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

[ANYWEATHER]

Well luckily Humberto has come up trumps & supported a building ridge in the atlantic- infact it looks pretty good from Sunday onwards-

 

What a crackerjack ECM!

 

S

Hiyer Steve , you getting fed up with a warm Autumn:::????  

Edited September 16, 2013 by ANYWEATHER

[Captain Shortwave]

ECM ens show pretty good support for the operational even out to day 10, usual mixing out by this time with respect to uppers, but this is pretty good for day 10

Stonking charts for the mean anyway.

Edited September 16, 2013 by Captain shortwave

[DAVID SNOW]

So then...

 

in the space of 48 hours-

 

Gone is the forecast for settled conditions next weekend ( Unless you fancy the worst run of the GFS )

Gone is the ensemble support for any settled weather -

Gone is the decent UKMO update....

 

The trend is clear ( although there is still a chance that it could swing back) that the ECM is paving the way & the other models are following-

The climo charts I posted last night SEEM to be continuing for a 6th year with the polar heights being more prevelant-

 

If I was asked to take a punt on the next 6 months inc sept I would say-

1 ave

1 above

4 below.

Back is the forecast for settled conditions next weekend

Back is the ensemble support for settled weather

and back is a decent UKMO update.

 This weather forecasting is a tricky business.

[Frosty.]

Steve said it could swing back and he is right..it has swung back to a settled outlook, I have total respect for sm, he makes predictions and backs it up with data and his vast knowledge. Please keep posting steve.

[Cloud 10]

Steve said it could swing back and he is right..it has swung back to a settled outlook, I have total respect for sm, he makes predictions and backs it up with data and his vast knowledge. Please keep posting steve.

 

 

Its the "polar heights" part of Steve's post which grabs my attention,and certainly plenty of anomalies in that region in the mid-term model output.

 

NAEFS day 10..  ECM day 10..

 

The AO and NAO set to go negative..

 

AO..  NAO..

 

 

In the closer timeframe however,it looks like a return to summer for many areas as we head into the weekend,especially if the 12z ECM verifies!

 

Good old Humberto 

[johnholmes]

I'm not showing the charts tonight but all 3 models, especially ECMWF and GFS, have at last settled it seems on a slackish surface low in a similar area to where GFS for several outputs had a centre of marked depth. They also deepen it considerably around 20W by T+144 with a plume of fairly high 850mb temperatures being brought over the UK by the SW'ly flow. This allows for almost muggy weather for many parts of the UK over the weekend. Possibly lasting into next week, although by T+240 as might be expected the two main models begin to differ on the crucial positioning of the surface high partly set up by ex Humberto.

There is still no continuity from the 3 anomaly charts so I offer no advice based on their outputs, oscillating between fairly mobile W'ly flow to something that could be almost more settled although not with any persistent blocking showing ( near the UK). As I have said many times they are not a lot of use when hurricanes are in the North Atlantic.

Edited September 17, 2013 by johnholmes

[Gaz1985]

GFS 18z still showing strong high pressure this weekend, looking great 

 

 

 

 

 

Still in control into Tuesday with it shifting a bit westwards 

 

 

By Thursday the high pressure moves back east slap bang over the UK, great run tonight 

 

[lorenzo]

Humberto delivering the fun !

 

Reforecast mean 150 -192 hrs

 

Then what we have eyes on at the earlier timeframe

 

The real anomaly is elsewhere.. out to the 27th..

 

Not wishing to thrown calm over the cracking ECM 144 'mean' just a quick look beyond and the future anomalies provided, that high arctic block signature hanging around.

 

 

 

[TwisterGirl81]

Oh what I would do for a good old fashioned wind storm! Today was interesting, very blustery but I hope we do get some severe gales in the south in october

Edited September 16, 2013 by TwisterGirl81

[A.J]

A polite request. This is the Model Output Discussion thread, please post other weather related posts in their relevant threads.....cheers

[mushymanrob]

oh if only these charts came 6 weeks ago...

 

cracking runs for sun/warmth, and these runs have imho reduced significantly the fog chances (concernes were raised when the expected high wasnt so strong and cooler uppers were more prevelant) thankfully the expected pressure rise is much stronger and atm orientated perfectly for the warmest weather. and its looking like being more then a transient feature too.. lasting most of next week.

[bluearmy]

apologies to naefs for 'dissing' its week 2 progged high anomolys post 20th. It seems the 10/14 day output was more reliable than the 6/10 day stuff!

All likely down to the way the models dealt with humberto when it came into view. At 10/14 days, it was insignificant.

The question of sustainabilty remans.

Edited September 17, 2013 by bluearmy

[BlueHedgehog074]

The brand new sparkly 00Z ECMWF seems to be another great run for warm and rain-free weather next week with the High Pressure looking all mighty and strong over the UK for early next week. The 15*C upper line gets very close to the South/South-Western coast at times, but with slight Eastward adjustments of the High Pressure cell, the 15*C uppers could easily get hoovered up further North. The High Pressure does slowly pull away a little bit further North-Westwards near the end of the run (although never leaves the UK completely).

It is indeed looking more and more probable that summery-like weather could be coming back to greet the UK. Some moderate changes are still to be expected, but a High Pressure dominated setup does seem to be the most likely scenario for the moment with the 3 main models in general agreement with this (albeit with some slight differences with their positioning of the High for early next week. E.g: UKMO has the High a litter further East than ECMWF. Would post some charts, but being doing this on a phone. Apologies).

[Captain Shortwave]

Great runs again this morning, UKMO looks the best to be honest up to T144

 

Beauty of a chart.

The ECM deviates from the GFS/GEM models by moving the high northwards from day 8 (is it over-amplifying the pattern?) but again output is high pressure dominated.

Just to note the GFS has yet again increased the predicted maximum temperatures with the mid-twenties possible at the start of next week.

Edit just for fun

 

ECM again is wanting develop a nice big cold pool over Siberia.

Edited September 17, 2013 by Captain shortwave

[shedhead]

oh if only these charts came 6 weeks ago...

 

cracking runs for sun/warmth, and these runs have imho reduced significantly the fog chances (concernes were raised when the expected high wasnt so strong and cooler uppers were more prevelant) thankfully the expected pressure rise is much stronger and atm orientated perfectly for the warmest weather. and its looking like being more then a transient feature too.. lasting most of next week.

Wouldn't mind a tenner for everytime I've heard that line, or something similar!

[Captain Shortwave]

Wouldn't mind a tenner for everytime I've heard that line, or something similar!

You could not only afford a holiday to somewhere warmer and drier, but probably buy the whole island 

[Summer Sun]

ECM keeps us settled from Saturday to at least next Friday this morning - http://www.null/ds/ecm.htm

 

UKMO has pressure building in during the weekend covering all the UK by Sunday - http://www.null/ds/ukmo.htm

 

GFS is settled till next Thursday before the high loses its grip - http://www.null/ds/gfs.htm

[Summer Sun]

Latest from Gibby

 

Hi everyone. A little late today but here is the report from the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Tuesday September 17th 2013.

 

All models show a cool and unstable airflow over the UK with a wave depression running SE then East across Southern and SW areas of the UK through the day with a period of rain, sometimes heavy here. The North and East will continue bright and showery and all areas away from the far SW will be cool. Tonight sees changes as the rain steadily clears East out of the South tomorrow with rising pressure over the UK to give a dry and bright day tomorrow with just isolated showers here and there in the North. Through Thursday a new depression will be crossing East to the North of Scotland with it's fronts crossing the UK with rain followed by clearer weather again with a few showers in the NW. It will become somewhat less cool. Friday should be a dry and bright day for most with just isolated showers possible in the North. Then on Saturday winds back SW and warm and moist air is filtered NE on a warm front bringing low cloud and drizzle for a time to many parts to start the weekend, especially in the North and West. By Sunday this is shown to be pulled away North with skies breaking over the UK with some warm or very warm sunny spells developing on Sunday as High pressure centres close to the SE.

 

GFS then shows a sustained fine spell for quite a while in the second half of it's run with dry, bright days with misty and sometimes foggy nights. Late in the output Low pressure from the Atlantic does gradually exert it's influence towards Northern and Western Britain and the strongest warmth late in the weekend and start of next week does ease away but all in all not a bad GFS operational run today.

 

UKMO shows warm SE winds wafting NW over the UK from Europe with High pressure close to the SE. Most if not all areas would be fine and warm by day with sunny spells and patchy mist and fog problems overnight.

 

GEM is very anticyclonic today with High pressure having arrived at the weekend sustained for the rest of it's run close to or over the UK with fine and quite warm conditions but again with fog problems quite hazardous overnight, slow to clear in the morning's locally.

 

NAVGEM paints the same picture with High pressure dominant over the UK at the start of next week.

 

ECM also shows High pressure over the UK dominant next week before it shows signs of slipping further North later next week with fronts queuing up to the SW with rain knocking on the door of the far West late next week. As with the other output fairly warm conditions by day would be balanced by cool and misty nights and mornings.

 

The GFS Ensembles show a distinct and sustained period of above average uppers from the weekend and through next week only easing off to more average levels at the end of the run. Rainfall is very limited for all areas as the High pressure becomes influential picking up a bit in quantity at the end of the run as low pressure battles the high for supremacy. With such mild uppers above and radiation loss under clear skies at night mist and fog near the surface could become quite a hazard night and morning.

 

The Jet Stream Ensemble show the current NW to SE flow over the UK backing over the next few days SW to NE as well as being pumped north clear of the UK at the weekend and through much if not all of next week.

 

In Summary a settled spell is on the way. We have more or less universal support now for a spell of fine and potentially warm early Autumn weather next week though we will be reminded that we are now into Autumn by the chance of extensive mist and fog problems night and morning almost anywhere. High pressure is shown by all models to settle over or near the UK for quite some time this morning with the longer range models only showing incremental evidence of a potential breakdown from the West later in their outputs. So when compared to the early Autumn type weather at the other end of the spectrum that we will all experience through the remainder of this week it is a good example how September in the UK can offer some diverse and wide ranging of weather types.

 

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

[MR EXTREMES]

well im back to eat humble pie excellent summery charts and even better for future wintry developments its gonna be an exciting rollercoaster ride.

amazing charts

[Tamara]

The thinking a few days ago was that Humberto could serve to settle the weather down again and that has proved to be the case with some very late pleasant and warm weather once more to look forward to . The question has been how long might this last? One other aspect that hasn't changed is the high pressure anomalies indicated to the N/NE which still places the same potential emphasis as before on unreliability of future output beyond the arrival of the high pressure ridging this weekend and into next week. Also we have other tropical developments than can/could change things again at short notice as we have seen.

 

The EPS members this morning illustrate such vaguaries quite well as we get beyond Monday next week

 

 

Amongst those, there is something of a suggestion of low pressure starting to return towards NW areas by this time and perhaps the high pressure at our latitude retracting westwards into the atlantic. With the -AO signal it is conceivable that this could lead to pressure falling more widely thereafter as the jet stream is forced south once again..although this might be premature to happen next week. The favoured outlook is probably remaining quite settled for the foreseeable future further south but rather more changeable in northern most parts. However, at some stage another more widespread unsettled and quite chilly period of weather is possible with low pressure perhaps tracking NW-SE like the one we have seen in recent days..before High pressure returns again in time to start October. A lot of uncertainty about all this however.

 

The longer the broader NH pattern persists though, the more it sets up an interesting descent further into autumn...Perhaps right now we have the best of both worlds? Some pleasant late warmth, but with the feedback patterns starting to become established that we will wish to see sustained for interest in times to come

[draztik]

well im back to eat humble pie excellent summery charts and even better for future wintry developments its gonna be an exciting rollercoaster ride.amazing charts

no need, the models only a couple of days ago showed almost the exact opposite to what is being shown today. We really can only analyze what they show, and that was cool/unsettled weather, until 'humberto' changed everything.as for the ec32, the update indicates a prolonged settled spell from the coming weekend, until at least the 1st of Oct, with little (if any) rainfall over England or Wales. After this date, the ec32 slides back into Autumn proper, with a deep low west of Ireland pushing in. This low becomes 'stuck' close to our NW for a few days, giving all areas a wet and windy period. After this, unsettled conditions appear to rule the roost, with a succession of lows sweeping the country. In terms of temp, nothing particularly cool or warm for Southern areas (if you exclude next week, which will be pleasant for a lot of areas). The North & NW will see cooler conditions, in line with seasonal averages for October.the MetO/BBC showing a max temp range of 14/23 from period Sunday thru Thursday in the South East, and indicating a cloudy affair. This will likely change, but still nothing exceptional in terms of temp, yet. Edited September 17, 2013 by draztik

[snowking]

The thinking a few days ago was that Humberto could serve to settle the weather down again and that has proved to be the case with some very late pleasant and warm weather once more to look forward to . The question has been how long might this last? One other aspect that hasn't changed is the high pressure anomalies indicated to the N/NE which still places the same potential emphasis as before on unreliability of future output beyond the arrival of the high pressure ridging this weekend and into next week. Also we have other tropical developments than can/could change things again at short notice as we have seen.

 

The EPS members this morning illustrate such vaguaries quite well as we get beyond Monday next week

 

 

Amongst those, there is something of a suggestion of low pressure starting to return towards NW areas by this time and perhaps the high pressure at our latitude retracting westwards into the atlantic. With the -AO signal it is conceivable that this could lead to pressure falling more widely thereafter as the jet stream is forced south once again..although this might be premature to happen next week. The favoured outlook is probably remaining quite settled for the foreseeable future further south but rather more changeable in northern most parts. However, at some stage another more widespread unsettled and quite chilly period of weather is possible with low pressure perhaps tracking NW-SE like the one we have seen in recent days..before High pressure returns again in time to start October. A lot of uncertainty about all this however.

 

The longer the broader NH pattern persists though, the more it sets up an interesting descent further into autumn...Perhaps right now we have the best of both worlds? Some pleasant late warmth, but with the feedback patterns starting to become established that we will wish to see sustained for interest in times to come

 

As ever Tamara a fantastic summary and one I wholly concur with.

 

It is a very unclear picture at present heading in to the medium term but at the moment the best punt is based around the idea that as we lose the tropical forcing once again (both MJO and GWO look likely to flatline) we could well end up heading back towards the same scenario we have had for several months now without any tropical forcing, and that is of a tendency for the Azores HP to ridge - so the assertion of a Settled-Unsettled-Settled outlook out to 15 days is one I would very much back.

 

SK

[Frosty.]

The ECM 00z ensemble mean looks about as comprehensive as you could get for supporting a warm and anticyclonic outlook, warmest across the southern half of the uk where temperatures could eventually reach the mid 20's celsius or a touch higher, nearer low 20's celsius for scotland & n.ireland. Only the far northwest corner of the uk will still be relatively unsettled through the weekend with all other areas becoming warmer and sunnier with lighter winds as the azores high builds in and intensifies, next week it looks warm or very warm across the whole of the uk with long sunny periods and light winds, more like mid summer than autumn. 

[johnholmes]

It is a very unclear picture at present heading in to the medium term but at the moment the best punt is based around the idea that as we lose the tropical forcing once again (both MJO and GWO look likely to flatline) we could well end up heading back towards the same scenario we have had for several months now without any tropical forcing, and that is of a tendency for the Azores HP to ridge - so the assertion of a Settled-Unsettled-Settled outlook out to 15 days is one I would very much back.

 

Yes I would agree with that idea sk. With MJO looking like being a non player in any effects on upper air patterns for the time being then once the Humberto effects have played out then returning to what the last weeks have given, albeit a fairly westerly upper flow with temporary rather than permanence from any surface ridging from the SW seems the most likely.

[SMU]

Back is the forecast for settled conditions next weekend

Back is the ensemble support for settled weather

and back is a decent UKMO update.

 This weather forecasting is a tricky business.

You r right david it all back-

 

However before it was Thurs- into Sunday on the initial GFS model runs-

 

Now its 00z sunday ( for the main) through the start of next week-   So yes back- only 96 hours later...

 

All driven by a different hurricane track-  Of course if a model keeps forecasting the same thing for long enough then its bound to come up trumps eventually...

 

 

My eyes still though are drawn to the poles & the +VE blocking... I see support gathering for a Negative Wind anomaly around 70 N which may well spawn another colder outbreak in 8-10 days time....

 

 

s