Model Output discussion 1st September 00z------->

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON SUNDAY SEP 6TH 2015.

 

THE CURRENT GENERAL SITUATION A strong Anticyclone will move gently East into the UK from the West over the next 24-48hrs with light winds for all as a result.

 

http://www.wetterzentrale.de/pics/Rtavn001.gif 

 

MODELS-2 WEEK HEADLINE  Becoming more settled through this week with a return to more unsettled and cooler conditions from nest weekend.

 

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows the flow troughed over the Atlantic and ridged well to the North of the UK. The pattern slowly shifts East later this week with the trough section to the flow moving East into the UK late next week when the flow strengthens to blow West to East across the UK at the start of the second week. Thereafter until the end of the period the flow is shown to ridge over the North Sea and Eastern Britain and flowing North across Western Britain. 

 

http://www.netweather.tv/index.cgi?action=jetstream 

 

GFS OPERATIONAL The GFS Operational Run today shows High pressure controlling the weather over the UK throughout the next week as it moves gently East across the UK over the coming days and then East into northern Europe maintaining a ridge back across the UK. Fine, dry and eventually somewhat warmer weather is likely as winds shift towards the SE later next week. Pressure will then gently fall and low pressure will take control of the UK weather from later next weekend with rain and showers and cooler and stronger west or SW winds in week 2. Pressure rebuilds to the East later in Week 2 with perhaps a return to drier and warmer weather in the East to end the period while the West stays cloudier and breezier with occasional rain..

 

http://www.wetterzentrale.de/pics/Rtavn1441.gif

 

http://www.wetterzentrale.de/pics/Rtavn3841.gif 

 

THE GFS CONTROL The theme of the GFS Control Run this morning is broadly similar to the Operational run throughout this morning with a decline in conditions from next weekend with rain, strong winds and cooler air engulfing the UK under a deep Atlantic depression to start Week 2. The unsettled and breezy conditions then are shown set to continue for the remainder of the period. 

 

THE GFS CLUSTERS(14 Days) The GFS Clusters this morning show the majority of members going for cyclonic influence across the UK in two weeks time as Low pressure looks likely to dominate the UK positioned either to the North or NW of the UK.

 

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

 

UKMO UKMO today shows High pressure crossing the UK and away to the NE through this week. Quiet settled weather will dominate with a warmer SE breeze developing from midweek. By Friday and more certainly the start of the weekend troughs will be perilously close into the SW and these are shown to enter Southern and Western Britain with some rain by Saturday.

 

http://www.wetterzentrale.de/pics/Rukm1441.gif 

 

THE FAX CHARTS The Fax Charts this morning show similar sequences to events as the raw data output this morning with a decline in High pressure influenced conditions occurring at the end of the week from the SW.

 

http://www.weathercharts.org/ukmomslp.htm#t120.

 

GEM GEM today shows High pressure crossing the UK and away to the East over the next 3-4 days. The weather will stay largely dry with some sunshine and light winds until midweek when the High has crossed East into Europe setting up a warmer South-easterly flow. Troughs are ganging up to the West and finally make it across the UK next weekend with some rain edging NE across the UK and eventually setting up an East/West split with rain at times in the West but still drier weather further East as High pressure remains locked in over Europe and Low well to the West and SW of the UK.

 

http://www.wetterzentrale.de/pics/Rgem2401.gif 

 

NAVGEM NAVGEM too shows a largely fine and settled week to come under High pressure crossing the UK and away to the East from midweek. Changes on this run are slow and next weekend is the point of change when some showery rain crosses NE across the UK followed by a slow change to Atlantic based Westerly winds and Low pressure up to the NW to start the second week.

 

http://www.wetterzentrale.de/pics/Rnvg1681.gif.

 

ECM ECM this morning shows the same theme of moving High pressure across the UK from the West and away to the East of the UK by midweek or soon after, This sets up a warmer SE flow with sunny spells and dry weather continuing until troughs edge slowly over from the West or SW next weekend and brings more changeable conditions for Week 2 with Low pressure up to the NW with rain at times for many but probably not much to the South and East.

 

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

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from this morning shows Low pressure just to the NW with a trough down across the UK meaning most members indicate a shift back towards more unsettled and breezy SW winds likely across the UK by day 10.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models maintain their theme of High pressure migrating East away from the UK later next week with a return to more unsettled Atlantic winds thereafter though in varying degrees of extent.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The Verification Statistics of GFS, UKMO and ECM This morning's verification statistics show ECM and UKMO at 96.0 pts  while GFS lags behind at 95.0 pts at 3 days. At 5 days UKMO is king at 85.9 pts followed by ECM at 85.4 and GFS at 83.3 pts. Then at 8 Days ECM still leads at 60.8 pts over GFS's 53.5 pts. Finally at Day 10 ECM leads GFS at 42.0 pts to 34.9 pts from GFS.

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png 

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.prig

 

MY THOUGHTS High pressure remains the main theme from the models this morning for the first week of the two week period as it drifts from a position West of Ireland across the UK over the coming days and away to the East and NE by midweek or soon after. The Northerly drift of today should be largely cut off tomorrow with little or no wind until midweek when a SE flow develops. This will have the effect of warming the air temperatures close to the surface as the flow drifts from a warmer continent. Amounts of cloud still look troublesome until this warmer SE breeze sets up sending dry air NW over the UK with largely sunny and warmer conditions to many. From the same time pressure looks to fall from the West and SW by next weekend and rain will reach the SW from as early as next Friday before marching it slowly NE to other areas over next weekend. The general theme from then on is for the Atlantic to regain control but to what extent is unclear again this morning with some output suggesting High pressure may hold to the East or SE making the West and NW most favoured for rain, showers and cooler winds while the South and East looks like they may hold on to some drier and brighter and somewhat warmer weather. However, this is not a guaranteed scenario with this morning's ECM 10 Day Mean Chart indicating Low pressure close enough into the UK to affect all areas with rain at times which isn't as supportive of the better weather theory for the SE as the operational suggests. So uncertainty on the longer term is still a feature of the output this morning but at least in the short term we are guaranteed a working week of fine and dry weather with increasingly warmer conditions if rather breezy weather from midweek. Then from next weekend a spell of more typical early Autumn weather looks likely with rain at times perhaps more focused towards the North and West with some dry spells in between more likely over the South and East.  

 

Next update from 09:00 Monday Sep 7th 2015

[phil nw.]

The gradual improvement this week looks like peaking around Thursday if the 06z GFS run is close to the mark.

The high by then over Scandinavia/E.Europe wafting warmer and drier air off the continent.

 

so a little taste of what many of us have been missing through much of August a bit of warmth and sunshine for 2 or 3 days with temperatures maxing into the high teens/low 20's C quite widely.

 

By the weekend though some sort of breakdown off the Atlantic does now look likely.

 

good agreement in the ECM/NAEF's 500hPa height anomaly charts for the approach of an Atlantic low pressure area just to our west by day 8.

[knocker]

And with the 00z T574 it's all hands to the pumps.

Chart weatherbell

 

 

[Tamara]

Following the massive MJO induced Nino spike injection in the Pacific to the atmospheric circulatory pattern at the end of June/early July, we are now well into a defined  +atmospheric angular momentum amplitude cycle (AAM), and, evidentially of this  (courtesy of a very useful link provided on the ENSO thread) we see the Pacific having spawned virtually double the year to date accumulated cyclonic energy into the atmosphere

 

http://models.weatherbell.com/tropical.php.

 

A large percentage of this activity occurring since the Nino atmosphere/ocean coupling that occurred in tandem with that massive MJO Phase 7/8 spike

 

The Global Wind Oscillation has classically reflected this very defined Nino pattern with poleward fluxing of the Pacific energy as advertised through Phase 5-6-7 orbits right through the heart of the summer, and this atmospheric sequence set to continue tanking the atmospheric circulation through the new season in September.

 

Look how the atmosphere responded from its decoupled (to the ocean) Nina-esque low state in early June to the intense MJO forced ocean/atmosphere coupling as manifested by soaring AAM and the laddering up of the GWO through Phases 4/5/6/7 in the late stages of June and early July

 

http://www.atmos.albany.edu/student/nschiral/research/gwo/prev60_phase.png

 

Under the +AAM regime, in this way, the amplifications wave signals that keep emanating from the Pacific revolve around a default climate Nino signature response of lower pressure anomalies in both the Pacific and Atlantic and with pressure higher over NW Europe

 

Much as we have seen dictate the pattern through this summer, with the UK on this occasion in 2015 too peripheral between the trough and downstream ridge. The poor throw of the dice in this seasonal pattern, which could have been more favourable in other similar composite years, has been because transition stages of a Nina imprinted atmospheric circulation (low AAM) to a Nino imprinted atmospheric circulation signal (+AAM) such as happened, unluckily timed, fairly early in summer this year often features a hangover of cooler and more unsettled conditions as a legacy of the effects of cool air flooding the Atlantic from upstream and consequent depressed SST anomalies. This sequence further imprinted by the upper trough perpetuated there.

 

Clearly, as everyone knows, the cold SST imprint had quite an impact on conditions most especially further north west in the UK.

 

This created the omnipresent NW/SE split which has entered the swear filter through the weeks and frustrated many with a heat supply so close by the other side of the channel

 

Back to the future, and in the coming 10 to 15 day period, a subdued tropical convection signal in the Maritimes is reflected in model agreement between GFS/ECM for the MJO to traverse through "no mans land" into weak/indiscernible amplitude Phase 4. (Uncertain 5 thereafter which suggests migration of the trough eastwards to the north)

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/NCPE_phase_21m_small.gif

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ECMF_phase_51m_small.gif

 

Phase 4 MJO composite for September further underlines the Atlantic trough and NW Europe ridge pattern. This linked composite reflects a higher defined amplitude than currently forecast, but within the context of the underlying Pacific forcing, and NWP modelling indicators is probably the closer match

 

http://www.americanwx.com/raleighwx/MJO/MJO/SeptemberPhase4gt1500mb.gif

 

The base Nino state still continuing to be the driving force in controlling the GWO in a phase 5/,6,7 returning orbit and determining the dominant quasi permanent macro pattern

 

http://www.atmos.albany.edu/student/nschiral/research/gwo/gfsgwo_1.png.

 

With an FI indicated drop in trade winds later in September it is *disclaimer conceivable* that the MJO may come to life much more in the Pacific sector with a track from indiscernible forcing Phase 4 or 5 to another defined Phase 7/8 amplitude and exert augmented extra forcing on top of the existing Nino pattern. Quite some debate and conjecture obviously, at this stage, but with an already active Pacific cyclonic pattern in place, it *might* represent the highest peak of Nino 2015 - before a very slow decline through the autumn and winter.

 

Putting all this into synoptic value and simple English closer to the present time -  our current anticyclone slowly edges eastward, and, following an initial breakdown from the W/SW,  the default Atlantic upper trough returns from the NW.  Modelling which indicates any full blooded unsettled conditions may, imo, be too bullish after a more generally changeable weekend, and the trough in week 2 might get modelled slightly backed west into the NE Atlantic. Therefore most unsettled further west and north and perhaps drier at times further south and east.

 

In the very extended period, subject to obvious ^^ caveat uncertainty, perhaps a transition from changeable westerlies as the trough migtates eastwards towards Scandinavia to a defined amplification signal arriving from upstream creating another (transitional) Atlantic ridge before default pattern occurs once more.

 

In the medium term, the GEFS/ECM circa 8/10 day mean heights obviously not an indication of exact surface feature pattern and conditions, but gives a guide to where controlling upper features may reside

 

GEFS 0z mean H500 pressure pattern day 8

 

http://modeles.meteociel.fr/modeles/gens/runs/2015090600/gens-21-1-192.png

 

ECM  bullish  regarding inroads of the upper trough by day 10

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015090600/EDM1-240.GIF?06-12

 

NAEFS suggesting some slight edging of the trough anomaly back west in week forecast 2 and the most unsettled conditions further west

 

http://modeles.meteociel.fr/modeles/gens/naefs/run/naefs-0-0-300.png?0

 

As JH posted earlier, NOAA will reflect trend changes as usual as time progresses

 

NWP indicators at least a reasonable match for current MJO forecasts, and the direction of travel of the Global Wind Oscillation within the framework of the background Nino hemispheric drivers as described above

 

Further Edit : H500 link narrative edited to clarify intended meaning more clearly 

Edited September 6, 2015 by Tamara

[Polar Maritime]

Yes Knock the GFS 6z continues the theme from around Mid-Month onwards, With the Atlantic roaring through from the West.

Edited September 6, 2015 by Polar Maritime

[Frosty.]

The Gfs 12z shows the Atlantic cranking up soon with the northern arm of the jet flexing its muscles and sending a sequence of depressions hurtling our way, especially targeting the north of the UK...but not just yet. The week ahead looks benign with high pressure migrating eastwards across the uk, rather cloudy early in the week but still with some sunny spells and then once the high is to the north east of the UK we pick up a SEly breeze with sunnier and warmer weather during the second half of the week with temps into the low 20's celsius, at least across southern UK. By next weekend the highs influence is fading with a trough moving in from the southwest but temps are still on the warm side despite an increasing chance of showers, some heavy, prolonged and thundery. Then we see a more mobile Atlantic pattern develop through week 2 but high pressure still builds in close to the south at times to bring some fine and warm weather between occasional unsettled spells with the northwest of the BI bearing the brunt of the wind and rain off the Atlantic.

Edited September 6, 2015 by Frosty.

[Frosty.]

The Ecm 12z shows a change to increasingly unsettled weather through next weekend which continues to the end of the run and beyond. In the short term it's all about the high gradually drifting east across the uk and away to the NE with increasingly sunny and warmer second half of the week with a freshening SEly breeze before a change to more typical autumnal weather sets in.

Edited September 6, 2015 by Frosty.

[ANYWEATHER]

Evening all! What a beautiful day across many areas . low dewpoints . low humidity sparkling sunshine . In all fairness the models have predicted this short settled spell well. Enjoy it while it lasts , as the high pressure is eroded from the southwest by the end of the week. It looks like Scotland especially the western half wlll continue enjoy the best and settled weather for longest They deserve it...

[Geordiesnow]

Going from experience, whilst a trend is for low pressure to try and undercut the high, I still would not say its a full gone conclusion the low will be directly affecting the UK's weather by the weekend, no doubt it will take a few days to clear everything up but there is some hints the influence of the high may hang on longer. 

 

I think right upto Friday does look more or less stright forward with the exception of cloud amounts but the trend is for the weather to turn warmer, probably sunnier but also winds increasing(could be quite gusty on windward coasts and to the lee of high ground) as the high drifts NE'wards. Got to admit, moving to Lancashire does make this set up a lot more pleasing to see than if I was still living in the NE! 

[Singularity]

I've been away all day, just had a chance to catch up with the models and it appears that they're pretty much clueless about what happens Friday onward beyond the broad theme of a high to our NE. Whether low pressure pushes in during the weekend or stays to our west remains unclear following what is notably different GFS 18z operational run, as is the behaviour of further areas of low pressure crossing the Atlantic during the following week.

 

In fact the uncertainty for next week is about as high as it gets - just look at how much further south the lows travel on the ECM 12z (a troublesome looking outcome) when compared with the 00z (soon reverts to 'standard westerlies'). It all looks to be down to how different areas of low pressure interact - or avoid interaction.

 

At least a day's more runs are needed before conclusions can be drawn with more than shaky levels of confidence. In the meantime, at least we seem to have put to bed that risk of rain affecting the western fringes of the UK midweek, though I'll admit UKMO is still a bit of a close shave.

[knocker]

Looking at the 18z anomaly for the T574 sees the trough orientated NW/SE with deep area of LP NW Spain. Ergo no rush to let the Atlantic in through the front door.

 

This mornings ops run sees the HP hanging on over the weekend with low pressure near Spain on Saturday which is very slow moving before it trundles NE through France and then NNE into the North Sea by midnight Tuesday. Thus a dry pleasant weekend instead of a wet and windy one. At the moment anyway.

Chart weatherbell and http://www.tropicaltidbits.com/

 

[Frosty.]

The Gfs 00z prolongs the fine and warm spell by a few days with a stronger and better aligned scandi high later this week which keeps a strong ridge across the uk until the end of the weekend. This week we will see a return to warmer and sunnier conditions with temperatures into the low 20's celsius during the second half of the week with just about the whole of the UK staying settled. Into next week, the high is replaced by a trough moving up from the south with heavy showers pushing northwards and next week is looking generally unsettled, especially mon/tues before a window of fine weather returns for a day or so and then very unsettled later next week but there is then a return to anticyclonic conditions later in the run.

Edited September 7, 2015 by Frosty.

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON MONDAY SEP 7TH 2015

 

THE CURRENT GENERAL SITUATION High pressure will drift slowly East across the UK today and tomorrow.

 

http://www.wetterzentrale.de/pics/Rtavn001.gif 

 

MODELS-2 WEEK HEADLINE Becoming more settled through this week with a return to more unsettled and cooler conditions from the coming weekend.

 

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows the flow troughed over the Atlantic and ridged well to the North of the UK. The pattern slowly shifts East later this week with the trough section to the flow moving East into the UK late next week when the flow strengthens to blow West to East across the UK at the start of the second week. Thereafter the pattern becomes variable and ill defined at this range.

 

http://www.netweather.tv/index.cgi?action=jetstream 

 

GFS OPERATIONAL The GFS Operational Run today shows High pressure controlling the weather over the UK throughout this week. The High will retreat away to the East later in the week with an East or SE flow developing introducing warmer continental air. At the same time pressre will be falling to the South and SW with some thundery rain or showers reachig the South over the weekend. More unsettled conditions are then shown to spread to all areas from the Atlantic at the start of next week. This lasts several days before High pressure builds back across the UK from both the SW and East so that the UK returns to largely dry settled weather at the end of the period.

 

http://www.wetterzentrale.de/pics/Rtavn1441.gif

 

http://www.wetterzentrale.de/pics/Rtavn3841.gif 

 

THE GFS CONTROL The theme of the GFS Control Run this morning is broadly similar to the Operational run through the next week or so with the breakdown from the South and SW next weekend leading on to a spell of windier and more unsettled weather. This run also shows better High pressure based weather returning through Week 2 with High pressure across the UK bringing back fine and warm weather with sunny spells with just a hint of a cool down from the North right at the end of the period.

 

THE GFS CLUSTERS(14 Days) The GFS Clusters this morning are split 65/35% in favour of Atlantic based Westerly winds blowing over the UK at Day 14 with wind and rain at times in average temperatures, the worst of the weather in the North and West. Of the remaining 35% of members the weather looks better under a ridge from the South with 20% showing High pressure across Northern Britain at the same time point.

 

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

 

UKMO UKMO today shows High pressure moving steadily East over the UK over the next few days and away to the East late in the week. Pressure falls from the SW and thundery rain reaches the SW on Saturday and spreads further NE so that by Sunday all parts of the South and West will have turned more unsettled.

 

http://www.wetterzentrale.de/pics/Rukm1441.gif 

 

THE FAX CHARTS The Fax Charts this morning show similar sequences to events as the raw data output this morning with a decline in High pressure influenced conditions occurring at the end of the week from the SW but with any major rain bearing systems holding off to the West of the UK until the second part of the weekend.

 

http://www.weathercharts.org/ukmomslp.htm#t120.

 

GEM GEM today shows High pressure crossing the UK and away to the East over the next 3-4 days. It then shows Saturday as the day of change as falling pressure and frontal troughs edge their way NE across the UK through the weekend to set up a cooler and windier spell of weather next week with showers or longer spells of rain at times for all under typically Autumn cyclonic conditions.

 

http://www.wetterzentrale.de/pics/Rgem2401.gif 

 

NAVGEM NAVGEM too follows the theme of falling pressure from the SW at the end of the working week with a potentially thundery Low developing near SW Britain at the weekend bringing showers or rain at times North over Britain through the weekend.

 

http://www.wetterzentrale.de/pics/Rnvg1681.gif.

 

ECM ECM this morning shows the same theme of moving High pressure across the UK from the West and away to the East of the UK by midweek or soon after, This sets up a warmer SE flow with sunny spells and dry weather continuing for a while though with falling pressure Low pressure develops near Ireland on Saturday with some showery rain extending North and slowly East over the UK. The pattern then turns to an Atlantic Westerly then SW'ly as Low pressure returns to it's recent habitat to the NW with rain or showers at times while the South and eventually see rather less of this than elsewhere where it also may become rather warm and humid again towards the end of next week.

 

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

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from last night shows a strong trough near to the NW of the UK with SW winds and rain at times for all the most likely position we are in at Day 10.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models maintain their theme of High pressure migrating East away from the UK later next week with a return to more unsettled Atlantic winds thereafter though in varying degrees of extent.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The Verification Statistics of GFS, UKMO and ECM. This morning's verification statistics show ECM and UKMO at 96.0 pts  while GFS lags behind at 95.0 pts at 3 days. At 5 days UKMO is king at 85.6 pts followed by ECM at 85.0 and GFS at 83.0 pts. Then at 8 Days ECM still leads at 59.6 pts over GFS's 52.5 pts. Finally at Day 10 ECM leads GFS at 40.6 pts to 34.1 pts from GFS.

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png 

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.prig

 

MY THOUGHTS We wait all Summer to see one then lo and behold one appears right across the UK in the first week of September. I am talking of course about High pressure which finally has made landfall across Western Britain today and over the coming days will extend Est across the UK and away into Europe later in the week. I can finally stop talking about the cool Northerly flow and instead await the flow of warmer SE winds which will develop for many from midweek bringing dry and clear continental air NW to many with some warm temperatures too for several days towards the end of the week. Then it's all eyes down to the SW or maybe South as pressure will be falling down there later in the week with Low pressure coming into play over the weekend. The first signs of this could be on Friday in the SW with hazy cloud and the risk of a shower while over the weekend all output shows further progress North and East of this change in conditions with showery rain affecting all places by the end of Sunday and setting up an unsettled Westerly flow early next week with teperatures returning to average and winds possibly rather strong at times. Thereafter the jury is split. WE have GFS who show a split within their own camp with 65% of members continuing an unsettled and changeable theme while the other 35% show something rather more settled especially over the South and East while the rest of the model output suggest a return to what has been the pattern all Summer of Low pressure to the NW and rain at times with the emphasis of rain in the NW while the SE could see drier and warmer weather at times. The latter pattern is where I will hang my hat this morning as it looks like the Jet Stream has the tendency to drift back North somewhat next week after a few days of having moved South to the UK at the start of the second week. Still two weeks is a long time in model terms and we have a good 4-5 days of good weather still to come from this current anticyclone before looking into the mist of next weeks more unsettled phase which will probably chop and change within the output many times in the week to come as the pattern upwind becomes clearer as new data becomes available and we get nearer the time.  

 

Next update from 09:00 Tuesday Sep 8th 2015

[ANYWEATHER]

Big Difference in the models as early as early as Friday/Saturday, from ecm and gfs....

[I remember Atlantic 252]

Big Difference in the models as early as early as Friday/Saturday, from ecm and gfs....

 

guessing ECM right, huge backtrack I guess coming on GFS 12Z

[Summer Sun]

Big Difference in the models as early as early as Friday/Saturday, from ecm and gfs....

 

UKMO and ECM look similar

 

[Polar Maritime]

ECMWF shows a stormy end to the run around the 16/17th, Some big swings in the GFS suite of recent days to be expected given the 'Hurricanes' skitting the signals, And with seasonal changes in the Northern Hemisphere as the PV starts to ramp up. So an interesting few days coming up as they play/toy with different evolutions. But it is looking like the 2nd half of September could be much more mobile.

Edited September 7, 2015 by Polar Maritime

[Frosty.]

ECMWF shows a stormy end to the run around the 16/17th, Some big swings in the GFS suite of recent days to be expected given the 'Hurricanes' skitting the signals, And with seasonal changes in the Northern Hemisphere as the PV starts to ramp up. So an interesting few days coming up as they play/toy with different evolutions. But it is looking like the 2nd half of September could be much more mobile.

Yes PM the ecm is looking good for some wet and very windy weather next week. I think the gfs 00z is wrong to show the fine spell lasting through next weekend, the ecm looks more realistic with rain spreading from the west by the end of this week but before all that, a fine and warmer spell with sunny periods.

Edited September 7, 2015 by Frosty.

[knocker]

The detail for this weekend is very dependent on how the models handle the LP to the SW as has been mentioned. Either way the anomalies are in agreement for the beginning of next week with the upper trough plonked over us giving some very unsettled conditions.

http://www.tropicaltidbits.com/

 

[Singularity]

Curious that GFS has suddenly started taking that low further southwest - two operational runs in a row with that outcome now. It takes until next Monday for things to break down from the south as the low moves slowly into the UK. Apart from some slow moving areas of heavy rain early next week, the run features a lot of dry weather until about 10 days from now.

 

ECM is a very different story with low pressure arriving on Saturday and the jet stream firing up during the weekend to bring an onslaught of wind and rain events, though not at all severe in isolation (see examples below).

 

 

I reckon there's three or perhaps four rain events in the period Saturday-Wednesday next week. Then things get a little more dramatic for 10 days from now, though we all know not to take this too seriously at such long range:

 

 

GFS does also have an intense low tracking level with the UK, but the jet stream remains flatter so we don't see that 'scoop' of hot air being drawn up ahead of it.

 

As you can probably tell based on which charts I have posted, I'm feeling inclined to go with ECM over GFS at this point in time, what with UKMO now in support and the tendency over the past few months for the jet to be stronger than we'd like to see (unless you enjoy wet, windy weather, that is!).

 

I see GEM has also boarded the rain train as well this morning. It seems my concerns expressed about a week ago about a very wet period of weather may prove well founded - however, it seems to be scheduled to kick off about 5 days earlier than I had imagined back then. If it does follow such a timetable, then we'll need another pattern shift to avoid a soggy September overall - the likes of which GFS showed us on its 00z operational run this morning, though there are others ways of going about it.

 

We still can't rule out the low staying away during the weekend though, and if that turns out to be the right way forward, the game will change somewhat, as the blocking high to our NE will be better able to resist the Atlantic jet stream as it changes up a gear or two.

[Frosty.]

The Gfs 6z shows our weather becoming unsettled during next weekend, especially by sat night / Sunday and then next week looks v unsettled with bouts of rain and gales which continues for the rest of the run. The message from this run is enjoy the fine and warm spell this week then batten down the hatches. Personally, I'm glad to see there is a more unsettled spell on the way, it makes model watching more interesting than looking at benign charts all the time.

[Frosty.]

The latest Gfs 12z run continues to show a descent into an increasingly unsettled outlook from the end of this week onwards with bouts of wet and windy weather affecting all parts of the uk at times. By contrast, most of this week looks fine and pleasantly warm, indeed, becoming warmer by Thursday with temps across southern Britain in the 21-23c range between thurs/sun. During the weekend the fine spell gradually crumbles with pressure falling although Saturday looks a largely fine and warm day, but by sunday there is a growing chance of showers and then the Atlantic really cranks up next week with the most unsettled weather of the autumn so far heading our way during the extended range but still with some occasionally fine and pleasantly warm weather further s/e.

Edited September 7, 2015 by Frosty.

[tinybill]

having a quick  look at  the  models its looking nice  up to sept  13   then it looking like its going down hill fast  and looking into fantasy world its looking a  bit damp!!

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=6

 

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

[ANYWEATHER]

Evening campers! Lovely weather to the end of the week, then unfortunately unsettled conditions move in.

[Frosty.]

then unfortunately unsettled conditions move in.

Bring it on, we need variety in our weather, it would be boring if we had a high over us all the time wouldn't it?

Ecm 12z turns very unsettled next week.

Edited September 7, 2015 by Frosty.