Good evening. Here is the report on the 12 noon outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Thursday August 29th 2013.

All models show a series of weak fronts moving SE over the UK with some bursts of light rain in places as they pass. Cloud amounts will be large overall with a moderate Westerly wind blowing and just brief sunny intervals. Over the weekend the troughs clear away with a NW flow bringing cooler and clearer weather across all areas with sunny spells and the odd shower in the North. By Monday and Tuesday pressure builds across the South with some warm sunny intervals developing as winds back towards the SW. In the North cloud and occasional rain will develop as fronts move in from the west on a freshening breeze.

GFS then shows a deepening depression up to the NW gradually extending it's influence to all areas with rain or showers before the weekend. The Low then fills as it moves SE over the UK then Europe. Then through the rest of the run a period of slack pressure develops before High pressure builds West over the South for a time at the end of the run with some fine and warm weather in the South.

The GFS Ensembles are broadly similar to this morning when taken as a whole with a breakdown occurring in the South around the 5th with rain at times for the rest of the run. Temperatures after a few more warm days early next week settle close to average though with some marked fluctuations shown through the second half of the run especially in the South.

The Jet Stream shows the flow gradually moving slowly South towards the UK on a West to East pattern although accessing data tonight is rather difficult and this statement os based on the 6z output.

UKMO tonight shows High pressure out to the SE with a warm South flow albeit light across the South and east. Out to the West a front is poised to move into the UK late in the day with some rain possible.

GEM shows a shift tonight to a decline in conditions later next week as Low pressure sinks South and develops into a deep feature close to the SW by the end of the run. A progressive spell of deteriorating weather would be likely from the middle of next week with showers or longer spells of rain in places as well as increasing winds and cooler conditions.

ECM shows Low pressure developing to the NW with a broad trough extending South over the UK with rain and showers developing for all later next week. The end of the run indicates Low pressure in control to the North of the UK with abroad and unstable westerly flow across the UK with rain at times for all in average temperatures at best. 

In Summary tonight the trend I alluded to this morning is shown again tonight with the prolonged High pressure based ridge from the Azores over the South showing signs of declining away as the Jet Stream steers Low pressure down over the UK later next week with some useful rain and showers for all. To what extent and duration such a change will take is unsure at the moment but it does look increasingly likely to happen with each run so best enjoy the decent weekend and start to next week while we still can.

http://www.wetterzentrale.de/pics/Recm2161.gif

Unsettled later from ECM

http://www.wetterzentrale.de/pics/Recm2401.gif

Looks OK here.

How accurate it is another thing altogether.

http://www.jp2webdesign.co.uk/ds/gfs.htm

The ECM 12Z would give us weather very reminiscent of September 2002 with the Scandi High developing, which was one of the best September's of the last 15 years in my neck of the woods. It came after a summer which saw a very poor June and July, and then a rather better August.

That would be a nice cooler but dry arrangement, and the High Pressure there initiates an early cool down over Western Russia.

Looks superb.

I daresay that ECM run could have evolved very differently had it not found so much energy from the thermal contrast. I do suspect that the model tends to overestimate the amount of energy available to storm systems that arises from the thermal gradient.

GFS is more restrained and keeps the HP across Scandinavia in place until the last few frames of the run. It's resilliance, even as the Azores High is squashed and squeezed aside, allows us to recieve another burst of warmth in a couple of week's time, before the Atlantic finally manages to aim it's sights at us.

The setup for mid-week is starting to look like a complicated one now that the models are firming up on the idea of some energy dropping south in a split-jet scenario. Kudos to ECM for spotting that first, but a shake of the head for dropping the idea again this morning!

Good consistency this morning for the fine, very warm and settled conditions to give way by Thursday 5th September as a fairly weak trough establishes itself close to the UK. 

A warm run of temps on the way for next week

Good morning. Here is the report on the midnight outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Friday August 30th 2013.

All models show a series of weak fronts crossing SE over the UK today and tonight, the last of which brings clearer, cooler and fresher weather to all areas before tomorrow morning. The weekend will then see pressure rising again with the cool NW flow for both Saturday and Sunday being snuffed out by Monday. bright and sunny if cooler conditions will affect all for the weekend with cool and dewy night's Monday and Tuesday are both shown to be bright and dry and altogether warmer again in the South while the North clouds over with time with an increase of SW wind and a little rain late Tuesday.

The Fax Charts appear to be having none of the breakdown anytime soon next week as the High building over the South at the weekend and start to next week looks very reluctant to leave the South on the 120hr chart released last night with no more than a glancing blow from troughs over the north by midweek.

GFS then shows more unsettled conditions spreading East across the UK later next week with some rain at times for all in average temperatures. Fronts then continue to affect the UK at times until the start of the second week and rather longer in the North before High pressure builds over the UK from the South and West with fine and dry weather dominant with mist and fog at night at the end of the run.

The GFS Ensembles continue the theme as before with a cool weekend and then a warmer couple of days before a period of average uppers or thereabouts are accompanied by occasional rainfall even in the South. The operational was a warm outlier at the end of the run but with plenty of spread I wouldn't discount it.

The Jet Stream prediction is based on the GFS output and with High pressure based over the UK in the latter part of the run the flow remains located North of the UK for much of next week. However, the general consensus from other output is to bring it somewhat further South though not alarmingly so with the main thrust of it crossing near the North of the UK next week.

UKMO today shows a trough of low pressure crossing East over the UK next Thursday with some showery rain for all for a time, heaviest in the North. I would suggest a ridge of High pressure would possibly follow at the end of the week with things drying out again.

GEM shows a similar trough crossing East after midweek with High pressure building back over the North from the Atlantic by the weekend while low pressure develops near the SE with a cool North then NE flow bringing some rain or showers for these areas in cool weather while for a change the North and West see the driest and brightest conditions though none too warm.

NAVGEM today shows a weakening trough cross east too midweek before pressure begins building again from the SW towards the end of the run with the rain petering out in the East as dry weather spreads back in by the weekend from the South and West.

ECM is this morning somewhat similar to GEM bringing a trough across midweek which is followed by a cut off depression which locates near SW Britain at the end of the run with rain or showers likely in the South from midweek. The North too would see rain at times before High pressure ridges across from the Atlantic here drying things up and allowing some sunny spells.

In Summary there is a lot of disagreement on the events of weather beyond the still broadly agreed pattern of a trough of Low pressure bringing some rain across the UK from the West around midweek. Then things diverge between the models with no model showing a full blooded breakdown that was being indicated yesterday. Instead we have a cocktail of options which range from cut off lows to the South and further High pressure building from the SW yet again. So it looks like we will have to wait until nearer the events before a clear pattern is drawn but imo I wouldn't bet against High pressure to the SW continuing to show further dominance over the UK weather next week and beyond too, being that it has played such a major influence over the nation's weather this Summer.

Thank you martin..

No doubt the farmers with crops in the field will be happy for the next week or so..

Thanks for the usual great summary, Martin.

There is strong evidence at the moment that the annual slow change to Autumn is underway, with cooler nights, darker evenings and a 'fresher' late summer feel to the days. The UK government however feels that the evidence is not strong enough yet to declare that Autumn will start as scheduled on 1st September, and in line with public opinion is going to vote to delay it. I understand the opposition has even tabled a motion to cancel it altogether. If, despite overwhelming signs and the certain motion of the Earth on it's orbit, Parliament decides against having Autumn this year, Summer will continue until December 1st when the government will be recalled to debate whether Winter should also be dismissed and we can all move straight to Spring.

I think it is a civil servant's plan to avoid Winter Fuel Payments, Humphrey! 

Could turn thundery by mid week;

http://wwww.wetterzentrale.com/pics/Rukm1441.gif

http://wwww.wetterzentrale.com/pics/Recm1442.gif

http://wwww.wetterzentrale.com/pics/Rtavn1442.png

Haha! Nice one, good enough to allow it to stand

The models are still figuring out how the energy will move around next week, with some looking to drop south while the rest remains to our NW. ECM fancies another energy split for day 10 while GFS opts to keep it all to our NW with a nice extension of the Azores High through the UK for a time.

The end of the GFS 00z is in the deeply unreliable, but entertaining in showing a strong high moving through the UK while a tropical storm heads due east to the Mediterranean; I daresay a notable spell of heat and instabillity could unfold from such a situation should it materialise (really don't count on it!).

and the 6z is completely different

Hi all,

Here's the September look-ahead video;

http://www.gavsweathervids.com

I think "changeable" best sum's it up.

September month ahead forecast will be on Monday.

Some much warmer temps on the way for a few days next week

Can't complain at this.

http://www.jp2webdesign.co.uk/ds/gfs.htm

LOL!

Temps IMBY for the next 7 days

19c  20c  20c 24c 25c 27c 25c

Some warm weather on the way

Well they were certainly very late in voting for the start of spring this year, not getting around to it until well into April.

ECM has notably higher heights in the Svalbard area from as early as 72 hours, with major differences to UKMO and GFS by 96 hours.

This leads to a major Scandi High which is still going strong on day 8.

From a CET prediction perspective, this isn't just a spanner in the works, it's a landmine on the road!

The ECM 12z looking potentially convective from 144hs onwards.

http://wwww.wetterzentrale.com/pics/Recm1442.gif

http://wwww.wetterzentrale.com/pics/Recm1682.gif

http://wwww.wetterzentrale.com/pics/Recm1922.gif

Though anything could happen.....

http://www.wetterzentrale.de/pics/Recm2161.gif

http://www.wetterzentrale.de/pics/Recm2401.gif

LP moves across the South from ECM