Model output discussion 14/04/18

[SizzlingHeat]

6 minutes ago, Frosty. said:

Don't get me wrong, I'm loving this hot settled weather, think I've more than proved that recently!! but the Ecm 00z ensemble mean indicates a change around mid July to something more unsettled..or at least more changeable with some welcome rain for most of us!

Yes but thankfully that's 10 days away and subject to change

[East_England_Stormchaser91]

6z if anything looks better as we see the heights orientated a little further NE which would prolong the warmth more. I hope we see our breakdown when it does happen from the S and SW too. I wasn’t liking the look of the past few runs, which were pointing towards a dry and non exciting breakdown, with little in the way of ‘good storms’. That has now begun to change somewhat, with the latest run having the more pronounced low heights to the W of Iberia and France. 

Worth noting that despite having low pressure in control towards the end, it looks very August 2004 style (warm and showery/thundery) which I would happily take over featureless, boring northerlies or northwesterlies! 

[northwestsnow]

Seems Exeter are buying the 6z script.. quite a noticable shift in their update today towards unsettled weather.

12z runs will be interesting.

 

[irish1]

36 minutes ago, Man With Beard said:

Still just one cluster in the ECM ensembles, so back to figuring it out from the individual ones.

By 18th July, we have about 60% members looking changeable for all, 20% with a north/south split, and 20% fine for all.

By the end of the run at the 21st July, it's rather more evenly spread between more settled / less settled members. 

So a reasonable signal for an Atlantic driven period after next weekend, even if just for a few days. 

Where is the easiest location to see ECM ensembles ?

[Frosty.]

7 minutes ago, Alderc said:

I know its a consequence of living in generally one of the most boring and temperate climates in the world but just like our lack of ability to cope in Winter with snow I struggle to understand how the farming industry struggles with climatic conditions outside the long term norm in summer. While comparisons can't be made with Spanish/Italian climates there are parts of France/Germany etc which produce similar crops and graze the same livestock but have to deal with periods of much hotter, drier conditions than this is summer is currently handing and cope perfectly well. Is it a lack of investment in irrigation etc?

And back to the models. high res still looks predominantly settled and very warm / hot but mid July indicates a more unsettled period which may be no more than a blip before the fine weather returns..time will tell!

[gottolovethisweather]

14 minutes ago, Alderc said:

I know its a consequence of living in generally one of the most boring and temperate climates in the world but just like our lack of ability to cope in Winter with snow I struggle to understand how the farming industry struggles with climatic conditions outside the long term norm in summer. While comparisons can't be made with Spanish/Italian climates there are parts of France/Germany etc which produce similar crops and graze the same livestock but have to deal with periods of much hotter, drier conditions than this is summer is currently handing and cope perfectly well. Is it a lack of investment in irrigation etc?

It is the longevity of the dryness that is the problem as far as I know. Everything in nature is thirsty, all crops and livestock need a constant supply. Plus, these days the extremes don't lend themselves to a situation which helps farming or nature in general. It is a very different climate and world to that of 1976, think overpopulated lands and the problems these bring with them and you'll see what I mean. A few hours of steady prolonged light to moderate rainfall over all parts of the UK right now would be most helpful but that will not be happening any day soon. Still, enjoy the weather for what it is, I say, a memorable summer and one for the record books.

[Tamara]

1 hour ago, northwestsnow said:

Seems Exeter are buying the 6z script.. quite a noticable shift in their update today towards unsettled weather.

12z runs will be interesting.

 

Always good to step back from all NWP to take a look at possibilities, as without repeating chunks of my own previous post, numerical models do not always read tropical and extra tropical signals especially well at given distances. With that in mind, I'm sure that the Met Office have assuredly not made this update (or any other update at any time for that matter) based on some operational output beyond day 10

But, to take up a response fitted to the quoted post at face value, if we are for purposes of this reply going to focus on one single operational (which of course is not sensible at any time) then @Singularity does earlier on make relevant observations with respect to the Atlantic troughing profile.

Recent posts of my own have suggested (not forecasted) that the middle to later section of the summer might differ from the anticyclonic thrust from the SW and gradually morph into blocking scenarios focussed in origin more to the east and north east and with troughs attempting to bump up across this regime - likely featuring and resulting in the continuation of the entrenched heat from the first half of this glorious summer being highly reluctant to retreat into continental Europe. As much as NWP will probably be very progressive with this, taking into account the stated biases and climatology default, in trying to do so.

Its true that extended Euro ensembles and the GEFS are starting to pick up on the earliest signs of such a transition and its likely to be a messy and disjointed process and so certainly does pose the chances of something a bit more changeable as it occurs.

The main takeaway though is precisely the same as tried to be envisaged through the first half of the summer based on a crossroads appearing somewhere around the second third/half-way point of the summer. Namely, either low angular momentum stubborn continuation resulting in the friendly ridge extension to our west that has kept going for so long underpinned by shallow Iberian heat trough, finally submitting as assisted by changing mid summer wavelengths to a greater trough regime from the NW and more sustainably cooler conditions

or,

A switch to higher angular momentum regime timed very very nicely for the seasonal wavelength migration of the pattern to keep Summer 18 rolling along.

 

The considerable evidence for the latter scenario building credibility has been posted and updated regularly enough of late and doesn't need further repeating here. Suffice to say that tropical signals favour heading towards engagement of the warming Pacific pool(s) in the coming weeks and providing something of a Nino type kick to the atmosphere.

 

Eastward shifting tropical forcing

...and rising atmospheric angular momentum in mid summer do not equate, sustainably, to retracted strong mid N Atlantic ridge and jet stream coming south downstream. Quite the opposite - so best not be sucked into any operational (or ensemble means) in the coming days that wants to keep persisting unduly long beyond the mid month period with such a profile and jet stream trying to angle troughs south east across the UK.

Support for this may currently come from the extra tropics in terms of the lagged effect of easterly winds propagated from the recently entrenched tropical signal in the Western Hemisphere - (a -ve Asian mountain torque still persisting as a result of this associated trade wind burst).

 

But once the modelling catches on that the tropics are set to sing a different tune, then suspicions of the longevity and geographical extent of any mid month pause in this summers lovely bandwagon become quite grounded for sure 

 

 

 

Edited July 6, 2018 by Tamara

[Methuselah]

5 minutes ago, MP-R said:

The fact that there is a dedicated moans thread says it all...

lol

I was merely going by what the models are saying (or, rather, what they are not saying) in that there's no concrete suggestion of any useful rainfall occurring, any time soon...

[BlueHedgehog074]

As @Frosty.says, back to the models please guys. I understand people’s concern about lack of rainfall, but there is the moans and banter thread, or the general Summer chat threads, for that. Cheers.

[mb018538]

1 hour ago, northwestsnow said:

Seems Exeter are buying the 6z script.. quite a noticable shift in their update today towards unsettled weather.

12z runs will be interesting.

 

Doesn’t look awful, but reflects perhaps a trend towards a spell of unsettled weather....they don’t fancy it being long term though, and as Tamara has pointed out, in her estimation global teleconnections don’t really favour a NW-SE jet either. Let’s hope it’s just a week or so to re-align back to the heat!

[Paul]

A bunch of posts have been removed, as they're nothing to do with the model output. 

If you want to talk about summer generally, this is the thread for it:
https://www.netweather.tv/forum/topic/89703-summer-2018-moans-ramps-chat-etc/

There's also a thread about drought here:
https://www.netweather.tv/forum/topic/89866-drought-summer-2018/

 

 

[Frosty.]

Looking at the GEFS 6z mean, it's a hot sunny weekend and start to next week across southern uk, not as hot further north but still largely fine,  just a little rain for the far north, there is then a cooler blip on tues / wed further south and it's not cool anyway, just relatively compared to the current heat but through the second half of next week it becomes very warm again across most of england and wales..and high pressure / strong ridging dominates throughout next week.

Edited July 6, 2018 by Frosty.

[Snowjokes92]

I think the models have recently been over estimating the influence of low pressure to north west. Today the models are making less of it and because of that the jet stays to the north, allowing pressure to stay high or keep us under a ridge. Ive not seen anything remotely  unsettled come inside 240 hrs period and as is the case its still in fi. Have you noticed how just before FI, it stays settled. That should be enough reason to not pay too much attention to anything unsettled, as the runs still carry on holding it back and keep us dry longer

[Frosty.]

Unless I'm missing something, the ukmo 12z looks very nice next week under high pressure / strong ridging and there should be plenty of sunshine and warmth across the board. This weekend and start of next week will be hot and sunny across most of england and wales (high 20's / low 30's c) and then temperatures drop back towards the low / mid 20's c across southern uk for a short time around next tues / wed and then becoming very warm again.

[shaky]

Fantastic ukmo from start to finish!!that north easterly from that shortwave seems to be getting pushed further south and east with each run!!even on the gfs barr wednesday there is no real.low cloud issue and if it does develop should burn off rapidly!!gfs looking brilliant up to 174 hours now!!

[Dominic Carey]

 

22 minutes ago, Frosty. said:

Unless I'm missing something, the ukmo 12z looks very nice next week under high pressure / strong ridging and there should be plenty of sunshine and warmth across the board. This weekend and start of next week will be hot and sunny across most of england and wales (high 20's / low 30's c) and then temperatures drop back towards the low / mid 20's c across southern uk for a short time around next tues / wed and then becoming very warm again.

So lovely to see a continuation of this fine/hot weather,

[Man With Beard]

4 hours ago, irish1 said:

Where is the easiest location to see ECM ensembles ?

weather.us, select ECM, fiddle around with options but the key one is "master", for many parameters, it's possible to change that for individual ensembles 

[Frosty.]

The Gem 12z is a beauty from start to finish, at no stage does high pressure lose control, it's a hot weekend and start to next week across southern uk, temps then drop back into the low / mid 20's c but it stays largely dry with probably still plenty of sunshine across the board and towards the end it becomes very warm again further south..no sign of anything unsettled in the pipeline right through to T+240 hours..indeed there's power to add more fine very warm days beyond day 10!

Edited July 6, 2018 by Frosty.

[mb018538]

GEM holding firm, gfs having a wobbly again around day 9, dropping the trough through the UK and turning things cool and  unsettled.

i still don’t think the models are handling the tropical depression particularly well to be honest.

[Snowyowl9]

Just in time for the school holidays much cooler wetter and just typical british summer.

[Frosty.]

25 minutes ago, Snowyowl9 said:

Just in time for the school holidays much cooler wetter and just typical british summer.

The GEFS 12z mean doesn't indicate anything like as unsettled in that timeframe or indeed any timeframe, it's more of a north / south split in week 2 with the south seeing the best of the temperatures, dry weather and sunshine. Coming back to next week, it starts hot further south, less so midweek and then hotting up again later and next week looks dominated by high pressure and plenty of sunshine for most of the uk.

Edited July 6, 2018 by Frosty.

[mother nature rocks]

14 minutes ago, Snowyowl9 said:

Just in time for the school holidays much cooler wetter and just typical british summer.

That’s 10 days away!! Gem up to 10days pretty bang on and UKMO all the way thru’ day 7, heat living on!! Until cross model agreement it’s as much use as t**ts on a bull!!!

[Craig84]

Just comparing the ECM 144 of last night at the bottom to tonight’s ECM 120 below. The jet looks on more of a sw/ne axis tonight with a more robust area of high pressure associated with it. Hopefully this result in a better second half of the run 

Edited July 6, 2018 by Craig84

[Mike Poole]

Comparison of models at T144:

ECM and GFS more inclined to retract the ridge, the other two prolonging it.  While I think it is possible that there may be a mid month wobble, I'm still of the view that this pattern will take more to shift for good than models reverting to zonal bias in FI.  Maybe it will need a tropical storm to shake things up to the required extent to change the overall pattern.

[I remember Atlantic 252]

38 minutes ago, Snowyowl9 said:

Just in time for the school holidays much cooler wetter and just typical british summer.

week later here, starts Jul 23rd