Model output discussion 14/04/18

[Matthew.]

22 minutes ago, Alderc said:

Not cool model reading this evening. The apparent across the bird switch that fails to rebuild brings in arguable worse conditions than a raging Atlantic. The summer UK trough is arguable the most disappointing setup the U.K. can experience and a pattern that once locked in usually takes a minimum of a couple of weeks to shift!! 

A flat zonal summer pattern could be dry and endless cloud whereas the U.K. bullseye trough would be sunshine and showers 

[Mike Poole]

Unfortunately, as far as I can tell without seeing the individual runs, the ECM ensembles seem keen on the UK trough evolution.  Here's the mean and spread at T240:

The higher uncertainty near Ireland would suggest low pressure there on some of the realisations.

[draztik]

1 hour ago, mb018538 said:

ECM backs up the gfs ensembles....this has come out of nowhere really, a couple of days ago high pressure looked like ruling the roost. Just shows things can and do change at very short notice. Flabby slow moving Low pressure parked over the U.K. is dire, normally what we end up with in the bad summers. Let’s hope it’s just a blip.

to be fair, the writing has been on the walls for a while now. Certainly if anyone had been paying attention to the ext EPS.

Edited June 2, 2018 by draztik

[Frosty.]

38 minutes ago, Mike Poole said:

Unfortunately, as far as I can tell without seeing the individual runs, the ECM ensembles seem keen on the UK trough evolution.  Here's the mean and spread at T240:

The higher uncertainty near Ireland would suggest low pressure there on some of the realisations.

Yes there's no point trying to sugar coat it, but obviously i hope it's wrong although the models have been suggesting a cooler / unsettled blip towards mid june but I remain very encouraged by the MO extended outlook for the second half of June which currently indicates a potential return to very summery conditions right across the uk.

[Singularity]

Until if and when we see the MJO head on through the Pacific, we are effectively riding our luck in the low momentum environment, hoping that none of the disrupting troughs deposit a low right over us.

Its intriguing that we’re seeing ECM suddenly lurch toward the undesirable outcome with the disruption at 5 days range; the exact same thing happened with respect to the low for last Wed-Fri.

That time it proved to be a rouge run, though the low never adjusted as far back the other way as it had been, and the south has suffered from that. Perhaps the same will occur with respect to Wed-Fri next week?

As much as it displeases me to type those words, I fully accept that even great summers usually have some more unsettled spells. Those which don’t are the rarest of the rare and not for the sane of mind to reasonably anticipate, no matter what the background signals - some degree of fluke comes into such a summer. Like, a tropical cyclone moving in the right way at the right time.

 

As far as I see it, there’s true scope for a changeable spell during the second week of June, perhaps fresher too with Atlantic sourced air in the mix (but not necessarily!), but no reason to expect that to persist beyond that week unless the MJO forcing and upward GLAAM tendency is derailed.

Fingers thoroughly crossed on that one!

Edited June 2, 2018 by Singularity
An I for an O? Unacceptable! XD

[Fourty Point Three Degrees]

ECM12z joins the GFS12z with a green snotty trough splattered over the British Isle as early as next Friday - a big flip turn in what we've seen recently and this is within a more reliable time frame and not just in FI.   This to me looks like a filthy pattern that could be hard to get out of so I wouldn't get too excited about the MO's end of June forecast, don't forget the end of last July - seven day before and they dropped the idea of a settled nationwide spell being forecast for early August . .

[Djdazzle]

The U.K. trough is gone on the GFS 18z.

[bluearmy]

Whilst there remains the probability that nw Europe becomes troughy in the 6/10 day period, the overnight runs remind us that the broad status quo default pattern is also on the table. should the latter verify, it will be a remarkably stable pattern that has ruled the roost for two months or maybe even more. 

should be noted that even if  the less pleasant extended eps pattern that is referred in an earlier post verifies, sceuro area remains above average with upper ridge and the trough across nw Europe (rather than Iberia or France)  is pretty much a variation on a theme 

[Matthew.]

The ECM looks predominantly dry this morning for the first 3rd of June with no U.K. trough. Low cloud for eastern and central parts at times though

[JoeShmoe]

Just now, Matthew. said:

The ECM looks predominantly dry this morning for the first 3rd of June with no U.K. trough. Low cloud for eastern and central parts at times though

Yep, remarkable on ECM how dead the Atlantic is ...some places will be looking at water shortages if the dry spell goes out to mid june

[Frosty.]

11 minutes ago, Matthew. said:

The ECM looks predominantly dry this morning for the first 3rd of June with no U.K. trough. Low cloud for eastern and central parts at times though

As if by magic, the green snot uk trough has vanished, the Ecm 00z looks a lot more pleasant now..and that also goes for beyond T+240 hours.

Edited June 3, 2018 by Frosty.

[Guest]

I have to say I was somewhat surprised when I looked at Gfs and ecm this morning, was expecting a horror film instead it’s was the Disney channel, calm, settled and a suitable for all the family - can’t believe I just wrote that analogy (too much wine last night). We really are in the middle of an extended period of Atlantic slumber, maybe the sort that only happens every decade or so and it’ll be very interesting to see how long this last as a very interesting summer could occur with Northern European warming up notably while the Med would remain very unsettled.

[mb018538]

Echo the above, let's hope that disastrous set of runs from last night are kicked to the kerb as it were.

http://www.wetterzentrale.de/en/topkarten.php?map=1&model=gfs&var=1&run=0&time=144&lid=PANEL&h=0&mv=0&tr=6#mapref

A quick look at the postage stamps shows that a few runs do still have a trough, but nothing like yesterdays shambles. Perhaps slightly more unsettled, though not especially so.

http://modeles2.meteociel.fr/modeles_gfs/runs/2018060300/240-777UK.GIF?03-0

The 10 day ppn charts don't show anything too alarming....a little wetter over Northern Ireland and NW Scotland, trending drier the further south you go.

[northwestsnow]

As above i was expecting a lot worse this morning.

ECM is lovely and warm out to day 10, although the behaviour of the Atlantic trough is still not 100% nailed i wouldn't have thought.

[thestixx]

15 hours ago, mb018538 said:

Sorry, but I disagree there. To me I don’t see an Azores high building in any time soon - I personally see a disturbance meandering it’s way towards us in the next 5 days, which will eventually lead to a more unsettled spell - though not greatly so - more or less a continuation of the last fortnight....more unsettled in the south, better in the north closer to higher pressure.

Your post was clearly reliant on one op run. I was asking about the longer term evolution. X

[bluearmy]

Just as too much faith shouldn’t be placed in the 12z from yesterday, neither should it be in the 00z from today. However, given what we’ve seen thus far this spring, you would tend to lean closer to the 00z having more right than the12z’s 

 

[mb018538]

1 hour ago, thestixx said:

Your post was clearly reliant on one op run. I was asking about the longer term evolution. X

Don't shoot the messenger! It was merely based on yesterdays output as well as viewing the BBC extended forecast (https://www.bbc.co.uk/weather/features/44344408) which was broadly similar. I'd be very happy if we didn't get any sort of low parked over the UK, they can take ages to shift.

[Frosty.]

The Gfs 6z operational becomes unsettled and much cooler towards and during mid june with quite a lot of rain across the uk. ..

[Frosty.]

The GEFS 6z mean shows a change to cooler more changeable / unsettled atlantic weather towards mid june with lowering heights to the NW and the azores high / ridge retreating back home..further n / nw looks most affected whereas the s /se could escape the worst of it but according to this it would be fairly short-lived with the azores high ridging towards the uk by or soon after mid month with at least southern uk becoming more settled and warmer again.

Edited June 3, 2018 by Frosty.

[I remember Atlantic 252]

7 hours ago, northwestsnow said:

As above i was expecting a lot worse this morning.

ECM is lovely and warm out to day 10, although the behaviour of the Atlantic trough is still not 100% nailed i wouldn't have thought.

depends on your location, EC not great for here, could be 15 degrees, drizzly and breezy

[Mike Poole]

Well after last night's horror show, what do the models say tonight?

First thing to note, from the recent runs, last couple of days or so, is that there is a change underway, it looks like we will lose the very northerly jet and total continental dominance of the weather in the UK.  But there's still a great deal of uncertainty about what this will actually mean.  But the 12s start positively, UKMO at T144 has a decent ridge from the Azores:

I really like the GFS 12z, here to T192:

Remaining largely settled and warm, while the Azores high ridges towards us.  I also think with the Azores high becoming the more dominant feature, compared to heights over Scandi, maybe the easterly winds that have plagued the east side of the country might give way to more generally sunny weather - eventually.

Will be interested to see the ECM later.

 

Edited June 3, 2018 by Mike Poole

[Djdazzle]

GFS 12z looks unsettled post 240, but that’s deep FI so not worth worrying about yet.

[Matthew.]

Ukmo is looking good this evening with a more south easterly influence over Wednesday and Thursday 

[Scorcher]

Things are certainly trending in the right direction again after the shock of some poor runs last night. The noticeable thing about the GFS 12Z is the persistence of the warm air over the UK. Nothing exceptional but no real signs of the 5C isotherm leaving our shores any time soon. Most of us remain closer to 10C upper air temps. The consistent warmth of the past few weeks over Europe and Scandinavia has really pushed any cool uppers a long way north. Long may that continue.

As mentioned by others, subtle changes towards the end of the week may benefit areas further east as we gain more of westerly influence.

[Frosty.]

The Gfs 12z is a tale of roughly two halves... largely warm through high res  into early low res with plenty of fine sunny weather and a few heavy showers dotted around..whereas most of low res is cooler and generally unsettled.