterday....

 

Yes - that's exactly what I meant - I translated clustering just above 25C equating to maxes around the 30C or a bit more.

Steve - you're very level-headed in the summertime!! I trust you'll have your ramping fingers back by Novembrrrr??!!

 

Edited August 9, 2016 by Man With Beard

[Frosty.]

55 minutes ago, ajpoolshark said:

It's a jolly good thing that the model output doesn't dictate the weather isn't it?.............The outputs are ebbing and flowing as usual when one considers all the variables that have to go into place for each data set especially when one takes into account how the verification percentages drop off rapidly the further the algorithms predict  future timescales. With that in mind, I do find it a touch ironic that some are looking at a breakdown of any warmth/decent weather before the warm/decent weather is actually showing its hand in the here and now!

I agree aj, let's give it chance to get here, it could yet upgrade again but as things stand, it at least looks equal to last month and could turn out hotter and longer!

[stodge]

Afternoon all

Yes, well, a lot does depend on the location and orientation of any pressure rise to the east or north-east. GEM had the core of HP in the southern part of the Norwegian Sea which left us in an unsettled warm and potentially thundery E'ly.

Other output holds the HP over Finland or beyond which leaves the UK in the trough as the slowing Atlantic LP systems hit the block.

The utopian (for heat fans) set up of an HP elongated north-south over Norway which was in some of the output yesterday evening seems to have been dropped for now.

The other aspect to the mood music is there seems no prospect of an early reload of heat. I wouldn't call it "autumnal" but GFS 06Z OP isn't inspiring in FI but it is FI:

[Mucka]

What a difference a day makes (In MO land anyway)

Edited August 9, 2016 by Mucka

[A.J]

22 minutes ago, coldcomfort said:

It's a model discussion thread is it not? Therefore if people wish to talk about a breakdown which is supported by charts from said models, does it really matter what the current weather setup is?

I'm well aware of the purpose of this thread thanks very much.....you sadly don't get my point, i.e there are some who seem too take great delight in the breakdown/shortness of synoptic patterns which the majority of members would enjoy, and have the habit of making such predictions as being 'set in stone'.....which they are not........to save going off topic, if you wish to reply for any clarification then please do so via the pm system....thanks

[Frosty.]

Those who think next weeks plume will be over in a flash should take a look at P1 Gefs 6z which is very similar to the Gfs 12z operational run yesterday, there are some more progressive solutions but some much slower ones too.

[Fourty Point Three Degrees]

Daily mirror reckon 35c will be hit everyday for two weeks.  Which model or ensillysembles did they look at because i'd like to see myself

[Man With Beard]

1 minute ago, Karl. said:

Those who think next weeks plume will be over in a flash should take a look at P1 Gefs 6z which is very similar to the Gfs 12z operational run yesterday, there are some more progressive solutions but some much slower ones too.

 

It is truly sad that I remember this, but P1 was one of the few ensemble members that picked out the July heatwave at distance - oh my goodness, I look at these charts far too much.

We're a million miles away from nailing down the breakdown yet. We haven't even mentioned thundery potential?

[Frosty.]

5 minutes ago, Man With Beard said:

It is truly sad that I remember this, but P1 was one of the few ensemble members that picked out the July heatwave at distance - oh my goodness, I look at these charts far too much.

We're a million miles away from nailing down the breakdown yet. We haven't even mentioned thundery potential?

Wouldn't p1 be wonderful in such a disappointing summer it would bring a warm glow to the end of the meteorological summer..I can dream.

[Man With Beard]

25 minutes ago, Karl. said:

Wouldn't p1 be wonderful in such a disappointing summer it would bring a warm glow to the end of the meteorological summer..I can dream.

I don't see any reason why P1 couldn't happen. It's not an outlier earlier in the run. It's all about timing. P1 is only very slightly different to the mean because, by T162, it does not develop a negative tilt between Iceland and Scotland on its leading edge, which means the first disturbance on the south flank of the main trough does not disrupt SE, but instead carries on around the low. Some heights get in between this disturbance and the second disturbance - and consequently, the second does disrupt SE. The heat is then caught between the two disturbances. It requires optimum timing, but it isn't ridiculous. 2 other ensemble members do exactly the same, just not quite as hot.

20% chance IMO.

[ChezWeather]

1 hour ago, 40*C said:

Daily mirror reckon 35c will be hit everyday for two weeks.  Which model or ensillysembles did they look at because i'd like to see myself

 

Can we please refrain from posting such utter garbage on these forums, the so called "journalists" who write these articles are just pathetic. 

[Summer Sun]

UKMO shows a southerly by Monday temperatures by this stage would be climbing into the high 20's and possibly low 30's in the London area

Edited August 9, 2016 by Summer Sun

[East_England_Stormchaser91]

From a general point of view. It is looking likely that we will see a plume of some kind. Probably a two day event to my view on things now. 

I'm grateful that we are getting another shot really considering how the outlook has been for the past two weeks. 30 degrees is looking likely. That is still way above average for UK standards! If you're hoping for 35c in every plume event or heat spike, have a word! 1976 if I'm right Only just managed to achieve that? and that was the summer of the century right?! 

Enjoy and make the most of what you get! 

Edited August 9, 2016 by East_England_Stormchaser91

[Scorcher]

30 minutes ago, East_England_Stormchaser91 said:

From a general point of view. It is looking likely that we will see a plume of some kind. Probably a two day event to my view on things now. 

I'm grateful that we are getting another shot really considering how the outlook has been for the past two weeks. 30 degrees is looking likely. That is still way above average for UK standards! If you're hoping for 35c in every plume event or heat spike, have a word! 1976 if I'm right Only just managed to achieve that? and that was the summer of the century right?! 

Enjoy and make the most of what you get! 

Yes expectations certainly seemed to be lowered by some. If you'd offered most of us tonight's GFS run a week ago we'd have bitten your hand off. Tuesday is looking like potentially a very interesting day with air coming from a long way south and most of the UK joining in with the heat.

The 15C isotherm covers almost all of the UK by Tuesday afternoon which is very rare indeed- it didn't even happen in the July hot spell.

There could also be a couple of very warm nights- particularly Tuesday night into Wednesday with some exceptional 850 hPa temps overnight.

As I've mentioned in the summer discussion, I also think Monday will turn out to be a hotter day than the GFS is currently suggesting.

Edited August 9, 2016 by Scorcher

[phil nw.]

Before the modeled warm up the north west of Scotland look like seeing as much 40% of the average monthly rainfall between Weds and Friday as wavering frontal systems move across off the Atlantic.The first image is just a snapshot of the surface pattern for the 3 day period and the second image is the percentage rainfall expected(colours representing percentages on the right of the chart) .

 

The approach of the Azores high by the weekend should bring the drier and warmer weather across much of the Uk after that wet period across the far north west.The height of the plume still looks to be next Monday and Tuesday on the GFS.By then we see signs of the Atlantic fronts already approaching western Ireland.Timing of this of course subject to change at this range.

Still a nice little Summery spell for many from the end of the week seems to on the way now-at least for a few days. 

 

[Frosty.]

The Gem 12z is a peach of a run from this weekend until next Wednesday inclusive with increasingly warm settled weather and then hotting up during the first half of next week with a long draw southerly plume bringing spells of hot hazy sunshine but an increasing chance of thunderstorms as humidity soars and then later next week looks very unsettled with thundery rain and showers.

[Man With Beard]

The GFS is colder on Wednesday next week than any of the ensembles (looking at surface temps) - about half keep it hot. Lots of fascinating possibilities for D8-D11

Edited August 9, 2016 by Man With Beard