Model Output Discussion 12z 01/06/13

[summer blizzard]

GFS0z is very much like the ECWMF12z in how it handles the trough in my opinion, in that it has the trough approach but the angle of the Jet Stream shifts and we see the associated front effectively die as the main low heads north. Afterward we get some stunning charts as high pressure develops and a probable 30C is breached...

 

[Frosty.]

This week is going to be GLORIOUS with fine, sunny and increasingly warm conditions, temperatures into the high 60's to possibly low 70's today but by the end of this week they should be into the mid to upper 70's F, 24-25c and with light winds, it will feel very continental, just a few areas missing out for a while, northeast scotland & northeast england bordering the north sea will have problems with stubborn low cloud and sea mist/fog and temperatures closer to 13c but most inland parts of the uk are in for a fabulous week with almost unbroken sunshine, just some small amounts of fluffy fair weather cloud and becoming very warm, locally hot.

Edited June 3, 2013 by Frosty039

[Bristawl Si]

 

This week is going to be GLORIOUS with fine, sunny and increasingly warm conditions, temperatures into the low 70's today but by the end of this week they should be into the mid to upper 70's F, 24-25c and with light winds, it will feel very continental, just a few areas missing out for a while, northeast scotland & northeast england bordering the north sea will have problems with stubborn low cloud and sea mist/fog and temperatures closer to 13c but most inland parts of the uk are in for a fabulous week with almost unbroken sunshine and becoming very warm.

Looks promising, for sure.Even the showery breakdown, that many have been forecasting, seems to be on the wane (compared to model runs a few days ago).Also will the warmth and dry conditions stretch beyond the 10th, which many saw as a pivotal point for the weather to turn cooler and less settled?

[Frosty.]

An excellent Ecm 00z this morning, the anticyclonic conditions persist until later next week and it becomes warmer and warmer with lots of sunshine throughout, a big improvement on the 00z yesterday, after the dismal spring, early summer is looking stunning.

[AWD]

A quick scan through the various output and data this morning shows much of the same as it has done over the last few days now. This week looking to be rather sunny and warm for the majority of us, with temperatures widely into the low 20c's, a few select spots creeping up into the mid 20c's by the end of the working week. Showers do start to break out for some from midweek onwards though, as has been suggested for a while now. Scotland favoured for this scenario during the midweek period, thanks to a weak low in the North Sea;

This shown by the UKMO PPN chart;

A slow relaxation in SLP values during the final few days of the week, so as we go through the weekend showers start to form more widely. By 144 hours, the main NWP models aren't too far apart from each other, with a trough forming in the Atlantic and a slack pressure pattern over the UK;

It's the behaviour of said trough that will help determine the weather the UK receives next week. We do look likely now to see a spell of more changeable conditions to start of next week with. This can be seen with the GEFS SLP suite, with pressure lowering enough to allow for more changeable conditions;

Also present in last nights EC ens, with rainfall scenarios increasing into week 2;

Worth noting that the GFS Op was at the very top of it's 850hpa suite;

So the heat the GFS Op was showing in FI, for now at least, is best left in the closet. How long the possible changeable start to next week lasts is another question and one with no clear answer currently. The 500mb anomaly charts aren't too far apart from each other this morning, with a trough in the Atlantic influencing our weather, especially the north and west;

Note also the broadly westerly upper level airstream, this is another piece of data suggesting no high temperatures are likely within the next couple of weeks. Also note the GFS 500mb blocking anomaly charts show the clear positive anomaly to the north east of the UK to start with, but the signal then weakens as we go through week 2;

Perhaps a change of pressure pattern in the second half of June? Who knows! Back to the temperature outlook and the EC ens continue to show average-warm temperatures for the foreseeable;

Again, no sign of the GFS Op scenario there.

So all in all a pleasant start to summer continues. More changeable weather is looking increasingly likely into week 2 but with any rainfall falling more in the way of showers rather than frontal (away from the far North West), then there will always be sunshine to be had for many still. The GFS Op FI has very limited support, so the idea of a heat wave any time soon is unlikely IMO.

[Gibby]

Hi everyone. Here is the report taken from the outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Monday June 3rd 2013.All models show High pressure over the UK for the coming days before it drifts slowly away to the North with a slack or Easterly flow developing over the UK later in the week. Conditions will remain set fair through the week with varying amounts of cloud and sunny spells for all. Coastal areas will be cooler with onshore sea breezes developing each afternoon and the build up of daytime cloud could promote a few showers midweek in the North and West and perhaps the risk extending to other areas too by the weekend though most places will see nothing of these and stay dry and warm.GFS then shows a trough moving into Western Britain late next weekend sparking off some showers or outbreaks of thundery rain, especially in the West with clearer and fresher winds from the Atlantic following midweek. Pressure then rebuilds from midweek and with higher humidities it would quickly become very warm with sunny spells away from the drizzly NW before the chance of thundery showers looks possible for Southern Britain by the end of the run.The GFS Ensembles show the operational largely unsupported late in it's run with the vast majority of members pointing to an increasingly warm week to come before things return to more average levels with occasional rainfall chances increasing with time.The Jet Stream shows a weak flow blowing aimlessly around through the coming week before a resurgence of strength to an arm of the flow crosses the Atlantic towards Southern Britain by the start of next week.UKMO today shows falling pressure next Sunday though with light winds and no major weather features close by the weather may stay largely dry at this juncture with sunny spells but the odd heavy daytime shower developing in temperatures still reasonably high.GEM shows slack pressure at the weekend with a lot of dry weather between well spaced showers for the unlucky few. Next week though does show a wakening Atlantic with Low pressure knocking on the door of the UK with some rain for the West before the end of the run.NAVGEM too shows a similar evolution today with an Atlantic Low early next week pulling a potentially thundery trough slowly North and East over Southern and Western Britain early next week.ECM completes the set with a similar weather pattern to the rest gradually bringing an Atlantic influence into the UK early next week with the prospect of fresher winds and some rain displacing the quite and benign weather pattern prior to this.In Summary today there is a pattern beginning to emerge of a change to more Atlantic based weather pattern as we move into next week. This week is more or less set in stone now with the vast majority of the UK continuing to enjoy warm and settled conditions with no more than the isolated shower or two to interrupt this for the unlucky few. As the Jet Stream gradually picks up some momentum at the start of next week it energizes the Atlantic to bring troughs from an Atlantic Low into at least Western Britain to start next week though it may have a struggle to reach Easternmost areas with mostly dry and brighter weather most likely to be maintained here. However, between now and then a lot of dry and warm weather to be enjoyed for all.

[Frosty.]

 Looks promising, for sure.Even the showery breakdown, that many have been forecasting, seems to be on the wane (compared to model runs a few days ago).Also will the warmth and dry conditions stretch beyond the 10th, which many saw as a pivotal point for the weather to turn cooler and less settled?

I'm just pleased that the ecm 00z has put back a possible breakdown until later next week, hope this trend continues. High pressure looks like being in control for a good while.

[johnholmes]

The 3 main anomaly charts do indeed continue to show rather different upper air patterns to what one might assume from looking at the 00z GFS output. No problem of any significance this week away from at times chilly eastern coastal fringes, just a shower here and there probably sums it up. However it is the 6-15 day period where the anomaly charts show and have consistently shown a difference from the synoptic charts. The two shown by AWD are supported by the NOAA version and give a flow at 500mb from south of west into the UK. However that air originates from well north so it will never be other than about normal or a bit below for daytime temperatures after this week. Fairly unsettled too with the upper trough, a closed circulation on 2 of them, having more effect for most parts of the UK than the upper ridge showing over Scandinavia. Whether that MIGHT retrogress, ie move west is not known at the moment; so enjoy this week for a decent start to summer.

Edited June 3, 2013 by johnholmes

[Summer Sun]

With each update the ECM ensemble is pushing the low in the Atlantic back by another day

 

 

The GFS ENS is positive as well with pressure never getting too high across Greenland allowing pressure to rise again from the south in time

 

[Summer Sun]

Another dry, warm and sunny day tomorrow however there will be some exceptions

 

Away from the east coast especially in east Anglia and the SE where it does remain cooler temperatures are widely in the high teens

 

 

Away from the north west and parts of Ireland it looks like remaining dry and summery with lots of sunshine

 

 

http://forum.netweather.tv/topic/69815-weather-online-european-summary/?p=2706446

Edited June 3, 2013 by Summer Sun

[AWD]

Gavin, look at when the forecast was issued!!

Edited June 3, 2013 by AWD

[Summer Sun]

Gavin, look at when the forecast was issued!!

 

LOL talk about confusing people on the home page it says updated today then as you pointed out it was issued on May 13th

Edited June 3, 2013 by Summer Sun

[AWD]

Yes this morning

http://www.weatheronline.co.uk/cgi-app/reports?LANG=en&MENU=204&FILE=eus&DAY=20130603

Issued 05:30 Monday 13th May 2013

[Summer Sun]

Issued 05:30 Monday 13th May 2013

 

Just realised see my above post

 

on the home page it says updated today then as you pointed out it was issued on May 13th

 

All sorted now

[Milhouse]

It looks like the threat of a breakdown from the south at the weekend has all but vanished and in its place we get a continuation of the fine and warm weather. It could turn very warm judging by the the GFS 0z. Thereafter, still positive signs for high pressure to develop again ahead of low pressure in the Atlantic.

 

GEFS mean has a slightly more unsettled look to it

 

[Thundery wintry showers]

Another upshot of the high pressure being planted further south is that the "low cloud in the east" issue has receded substantially for Thursday and Friday and into the weekend.  Tomorrow may well see some low cloud and suppressed temperatures lapping into eastern coastal areas and I think this may penetrate a fair way inland early on Wednesday, though probably burning back to coastal areas during the day.

http://cdn.nwstatic.co.uk/gfsimages/gfs.20130603/00/63/ukmaxtemp.png

 

But for Thursday and Friday any low cloud and suppressed temperatures look set to be confined to eastern coastal fringes with the rest of the country dry, sunny and increasingly warm:

http://cdn.nwstatic.co.uk/gfsimages/gfs.20130603/00/111/ukmaxtemp.png

[Frosty.]

Navgem 00z looks nice and settled at T+144 hours, so we have cross model agreement that this week will turn into a very summery spell with temperatures soaring into the mid to high 70's F during the second half of this week and that includes the weekend, next week the ecm 00z shows high pressure firmly in control to begin with but pressure slowly leaks away and that would probably be the recipe for heavy showers to develop, the Gem 00z shows a half hearted breakdown eventually next week as high pressure builds from the southwest and clashes with the approaching atlantic low which disrupts it, there are signs of the fine spell rebuilding beyond that, all in all, this will turn out to be a near perfect start to summer. 

Edited June 3, 2013 by Frosty039

[Frosty.]

The Gfs 06z shows an increasingly warm week ahead with high pressure intensifying over the top of the uk and migrating northwards but leaving a strong ridge across the south, whilst most of the uk will be warm and sunny, there are a few heavy showers shown on the 6z, mostly across parts of scotland but a few dotted around elsewhere but you would be unlucky to catch one, it becomes very warm later in the week and next weekend with temperatures possibly reaching 80f in southern england by the weekend but it looks warm across most of the uk this week. The 6z shows a breakdown to much cooler and more unsettled weather for a time next week but it doesn't last more than a few days before the recovery begins, the azores anticyclone ridges northeastwards and low pressure influence becomes restricted to the northwest of the uk, a northwest-southeast split develops with the south & east becoming very warm and sunny again and eventually most of the uk becomes very warm and humid for a time but with thundery showers becoming widespread, the run ends with high pressure in control once again, so a topsy turvy FI but warmth and sunshine outweighs cool and unsettled considerably.

[Frosty.]

The met office are now expecting this summery weather to last into next week however some heavy showers could develop in places

 

It "could" turn more unsettled from mid-week note the word "could" all is going to depend on where the high places its self and whether it can send the lows north and west of the UK or not

I think the Ecm 00z backtrack probably has something to do with the could turn more unsettled aspect since it was the ecm 00z yesterday which was so bullish about the atlantic depression sweeping through the uk early next week but now it looks more anticyclonic until the start of next week before pressure slowly starts to drain away with that increasing risk of heavy showers once the high loses control, now it's the gfs 06z which looks over progressive with that low, also, the gem 00z seems unsure about the breakdown. Next week might yet turn out much better than first thought but just enjoy all of this week's fine, mostly sunny and increasingly very warm weather, temperatures later this week will be into the 24-26c 75-79f range, especially in the south & east.

Edited June 3, 2013 by Frosty039

[legritter]

Yes i will take current conditions and whats forecasted modelled over coming 6/7 days .beyond that at this range it could go severall ways especially with atlantic lows waking up and knocking perhaps on our western shores ,certainly different to last year but i was not here as i spent five wks in Canada hol and bereavement ,but good old UK made it onto their weather show over there most weeks .Lets get some different air masses and a bit of action ,although we have had the full monty last 12 months .perhaps tonights runs will show where those lows if any are supposed to form and track ,cheers 

[William of Walworth]

It'll all be about the exact track of any low pressure incursions. I'd hesitate to predict anything about that, at this stage.

[Frosty.]

The Ukmo 12z is an absolute corker, this week is really looking amazing compared to what has gone before, increasingly warm and sunny, less cloud across the uk from tomorrow with long spells of sunshine all week, next weekend looks perfect, temperatures in the mid to high 70's or even the low 80's later this week.

[shuggee]

Thanks for getting us back on topic Frosty

 

Discussion about the Met Office 30 day extended outlook has been moved to the erm, Met Office 30 day extended outlook thread.  As always, the clue is in the title.

 

http://forum.netweather.tv/topic/75951-met-office-16-to-30-day-outlook/

[mushymanrob]

not a million miles into fi... just what we dont want to see.... pressure rising to the far northwest, jet stream blasting well south of the uk.... enjoy this week, it might turn out like 07 yet...

[AWD]

not a million miles into fi... just what we dont want to see.... pressure rising to the far northwest, jet stream blasting well south of the uk.... enjoy this week, it might turn out like 07 yet...

It is one plausible option I agree. After seeing previous GEFS there was always going to be a run like this one eventually.However, it's just as plausible as another pressure rise. The GFS Op in FI often swings around and nothing should be taken too seriously at that stage, be it unsettled or settled.Until more reliable medium range data comes into better agreement such as anomaly profiles and ensemble suites, then a multitude of options will remain on the table for week 2.Based on the UKMO ( the trough at 144 hours is clearly heading towards the UK in the days after ) and the GFS, there does look to be an increased confidence in a more changeable pattern emerging for week 2 now. The question is how changeable and how long for? No answer to those questions currently.As an aside, Thursday and Friday and Saturday this week are looking rather warm now with mid 20c's likely for quite a few of us.