Model Output Discussions 12z 01/06/2017

[Man With Beard]

Just now, knocker said:

And as you know, or should, I'm not saying the ecm is correct merely stating what the model is showing. If everyone wants to discuss what the max temps are going to be in their own opinion a week away that's fine but it's way above my pay grade. And I still feel discussions on whether a heat wave is immanent and what constitutes one, is not relevant to this thread.

I don't agree. A lot of terms e.g. "freeze" / "cold" / "mild" / "warm" / "hot" "heatwave" are used here to define the model output quickly - otherwise we'd have to use actually figures all the time which would be rather monotonous. So in order to be a model output forum where posts are understood by all, it's important to develop a collective understanding of what the terms we are using to describe output actually mean.

[Frosty.]

22 minutes ago, Man With Beard said:

I always use the 80F marker as my definition of "heatwave".

Perhaps 25C would be more appropriate north of Manchester

Agreed, 25c is a heatwave up north for several consecutive days, of course 25c in itself isn't hot but its very warm and combined with sunshine its warmer still and not forgetting humidity which makes 25c feel closer to high 20's celsius..anyway, it looks like next week onwards will become increasingly summery across the uk.

Edited July 12, 2017 by Frosty.

[knocker]

11 minutes ago, Man With Beard said:

I don't agree. A lot of terms e.g. "freeze" / "cold" / "mild" / "warm" / "hot" "heatwave" are used here to define the model output quickly - otherwise we'd have to use actually figures all the time which would be rather monotonous. So in order to be a model output forum where posts are understood by all, it's important to develop a collective understanding of what the terms we are using to describe output actually mean.

Interesting you say that but I seem to recollect the meaning of the terms you have mentioned being discussed at frequent interval and a collective understanding always seems very elusive Not surprising as they are all subjective.Perhaps a glossary of terms used in the thread, freely available, would solve the problem. For example in winter people would then understand that a 'Greeny High' is a a high cell anywhere within 2000Km of Thule.

In any case the important factor here, as far as I'm concerned, is the dry warm weather the rest of July is certainly looking the percentage play.

Edited July 12, 2017 by knocker

[Man With Beard]

Just now, knocker said:

Interesting you say that but I seem to recollect the meaning of the terms you have mentioned being discussed at frequent interval and a collective understanding always seems very elusiveNot surprising as they are all subjective.Perhaps a glossary of terms used in the thread, freely available, would solve the problem. For example in winter people would then understand that a 'Greeny High' is a a high cell anywhere within 2000Km of Thule.

This would be a good idea. I will PM the powers that be.

[Fourty Point Three Degrees]

Well the 06z has backed down a little in my opinion but I'm hoping it picks back up if trends are there.

[Frosty.]

1 minute ago, Frosty. said:

The GEFS 6z mean still looks pretty darn good to me with extensive azores high influence and increasing heights across scandinavia too. It looks to me like we are on track for a nationwide summery spell, best further south but the first sustained good spell for northern uk.  

Bank

Edited July 12, 2017 by Frosty.

[Frosty.]

Well it's a great update, better than yesterday and despite what the Gfs 6z operational run showed, the mean looks a lot better and could become better still!

As far as i can tell, good summer weather is on the way back next week onwards and the north will join in at last..also a risk of thunderstorms at times to spice things up, especially further south but most importantly it looks like temperatures will climb above average with a good deal of settled weather across the uk and very warm spells increasing.

Edited July 12, 2017 by Frosty.

[Singularity]

If I didn't know better I'd swear the operational runs have a built-in 'nudge' toward taking small lows across southern UK at the mid-longer range .

Such a path is a possibility, sure, and one that leaves us looking for a nice clean realignment of the jet stream to stay far enough NW of the UK that the Atlantic troughs are unlikely to move close enough to open a doorway for lows  over W. Europe to move north. The GFS 06z keeps the jet more wavy and this is not helpful unless the S-tracking low stalls out well west of the UK in which case it may simply pump more warm air into the ridge aloft and help it to become/remain strong across the UK. This is a more common outcome for fine summer spells in the UK but the resulting as settled weather doesn't tend to last as long. The trapped Euro 'heat low' is more effective - and while harder to achieve, it does usually depend on something the models strongly agree upon; a deep quasi-stationary trough across Greenland.

So we have a good shot at it but as usual, no guarantees - so best keep those fingers crossed!

Edited July 12, 2017 by Singularity

[johnholmes]

4 hours ago, Man With Beard said:

GFS 06Z - ooops!

Thankfully @johnholmes will be on here soon to remind us not to get hung up on each individual operational run!!

General picture is - main trough lifting far from Scotland, lots of settled weather, some minor troughs mixed-in - GFS still following this bigger picture, just that the minor troughs have our name on them!!

It's either 7 settled days next week, or 5/6 settled days ... for the south, a continuation of the summer to date, but for the north, a massive improvement regardless of which one we get.

Heatwave claims? I was playing them down yesterday, but entirely justified this morning to me. The ECM has that 12C 850Hpa line well into the UK from T168 to T240, and 10C over almost all populated areas. At this time of year, optimum conditions will bring ground temperatures in optimum locations of 25C-28C in the north / 28C-32C in the south from that. That qualifies as a heatwave to me?

Next Wednesday/Thursday certainly on my watch for 30C in the SE, a little way to go yet of course.

    

I'll give a view on the usual 500mb anomaly charts tomorrow morning when the evening input from NOAA is in tonight followed by the EC-GFS in the morning.

The EC-GFS have been trending to a ridge developing but much less so with NOAA, in the area needed to give settled and probably some warmth, how far, how much, is unclear even with EC-GFS so far.

[Ice Man 85]

Just now, Frosty. said:

You could always try telling us what the various models are showing instead of moaning all the time..just an idea!

Okay then (from my understanding at least)

GFS: around 24 from next wednesday. Factoring the undercook, likely 26 at least. 0z shows a breakdown early next week and back to more reasonable temps. 6z shows a sharp breakdown but a rebuild at the end of the following week.

ECM: same as the GFS out to the 10 day range. Likely upper 20s from next wednesday

GEM: same general trend as the above but not as warm. Still, who takes that seriously anyway?

GEFS: same trend but different raw temps and perhaps a return to less oppressive temps next week.

Ensembles still don't agree with upper 20s being achieved in my area at least.

 

Thats the best I can do.

[MR EXTREMES]

Looking at the noaa jet flow Id bet bottom dollar that the azores heights will win out. 

I'm confident of a prolonged summery spell of weather. 

Often warm very warm to hot at times with possibly some home grown heat,

I'd bet bottom dollar there's a possibility of 38c at some point through the last part of summer. 

As has been suggested a little blip over night and a steady return to summer. 

 

[Nick L]

Several posts hidden. This is not the thread for guilt-tripping folks about their weather preferences, nor expressing your dislike of certain weather.

[Matthew.]

UKMO going for a settled start next week. Looks very pleasant. Maybe the best summer spell since 2014 on the way. No getting carried away with 2013, 2006 or 1995 just yet though

[Captain Shortwave]

UKMO/GFS

   

Good agreement on high pressure building through the UK early next week, we may get some hiccups but that is a good start. Fronts could affect the north west and the risk of thunderstorms developing close to the shallow trough to our west as it becomes slowly cut off, the south west being at highest risk. The GFS hotting up by day 7 as we pull in the heat from France.

[Singularity]

Yes... Nice little adjustment west with the dropping low on the 12z runs giving us a wider margin of error for trapping the heat low in place S of the UK with warm or hot dry air wafting into England and then (later) remaining countries from the continent .

[Frosty.]

Looking at the Gfs 12z, summer is back with a bang, literally next week with increasing warmth, sunshine and humidity and also a growing chance of thunderstorms across the south as continental air wafts north across the south of the uk. The north doesn't miss out on warmer weather with some sunshine but the real heat is further south where low 30's celsius is again indicated for a time.

Not forgetting this weekend which looks warm and fine with sunny spells across the south under the azores ridge, more changeable and less warm elsewhere but then high pressure builds in from early next week.

Edited July 12, 2017 by Frosty.

[TJS1998Tom]

23 minutes ago, Frosty. said:

Looking at the Gfs 12z, summer is back with a bang, literally next week with increasing warmth, sunshine and humidity and also a growing chance of thunderstorms across the south as continental air wafts north across the south of the uk. The north doesn't miss out on warmer weather with some sunshine but the real heat is further south where low 30's celsius is again indicated for a time.

Not forgetting this weekend which looks warm and fine with sunny spells across the south under the azores ridge, more changeable and less warm elsewhere but then high pressure builds in from early next week.

I hope the West side of the country gets thunderstorms between 22nd and 29th July as we woud get a great view, it'll be typical though if the East gets some when I'm not there lol

[TJS1998Tom]

12z for the end of the month looking very nice

[Frosty.]

The Gem 12z goes for a very warm and humid continental SEly incursion next week with a thundery outbreak before it becomes cooler and fresher from the w / nw.

Edited July 12, 2017 by Frosty.

[Flash bang flash bang etc]

6 minutes ago, Frosty. said:

The Gem 12z goes for a very warm and humid continental SEly incursion next week with a thundery outbreak before it becomes cooler and fresher from the w / nw.

I'll happily take the humid if it does indeed breakdown

[Frosty.]

Just now, Flash bang flash bang etc said:

I'll happily take the humid if it does indeed breakdown

Amazing how different the Gem looks compared to this morning which was very anticyclonic..definitely some ????about next weeks evolution.

[Flash bang flash bang etc]

Just now, Frosty. said:

Amazing how different the Gem looks compared to this morning which was very anticyclonic..definitely some ????about next weeks evolution.

Yeah for sure! it's great to have something to get excited about again...

Looking like a great summer in store - for southern areas at least - provided we get some cooler interludes (especially at night)

[Man With Beard]

All models a little fiddly at the end of next week, unlucky if it goes wrong I feel - but the ECM has that upper low in prime position to our SW at D9/D10 to suck up some serious heat.

[Ice Man 85]

1 hour ago, Flash bang flash bang etc said:

Yeah for sure! it's great to have something to get excited about again...

Looking like a great summer in store - for southern areas at least - provided we get some cooler interludes (especially at night)

If the scenario most on this forum wants comes off, it won't be cool in the south for a good while.

[knocker]

Stornoway basking along with the Royal Duchy. Looking good Sid! A good old positive tilt to the trough works wonders.

Edited July 12, 2017 by knocker