Model Output Discussion 06Z, 13 Sep. 2013 ---->

[Cloud 10]

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/

 

 

I think if you look at the 5 and 6 day checks ba you will find that they all dipped at the beginning of the month and again a few days ago (that is for the northern hemisphere) but through it all ECMWF led with Met 2nd and GFS 3rd.

 

 

That link by Yarmy also includes data on ensemble mean verification which shows the NAEFS doing best,although crucially doesn't include the ECM ensemble mean!

 

NCEP EMC Global Model Verification

 

 

This seems to show that the NAEFS verifies better at 120 hrs than the GEFS mean or the GFS operational run.

 

Edited September 27, 2013 by Cloud 10

[Summer Sun]

At t144 ECM keeps the high closer to the UK unlike GFS and UKMO

 

 

GFS and UKMO at the same time

 

 

With ECM keeping the high closer to the UK it has warmer uppers in the east unlike GFS

 

 

t168 sees the low heading away leaving us in a slack flow of pressure

 

 

Looking at ECM's pattern I can see the Azores moving up at either t192 or t216

Edited September 27, 2013 by Summer Sun

[Frosty.]

The GEFS 12z mean brings the warm and calm weather back after the warm, windy and unsettled spell next week, the southeastern half of england would be nice and warm through early october with max temps in the high teens celsius to low 20's celsius, you can add 2-3c to these 12pm temps, cooler and more unsettled the further north and west you go from the SE.

[Summer Sun]

ECM holding firm again this evening building pressure later next week this is 4 successive runs now its had this

 

As expected the Azores moves up at t192

 

 

t216 see's it extending further north

 

 

T240 should see the high expanding out if it follows the 00z run at t240

 

Edited September 27, 2013 by Summer Sun

[Summer Sun]

And there we have it the high expands out keeping lows well away so we are getting consistent runs from ECM at the moment for later next week and into the following

 

 

Edited September 27, 2013 by Summer Sun

[ANYWEATHER]

And there we have it the high expands out keeping lows well away so we are getting consistent runs from ECM at the moment for later next week and into the following

 

 

In all fairness, no model shows consistency at the moment, and regards the timeframe rarely at this stage is that right...

[Frosty.]

The bbc forecasters are describing the weather this weekend as usable, bit of an understatement there, I would go a lot further, it's actually a very nice weekend coming up for most of the uk apart from the top and tail of the uk tomorrow, a few heavy showers for the southwest and far south but very hit and miss affairs, and some rain across the far north of scotland but apart from those areas, the majority of the uk looks sunny and pleasantly warm with just some patchy cloud blowing across in the freshening SE'ly breeze and max temps between 18-20c, even windier on sunday but clear and sunny with temps similar to tomorrow..so it's better than usable, it's actually very good for the last few days of september and there is more good weather for a while next week the further east/ne you are.

[smithyweather]

And there we have it the high expands out keeping lows well away so we are getting consistent runs from ECM at the moment for later next week and into the following

 

 

 

Oh how fantastic.

[Summer Sun]

Latest from Gibby

 

Good evening. Here is the report on the 12 noon outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Friday September 27th 2013.

 

All models show a slowly increasing ESE airflow over the UK carrying still reasonably warm air across the UK. A cold front approaches the far North tonight before weakening tomorrow. Southern Britain will be at risk of showers coming North from Biscay in association with Low pressure near Iberia. The chance of showers waxes and wanes over the weekend in the South and SW before the risk extends further North and East early next week as Low pressure edges North close to Western Britain and winds swing more towards the SW.

 

GFS then shows changeable conditions continuing through the remainder of the run with a short drier interlude possible in the South before markedly colder weather with Northerly winds and showers, wintry on hills arrives late in the run with frost at night in the North.

 

UKMO keeps unsettled conditions throughout next week as winds veer more towards the SW and temperatures fall back somewhat with Low pressure close to NW Britain late next week.

 

GEM shows the weather slowly improving later next week as High pressure ridges first across Northern Britain before extending further South. The SE is last to improve as a cut off Low near SE England late in the run keeps things more showery here. Temperatures would be on the warm side still at first cooling off a bit late on.

 

NAVGEM shows a SW flow across the UK in a week's time with Low pressure close to the NW influencing all of Britain with a mix of sunshine and showers in decreasing winds and average temperatures.

 

ECM still shows an unsettled week similar to some of the other output in that it shows a rise of pressure at the end of next week with some quiet and fine weather replacing the early wind and rain. Mist and fog would become likely at night though the SE could see a NE breeze and the occasional shower for a time as pressure remains lower over the near Continent. The run ends with High pressure formed strongly over the UK with fine quiet weather by day with fog at night.

 

The GFS Ensembles show another set indicating a slow decline in uppers to levels around the seasonal average by the end of the period. The weather is also indicated to be changeable with rain at times throughout the period and across the UK though the North will stay mostly dry now until the turn of the month.

 

The Jet Stream is strongest to the South of the UK over the coming three to five days with a weaker arm continuing to flow to the North of the UK. Later on the prognosis for the flow is very much undecided and shows no particularly reliably accurate prediction from tonight's output.

 

In Summary the weekend doesn't look too bad away from Southern England tomorrow. Early next week it appears that unsettled and windy conditions extend across the UK for all as winds veer SW in response to Low pressure edging North towards the NW of the UK. Longer term the output is quite mixed and though some High pressure intervention is shown on some output the current patterns are inconclusive on how this develops.

 

http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htm

[Tony27]

so 18c-20c at the end of the september "is very good"  lol its quite normal, we do get temps a couple of degrees above and below average quite often you know, temps are not dead on average every single day, if it was 25c i'd agree that's very good

Edited September 27, 2013 by Tony27

[Barry12]

The 30c in october 2011 was very very good!

[Summer Sun]

ECM ensemble remains consistent with a huge area of high pressure show to build across a lot of mainland Europe and the UK later next week and into the following

 

[Summer Sun]

NAO showing signs of going positive as we head into October

 

[Frosty.]

There is a lot of Fi eye candy on tonight's models, the ecm 12z ens mean is again showing summery synoptics and the Gefs 12z control run shows a very warm early october for southern britain with temperatures well into the low 20's celsius so summerlike weather could still be ahead of us even through to the middle of october, amazing.

[johnholmes]

That link by Yarmy also includes data on ensemble mean verification which shows the NAEFS doing best,although crucially doesn't include the ECM ensemble mean!

 

NCEP EMC Global Model Verification

 

 

This seems to show that the NAEFS verifies better at 120 hrs than the GEFS mean or the GFS operational run.

 

cor_day5_HGT_P500_G2NHX.png

 

 

interesting data set and it again shows all the models showing issues at the same dates that I mentioned in my earlier post, winder what they had an issue with?

[Methuselah]

Very quiet in here...?

[Summer Sun]

Consistency is the name of the game and thats what we have from ECM 5th run in a row now for high pressure to build later next week and into the following

 

[Captain Shortwave]

^Again backed up by the ECM ens

 

Could be 2 good weekends on the bounce here if this is close to being correct.

Edited September 28, 2013 by Captain shortwave

[Summer Sun]

As CS has said ensemble support from ECM here's t216 and t240

 

 

Consistency is what its about and thats what we have currently

[Summer Sun]

Latest from Gibby

 

Good morning. Here is today's look at the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Saturday September 28th 2013.

 

All models suggest a similar pattern over the next 7 days. Low pressure currently to the South and SW of the UK has meant a freshening ESE flow has developed over the UK. While fairly warm in origin it's effect will be to temper any meaningful warmth felt from temperatures well above average. In addition a cold front near NW Scotland will maintain cloudy weather here with occasional rain while Southern and SW Britain remain at risk from heavy and thundery showers throughout the weekend especially today. Early next week will see slow but subtle changes take hold as the Low that's down to the SW drifts North to the West of Britain reaching a point close to NW Scotland by the end of the coming working week. This will have the effect of veering winds from ESE through South and eventually SW which will carry the showers and rain from the South and West early in the week across all areas by midweek with somewhat lower temperatures as the continental drift is lost. Late in the week most models show some sort of rise of pressure to the South with rainfall becoming more and more confined to the North and West of Britain by next weekend.

 

GFS only half-heartedly develops such a ridge temporarily close to the South before another surge of Atlantic energy fairly well South in the Atlantic returns us to square one with Southerly winds and heavy rain at times especially in the South and West which then extends quickly North to be followed by yet another rise of pressure from the South at the end of the run with fine conditions chasing the rain that's left over the North away in temperatures returning to temperatures close to average.

 

UKMO closes it's run with a SW flow blowing over the UK next Friday with the most likely weather type being sunshine and showers with the heaviest of these by then in the West and North. Pressure will be rising steadily from the South so just outside the range of the output it looks as though the weekend may not be too bad.

 

GEM builds pressure strongly over Britain next weekend with sunshine for all but with the risk of mist and fog very high following the previous week's rainfall. Southern Britain is afflicted by an Easterly breeze on this run which would indicate more cloud and a potential light shower risk towards the far SE.

 

NAVGEM is less enthusiastic about much in the way of ridge development next weekend instead maintaining a SW feed for all with fronts moving NE across Britain delivering spells of rain and showers at times in average value temperatures.

 

ECM is still as keen this morning as it was last night to develop High pressure over the UK next weekend with remaining rain in the North and West to start next weekend being slowly eroded away for a time with all areas settling into a period of calm and more settled weather for a while with fine and bright days when it may feel luke warm mixed with potentially foggy and chilly nights especially in the South though pressure does look to be slowly leaking away again by Day 10.

 

The GFS Ensembles support a steady but slow decrease in temperatures in the atmosphere this morning to levels close to average for early October by next weekend and maintained thereafter. Rainfall is fairly common for all through next week before suggestions of a drier phase are shown in the South for a time before more unsettled conditions return towards the end of the run.

 

The Jet Stream shows the main thrust of energy to the South of the UK through the coming week before it lifts slowly North to be over or just to the North of the UK in the second half of the run.

 

In Summary today we have fairly firm agreement that the next week is going to maintain it's unsettled phase in the far South and West and this will extend North and East in the early part of the working week. Winds will shift towards the SW later lowering temperatures somewhat with the heaviest rain shifting towards the NW by Friday. There is reasonable support for a build of pressure again then across Britain with GEM and ECM showing a similar evolution toward this at least for a time. GFS and NAVGEM are less keen to make much of this either maintaining or bringing back changeable conditions again soon after next weekend. There is no likelihood of anything cold at the moment with temperatures most likely to fall from their current above average values to near normal levels by next weekend and beyond.

 

http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htm

 

[lorenzo]

interesting data set and it again shows all the models showing issues at the same dates that I mentioned in my earlier post, winder what they had an issue with?

Saw on Twitter that a buoy in the Atlantic was mis reporting temperatures and directly messing up model initialization. Due to be fixed by Tuesday. How much error can be attributed to this, unsure. But a definite error impacting UKMO and ECMWF.

[johnholmes]

Nothing on NOAA or Met about it and it would seem unlikely that either of those major weather centres would not pick up an error pretty quick and 'manipulate' its readings to fit their initialisation data programmes until it was fixed?

[Cloud 10]

interesting data set and it again shows all the models showing issues at the same dates that I mentioned in my earlier post, winder what they had an issue with?

 

Seems to be around the 24th of September when the biggest dip in verification occurred.

 

The charts 5 days earlier from the UKMO and ECM both had a deep low to our N/NE (amongst other things!) which was replaced by a ridge on the actual chart.

 

Actual chart..

 

ECM 19th Sep..  UKMO 19th Sep..

[johnholmes]

thanks for that C

[Methuselah]

Saw on Twitter that a buoy in the Atlantic was mis reporting temperatures and directly messing up model initialization. Due to be fixed by Tuesday. How much error can be attributed to this, unsure. But a definite error impacting UKMO and ECMWF.

I am very sceptical, Lorenzo...How often has the spectre of 'insufficient data' been raised in here?