Hi everyone. After a disappointing Saturday here with incessantly grey skies lets see if there is any light at the end of the tunnel from the 12 noon outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Saturday September 21st 2013.

All models show a mild and moist SW flow covering the UK currently with a warm front clearing NE out of Northern Scotland tonight. All areas are prone to extensive cloud cover overnight lowering to modestly high hills with drizzle in places. Tomorrow will see Eastern areas, mostly those in the lee of high ground to the West and South such as parts of Eastern Scotland, East Wales, parts of the Midlands and SE England later. Western hills and coasts will continue to endure the low grey stratus cloud throughout with little chance of brightness here. Through Monday and Tuesday the brightness may extend to other areas for a time with temperatures well above average. By midweek winds of change are shown by the output but it does look as though dramatic changes are unlikely to occur quickly.

GFS then shows Low pressure gradually taking shape somewhere near the North of the UK with rain at times developing from later in the week with temperatures falling back somewhat. Thereafter through to the end of the run changeable conditions develop with High pressure parked to the North of the British Isles for much of the time. With the Jet flow to the South Low pressure is pushed across the Atlantic towards the UK bringing rain at times across the UK in temperatures close to normal and maybe a shade below at times in the North.

UKMO shows Low pressure developing across Northern Britain at Day 6 with increasingly unsettled weather with rain at times and cooler temperatures.

GEM shows a complex situation of developing Low pressure close to the West of the UK with rain breaking out in many places before the end of the week. through the weekend and start of the following week the weather winds up quite a bit with the potential of gales and heavy rain for many for a time.

NAVGEM shows deepening Low pressure moving East across Northern Britain late in the run with rain and strong winds spreading across many areas next weekend, most prolific in the North.

ECM shows complex Low pressure down to the SW mixing with a new centre to the NW with the whole setup moving bodily NE over the UK next weekend with rain for all, some of which could well be heavy and thundery for a time. By the end of the run Low pressure sits over the UK with rain and showers for all in fresh to strong winds and temperatures no better than average.  

The GFS Ensembles shows much of week 1 being relatively warm and dry though with a cooling trend through the second half of the week. The second half of the output shows the risk of rain increasing with Low pressure in close proximity with temperatures much closer the seasonal average for all.

The Jet Stream shows the flow just to the North of Scotland currently with it's position maintained for several more days whilst weakening in situ. Later the flow such as it is sinks steadily South ending up South of the UK towards the end of next week and through Week 2 though there is not much unity on any particular outcome at that range.

In Summary tonight the trend is well set for a gradual but notable return to more Autumnal conditions later next week and more especially over the weekend and beyond. Pressure and temperatures are both expected to fall steadily over the second half of the coming week with the warmth of the first few days ebbing into cloudier conditions with some rain almost anywhere before the weekend. It then looks like Autumn turns the screw somewhat with the potential for some proper wet and windy Autumn weather as deep Low pressure areas cross the UK as pressure looks like staying High over the Arctic and the Jet flow having moved well South by then.

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Agreement of sorts out to Thursday now. Still some differences, with ECM diminishing the ridge across Europe more quickly than GFS. The ECM run has a more active jet overall when compared to GFS.

Longer term, the models continue to show the Atlantic barging its way NE and displacing the ridge trying to build there. After the massive changes regarding this week (remember the onslaught that was progged at times when it was at 7+ days range?), I'm wary of taking that longer-term evolution all that seriously at the moment.

There is room for the Atlantic to track even further south, but only if the trough energy becomes disrupted rather than consolidating into a chain of powerful systems.

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An interesting contrast and indeed test for the competing models as to how fast Atlantic systems will break in and how deep they'll be (from the TWO chart viewer):

GFS 06Z - slow and shallow (324h, over central UK)

ECM - quicker and deeper (240h, over central UK)

GEFS - timescale similar to GFS (360h) but deeper and further north

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Good morning. Here is today's and this week's extended look at the midnight outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Sunday September 22nd 2013.

The General Situation. A broad and warm SW flow covers the UK on the NW flank of High pressure close to South Eastern Britain. With the air very moist in it's lowest levels a lot of low cloud, mist and hill fog affects many upland areas of the UK and will continue to do so for a while to come. Well inland and in the East the cloud should break with some warm sunshine over the coming few days with temperatures well above average. Towards the middle of the week pressure is shown by all models to begin to fall with details in weather conditions at the surface very hard to pin down currently as slack pressure develops over the UK. This should mean temperatures slowly falling away to average with areas of cloud drifting South over the North as well as up from the SW. This will bring some outbreaks of rain almost anywhere by the latter days of the week as pressure continues to fall. By the weekend most output shows Low pressure forming somewhere near the North or West of the UK with rain moving NE in strengthening South or SW winds in average temperatures.

The GFS operational this morning shows slack conditions persisting well into next weekend with no one pressure system High r Low having overall control over the UK weather. As such there will still be a lot of dry weather around with just patchy outbreaks of rain in what would most likely cloudy and misty conditions. It's not until well into the following week when conditions deteriorate more markedly as Atlantic low pressure more meaningfully crosses the UK with windier and wet conditions for all towards the end of the run in average temperatures.

UKMO today shows a cocktail of weak troughs over the UK next weekend having either fed down from the North or up from the SW. As a result there will be patchy rain spread about over the UK with almost anywhere at risk of some showery outbreaks from cloudy skies. By the end of the run it does look like a more organised area of rain will form over the North as Low pressure develops there.

GEM is also slow to deliver Low pressure in any meaningful sense to the British Isles this morning with the benign pattern of rather cloudy weather late in the week with patchy rain lasting into the weekend. Banks of Low pressure are queing up in the Atlantic and they make there move early next week with marked and substantial areas of rain moving bodily East and NE through the British Isles then with some heavy rain for all along with strengthening winds from the SW innitially but turning NE from the North by Day 10 as substantially colder air arrives from the North.

NAVGEM today shows Low pressure gradually becoming more dominant over the British isles next weekend as systems move NE across the UK. At the same time a deep Low forms West of the UK and looks set to swing NE over the UK early next week with rain and strong winds likely for all then in temperatures close to average in mostly overcast conditions.

ECM also shows Low pressure strengthening close to the West and SW late this coming week and more especially over the weekend. After a cloudy end to the week with patchy outbreaks of rain the weather looks like turning decidedly wet and windy before the start of next week as troughs cross the UK from the SW with a strong and chilly SE flow shown affecting the North by midweek next week. the heaviest rain looks like affecting the South and West though all areas are at risk from some in temperatures close to average overall.

The GFS Ensembles point towards a more changeable pattern developing over the UK from the 27th in the South and before in the North. In the interim period the warm uppers currently felt will dissolve away back towards the seasonal average by the end of the week, a level at which they are generally maintained thereafter. Some members indicate some quite wet periods through Week 2 when 10mm plus could fall on some days both North and South of the UK.

The Jet Stream driving this pattern shift is complex this morning with the general consensus being that the flow weakens to the North of the UK later this week to relocate at a more Southerly point across the Atlantic where it is then steered NE across the UK, probably close to Southern England from next weekend.

In Summary this morning the models are again struggling to deal with complex synoptics as Autumn 2013 digs it's heals in. With pressure fairly high over the Arctic with time the Jet Stream is forced South opening the door to the engagement of cool Autumnal air well formed to the north of the UK with the tropical maritime air out to the SW of the UK. The potential for some quite potent depressions and areas of attendant heavy rainfall is very real by next weekend but in the short term things look like remaining quite benign if rather cloudy with patchy rain late in the week. After a period of warm temperatures early in the week temperatures will fall back to levels we would normally expect at this time of year by the end of the week. As we look deeper into the following week it looks like a classic October setup could develop with deep low pressure areas tracking across the Atlantic and ending up near or over the UK with heavy rain and potential gales at times. There is some hesitancy in taking these depressions right across to exit East of the UK though and if things happen as shown it could feel quite warm and humid in the SE at times. However, if a GEM type route is taken cold northerlies could blow down over the UK in the wake of the depressions and bring some very cool air down from the North with wintry showers over Northern hills. So taking everything into account there is something for everyone in todays extended report with a lot of scope for changes as the day to day detail looks impossible to account for at the moment beyond the general trend.

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Thank you Martin.

Very good mixed bag of weather. Fax charts looking good with the lows...

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As I figured might happen, GFS has adjusted the troughing even further south on this morning's 00z op run.

ECM is still more energetic but even it has the lows taking longer to push NE and in fact struggling to get as far against heights rising to the NE.

I'm seeing many hints from the models for blocking to retrogress from our NE to our NW during the first 10 days of October. CFS has been suggesting this for a little while now. ECM is faster than GFS in that direction, while GFS serves up a good representation of what we could end up with by around 10th October, or quite possibly sooner:

http://cdn.nwstatic.co.uk/gfsimages/gfs.20130922/00/384/h850t850eu.png

I expect - based on past experience - that the troughing will end up further south if we do go down that route.

Mid-late October has the potential to be exceptionally chilly if we end up somewhere close to that GFS chart. A test run for winter, of course but it would not surprise me if it was a 'false start' with something more westerly for November, giving way to the real deal at some point in the winter. Getting way ahead of myself I know!

In the meantime c'mon sun, I know you can do it...! The low cloud is melting away on satellite but I've got a particularly stubborn blob overhead.

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Bah. weather for my golf trip on 27/28th to Kinross is proving very hard to forecast...  May have to wait until the day before!

I was shocked to see the graph showing 15C uppers as I haven't check it for nearly a week and outside being cool and overcast is completely a big failure on the models predicting mid 20's temps.  To get those temps for late September we need to see sun from the start to generate those temps but now is mid-day and still rather cool at high teens.

Massive failure again and glad I don't view the models often now because of failing and same to media forecasts too.

Still looks a reasonable week coming up for this time of year for most. Thereafter is up for grabs.
Over the last few years, felt that the rest of the year was going to be quite different and in the past two weeks feel the same. Quite what we will get.

Well after a dissapointingly cloudy weekend for the SW'rn third of the UK, I'm glad to see good signs that the warmer than average conditions will persist throughout the coming week, with ECM coming around to GFS in terms of not displacing the warm air before the end of the month.

Today has seen reductions in the modelled amount of energy going into the northern arm of the jet. As a result, blocking to the NE is being increasingly shown to hold back the Atlantic and/or force it to undercut i.e. dive south into Europe.

http://www.wetterzentrale.de/pics/Recm1682.gif

Not long ago, the Atlantic was being modelled blasting across to the NE, sweeping out our warm airmass by Thursday night and bringing a stormy weekend (that last bit shown by ECM more than the other models, I should add).

The massive changes from that are representative of the short-term adjustments that in winter can bring about a potential cold spell from seemingly out of nowhere... unless you know what signs to look out for. It took me until the evening before last to really spot much potential, and until yesterday evening to have any real confidence in that possible outcome.

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Good evening. Here is the report on the 12 midday outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Sunday September 22nd 2013.

All models continue to show a large High pressure area close to SE Britain with a warm and moisture laden airflow over the UK. The resultant warmth will be accompanied by low cloud, mist or fog over the next few days but some warm and sunny weather increasingly likely at times. Through midweek a Low pressure trough intensifies near Northern Scotland and pushes South somewhat with rain affecting Northern areas then as well as a marked drop in temperature. As pressure falls elsewhere too Low pressure to the SW could throw up some showery rain at times but the South should at least stay warm until the end of the working week. Over the weekend to come things take a more notable turn downhill as Low pressure makes a more meaningful impact on a larger part of the UK.

GFS shows Low pressure extending North across Southern britain at least with rain at times down here while the North holds on to drier weather following the late week rain. Then through next week the mild and unsettled air over the South makes it's way North to all areas with a brisk and cooler westerly wind with showers following before a shift of wind towards the NW or North at the end of the run turns things very much colder then but drier as pressure builds to the West.

UKMO tonight shows next weekend with Low pressure North and South of the UK with rain at the top and tail of the UK while a large swathe of Central Britain while at risk of a few showers would still see plenty of dry if rather cloudy weather and mild weather.

GEM shows Low pressure gradually strengthening down to the SW later this week with a deep depression spinning North up the Western side of the UK through the weekend and start of next week with spells of heavy rain followed by thundery showers, heaviest in the South and West where gales would also be likely. Overall temperatures would hold well up to average despite the wind and rain.

NAVGEM also shows Low pressure deepening and spinning around NW Britain next weekend and at the start of the following week. There would be gales in the West with some heavy rain for all at times. It would probably feel cool but temperatures would not be far from the seasonal normal.

ECM tonight shows Low pressure becoming dominant over and then to the NW of the British isles from next weekend. High pressure to the NE will restrict the Eastward progression of these Lows with the majority holding to the NW and West and ensuring mild SW winds hold sway over the UK. So despite frequent bouts of wind and rain temperatures would stay respectable overall.

The GFS Ensembles show a steady cool off through the week with average levels of temperature sustained thereafter. After a dry few days the cooler air will usher in rain fro tthe North innitially before more generally from the SW next weekend and beyiond with some quite heavy rain possible at times thereafter.

The Jet Stream shows the flow weakening to nothing North of Scotland over the next few days. The Low to the SW engulfs a new arm of the flow exiting the States later in the week and encourages the Low to deepen as it moves steadily Northeast next weekend and beyond.

In Summary tonight we are seeing a delay in bringing the unsettled weather across all of the UK in meaningful fashion. It now looks that the far North will see rain from Tuesday with some other northern areas too at risk midweek. The far South too may see a few thundery showers later in the week as it stays warm here until next weekend. It's then that the Low pressure complex to the SW spreads it's wings NE to affect the UK with rain and showers at times with potential strong winds at times. It does look less likely that any cold weather will affect our shores anytime soon as away from the far North for a time this week winds will flow from a warm Southerly source maintaining temperatures at average levels despite wind and rain.

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Thanks Martin

 ps nice picture

Ecm Impressive early push of cold into scadi

 

http://www.meteociel.fr/modeles/ecmwf.php?ech=240&mode=0&map=1&archive=0

turning very wet in western parts later on?

 

http://wxmaps.org/pix/prec4.html

air mass collision  navgm http://www.meteociel.fr/modeles/navgeme_cartes.php?&ech=132&mode=1&carte=0

 

energy correction south from the mean cool looking winter chart later on as second dives further s/e

 

.http://www.meteociel.fr/modeles/gefs_cartes.php?code=21&ech=156&mode=0&carte=1

 

goodness me any further south from the japs\\

http://www.meteociel.fr/modeles/jma.php?ech=144&mode=1

http://www.meteociel.fr/modeles/jma.php?ech=120&mode=0

More hopeful of seeing the sun in the next few days and warmer days as fax charts confirm dryer air moving into Southern England.

http://www.meteociel.fr/modeles/ukmo2.php?ech=36&carte=2000

 

 

That has got to be watched that has. I'm sure that has ramifications for later on this autumn - 2010 or what??

 

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Thanks. Presuming you mean the one on my websites homepage it is a bit addictive and remarkably accurate as it changes as the weather does. Tablet and iphone users need the Puffin browser to view it though as it uses 'flash' .
Anyway back on topic and the ECM 240hr mean chart suggests Low pressure just to the West at Day 10 with pressure between 1000-1005 mbs nationwide with an unsettled spell with wind and rain for most in average temperatures.

http://www.wetterzentrale.de/pics/Reem2401.gif 

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Hi everyone. Here is this morning's walk through the midnight outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Monday September 23rd 2013.

All models show a warm and moist layer of air over the UK currently with either extensive low cloud and mist or fog overnight with some pleasant, warm and sunny weather for some areas through the daytimes. This pattern remains in place for several days as rain develops across the far North by midweek as a trough edges down from the North. All models show a slow decline in temperatures and conditions later in the week although they differ on timing and specifics as the general trend is still for cloud and rain to move slowly North and East across the UK towards next weekend with the warm conditions slowly easing back especially over the North.

GFS shows the rain moving NE across the UK next weekend with some heavy rain in places before drier conditions follow the rain through the early part of the second week in association with a ridge crossing East over Britain. It would be much cooler at this point though. Then a re-run of rain crossing from the SW keeps the changeable theme going late in the run with a switch to Northerly winds at the close of the run with rain or showers in cool conditions as High pressure builds North through the Atlantic.

UKMO shows Low pressure closing in on the British Isles next weekend from the SW, West and North with the threat of rain becoming widespread very likely as we move into Sunday and the days that follow.

GEM shows a strengthening South or SW flow as a deep Autumn Low pressure area moves NNE up the Western side of the British Isles with strong winds and bands of heavy rain affecting all areas at times. Although the weather will be mild innitially as winds swing Westerly through next week more showery and cooler conditions look likely for all.

NAVGEM shows Low pressure spilling close to the UK from the SW next weekend with troughs moving NE across Britain with rain followed by showers with plenty more Atlantic frontal activity bringing further rainfall in across the UK next week.

ECM shows an unsettled end to next weekend with rain at times as fronts and Low pressure makes it's way into the UK from the SW. Through next week a mild and unstable South to SW airflow maintains cloud and rain at times for most of the UK, especially over the West.

The GFS Ensembles show a slide into cooler conditions as we move through the next 10 days or so though it takes more than a week to bring levels down closer to the seasonal average for most. Rainfall becomes a much more common feature too starting in the North on the 25th and spreading to the South too by the 27th or 28th.

The Jet Stream continues to show the flow weakening to the north of the UK with a relocating arm to the SW of Britain developing by the end of the week.

In Summary conditions are set to deteriorate over the coming week to 10 days. The weather is in no hurry to do so with most parts seeing a reasonable week to come with warmish conditions hanging on in the South until the weekend with just scattered outbreaks of rain possible after midweek, especially in the North. All models then show a more coherent area of Low pressure meandering north and East across the UK at the weekend  and probably others to follow with the period thereafter looking changeable with wind and rain at times with temperatures still well up to average for this time of year. The heaviest rainfall looks likely for the West with Northern European High pressure blocking any transit East of most Low pressure.

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Can anyone tell me how on earth you can predict cloud cover? I have found it impossible this weekend. The high resolution models are totally useless with it.

Thank you Martin..

10 days to deteriorate . Winds might not be so strong yet.

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Also how they how on earth they kept talking abouty 24-25C temps yesterday that failed to happened and again today possible as it overcast. It always clear at dusk and overnight but not at day time for no reason.  I mean no reason to keep the clouds in.

I am sure next weekend would be nicer, sunnier and warmer than yesterday.  I notice the warming trend on the ensembles had been increasing slowly with rain spikes downgraded on every run for next weekend.

Reachws 24C in 10 locations yesterday.

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