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

[Frosty.]

Yes Karl, The 6z really shows the Atlantic firing up as we head towards Months end into Autumn proper. With a cool/unsettled Pm flow from the N/W it would feel raw in the wind, With a Wintry mix possible for the Scottish Mountains. There's some pretty cold uppers sat over Greenland, Which gets dragged into the mix on-route across the Atlantic.

Yes pm, these are the type of charts I look forward to seeing as we go further into autumn, on the other hand, I really liked the strongly anticyclonic gefs 00z control run but once we are into october i'm looking for the first polar maritime blast

Edited September 16, 2015 by Frosty.

[Captain Shortwave]

You kind of wish that it was December rather than September given set ups like these appearing. Next week looks particularly messy as the high which will settle the weather down this coming weekend drifts north east allowing cold air to sink south east from Greenland along with the next Atlantic system as well as low pressure over the Baltic sea allowing the jet to eventually undercut the high shown in the second image.

At this point any major Atlantic onslaught should be treated with scepticism I think as this set up could repeat itself over the coming weeks. That said the outlook does look changeable and with the jet favouring a meridional pattern then I suspect temperatures will on the whole be a little below par. 

Edited September 16, 2015 by Captain shortwave

[Summer Sun]

After a decent weekend UKMO shows pressure falling as we move into next week Monday is likely to see some rain moving across the UK arriving into eastern parts last. Tuesday could be a drier day though the odd shower can't be ruled out

 

[stodge]

Evening all

 

The story for the next few days seems fairly well set - out at T+240 GEM picks up a hurricane which pushes the Azores HP up and over the British Isles:

 

http://modeles.meteociel.fr/modeles/gem/runs/2015091612/gem-0-240.png?12

 

GFS very different as you might expect:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015091612/gfs-0-240.png?12

 

I know, I know but that's about as negative an NAO chart as you could ever see:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015091612/gfs-0-384.png?12

[Frosty.]

The Gfs 12z becomes predominantly fine from next thursday onwards with high pressure linking up from the azores to scandinavia, bar the odd shower spreading up from the continent its fine and pleasantly warm with plenty of sunshine until the end of the run but with chilly nights where skies clear, especially where winds are lighter in the north and a risk of mist/fog patches too. Having read the latest Met Office 6-15 day update which is calling for a change to more settled conditions from around the middle of next week, it looks like this run gives a good idea of how our weather from the second ½ of next week onwards could develop.

[Singularity]

 

 

ECM (1st image) and UKMO (2nd image) have been reluctant to develop the potential sliding low for early next week... until now.

 

As often seems to happen, GFS has at the same time backed off a bit since yesterday's highly convective 12z operational run.

 

The UKMO offering looks ripe for some unusually strong home-grown convection for the time of year, as a substantial wedge of cold air circulates overhead and allows for large lapse rates once the surface warms up each morning.

 

ECM is more restrained in that respect, but still cold enough at the 850 hPa level to suggest some feisty daytime showers with hail and thunder on the cards.

The low locates itself just SE of the UK for the following day, but remains in control across most of the southern half of the UK, with the low 850's maintained there.

 

 

Looking further ahead, GFS wants to ramp up the Atlantic jet and set up a SW-NE jet stream alignment well northwest of the UK, but from the looks of ECM's +168 chart, that model is looking to keep the jet aligned between W-E and NW-SE, just as it did in its 00z operational run.

In fact, +192 has just rolled out and confirms my suspicions with the jet diving southeast from the Atlantic - could be a soggy end to the run? 

[ANYWEATHER]

After, a relatively settled spell this weekend , this September proves that this month is not always settled ...

[Wildswimmer Pete]

After, a relatively settled spell this weekend , this September proves that this month is not always settled ...

Appears to me that all the usual "weather singularities" seem to have been jumbled or even missing.  I was comparing wetterzentral's Top Karten from the 1960s and now and nowadays the atmosphere over the North Atlantic appears to be highly turbulent.  Of course I know the Top Karten from the Sixties are "re-sampled" from physical charts so obviously can't have the fine detail of contemporary model output.

[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 THURSDAY SEP 17TH 2015

 

THE CURRENT GENERAL SITUATION.  A slack and showery Westerly airflow will cover the UK today and tomorrow with a ridge of High pressure approaching the West of the UK later tomorrow.

 

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

 

MODELS-2 WEEK HEADLINE  Becoming less unsettled next week with longer drier spells with most rainfall likely in the form of scattered showers.

 

THE GFS JET STREAM FORECAST  The GFS Jet Stream Forecast shows a ridge of High pressure approaching Western Britain over the coming days changing the orientation of the Jet Stream from South of the UK to the North for a while.Then a new trough slips it back South across the UK for a time but overall though details are sketchy the flow looks like remaining more to the North of the UK over week 2 probably enhancing the theme of dry weather across the South of the UK at least.

 

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

 

GFS OPERATIONAL The GFS Operational Run today shows a ridge of High pressure settling things down across the UK at this weekend before a trough returns cloud and some rain for a time early next week. This is then shown to be the precursor to a more North/South split in the weather with the North seeing breezy and changeable weather next week while the South becomes largely dry and fine under a ridge from the SW. This ridge is then shown to intensify exerting it's influence to all other areas with fine and dry weather with mist and fog at night. Then the theme at the end of the run is to push this ridge to the East of the UK where it draws some rather warm air NW over the UK while maintaining fine and dry weather for most.

 

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 nothink like as High pressure based as the operational bringing down Low pressure across the UK next week where it hangs on across the South for quite a while gradually being reinforced from the Atlantic by other weakish Low pressure ensuring that after a dry weekend the rest of the run looks changeable with some dry and bright weather mixed with cloudier and more unsettled periods with rain or showers at times, probably most enhanced towards the South than elsewhere

.

THE GFS CLUSTERS(14 Days) The GFS Clusters this morning show no set pattern likely by two weeks with equal options shown between Low pressure based conditions with showers or rain and rather drier weather under higher pressure.

 

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 a High pressure ridge at the weekend collapsing as shallow Low pressure slips SE across the UK in the first days of next week. After a dry weekend some rain on a trough will introduce a showery period next week but with light winds and some sunshine in between daytime conditions shouldn't feel too bad with mist and fog though a probability under any clearing skies after dark.

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

 

THE FAX CHARTS  The Fax Charts this morning show complex troughs slipping down across the UK on the Western flank of yesterdays depression introducing a simplified weather pattern of a ridge moving across the UK from the West with a dry and fine weekend before further troughs approach the West by Monday.

 

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

 

GEM  GEM today shows a fine weekend as a ridge moves across from the West. This is shown to collapse early next week as Low pressure sinks SE across the UK with some rain or showers for all. Later in the week the Low responsible is reluctant to leave our near continental neighbours and continues to exert a showery influence to the South and East with the best weather likely over Scotland and Northern Ireland as another ridge builds in.

 

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

 

NAVGEM NAVGEM also shows the weekend ridge giving way to a trough early next week with some rain for all before another ridge links across Central parts of the UK with the South slowly becoming dry and fine while fronts on Westerly winds over the far North bring the risk of rain at times here later next week.

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

 

ECM ECM this morning follows the theme of Low pressure moving SE across the UK early next week with two or three days of changeable conditions with some rain or showers for most before a trend for things to quieten down slowly later in the period culminating in a very pleasant picture by Day 10 as High pressure builds across England and Wales with dry and fine early Autumn conditions for many with the whole of the UK likely to be dry at that stage.

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

 

ECM 10 DAY MEAN  The ECM 10 Day Mean Chart  from last night indicates to me that there is a good chance of High pressure lying close to England and Wales with a lot of fine and dry early Autumn weather here while any fronts from off the Atlantic become restricted to affecting the far North only by Day 10.

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models are still undecided on whether next week's slip back under Low pressure is just a short blip before fine and settled weather returns to most of the UK thereafter or not.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The Verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ties with UKMO at 99.4 pts each with GFS coming in third at 99.2 pts.  At 3 days ECM leads at 96.5 pts with UKMO  at 96.4 pts while GFS lags behind at 95.6 pts. At 5 days ECM is king at 86.3 pts followed by UKMO at 86.2 and GFS at 84.0 pts. Then at 8 Days ECM still leads at 59.4 pts over GFS's 51.4 pts. Finally at Day 10 ECM leads GFS at 38.0 pts to 33.5 pts from GFS.

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day1_PMSL_MSL_G2NHX.png

 

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.png

 

MY THOUGHTS   There are tentative signs that the UK may come more under the influence of High pressure later next week. It is yet to be decided in what shape or form that may take as only ECM offers a UK based anticyclone across our shores and this is shown at Day 10 so a lot of scope for error in that chart. The genral theme though is slowly straightening out as yesterday's Low has now made it's exit East and NE away from the UK. A strong ridge looks like producing a decent weekend for most if not all as the last of the coming few day's of showers finally clear the East late tomorrow. It then looks like 48hrs of decent fine and settled early Autumn weather with some chilly and misty nights is likely before a trough moves in from the West late Sunday and more significantly on Monday. This then brings rain followed by a scattering of showers as weakish Low pressure slips SE across the UK towards NW Europe. Once arriving there some output shows that it gets held up later next week and continues to affect the South and East with further showers while other output shows it clearing away and the South coming under a ridge while the North becomes at greatest risk of a little rain from troughs crossing close by to the North. Whichever way the dice falls High pressure should play some sort of role in what happens through Week 2. I particularly like the ECM evolutions as it shows a full scale move towards High pressure sitting across the UK in the second week and this is largely backed up by it's ensembles. It's harder to see where UKMO is heading but my betting would be similar to ECM. GFS shows a decent operational while the control is less favourable with the clusters a complete mess this morning so not much useful guidance there. So putting all this together while I cannot see a prolonged dry spell UK wide, certainly not in the short term I think with time many places will see much more dry weather than wet and some pleasant sunshine by day could lead to chilly and very misty nights at times, slow to clear in the morning's draggng the overall mean temperature down to probably just below the seasonal average for mid to late September. Still with no major atlantic storms looking likely across the UK over the next two weeks I think most perople will accept this morning's output with open arms because it could be an awful lot worse.

 

BEST CHART OF THE DAY 00z RUN

 

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

 

The best chart of the day today goes to ECM with a peach of a 240hr chart showing High pressure in excess of 1030mbs lying across England and Wales with fine and dry early Autumn weather for most if not all of the UK.

 

WORSE CHART OF THE DAY  00z RUN

 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=360&mode=0&carte=0

 

For the worst chart I have gone for the Day 15 chart from the GFS Control run which illustrates aLow mobving in across the UK from the West bringing rain and showers for all. What's significant with this chart is that pressure is High across the Arctic stretching from Scandinavia to Greenland pushing all rain bearing Atlantic Lows and fronts on a collision course with the UK. Thankfully it is 15 days away and unlikely to verify.

 

Next update from 09:00 Friday Sep 18th 2015

Edited September 17, 2015 by Gibby

[knocker]

Looking at the GEFS upgrade and the ecm anomalies for 00z isn't all bad news. The trough next week isn't digging as far south as previously forecast and straight after that they are both looking at height rises over the UK and to the west with the Scandinavian block no more. Fingers crossed

Charts courtesy weatherbell

 

[phil nw.]

Indeed not a bad outlook if today's outputs are anything to go by.

We have another 24/36hrs of showers here and there before a decent weekend is promised for much of the UK as pressre builds from an Azores ridge.

However this is shunted aside by Monday as Atlantic fronts move east.This from the GFS06z run.

 

This doesn't appear to herald any prolonged breakdown as later next week both ECM and GFS mean charts are looking at a more pronounced build of pressure across NW Europe and day 10 looks like this.

 

so the Autumnal jet not yet into full gear with the Atlantic trough easing back from the UK.

A possible mainly dry and pleasant end to the month could well be on the cards.

Edited September 17, 2015 by phil nw.

[Polar Maritime]

It will be interesting what the models evolve into as we head towards the end of the Month, As again this evenings GFS shows cooler air from the N/W trying to push in as the Atlantic gears up.

 

[SMU]

If only it was .......

S

[Polar Maritime]

Yes Steve that did spring to mind!

 

[Nouska]

I've a hunch we will not hear from the OPI team this october but having read their full workings, in the original pdf, I would guess the figure would be off the negative scale if charts like the one below were the order of the day when October arrives.

 

[summer blizzard]

Cool surface air for the time of year too..

 

[Scorcher]

Cool surface air for the time of year too..

 

 

 

And this, which is a good deal closer to the reliable timeframe, doesn't look cool at all.

[Singularity]

Grouping the GEFS into clusters of ensemble members suggests that we're finally seeing a majority vote emerge with respect to whether LP slides down across the UK early next week.

 

 

That's what 35% of the runs look like. With the 1008 mb contour encompassing much of the UK it looks like a well defined low, but not a very deep one. Possible frontal rain followed by diurnal showers for 1-3 days depending on how the low moves about.

 

 

 

20% of the runs look like this, suggesting a deeper low that would probably tend to keep the UK unsettled or at least changeable for a day or two longer.

 

 

 

15% of the runs make little of the potential slider, with a day or two of slow moving showers before it most likely settles down either from the east or the southwest.

 

 

 

Looking further ahead, the cluster analysis for Friday has a large Atlantic low in control bringing unsettled westerlies (most so for the north) on 25% of the runs, but a whole 60% of the runs have high pressure ridging in from the Azores with unsettled conditions restricted to Scotland and a trend to settle things down further through the weekend. The remaining 15% have already built high pressure in by Friday.

 

Amazingly, the weekend starts of settled and dry for all but the far northwest on 85% of the runs, and becomes settled for the whole of the UK by Sunday on 100% of the runs. Yes, every single one of them! 

[Swave Snow]

Yes Steve that did spring to mind!

 

 

July that would be a heatwave (no?)

[Cloud 10]

Please connect your charger...

If only it was .......

image.jpg

S

 

 

.....October...

 

 

[ANYWEATHER]

July that would be a heatwave (no?)

It certainly would be if like this year the continent was baking!!! The CURSE on tonights models from gfs and ecm show them holding hands at T+240.  Oh Dear, I hate it when these two models agree at this time frame......    

[knocker]

The GEFS and ecm anomalies are both still looking at the change around Friday with the trough in the eastern Atlantic withdrawing and realigning south of Greenland and heights building in the eastern Atlantic. This looks set to remain until the end of the extended period. Could give a period of pleasant weather with temps above average.

http://www.tropicaltidbits.com/

 

Edited September 17, 2015 by knocker

[Geordiesnow]

The GEFS and ecm anomalies are both still looking at the change around Friday with the trough in the eastern Atlantic withdrawing and realigning south of Greenland and heights building in the eastern Atlantic. This looks set to remain until the end of the extended period. Could give a period of pleasant weather with temps above average.

http://www.tropicaltidbits.com/

 

Certainly the trend is fairly strong for strong heights to build over Scandi coupled with a possible ridge over the UK which could lead quite a large block forming with a lot of warm air heading towards Svalbard. That said, the trend is a bit past the medium range at the moment and its a case in the coming days whether models keep this sort of trend or not.

 

One thing for sure, the outlook is looking average to above average in terms of temperatures, although the start of next week could be a little cool with the rain, there is no signs of a true cool outbreak at the moment so there is nothing in the true sence of Autumn(where for me is when its sunny by day but temperatures are quite low),appearing on the outlook yet. 

[knocker]

A very brief overview of the latest EC32 run

 

It too is looking at the transition from trough domination to the benign influence of HP around next Friday. It signals the start of a period of pleasant weather with temps average or above. This could well last until around the 8th October. Even after that (until the 19th) there doesn't appear to be anything deadly lurking in the woodshed with a return to a familiar scenario of LP to the NW and the HP to the SW giving a westerly airflow and the not unfamiliar N/S split. Keep in mind this is pretty broad brush towards the end of the run, I obviously don't have access to the full ecm suite, but even so I feel a quick play of a well known Dave Clark five song is called for. I might even order an Indian as well.

[joggs]

Please connect your charger...

.....October... gensnh-5-1-384.png

Please connect your charger...

.....October... gensnh-5-1-384.png

if the vortex is aligned like that this winter,chaos will decend. Edited September 18, 2015 by joggs