Good evening. Here is a quick look at the 12 noon outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Friday August 30th 2013.

All models are in pretty sound agreement on the course of events between now and a semi breakdown midweek next week. The cold front currently crossing Southern Britain will move clear of the SE by morning with a cooler and fresher NW flow with rising pressure from the SW. the weekend will be dry and bright spare a few showers for the far North with temperatures close to average but cool Autumnal nights. As High pressure then transfers across and to the East of Southern Britain early next week warmer winds will be imported with some very warm weather possible in the SE for a time towards midweek. In the North and later the West too cloud will be thicker and rain will proceed East across the UK midweek, some possibly heavy and thundery marking the commencement of a more unsettled phase of weather.

GFS then shows a showery period later next week with cooler temperatures before things dry up from the west later in the weekend with a ridge of High pressure giving a couple of dry and sunny days with reasonable temperatures. Slightly more changeable weather does threaten again later in the run under slack pressure but High pressure never strays far away to the West.

The GFS Ensembles show a 4 day warm up starting at the beginning of next week in the South before temperatures return to more average values at the same time as more unsettled weather develops with rain at times. Things from the Ensembles look typically spaghetti like for the North from early in the run with all kind of options possible.

The Jet Pattern shows a flow to the North of Scotland currently before an undulating pattern develops next week as the troughs pass east. By the end of the run the pattern shifts more direct West to East close to Northern Scotland.

UKMO tonight shows a trough having passed East on Wednesday night with rain for all replacing the warm and humid conditions in the SE with cooler and fresher conditions with sunshine and scattered showers for all through the day.

GEM tonight shows a similar scenario moving forward behind the trough with a new build of pressure from the SW promising further dry conditions developing by the end of the weekend.

NAVGEM shows a weaker trough crossing East soon after midweek before a slack ridge builds back by the weekend with dry and bright weather with average temperatures following the showery midweek period.

ECM tonight shows a complex Low pressure system developing over the UK later next week revolving around Southern England and eventually being displaced in the far NW by higher pressure later but with a cool east wind. Cloud and rain could be quite heavy and thundery at times in the South in average temperatures. The Northwest would gradually turn less unsettled at the end of the weekend as the low relaxes further South over France.

In Summary nothing seems any clearer tonight as all models continue to serve up differing outcomes for the weather behind the agreed upon midweek trough. In the meantime there is a few more good days of weather to come for all and a bonus of a very warm interlude in the SE early next week before the trough arrives with it's attendant showery and potentially thundery rain. After that it appears to be anyone's guess at the moment.

Off Topic but apologies for the loss of webcam stream today and thanks to those that notified me that the webcam links were not working within my signature below. Apparently there was some sort of crazy power surge overnight here last night which knackered my PC settings up as well as others around here. All up and running again now though with new url's.

Cheers Martin, looks like a potentially interesting period of weather possibly.

Good morning and welcome to my daily review of the outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Saturday August 31st 2013.

All models are now in solid agreement on the weather pattern for the next week over the British Isles. The last of a cold front is clearing the SE currently with a bright and fresh NW flow over the UK under strongly rising pressure from the SW. A couple of bright and fresh days are expected for all but more cloud in the North tomorrow as winds back Westerly. High pressure then builds strongly over Southern Britain through the early week while the North sees weak fronts deliver more cloud which may spill SE to other Eastern areas at times. By midweek the High over the South will of moved off to the East allowing falling pressure and a broad trough to move in from the West which hangs around in one form or another for the remainder of the week. Outbreaks of rain would reach the West late Wednesday, extending East to all areas Thursday. Some of this could be heavy and thundery and will be accompanied by a reduction in temperature values across the South from those of earlier in the week.

The Fax Charts confirm the above text well showing the trough approaching Western Britain on the 120hr chart as pressure falls on Wednesday.

GFS then decides to develop a North/South divide in conditions for the extended part of it's run with troughs crossing the North at times in occasional rain while our old friend the Azores High never strays far away from the South maintaining dry and bright conditions here with just very occasional light rain and temperatures well up to average if not slightly above. Once more unsettled weather on a national basis is indicated in the far reaches of the run.

The GFS Ensembles show a warm period in the South from the 2nd-6th before a cool off develops in association with more unsettled weather as documented above. However rainfall amounts over all parts of the UK are never excessive and some dry, bright and pleasantly warm feeling weather in brighter conditions can also be expected under uppers still a little above average later in the run.

The Jet Stream shows the flow riding over the UK High early next week before undulating South across the UK in association with the midweek trough. The trend thereafter is for a strong surge of the flow just to the North of Scotland with the chance shown of it migrating even further north again late in the extended part of the run.

UKMO today shows the trough having cleared East on Thursday leaving Friday with the UK under an unstable flow with pressure rising once more from the West. Showers could be expected in the North and East while the SW becomes dry again by Friday.

GEM today also shows a Northerly flow behind the midweek trough but moves on to show high pressure building back close to the South with any changeable conditions with further rain at times reserved for more Northern areas in a westerly breeze while the South sees more benign and bright conditions in average temperatures.

NAVGEM too shows a ridge of High pressure building across the UK late next week with fine if rather cool weather developing for all in the wake of a showery Northerly flow exiting East by Friday.

ECM continues to be slightly different from the rest developing a depression close to SW Britain midweek instead of a trough. This then sets up a spell of complex Low pressure close to the UK briefly before rising pressure from both the East and SW over the North brings drier conditions here next weekend and beyond. The South would continue to see some thundery showers close to filling Low pressure near Biscay.

In Summary there is good agreement now for next weeks pattern with the week summarised as being dry and bright with some rain or showers from midweek with average temperatures from then. In the following period things are not quite so clear cut as some output wants to bring a new Azores High back into play at least across the South while more Northern areas see rain at times. Alternatively ECM looks a little lonely in it's suggestions this morning but if verified would give the South some welcome thundery rain in the form of showers from midweek extending into the following week though High pressure looks like eventually winning through here too, this time from the NW.

Thank you Martin..

And for the Cams..

Love the ECM this morning for some early autumnal convection.

Looks good .

Warm rain though Michael...

Very quiet in here, the 12z brings us some decent temps for the coming week

Looks like at least 10 days warm  weather  to come.

Certainly does, lets then start to hope for a few Autumnal storms then some foggy stuff beofre the frosts and then the snow, would complete the year weather wise

Really? That's not what the models are saying...

GEFS: http://www.meteociel.com/cartes_obs/gens_display.php?x=306&y=141&run=12&ville=Londres&runpara=0&type=3&ext=1

A marked cooldown in the majority of ensemble members from the 6th.

ECMWF: http://www.weathercast.co.uk/services/ensemble-forecast.html

The same - note how the operational run went off on one.

Although it's possible the heat will cling on for the 6th and beyond, surely you'd have to say that at the moment the most likely option is for cooler, more seasonal conditions to occur from the 6th.

Good evening. Here is just a short version of my normal report tonight.

All models show a ridge over the UK at the moment declining towards the South over the next 3-4 days as weak fronts cross the North. Cloud and patchy rain will affect the North over the next few days while the South becomes increasingly warm and bright with some very warm sunshine in the SE. By midweek pressure will be falling steadily everywhere and a trough or a Low centre will inhabit the UK by the end of the week with rain at times and cooler temperatures likely for all by Friday.

GFS then shows pressure rising again next weekend with a drier spell when just very scattered showers are likely but a lot of fine and bright weather too. The trend towards High pressure continues in the latter half of the run with High pressure sitting over the UK with subsequent dry, warm and settled conditions with light winds and sunny spells by day and clear, cool and misty nights.

The GFS Ensembles show the warm spell this week dissolving at the end of the week to a cooler and more unsettled phase with rain at times. Later in the run the rain becomes more scarce again as High pressure returns close to our shores with temperatures still bordering the warm side of average for most.

The Jet Stream shows quite a turbulent pattern tonight with the flow dipping and ridging North and South over the two weeks in the vicinity of the UK or to the North.

UKMO tonight shows Low pressure having moved South of the UK late next week with showers and rain at times becoming increasingly confined to Southern areas for the weekend.

GEM develops an ECM'esque type solution tonight with a deep Low developing over Ireland later in the week and settling SW of Britain with some rather unsettled and showery weather for most and some longer spells at times especially towards the SW.

NAVGEM too shows Low pressure developing over the UK late in the week and encircling the UK for the weekend with rain or showers for all and cooler temperatures.

ECM shows Low pressure dominating too later in the week and weekend eventually settling to the South of the UK with the driest and brightest conditions transferring to the North of the UK late in the period.

In Summary tonight there is still some indecision shown on the events following the midweek trough. There has been some hardening of attitude supporting a rather deeper Low pressure feature later this week from ECM, NAVGEM and GEM in particular while GFS on the other side of the fence GFS strives to bring High pressure back in the second half of the run.

The 12z runs see UKMO joining ECM in splitting the energy big-time to create a cut-off low to the south of the UK by day 6. The Atlantic energy trundles off to Svalbard.

GFS is still finding more Atlantic energy and using it to muscle east into Scandinavia, with HP splitting instead (between Svalbard and SE Europe). The jet stream is too vigourous for the cut-off low scenario to evolve.

With GEM also developing the cut-off low and keeping a lot of warm air around, the consensus from the operationals has moved in favour of a warm but unsettled regime.

Ensemble-wise, GEFS are split 50:50 between warm and cool, with the op and control runs both right at the cool end.

...so the big question is, will the ECM ensembles continue to favour the cooler evolution or will they start supporting the ECM/UKMO/GEM operational consensus? I must say, ECM has played the fool lately; it was showing a violent Atlantic only a couple of days ago, with the reduction in energy since then being truly immense!

http://modeles.meteociel.fr/modeles/cfs/run1m/cfs-0-702.png?06

For anybody on late today - a classic CFS chart. The fact that it produces these fairly frequently means that the 500mb anomaly charts are generally more likely to end up looking zonal. What that means is that any anomalies that aren't zonal are worth taking note of IMO

The CFS model had that cool down around 6th September picked out 3-4 weeks ago.

Good morning folks and welcome to meteorological Autumn 2013. Here is the report on the midnight outputs of GFS, UKMO, GEM, NAVGEM and ECM along with the Fax Charts, GFS Ensemble review and the Jet Stream forecast for today Sunday September 1st 2013.

The General Situation. All models show a Westerly flow over the UK with High pressure to the South and Low to the North. In the South winds will be light today while the North will be blustery. Warm fronts will carry cloud and damp weather to the North today and rather more than damp for the far NW later as wet  weather spreads in here. In the South some bright weather is expected with hazy sunshine and temperatures a little warmer than yesterday. Through the next few days this pattern persists with the best conditions in the South where it will become warm or very warm by midweek, especially in the SE as High pressure migrates to the SE of Britain feeding up warm winds from the South. By midweek though pressure will be falling everywhere and a broad trough will move in from the West on Thursday with some potentially quite heavy and thundery outbreaks of rain or showers in a slack Southerly breezy. Towards the end of the week the trough continues to dominate the weather as it slows down over eastern britain while developing Low pressure along it which relaxes down to the South of the UK for next weekend setting up a cool NE flow with rain or showers at times in the South. Northern areas will see better conditions next weekend as a strong ridge of high pressure builds across these areas.

The Fax Charts back up the above text pretty well with a broad trough of low pressure crossing East on Thursday with widespread showers and outbreaks of rain working their way West to east across the UK late in the week with Low pressure forming near Eastern England.

GFS then shows a North/South split in the weather for next weekend and the start of the second week as Low pressure to the South of the UK maintains fairly cloudy and unsettled conditions in the South with thundery rain at times while the ridge across the north continues to ensure drier and brighter conditions are likely here in average temperatures for early September. The end of the run shows little change with the axis of low pressure always maintained closest to the SW of Britain with further rain at times which could extend to northern areas too as a trough crosses East and the outer limit of the run.

The GFS Ensembles show a lot of spread this morning following the warm phase this week. There are options shown for both cool and warm solutions but many do indicate rain at times for the South too with the North if anything trending to rather less rain as high pressure builds somewhat here. The operational was on the warm side of the crop this morning.

The Jet Stream maintains an overall thrust of being positioned just to the North of the UK for much of the time. However, an arm of it is shown in a confused and diffuse state for much of the time over the UK and Europe as the Low to the South of the UK complicates it's usual West to East flow.

UKMO would most likely evolve in a continuation of a North/South split in conditions with the South seeing the biggest share of showery conditions as Low pressure to the South on Day 6 looks like it could start to edge back up towards Southern Britain in the days that follow.

GEM today keeps low pressure to the SW and later west of the UK, close enough to promote showers across the South and West with the North and NE seeing the driest and brightest conditions in a cool East wind while elsewhere sees average temperatures but a lot of cloud.

NAVGEM too has Low pressure over France at the end of next weekend with cool and unsettled weather across the South while the North closer to high pressure to the North stay largely dry and bright with some sunshine in average temperatures. It will be cool in the blustery East or NE wind though everywhere.

ECM finally shows a similar pattern to the rest with the South bearing the focus of the cloud, rain and showers while the North sees the best of the dry and bright conditions with Western Scotland probably seeing the brightest and driest weather with the highest temperatures away from the cool and fresh East or NE flow blowing elsewhere.

In Summary today we have unity from all models that a trough of low pressure will replace the fine and dry conditions in the South up until Thursday with rain and showers developing for all for a time. From the weekend as Low pressure develops either close to the East and eventually the South of the UK the weather will become least settled in the South where thundery rain or showers look like continuing for some considerable time. The North looks like there will be a good deal of dry weather developing though onshore winds in the East will keep things cool here while the best weather may end up in the NW of Scotland with some sunshine at times. For the first time for a long period it looks as though if the above outputs verify the Azores High will at long last have lost it's influence over the UK with a more cyclonic pattern for most with High pressure close to the North for a change. The chances are that towards the end of the second week Atlantic depressions may stroll across the Atlantic to extend more unsettled conditions for all by the end of the period hinted at by GEM today.

anyone think NOAA are bothered about gfs op being unable to model split flow enery in the northeastern atlantic ? me neither - gonna be a long winter again for those who hang on its every run!

http://www.wetterzentrale.de/pics/Rtavn11417.png

Heat hangs on.................just

http://www.wetterzentrale.de/pics/Rtavn13817.png

Cooler for all

Here's what I think we could potentially see next week:

Warming up for many central, southern and eastern areas early next week. Cooler and at times more unsettled for northern and western areas (this bit is pretty much nailed on).

Potential warm plume for eastern/south eastern areas later in the week with low pressure bringing cooler and more unsettled conditions elsewhere. Potential for some thundery downpours as low pressure across western areas comes up against the warm and humid air over eastern/south eastern areas, and/or thundery showers moving up from France to affect some areas.

Likely cooler and more unsettled for the UK as a whole thereafter.

Potential for low pressure to drag down enough cold air late in the week for early season rural frosts in northern areas and perhaps to turn some showers wintry over the top of the Scottish mountains.

bump - shouldnt be on page 2 !

GFS confuses me with it's predictions at the surface next Friday; it has the warm ariflow off the continent and plenty of sunshine for all but the SE, yet temps are in the high teens to low 20's, the latter restricted to the far south. Go figure!

It then finds a lot of cloud and some rain for Saturday... fair enough given the proxmity of the low pressure to the south. Things improve for Sunday, but central parts of England are given highs in the low 20's at best despite plentiful sunshine and uppers exceeding 10°C. Again, go figure! 

Good evening. Here is tonight's look at the midday outputs of the big 5 computer models for September 1st 2013.

All models show the week to come split into two with the first half seeing a North/South split with the North staying mostly cloudy with a little rain while the South stays dry and becomes very warm with some sunny spells. Late in the week a trough of Low pressure moves over from the West with sunny spells becoming harder to find with an increased risk of showers and outbreaks of rain.

GFS then shows NE winds developing over the South at the weekend with a few showers possible and still very respectable temperatures while the North lies under a ridge from an Atlantic Anticyclone. Here dry weather would develop with some sunshine but chilly conditions could develop by night. Longer term and slack pressure seems to be projected across the UK with some showers in places but a lot of dry and benign early Autumn weather too with no overall pressure system having overall control over the UK.

The GFS Ensembles show a warm couple of weeks to come with uppers remaining above average over the South throughout. The operational was slightly on the warmer side of the set and rainfall is shown to fall over the South at times from the end of the week on but all in all not a bad set of ensembles tonight.

The Jet Stream shows complete confusion in the second half of the output with no set pattern shown from the varied options on offer from the members of the set. In the short term though the flow is shown flowing East North of Scotland then it does turn South to the West of Britain later this week to accommodate the Low pressure trough over the UK at the end of this coming week.

UKMO tonight has watered down considerably the extent of the unsettled weather at the weekend with any rain form the Low to the South restricted to the extreme South with the vast majority of the UK under dry and bright conditions with some sunny spells, especially in the West.

GEM tonight does keep things closer to this morning's formula with Low pressure to the South at the weekend keeping things rather unsettled with rain at times with the North staying drier and brighter closest to a High pressure ridge.

NAVGEM too keeps things unsettled from the weekend with Low pressure dominant close to the South or SW with outbreaks of rain or showers in the South while the North stays dry and largely fine.

ECM too shows a cut off Low to the South of the UK but further South than this morning meaning less of the UK would fall under it's influence with just the far South and SW at risk of thunder showers at times while the rest of the UK lies under High pressure with fine and dry conditions if less warm than this week.

In Summary the main difference tonight is that the operational runs of GFS, UKMO and ECM show the Low next weekend further South than on this morning's output with less of the South of Britain affected by it's circulation, hence the fine weather shown for the North on this morning's output is extended to affect more of Southern Britain too on tonight's offerings. With so much uncertainty still being shown on this mid range charts there is no point in speculating on the thereafter tonight.

Well it seems that a major defeat by the GFS model hasn't been followed by many of TWO's members... but I refuse to let it get off so lightly

The model's operational output was persistently taking the option of an autumnal spell of weather up until yesterday evening, when it suddenly started mirroring ECM very closely indeed. This was due to it taking a couple of days longer to figure out that the split-jet would create a cut-off trough to our south. To be fair, UKMO was only about a day ahead of it, and as for ECM, it was showing a raging Atlantic for a couple of runs before modelling the cut-off low.

GEFS didn't fare too badly thanks to about half of the members following the ECM evolution in each 00z and 12z suite up to this evening. I suppose this means it was only ever half-wrong overall.

GFS still hasn't quite joined UKMO and ECM in their boat; it doesn't amplify the trough/ridge combination as much, resulting in less in the way of warm uppers being pulled up from the continent. The UKMO and ECM output is more interesting in terms of the potential for some notable warmth combined with shower activity that could be thundery in nature.