Model output discussion 14/04/18

[Gordon Webb]

47 minutes ago, johnholmes said:

The anomaly charts to me suggest a NW-SE split, warmer and more settled on average the further SE one live. Less settled the further NW and fairly changeable. I cannot see anything in the next 2 weeks to suggest any major upper ridge development to give a return to the weather just leaving many areas.

in essence typical UK summer weather

[Singularity]

2 hours ago, northwestsnow said:

Yes ECM concurs that sun/mon/tues will be warm dry and increasingly sunnier the further south you head, bit of a north south split which will probably become more apparent from mid week onwards, further on i would like EC to drop its hints of northern blocking ..

I was pleasantly surprised to find that ECM raw data has 22-24*C widely across CS and SE England Monday.

The following two days are very similar for CS England, but SE England edges up a degree or two. More in the way of cloud counteracts the higher 850s, hence no high 20s, but the warmth also spreads right up across central and eastern parts of the UK. Mostly in the high teens elsewhere, but nearer mid-teens on western coasts.

After that, it's 20-23*C widely across CS and SE regions through to Saturday, which is not bad going, but mid-high teens elsewhere, which is undeniably a bit naff - but signs are this shouldn't be a long-term change.

Yes, I know... you could fill an Amazon warehouse with the number of signs being brought up lately, but that's just how it works with the longer-range .

 

[rain_shadow]

1 hour ago, johnholmes said:

The anomaly charts to me suggest a NW-SE split, warmer and more settled on average the further SE one live. Less settled the further NW and fairly changeable. I cannot see anything in the next 2 weeks to suggest any major upper ridge development to give a return to the weather just leaving many areas.

For now. But things and output can change in a day, therefore 2 weeks ahead of no ridging is not set in stone. Fortunately.

[Gordon Webb]

27 minutes ago, rain_shadow said:

For now. But things and output can change in a day, therefore 2 weeks ahead of no ridging is not set in stone. Fortunately.

it's a pity that scepticism is not there when charts show plumes wall to wall sunshine and high temperatures where some are of the attitude that it's nailed on no matter what the time frame

Edited June 14, 2018 by Gordon Webb

[Methuselah]

1 hour ago, Gordon Webb said:

in essence typical UK summer weather

And, in terms of UK summer weather, the term 'typical' can hide a multitude of sins IMO: just because rainfall/sunshine/temperature might all come out as 'average' (+/- a SD or so) overall, that says little or nothing about day-to-day variation...?

Also, IMO, what the models might show, post day 10, is also of little use as, by that time, timings alone will be so far out as to render details almost meaningless...?

At that point I tend to turn my attention more onto what the teleconnection guys are thinking...

[Djdazzle]

GFS 6z continues to show the AH ridge gaining more of a foothold in the medium term.

[Frosty.]

The Gfs 6z operational shows a good deal of fine warm weather across southern uk next week thanks to azores high ridging and then rebuilding in later next week with temperatures mostly into the low / mid 20's celsius range, warmest for the SE, not completely settled but better than further north which looks considerably cooler with some rain / showers at times but also fine spells too. Into the following week a change to cooler unsettled weather as a trough swings down from the n / nw  but then warming up with plume like conditions as we see high pressure building strongly to the east and a low / trough stalling to the w and then drifting slowly N to the west / northwest of the uk enabling a very warm / humid continental inflow with an increasing risk of thundery activity, especially further s / e...the run ends with an atlantic / azores ridge edging in.

Edited June 14, 2018 by Frosty.

[Gordon Webb]

31 minutes ago, Frosty. said:

The Gfs 6z operational shows a good deal of fine warm weather across southern uk next week thanks to azores high ridging and then rebuilding in later next week with temperatures mostly into the low / mid 20's celsius range, warmest for the SE, not completely settled but better than further north which looks considerably cooler with some rain / showers at times but also fine spells too. Into the following week a change to cooler unsettled weather as a trough swings down from the n / nw  but then warming up with plume like conditions as we see high pressure building strongly to the east and a low / trough stalling to the w and then drifting slowly N to the west / northwest of the uk enabling a very warm / humid continental inflow with an increasing risk of thundery activity, especially further s / e...the run ends with an atlantic / azores ridge edging in.

not set in stone as to take a little bit from a post above

[Frosty.]

7 minutes ago, Gordon Webb said:

not set in stone as to take a little bit from a post above

Did I say it was set in stone?..I just described what the run showed to the best of my ability!

[Man With Beard]

Well that didn't work out ... EC clusters 11.6 for T240 vs today's T168. 

  

Mind you the EC op has been ahead of the game here with the N Atlantic mini-ridge

    

So even if dry, probably not that hot as the flow becomes N of W for a time

 

[mb018538]

http://brunnur.vedur.is/kort/ec-ens/2018/06/14/00/ec-ens_nat_z500scenarios_2018061400_240.png

ECM 00z scenarios here - quite a bit different from last nights 12z actually, and not as good. Only 17% truly high pressure dominated, the rest are westerly based with varying strength ridges.

http://brunnur.vedur.is/kort/ec-ens/2018/06/14/00/ec-ens_nat_z500scenarios_2018061400_360.png

Just for fun the 360 ensembles...roughly 60% unsettled with a trough over the UK, 40% high pressure dominate with the low back up over Iceland. So no real trend there.

[Djdazzle]

The EC ensembles seem to flip like a pancake!

[johnholmes]

4 hours ago, rain_shadow said:

For now. But things and output can change in a day, therefore 2 weeks ahead of no ridging is not set in stone. Fortunately.

Rare that there is such a change as you suggest in the anomaly charts, which is why I use them for getting a feel for the upper air pattern beyond 6 days.

[Northern Sky]

Still hardly any rain in the model output for neck of the woods. It really has been a exceptionally dry few weeks. I keep hoping for a day of downpours but aside from Saturday which looks hit and miss the outlook is dry.

[Djdazzle]

7 minutes ago, Northern Sky said:

Still hardly any rain in the model output for neck of the woods. It really has been a exceptionally dry few weeks. I keep hoping for a day of downpours but aside from Saturday which looks hit and miss the outlook is dry.

Yes I think June will end up being exceptionally dry, if not consistently hot. 

[rain_shadow]

4 hours ago, Frosty. said:

Did I say it was set in stone?..I just described what the run showed to the best of my ability!

My answer is the same as Frosty's.

[rain_shadow]

6 hours ago, Gordon Webb said:

it's a pity that scepticism is not there when charts show plumes wall to wall sunshine and high temperatures where some are of the attitude that it's nailed on no matter what the time frame

Trust me, my scepticism is always there, warm or cold, sunny or rainy. Nothing is set in stone after a week or so, the models can flip. I apologise for wanting some summery weather in Summer.  

Edited June 14, 2018 by rain_shadow

[Djdazzle]

GFS 12z looking very good up to 168. Not much point going beyond that.

EDIT: UKMO looking very good also.

Edited June 14, 2018 by Djdazzle

[Mike Poole]

20 minutes ago, Djdazzle said:

GFS 12z looking very good up to 168. Not much point going beyond that.

EDIT: UKMO looking very good also.

Certainly agree re UKMO but that stops at T144.

But I think the GFS story is worth elaborating on.  It quickly goes downhill after that point, and given we thought there was a decent signal for the decent weather to be extended, it's noteworthy that this run again builds this Atlantic ridge which could become a major pain.  Here T240:

GEM isn't great either but it's totally different to this at the end of the run. Uncertainty reigns this evening.

Edited June 14, 2018 by Mike Poole

[Djdazzle]

14 minutes ago, Mike Poole said:

Certainly agree re UKMO but that stops at T144.

But I think the GFS story is worth elaborating on.  It quickly goes downhill after that point, and given we thought there was a decent signal for the decent weather to be extended, it's noteworthy that this run again builds this Atlantic ridge which could become a major pain.  Here T240:

GEM isn't great either but it's totally different to this at the end of the run. Uncertainty reigns this evening.

I would be worried but it’s in deep FI - the evolution beyond 180 has been changing a lot from run to run.

[Mike Poole]

8 minutes ago, Djdazzle said:

I would be worried but it’s in deep FI - the evolution beyond 180 has been changing a lot from run to run.

Maybe today it's changing, but my recollection of the previous couple of days is different, it was more consistent.  Let's see what the ECM's take on it is, the ensembles will be interesting too.

i'm certainly not saying the GFS at T240 will verify, just that there seems to me to be much more uncertainty today.

Edited June 14, 2018 by Mike Poole

[Djdazzle]

4 minutes ago, Mike Poole said:

Maybe today it's changing, but my recollection of the previous couple of days is different, it was more consistent.  Let's see what the ECM's take on it is, the ensembles will be interesting too.

i'm certainly not saying the GFS at T240 will verify, just that there seems to me to be much more uncertainty today.

Can’t post chart at the moment, but the GFS mean at 240 looks a lot better than the op, although still not overly settled.

[northwestsnow]

UKMO 144 looks good to me..

Sun-wed look warm away from the NW of Britain.

*Hope we see the wind die back a bit its annoyingly gusty again today.

Edited June 14, 2018 by northwestsnow

[summer blizzard]

Trades and westerlies both weak but setting up on the Nino side of the board (trades over the Indian Ocean, convection over the Pacific) so those looking for a warmer pattern may all things being equal be in look as we move into July. No guarantee of course (summer 2004 and 2009 both saw poor July's during a neutral-weak Nino).

Current modelling is refreshingly poor with higher heights finally building north..

 

[johnholmes]

The latest ENSO output from CPC

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.pdf