Model output discussion 14/04/18

[Ice Man 85]

Just now, Ed Stone said:

You guys might be better-off moaning in the moaning thread? Not that I never make off-topic posts. Far from it!

its easy to get the 2 confused; lots of ramping in here after all if we're splitting hairs.

[Frosty.]

The Ecm 12z ensemble mean again turns into a fantastic run for summer warmth and settled weather.

Edited June 17, 2018 by Frosty.

[damianslaw]

Mmm whilst the models show the azores high becoming the dominant influential feature as we move through the next week, there is no signal for anything other than a rather weak tentative build of heights over the country - nothing robust locked and squeezed in situ by lower heights to the NE and NW, a sinking scenario looks likely, with pressure always most robust and highest to the south, with the north always at the mercy of a more atlantic influence. Very average, very standard fayre - it could be a lot worse, but those expecting a locked in warm protracted 'nationwide' spell should look away. Very decent though for the SE quarter of the country.

[Newberryone]

25 minutes ago, Alderc said:

This is a weather forum last time I checked, in the depths of winter you’d get nailed on here for bigging up charts that showed average maxes. While I’m sure it’ll be ok, there’s no there’s going to be a lot of cloud so I’m still not sure it’s going to be even as very averagely good as some of the charts are indicating.

You haven't been liaising with the Irish met people by any chance Alderc for despite their calling for a pronounced settled period from Thurs, disappointingly it has to be said they're only predicting temps to be in the mid to high teens. Hopefully this will be revised in the coming days to something far more favourable.  

[Djdazzle]

15 minutes ago, damianslaw said:

Mmm whilst the models show the azores high becoming the dominant influential feature as we move through the next week, there is no signal for anything other than a rather weak tentative build of heights over the country - nothing robust locked and squeezed in situ by lower heights to the NE and NW, a sinking scenario looks likely, with pressure always most robust and highest to the south, with the north always at the mercy of a more atlantic influence. Very average, very standard fayre - it could be a lot worse, but those expecting a locked in warm protracted 'nationwide' spell should look away. Very decent though for the SE quarter of the country.

You know a lot more about weather than me, but the other day you were saying that it was was very unlikely that the Azores high would build east, yet there is now a lot of support for that scenario. Is it a case of things can change despite the background signals?

[Frosty.]

I honestly don't understand the negativity in here, both the GEFS / ECM 12z mean show a fantastic extended outlook, you would struggle to find a better Ecm 12z ensemble mean than what I've posted above which indicates a nationwide summery spell on the way..Even before then, southern areas will see 25c tomorrow and 26 / 27c on tues / wed across the s / se....I'm hoping the met office are right, if they are there's lots to look forward to in the weeks ahead for those of us who love summery weather!

[Mokidugway]

2 minutes ago, Frosty. said:

I honestly don't understand the negativity in here, both the GEFS / ECM 12z mean show a fantastic extended outlook, you would struggle to find a better Ecm 12z ensemble mean than what I've posted above which indicates a nationwide summery spell on the way..Even before then, southern areas will see 25c tomorrow and 26 / 27c on tues / wed across the s / se....I'm hoping the met office are right, if they are there's lots to look forward to in the weeks ahead for those of us who love summery weather!

Have to agree frosty,even though I don't bother much with the mod thread current output is rather pleasing even for my neck of the woods .

[Mike Poole]

59 minutes ago, Frosty. said:

The Ecm 12z ensemble mean again turns into a fantastic run for summer warmth and settled weather.

Yes, I agree for ensemble mean charts these are very very good, and the ECM 12z op was also looking good.  If the main criticism of some runs was  the high centred west of the UK, if it is a ridge from the Azores it has to go through a period with the high centered west to get to a more favourable position to the east doesn't it?  

GEM 12z good to T174, then wobbly.

FIM9 ends very well tonight at T240:

Azores ridge over the whole UK 

Edited June 17, 2018 by Mike Poole

[Mike Poole]

GFS 18z, well the evolution in the later stages is interesting, high cantered out west to start with, moves east, and then combines with new link up with the Azores:

All in all, good runs today, roll on tomorrow.

[Thundery wintry showers]

For Friday highest pressure looks set to be centred over western and south-western Britain, although I think the GFS may be overdoing its central pressure, comparing with the UKMO and ECMWF which have it at nearer 1030mb.

I expect that this will mean plenty of warm sunshine for western areas but with that northerly flow eastern areas will probably be somewhat cloudier with isolated showers, probably stratocumulus trapped underneath a cap. 

Not sure about the posts referencing only weak ridges of high pressure - the UKMO admittedly has rather tentative ridging with westerlies over the top of the high which would promote a north-south split, but the GFS and especially ECMWF have a high of around 1025-1028mb central pressure sitting over a large portion of the UK around days 7-10.  I would expect the cloud in eastern areas to dissipate in that setup with a large majority of the country seeing warm sunshine.  The latter stages of the ECMWF run look potentially hot and thundery which is an outcome that I've been envisaging for late-June for some time, although my confidence in the hot thundery scenario is waning with a good chance of the high being too strong.

[Mike Poole]

Interesting on the GFS 18z ensemble mean, we're through to T336, and there's a signal for higher pressure just to the east of the UK:

This is what we want to see more of to land some decent hot summery spells.  Hopefully a lobe of high pressure breaks off to the east of us as part of the Azores high ridging.  I think this scenario growing in likelihood.

[SizzlingHeat]

Cracking morning run from ECM. Fine, warm and dry for most. The end of the run is particularly stunning with temps quite widely into the thirties by 216-240. All fi of course but nice to see anyway.

Weekend looks warm and sunny for many. Temps low twenties. Maybe mid twenties by Sunday. Lovely

[Summer Sun]

Cracking 00z from ECM with high pressure starting to dominate once more it get's progressively warmer as the run progresses 

[Guest]

Both ECM & GFS make a lot less of the troughing to our east later this week allowing higher pressure to build in a more favorable position. Both solutions looking at pushing the temperatures into the high twenties (ECM probably 30c). GFS ends the brief warm up with another northerly ECM looks towards the end of the run as though trough disruption in Biscay could occur leading to some very hot, thundery and humid conditions. 

Off course one thing to keep in mind, 3/4days ago the models looked as through they had got this week right so I wouldn't be surprised if the 12Z's have a screaming northerly in a weeks time......  

[Summer Sun]

Good news from 00z ECM ens it supports the idea of high-pressure rebuilding from later this week and temperatures will start to respond very nicely as well

 

[mushymanrob]

good news too from the noaa anomaly charts which support pressure gradually ridging in off the displacing azores high. however i dont think they support (yet at least) some of the ecm's stronger builds as we keep a (slacker) flow from the westerly quardant.

interestingly theres hints of pressure dropping over biscay. so a plume event later next week is a possibility with temps soaring along with humidity. but thats dependent on the expected ridging continuing its slow easterly track.

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

its also looking dry, very dry in fact after wednesday. at this rate ill be seeing brown lawns for the first time in 12 years.

[Pennine Ten Foot Drifts]

53 minutes ago, mushymanrob said:

its also looking dry, very dry in fact after wednesday. at this rate ill be seeing brown lawns for the first time in 12 years.

Yes I've been watching this, for the first time in I don't know how long (certainly years), I'm running low on all four water butts in the garden, and away from Scotland, NI and the very far north of England there's no noteworthy rainfall predicted for at least the next week. If longer term signals are to be believed I wonder how long before the first hosepipe bans are brought in?

[mb018538]

How about this for a corker of ECM ensembles. A week today - nothing other than a large ridge over the UK, just slight variations of the position.



Day 10 still looking great, every cluster remaining high pressure based.



It's not until right at the end of the run that anything unsettled starts to emerge, but even then 50% of the members are still settled.

[mb018538]

Just to show how quickly things can change as well....4 days ago at 240 hours, we had these options:



None of which really translate to the 168 hour charts generated today really. Fast moving game this weather lark.

[Man With Beard]

EC clusters D8-D15: Potential Heatwave Alert!!!

Last night's D10 clusters:

This morning's D10 clusters

It's one way traffic. Those red zones indicate much higher heights than usual, and they're all in good positions to make the UK hot.

EC mean 850s - on the brunnur site the bottom of the UK gets cut off but it's pretty obvious what's being missed out - the 10C upper line hits the midlands by D8, gets up to Scotland by D12, and is still over the south by D15 (look closely at the bottom corner). That's 7 consecutive days.

    

At the end of June, that should mean 24C-30C if low pressure muck doesn't infiltrate from France (like at the end of May). But the clusters don't really go for this Biscay/French low this time e.g. T300:

And the final lump of cream on top: of course, we know that on an anomalously high mean chart, the median will usually be even higher than the mean. Suggesting the middle ground may be even hotter than mean uppers charts propose.

I've seen enough. I'm ramping.

edit: @mb018538 you beat me to it

 

Edited June 18, 2018 by Man With Beard

[alr1970]

1 hour ago, Pennine Ten Foot Drifts said:

Yes I've been watching this, for the first time in I don't know how long (certainly years), I'm running low on all four water butts in the garden, and away from Scotland, NI and the very far north of England there's no noteworthy rainfall predicted for at least the next week. If longer term signals are to be believed I wonder how long before the first hosepipe bans are brought in?

Indeed, this is Manchester:

That's impressively dry right out to the end of the run. The 00Z was even drier.

The last hosepipe ban here was in 2010, starting July 9th. The rain started a week later, just as the schools broke up for the "summer".

[Guest]

Another reasonable run from GFS 06Z so pleasant and dry conditions looking likely for the next week or so. The Ensembles (which are unusually unanimous right out to the 27/28th)  paint a different picture than maybe the synoptics would suggest, the cold front racing south on Wednesday continues to accelerate forward in the model output to the extent that tomorrow is now likely to the be the warmest day of the week. Also the cold pool behind is quite potent for the time of year and takes around 4days to mix out before the ridge once again regresses westwards. 

Given how this week's brief ridge has panned out I have little confidence in any scenario beyond about Saturday (despite the good ensemble agreement), definitely more runs required but certainly a lot of dryness about. 

Edited June 18, 2018 by Alderc

[Summer Sun]

00z GFS run is very dry for England and Wales right out to D10 even in Scotland and NI it isn't exceptionally wet but enough rain to stop the grass going brown

[Gordon Webb]

22 minutes ago, Summer Sun said:

00z GFS run is very dry for England and Wales right out to D10 even in Scotland and NI it isn't exceptionally wet but enough rain to stop the grass going brown

On that chart is that rain on that day or from now until that day

[Guest]

1 minute ago, Gordon Webb said:

On that chart is that rain on that day or from now until that day

Accumulated amounts from now until then - basically nothing at all down here.