Model Output Discussion 18z 28/07/13

[ANYWEATHER]

Yep, next week is nailed on cool and unsettled, we have known that for the last few days, but the further outlook remains very good according to the experts, I would not argue against the met office forecasters, they have lots more data than we will ever see.

Yes, but there longer range forecasts including everyone elses is purely experimental....

[Captain Shortwave]

It's a meteorological cold war

US hurricane vs the high pressure iron curtain

If one of them didn't exist the outcome would be very easy, but with both goodness knows what will happen over our heads. 

[johnholmes]

Yes, but there longer range forecasts including everyone elses is purely experimental....

 

I would not describe the 16-30 day outlook as experimental, less accurate for sure but based on sound data they receive both from their own and ECMWF outputs.

[bluearmy]

I think that given we've an ex tropical development kicking around in the N Atlantic within the next week, we shouldn't be counting any chickens RE what happens after that. It could kick the Azores high NE and ridge it across us or it could serve to reinforce a mainly unsettled period. These things are notoriously difficult for the NWP to resolve on a short-medium range basis- Metoffice super computers included.

 

take note of this. the extended ens output that exeter will be using for the back end of next week and beyond will not really take this feature into account in any mean way. because the various ens members will do something different with it at this range, it will fail to be a mean feature and therefore the mean charts post day 7 will be hugely unreliable if the TD becomes a player in the atlantic. i would be sceptical of anything post day 6 at the moment until we know what this TD is going to do with its energy.

[Frosty.]

The Gfs 12z operational run shows a good recovery once the cool, unsettled and windy spell has blown itself out and the filling trough pushes away across scandinavia, a nice atlantic ridge builds across the uk but then gets flattened as another less vigorous low approaches northwest scotland, the azores/atlantic anticyclone ridges across the south of the uk bringing an increasingly settled and pleasantly warm further outlook with generally light winds and plenty of sunshine but with an increasing risk of overnight fog patches which could be dense and slow to clear through the following mornings, northern britain continues breezier with more cloud and some rain interspersed by sunshine and showers as further vigorous depressions track east from iceland but are on a more northerly track than this weekend so the southern half of the uk could be in for a prolonged spell of very decent, benign weather beyond the next week or so.

Edited September 12, 2013 by Frosty.

[Gaz1985]

As per the 18z last night the 12z is still showing High Pressure pushing down on the country next weekend 

 

[Summer Sun]

This low looks almost certain now none of the models are backtracking and I can't see any changes now for Sunday / Monday

 

[Captain Shortwave]

 

Well at least it would bring frequent, perhaps thundery showers for the triangle

ECM even more progressive and a new low joins the fun at day 8

Edited September 12, 2013 by Captain shortwave

[Summer Sun]

t192 has the low staying

 

[Frosty.]

The GEFS 12z mean shows a gradual improvement through the second half of next week from the west as an atlantic ridge pushes east across the uk as the spoiler trough to the northeast loses it's venom and drifts away into scandinavia as a filling feature, thereafter the further south you are, the more settled it looks thanks to the growing influence of the azores/atlantic anticyclone, it's unclear how long the subsequent fine spell would last and also unclear how far north the fine weather would reach but there is at least some light at the end of the tunnel in around 7-9 days time.

[Summer Sun]

The GEFS 12z mean shows a gradual improvement through the second half of next week from the west as an atlantic ridge pushes east across the uk as the spoiler trough to the northeast loses it's venom and drifts away into scandinavia as a filling feature, thereafter the further south you are, the more settled it looks thanks to the growing influence of the azores/atlantic anticyclone, it's unclear how long the subsequent fine spell would last and also unclear how far north the fine weather would reach but there is at least some light at the end of the tunnel in around 7-9 days time.

 

Nice to see the Azores dominating the Atlantic again there offers hope and inline with the met office's thoughts

[Summer Sun]

Unsettled at t216 but we do have a slight recovery in uppers

 

 

Bigger picture of what's happening up north

 

Edited September 12, 2013 by Summer Sun

[ANYWEATHER]

I would not describe the 16-30 day outlook as experimental, less accurate for sure but based on sound data they receive both from their own and ECMWF outputs.

Well Mr Holmes, I still think weather forecasts up to a month ahead is rather dodgy, but I certainly respect your post.... 

[SMU]

I would approach any optimism for the end of next week with strong caution-

 

the GFS which in my eyes we should never bother with again looks ok, however the ECM looks to be running the show with the significant shift south in the jet-

 

Low pressure stays in situ just to the east / North East & the tilted NW SE jet throws a series of shortwaves across the BI-

at no point in the ECM 12z is there anything close to settled or warm-  infact I would say a 10 day run of sub 10c CET is well on the cards.....

 

Christmas looks cold as well-

 

http://images.meteociel.fr/im/9350/cfs-0-2520_nlv2.png

 

 

S

Edited September 12, 2013 by Steve Murr

[Frosty.]

I would approach any optimism for the end of next week with strong caution-

 

the GFS which in my eyes we should never bother with again looks ok, however the ECM looks to be running the show with the significant shift south in the jet-

 

Low pressure stays in situ just to the east / North East & the tilted NW SE jet throws a series of shortwaves across the BI-

at no point in the ECM 12z is there anything close to settled or warm-  infact I would say a 10 day run of sub 10c CET is well on the cards.....

 

S

I would wait for the 00z, the Ecm is flip flopping around between 00z-12z, last night's 12z and this mornings 00z being a case in point, if there is any substance to the ecm trend, the met office will downgrade the fine warm outlook in the next few days although the ecm 00z ensemble mean this morning showed a slow recovery towards T+240 hours so the op could be out of sync with what eventually transpires.

[Summer Sun]

We end with another low from ECM however the Azores looks more organized by the end so maybe a renewed push for the end of the month

 

 

GFS ensemble for the same date as above

 

 

A renewed Azores push is possible

Edited September 12, 2013 by Summer Sun

[Tamara]

Seems that theme of trough disruption continues on and onwards. Its interesting that despite the change in the polar pressure profile this summer, low pressure has continued to want to track SE'wards towards us and interrupt the Azores High from time to time. It bodes well for the months ahead if this trend can continue with hopefully blocking returning to high latitudes

 

It seems the script has been changing these last few days and the jet stream is indeed on its way south with those seasonal longwave changes

[johnholmes]

Readers should I think be aware by now that there is often an 'agenda' from some posters, it may be a wish for cold, warmth, storms, gales, but not many on here actually post as close as is humanly possible to what the model they are quoting is showing through its run. They may pick the early part or the latter part to push their agenda. This is something that happens on here 365 days a year, more so through the 'hoped for winter' for some but it is there all the time.

Nowt wrong with that but it must be a touch confusing to visitors/newcomers who are trying to understand weather models?

My advice is if you can afford it pay for Extra and run each model sequence through for yourself, will it rain, what is the dewpoint predicted to be along with the wind speed to give a feel of how warm or cold. You will soon pick up enough understanding to form your own opinion and then it can be fun to read the, sometimes diametrically, opposed views on the same run. To help you go to the Net Wx Guides for all kinds of help in understanding charts, accronyms, storms, snow (will it won't it), hurricanes etc etc.

 

Post 2670 illustrates my point about two differing views, don't get me wrong, there is nothing wrong in what they are saying, just giving their viewpoint on a similar time scale. Also watch for when one poster quotes one model and another quotes a different one, often for the same time, and the two models are suggesting different outcomes.

Don't be put off please by this post, model watching is great fun, just be aware of how different folk will sum each model run up.

Edited September 12, 2013 by johnholmes

[Frosty.]

Seems that theme of trough disruption continues on and onwards. Its interesting that despite the change in the polar pressure profile this summer, low pressure has continued to want to track SE'wards towards us and interrupt the Azores High from time to time. It bodes well for the months ahead if this trend can continue with hopefully blocking returning to high latitudes

 

It seems the script has been changing these last few days and the jet stream is indeed on its way south with those seasonal longwave changes

I don't think anything has changed overall, we have known most of next week will be a bit cool and unsettled for a few days now and the extended ensemble mean charts are still showing a significant improvement further ahead, as are the met office, I don't understand how anyone could really bet against what the met office are saying, they are the experts...I don't think that low will regenerate and continue to haunt us beyond next friday, the azores/atlantic anticyclone will give it a shove once it begins to weaken later next week, i'm not buying a cool unsettled outlook at all.

[A.J]

I would approach any optimism for the end of next week with strong caution-

 

the GFS which in my eyes we should never bother with again looks ok, however the ECM looks to be running the show with the significant shift south in the jet-

 

Low pressure stays in situ just to the east / North East & the tilted NW SE jet throws a series of shortwaves across the BI-

at no point in the ECM 12z is there anything close to settled or warm-  infact I would say a 10 day run of sub 10c CET is well on the cards.....

 

Christmas looks cold as well-

 

http://images.meteociel.fr/im/9350/cfs-0-2520_nlv2.png

 

 

S

could you elaborate please for the many members who won't understand the reasoning behind said quote?.....cheers

[SMU]

Just to add to Johns post to put my 'SPIN' on it-  everyone here knows I love the cold - especially in Winter , however underneath that I still post with integrity- that is I comment on what I THINK will happen not what I want to happen- & more importantly when I have the time- Why it will happen-

 

For AJPOOL- ( & perhaps newer members)

 

Some will have you believe that the GFS is good, the reality is its not- it got thumped last winter by the UKMO & ECM- every single cold spell that came about was modelled poorly by the GFS- worse than poorly infact- the ensembles were a laughing stock-

 

It will from time to time pick out things that happen to land most notably Northerly topplers it seems to do OK on- however statistically V the Euros its wrong more often that it is right-

 

The added beef for me is ive seen its bias time & time again & it never changes, which means in most situations you can exclude the GFS & in nearly ALL situations in winter ( or late autumn) you can exclude the 18z & 06z- moreso when there is any time of eastern blocking.

 

The GFS is fun to look at all the pretty colours & time out to T*** & the CFS is the same with its crazy 9 monther- but when push comes to shove-

 

The UKMO + ECM through 72-144 / 168 are still streets ahead of the GFS-

 

 

As a footnote- when I logged on this first time the other day since april- the first Post in this thread was by Paul, stating that this thread isnt about point scoring, one up manship etc-

 

I agree & Im most certainly not interested in that - I dont care/ ive not got the time for it all- I come on here to share the experience of 12 years of model watching & for the fun of the cold - but I do get the feeling that the minute I post- people are waiting to post their opinions of my opinions below- tonight is sort of a prime example-

 

To be honest- if you want to ask a question like the above posted did- If I have time I will reply, if your just being plain awkward or posting irrelevent stuff then dont waste your time or mine just stick me on the ignore list-

 I think anyone who has taken the time to join this forum will have enough savvy to decide whos posts to follow-

 

If thats not me then I have no probs- theres loads of posts on here & TWO that add good value-

 

Cheers.

S

[Summer Sun]

Latest from Gibby

 

Good evening. Here is tonight's viewpoint from me on the midday outputs of GFS, UKMO, GEM, NAVGEM and ECM for tonight Thursday September 12th 2013.

 

All models maintain the pattern of weather now up to and including Tuesday of next week. The next 24-36 hours will see an array of fronts cross all of the UK tonight and across the South later tomorrow as a wave depression runs East across Southern England late tomorrow. This will bring outbreaks of slight to moderate rainfall but with some heavier bursts possible here and there especially in the South later tomorrow. Once this clears early on Saturday a respectable period of weather will occur with some sunshine and light winds. However, this is the lull before the first Autumn gale of the season which batters the North on Sunday with troughs sweeping East across all areas with widespread rain, heavy in places. Following a squally cold front SE Monday will be a very windy day for all areas with squally, heavy and thundery showers likely almost anywhere but most frequent in the North and West. On Tuesday Northern areas see another showery day while Southern areas see another small but vigorous trough feature run East across Southern England through the day with a spell of more prolonged rainfall before a return to squally showers in NW winds ends the day.

 

GFS then shows further disturbances running SE across SW Britain through the remaining days of next week with further cool and rainy weather here at times while the North and East seem more likely to stay rather showery but all areas stay very cool. Later in the output the South becomes drier and brighter for a time as a ridge to the South edges into Southern Britain for a time. However, the North stays breezy and changeable with this windy and changeable theme extending back South across the rest of Britain late in the run.

 

The GFS Ensembles tonight show a period of rather cool weather with good consensus between the members of cool and changeable weather with rain at times for a good part of the run. Some drier spells look probable at times but Low pressure looks likely to hold sway over the UK with at least some rain and strong winds for the UK, even in the South.

 

The Jet Stream shows the flow moving East to the North of the UK over the next few days before it dives SE on a very strong flow through much of next week and even shows little sign tonight of leaving the UK continuing to blow from the West or NW for the next 10 days or so.

 

UKMO tonight shows Low pressure moving SE over the North Sea with a very showery NW flow following a very strong taste of Autumn in the way of wind and rain in the days before. With High pressure showing rising heights to the North of the UK it looks like further Low pressure crossing the Atlantic later next week could have the UK in it's trajectory.

 

GEM shows a very windy and unsettled week throughout next week before the emphasis on the most changeable conditions shifts to the North of the UK with generally less wind and rain in the South later in the run as High pressure edges somewhat closer to the South.

 

NAVGEM shows a very deep Low trundling down the North Sea early next week with the centre making it's home somewhere near Denmark late in the week pulling down continually cool or very cool and showery North or NW winds with the final day's charts showing further Low pressure moving across the Atlantic towards the British Isles at the close of the run.

 

ECM tonight shows an extended cool and unsettled spell through next week and possibly beyond with showers or longer spells of rain and very cool NW or North winds as High pressure over the Arctic forces the Jet South over the UK with the UK in the firing line for a succession of depressions running through on a brisk and cool West flow though conditions warming a little late in the run. 

 

Tonight's Summary can best be described as a typical Autumn one with all models hardening their grip on the prospect of a very early taste of cool and potentially very windy weather next week when showers or longer spells of rain remain the order of the weather through the week. The prospect of High pressure building NE across the UK shown by previous output is looking a little less certain tonight with more members going for a continuation of changeable conditions albeit with something slightly less cool developing with time as winds become more westerly but still fresh to strong at times.

 

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

 

[Cheshire Freeze]

Just to add to Johns post to put my 'SPIN' on it-  everyone here knows I love the cold - especially in Winter , however underneath that I still post with integrity- that is I comment on what I THINK will happen not what I want to happen- & more importantly when I have the time- Why it will happen-

 

For AJPOOL- ( & perhaps newer members)

 

Some will have you believe that the GFS is good, the reality is its not- it got thumped last winter by the UKMO & ECM- every single cold spell that came about was modelled poorly by the GFS- worse than poorly infact- the ensembles were a laughing stock-

 

It will from time to time pick out things that happen to land most notably Northerly topplers it seems to do OK on- however statistically V the Euros its wrong more often that it is right-

 

The added beef for me is ive seen its bias time & time again & it never changes, which means in most situations you can exclude the GFS & in nearly ALL situations in winter ( or late autumn) you can exclude the 18z & 06z- moreso when there is any time of eastern blocking.

 

The GFS is fun to look at all the pretty colours & time out to T*** & the CFS is the same with its crazy 9 monther- but when push comes to shove-

 

The UKMO + ECM through 72-144 / 168 are still streets ahead of the GFS-

 

 

As a footnote- when I logged on this first time the other day since april- the first Post in this thread was by Paul, stating that this thread isnt about point scoring, one up manship etc-

 

I agree & Im most certainly not interested in that - I dont care/ ive not got the time for it all- I come on here to share the experience of 12 years of model watching & for the fun of the cold - but I do get the feeling that the minute I post- people are waiting to post their opinions of my opinions below- tonight is sort of a prime example-

 

To be honest- if you want to ask a question like the above posted did- If I have time I will reply, if your just being plain awkward or posting irrelevent stuff then dont waste your time or mine just stick me on the ignore list-

 I think anyone who has taken the time to join this forum will have enough savvy to decide whos posts to follow-

 

If thats not me then I have no probs- theres loads of posts on here & TWO that add good value-

 

Cheers.

S

 

It's been like that in here for most of the year Steve. I stopped posting in here for a good while due to obnoxious replies from certain people. I agree that there's no need for it.

[ANYWEATHER]

Just to add to Johns post to put my 'SPIN' on it-  everyone here knows I love the cold - especially in Winter , however underneath that I still post with integrity- that is I comment on what I THINK will happen not what I want to happen- & more importantly when I have the time- Why it will happen-

 

For AJPOOL- ( & perhaps newer members)

 

Some will have you believe that the GFS is good, the reality is its not- it got thumped last winter by the UKMO & ECM- every single cold spell that came about was modelled poorly by the GFS- worse than poorly infact- the ensembles were a laughing stock-

 

It will from time to time pick out things that happen to land most notably Northerly topplers it seems to do OK on- however statistically V the Euros its wrong more often that it is right-

 

The added beef for me is ive seen its bias time & time again & it never changes, which means in most situations you can exclude the GFS & in nearly ALL situations in winter ( or late autumn) you can exclude the 18z & 06z- moreso when there is any time of eastern blocking.

 

The GFS is fun to look at all the pretty colours & time out to T*** & the CFS is the same with its crazy 9 monther- but when push comes to shove-

 

The UKMO + ECM through 72-144 / 168 are still streets ahead of the GFS-

 

 

As a footnote- when I logged on this first time the other day since april- the first Post in this thread was by Paul, stating that this thread isnt about point scoring, one up manship etc-

 

I agree & Im most certainly not interested in that - I dont care/ ive not got the time for it all- I come on here to share the experience of 12 years of model watching & for the fun of the cold - but I do get the feeling that the minute I post- people are waiting to post their opinions of my opinions below- tonight is sort of a prime example-

 

To be honest- if you want to ask a question like the above posted did- If I have time I will reply, if your just being plain awkward or posting irrelevent stuff then dont waste your time or mine just stick me on the ignore list-

 I think anyone who has taken the time to join this forum will have enough savvy to decide whos posts to follow-

 

If thats not me then I have no probs- theres loads of posts on here & TWO that add good value-

 

Cheers.

S

Well said Steve. Looking forward to seeing you from now on, although I personally like the gfs  

[Paul]

And anyway back to the models - fwiw  regarding obnoxious posts and the like, if people are being deliberately awkward, deliberately trolling or anything which isn't in the spirit of the forum then please report it, as it's not something any of us want to see on here