Model Output Discussion 12z 01/06/13

[mushymanrob]

It's not vile or garbage, it's typical uk summer weather.

 

yyyeeesss.... please remember that in winter!   mild atlantic weather is fairly typical winter weather

 

Now this is more like it from the Gfs 06z, instead of a constant conveyor belt of atlantic depressions or troughs stuck limpet like on top of the uk, the 6z builds and rebuilds high pressure into the uk throughout most of FI with a good deal of dry, sunny and warm weather for all areas, the north of the uk doing well this week for dry weather and sunshine with pleasant warmth but becoming very warm and humid for england & wales for 2 or 3 days, especially warm in the southeast with temperatures nudging into the low 80's F with mid to upper 70's further north and west for a time, there will also be an increasing amount of thundery downpours for the very humid areas across southeastern britain but still with some sunshine, becoming cooler and more unsettled from the west next weekend with a cool and showery start to next week but then the atlantic/azores anticyclone pushes across the uk.

 

pity that run had no support karl... it might be shown in 1 run, but tbh its a waste of time commenting if it has no support, and the anomaly charts do not suggest any form of high pressure building over the uk. in fact, its only the good old warm loving gfs that has any hint of anything warm as shown on the current mjo.

 

ive lost alot of confidence in the gfs, i think its only worth taking much notice of when the ecm and ukmo broadly agree

[DTHFCJ]

rainfall charts even 24 hours out are at times wrong and looking for accuracy for Friday on Monday is, no offence intended, pretty much a waste of time.

Hi John,ive been keeping an eye on the 500mb charts you mention often i was just wondering if you knew what time they are normally updated?

http://www.meteo.psu.edu/~fxg1/ECMWF_12z/test8.gif

 

http://www.cpc.ncep.noaa.gov/products/predictions/814day/814day.03.gif

 

sorry for going off topic

[Buzzit]

ive lost alot of confidence in the gfs, i think its only worth taking much notice of when the ecm and ukmo broadly agree

Never would have guessed that... However, I for one am quietly confident that GFS is on to something and see no reason why it will not be onwards and upwards after the low pressure brings all the moaners out this weekend. The other reality is that there is a lot of spread in the ensemble members throughout the next 16 day period so I dont see any point in trumpeting any certainties be it good, bad, or indifferent.

[Tony27]

rainfall charts even 24 hours out are at times wrong and looking for accuracy for Friday on Monday is, no offence intended, pretty much a waste of time.

Agree which begs the question why do we comment on the models at all when they change all the time, is it to get a vague idea? vague isn't enough though, even though the nasty predicted synoptics probably won't change much for this weekend, some areas will get soaked and some will stay dry and that's what joe public care about not 500mb charts

 

even temp and rainfall charts at T0 are wrong 

Edited June 17, 2013 by Tony27

[chionomaniac]

Agree which begs the question why do we comment on the models at all when they change all the time, is it to get a vague idea? vague isn't enough though, even though the nasty predicted synoptics probably won't change much for this weekend, some areas will get soaked and some will stay dry and that's what joe public care about not 500mb charts

 

even temp and rainfall charts at T0 are wrong 

Joe public can look at the forecasts, Tony. This thread is to discuss the models including the 500hPa anomaly charts. We all realise that forecasting is not an exact science which is what makes the discussion what it is. 

[johnholmes]

You seem to have a very jaundiced view of forecasting, and having spent 4 years doing public service forecasting of course 'Jo Public' has no interest in how the forecast is arrived at why should 'he'?

Predicting the upper air pattern at T+24 let alone 5-10 days hence is both considerably easier and much more accurate than getting the surface isobars correct. Even more difficult is when you add moisture to the hugely complex thermodynam equaations used to work out what the weather will do at T+xyz hours.

Fascinating though which is why Net Wx and other such web sites is so appealing to those interested in the weather.

Edited June 17, 2013 by johnholmes

[johnholmes]

http://www.meteo.psu.edu/~fxg1/ECMWF_12z/test8.gif

these are available for the 00z issue about 0820 most days, that is BST so earlier in winter time. Another set based on the 12z output is available about 12 hours later.

 

http://www.cpc.ncep.noaa.gov/products/predictions/814day/814day.03.gif

 

The NOAA charts for 6-10 and 8-14 are also available about the same time pm

hope the above helps

[johnholmes]

Agree which begs the question why do we comment on the models at all when they change all the time, is it to get a vague idea? vague isn't enough though, even though the nasty predicted synoptics probably won't change much for this weekend, some areas will get soaked and some will stay dry and that's what joe public care about not 500mb charts even temp and rainfall charts at T0 are wrong

not sure where you get that from only GFS does a T+00 and neither T nor rainfall are shown as far as I know.I really do suggest Tony that rather than carping on about the models and how wrong they are you spend time on the GFS/NOAA, ECMWF/Met O sites to see how weather modelling is carried out, the limitations of them, and just how complex is the physics and mathematics used in the models.I am sure you will be interested and possibly quite surprised by what you discover? Edited June 17, 2013 by johnholmes

[DTHFCJ]

hope the above helps

many thanks John....

[Tony27]

why is it wrong to criticize the models though john, do you ever check if the models are right or wrong at T0,  i don't have time to check every model or every weather website. i used to but they are all the same really, now i only really look at the GFS, UKMO, ECM, BBC and sometimes the metoffice, as a gardener i have to pay extra attention to them  the bbc website sometimes is 3 or more degrees wrong at T0 and sometimes the GFS too, on friday last week  the models showed no frontal rain getting here even at only 5 hours out, so i watered all my plants but then it ended up raining heavily, other times the models said no risk of frost at T6 and it ended up very chilly 3c and my crops suffered, its things like this that annoy me about the models, it may sound trivial to you but this happens on a regular basis,

 

what can we do though to fix this very short term errors nothing i guess 

Edited June 17, 2013 by Tony27

[Captain Shortwave]

Better run weather wise from the ECM which is more in line with the ensemble from this mornings run. It's nothing spectacular but it's ok. At least the Azores high is doing something instead of happily loitering around in the mid atlantic. Wet and breezy weekend followed by a ridge building across the uk. Later on there is a north/south split with the north occasionally wet and windy and the south fine with some sunny spells and near average temperatures.

 

Edited June 17, 2013 by Captain shortwave

[Gibby]

Hi folks. Here is the report on the midday outputs issued by GFS, UKMO, GEM, NAVGEM and ECM for today Monday June 17th 2013.All models show a complex pressure pattern through this week before things simplify at the weekend. In essence the UK is under a fairly slack airflow pattern with a thundery Low pressure system to the South and a weak ridge over Scotland. Through the week a wedge of very warm and humid air moves up across South and SE England. Temperatures will be high and would be even higher were there more sunshine expected, instead we have to look out for showers and thunderstorms breaking out on occasion over Southern areas over the coming three days. Late in the week the weather turns cooler and fresher from the West as the thundery Low moves away East and NE. Following on behind will be an increasing Westerly wind with cloud and rain spreading East and South across the UK before the weekend. With Low pressure close to or over the UK at the weekend the weather will be showery with fresh and cool breezes and some more prolonged spells of rain at times too. In among all this will be some short drier and brighter interludes.GFS shows the Low filling and moving slowly NE early next week with showers gradually becoming more scattered with longer drier and brighter spells likely, especially in the South. FI shows a slack pattern tonight with High pressure quite close to the West of the UK allowing a lot of dry and bright weather in FI if not excitingly warm. Some rain will occur at times though mostly towards the SW for a time and SE later as High pressure builds strongly NE to the NW of Britain with a NE flow with the chance of enough instability in the flow to give sufficient risk of a few showers in the SE.The GFS Ensembles show another set of uninspiring uppers once the current warm phase ends. A rather cool spell then looks likely before things warm up a llittle at the end of the run. Through the very warm and humid weather the chance of storms shows rainfall (while present) would be very variable before a traditional spread of occasional rain is shown under Atlantic winds from the cooler phase on.The Jet Stream shows the flow West to East across the Atlantic currently troughed to the West of the UK with the returning flow drifting North over Britain. As the thundery trough eases away later in the week the flow reverts to a point West to East across Northern France later in the weekend and start of the new week.UKMO tonight looks distinctly unsettled with a slow moving Low pressure over Southern Scotland with cyclonic winds blowing across the UK with showers or longer spells of rain mixed with some drier and brighter spells with temperatures near or a little below average.GEM tonight shows the Low pressure over the UK at the weekend migrating away NE to Scandinavia with showers continuing for many into the new week. Towards midweek with winds then back to Westerly troughs moving across the UK and would maintain the changeable weather type with uninspiring temperatures.NAVGEM too shows the Low pressure as a slow moving feature over the UK at the weekend with a reluctance to move it away with any great speed thereafter. Further showers would therefore continue for many through the weekend and start to the new week.ECM finally shows the Low tracking off towards Scandinavia at the end of the weekend with a Westerly flow carrying a new trough East over the UK with some more rain for a time early in the week. Pressure is rising slowly to the SW of the UK but doesn't make too much impact on the weather as a whole though probably restricting the worst rainfall towards the North while the South becomes rather cloudy but would probably see just light rain or drizzle in a stiff West breeze.In Summary the weather remains as changeable and often unsettled as ever on tonight's output with good agreement on the thundery and warm period this week giving way to what could be a very unsettled weekend for some with rain and showers scattered around almost everywhere. The longer term models of GFS, GEM and ECM show nothing of significantly better conditions at the 10 day range though GFS does look like settling things down later in a NE flow over the UK with fine and dry conditions for many at the end. The better charts shown are at the end of the run from both GFS and to a degree ECM too need to be extended into following runs, other models as well as the ensembles before I will reflect them as a chance of a pattern change.

Edited June 17, 2013 by Gibby

[William of Walworth]

However, I for one am quietly confident that GFS is on to something and see no reason why it will not be onwards and upwards after the low pressure brings all the moaners out this weekend. The other reality is that there is a lot of spread in the ensemble members throughout the next 16 day period so I dont see any point in trumpeting any certainties be it good, bad, or indifferent.

Mr Sensible nails it.

Better run weather wise from the ECM which is more in line with the ensemble from this mornings run. It's nothing spectacular but it's ok. At least the Azores high is doing something instead of happily loitering around in the mid atlantic. Wet and breezy weekend followed by a ridge building across the uk. Later on there is a north/south split with the north occasionally wet and windy and the south fine with some sunny spells and near average temperatures.

 

 

 

 

And a modest amount of scope for some limited hopecasting for beyond the weekend, for further S at least. We'll see!

Edited June 17, 2013 by William of Walworth

[bluearmy]

hmmm - some interesting output over the past few runs wrt week 2. i'd say its the most optimistic i've seen the modelling for a fair few weeks re the limpet returning trough. the secret appears to be the dropping of the vortex just west of greenland which draws the trough nw and generally raises the pattern northwards. a word of caution at this stage would be that renewed atlantic jet energy could be the secret to an even worse spell of troughing for nw europe if the azores high stays to our west and allows the energy to dip back south towards us.  lets stay optimistic for the time being. the anomolys will hopefully begin to reflect this better longwave pattern soon.

[J10]

Latest Glastonbury forecast now out, and this update contains a lot of detailed analysis and charts from GFS 06Hz and 12Hz runs, ECM 00 and 12Hz runs, GEFS 06Hz and 12Hz runs.

 

Given the unsettled nature of the next 120 hours, it is not a positive update.

 

http://forum.netweather.tv/blog/189/entry-4626-photo-glastonbury-forecast-11-17th-june/

[ANYWEATHER]

Hi folks. Here is the report on the midday outputs issued by GFS, UKMO, GEM, NAVGEM and ECM for today Monday June 17th 2013.

All models show a complex pressure pattern through this week before things simplify at the weekend. In essence the UK is under a fairly slack airflow pattern with a thundery Low pressure system to the South and a weak ridge over Scotland. Through the week a wedge of very warm and humid air moves up across South and SE England. Temperatures will be high and would be even higher were there more sunshine expected, instead we have to look out for showers and thunderstorms breaking out on occasion over Southern areas over the coming three days. Late in the week the weather turns cooler and fresher from the West as the thundery Low moves away East and NE. Following on behind will be an increasing Westerly wind with cloud and rain spreading East and South across the UK before the weekend. With Low pressure close to or over the UK at the weekend the weather will be showery with fresh and cool breezes and some more prolonged spells of rain at times too. In among all this will be some short drier and brighter interludes.

GFS shows the Low filling and moving slowly NE early next week with showers gradually becoming more scattered with longer drier and brighter spells likely, especially in the South. FI shows a slack pattern tonight with High pressure quite close to the West of the UK allowing a lot of dry and bright weather in FI if not excitingly warm. Some rain will occur at times though mostly towards the SW for a time and SE later as High pressure builds strongly NE to the NW of Britain with a NE flow with the chance of enough instability in the flow to give sufficient risk of a few showers in the SE.

The GFS Ensembles show another set of uninspiring uppers once the current warm phase ends. A rather cool spell then looks likely before things warm up a llittle at the end of the run. Through the very warm and humid weather the chance of storms shows rainfall (while present) would be very variable before a traditional spread of occasional rain is shown under Atlantic winds from the cooler phase on.

The Jet Stream shows the flow West to East across the Atlantic currently troughed to the West of the UK with the returning flow drifting North over Britain. As the thundery trough eases away later in the week the flow reverts to a point West to East across Northern France later in the weekend and start of the new week.

UKMO tonight looks distinctly unsettled with a slow moving Low pressure over Southern Scotland with cyclonic winds blowing across the UK with showers or longer spells of rain mixed with some drier and brighter spells with temperatures near or a little below average.

GEM tonight shows the Low pressure over the UK at the weekend migrating away NE to Scandinavia with showers continuing for many into the new week. Towards midweek with winds then back to Westerly troughs moving across the UK and would maintain the changeable weather type with uninspiring temperatures.

NAVGEM too shows the Low pressure as a slow moving feature over the UK at the weekend with a reluctance to move it away with any great speed thereafter. Further showers would therefore continue for many through the weekend and start to the new week.

ECM finally shows the Low tracking off towards Scandinavia at the end of the weekend with a Westerly flow carrying a new trough East over the UK with some more rain for a time early in the week. Pressure is rising slowly to the SW of the UK but doesn't make too much impact on the weather as a whole though probably restricting the worst rainfall towards the North while the South becomes rather cloudy but would probably see just light rain or drizzle in a stiff West breeze.

In Summary the weather remains as changeable and often unsettled as ever on tonight's output with good agreement on the thundery and warm period this week giving way to what could be a very unsettled weekend for some with rain and showers scattered around almost everywhere. The longer term models of GFS, GEM and ECM show nothing of significantly better conditions at the 10 day range though GFS does look like settling things down later in a NE flow over the UK with fine and dry conditions for many at the end. The better charts shown are at the end of the run from both GFS and to a degree ECM too need to be extended into following runs, other models as well as the ensembles before I will reflect them as a chance of a pattern change.

Every summer is the same , high pressure and fine weather in 10 days so etc. We have been here many times before with summerlike predictions in the last seven years! Theres no doubt our weather has drastically changed since then and finding any worthwhile summer like weather is like trying to find life on Mars!! Winters are getting colder , summers cooler and wetter, its not a thought, its now a fact!!  

[J10]

I have been tracking the NOAA upper charts for days, and they have been consistent in having troughs over us, however the latest updated in the 8-14 day range is the most positive for over a week.

 

6-10  day charts

Trough bang on top of the UK

 

8-14 day charts

Trough gone from UK and High Pressure edging in from west.

Edited June 17, 2013 by Jackone

[johnholmes]

I have been tracking the NOAA upper charts for days, and they have been consistent in having troughs over us, however the latest updated in the 8-14 day range is the most positive for over a week.

 

6-10  day charts

610day.03 17.gif

Trough bang on top of the UK

 

8-14 day charts

814day.03 17.gif

Trough gone from UK and High Pressure edging in from west.

hi Julian

That is a bit simplistic in my view!

Yes the 8-14 is showing a 'flatter' pattern acorss the Atlantic. However if you look closely the +ve area is smaller in height anomaly, it was centred at 90dm, it is also similar to the 500mb flow a flatter type. That does not mean necessarily any pressure rises at the surface for the UK.

I would be very wary of suggesting this. Always get about 3 days with consistency before making any suggestions on any changes. Get that consistency at the same time scale with each model. Of course with NOAA only NAEFS goes out to 14 days, ECMWF-GFS is a 10 day outlook only.

To me I see no change today in the fairly unsettled/changeable pattern with just a small chnace of less changeable in the far SW, about 30-40% at the moment in my view.

[johnholmes]

why is it wrong to criticize the models though john, do you ever check if the models are right or wrong at T0,  i don't have time to check every model or every weather website. i used to but they are all the same really, now i only really look at the GFS, UKMO, ECM, BBC and sometimes the metoffice, as a gardener i have to pay extra attention to them  the bbc website sometimes is 3 or more degrees wrong at T0 and sometimes the GFS too, on friday last week  the models showed no frontal rain getting here even at only 5 hours out, so i watered all my plants but then it ended up raining heavily, other times the models said no risk of frost at T6 and it ended up very chilly 3c and my crops suffered, its things like this that annoy me about the models, it may sound trivial to you but this happens on a regular basis, what can we do though to fix this very short term errors nothing i guess

hi TonyI am happy to chat via pm rather than fill up the model thread with some folk perhaps not too interested in our discussions-please pm me, thanks

[J10]

hi JulianThat is a bit simplistic in my view!Yes the 8-14 is showing a 'flatter' pattern acorss the Atlantic. However if you look closely the +ve area is smaller in height anomaly, it was centred at 90dm, it is also similar to the 500mb flow a flatter type. That does not mean necessarily any pressure rises at the surface for the UK.I would be very wary of suggesting this. Always get about 3 days with consistency before making any suggestions on any changes. Get that consistency at the same time scale with each model. Of course with NOAA only NAEFS goes out to 14 days, ECMWF-GFS is a 10 day outlook only.To me I see no change today in the fairly unsettled/changeable pattern with just a small chnace of less changeable in the far SW, about 30-40% at the moment in my view.

To me it looks a bit better than previous runs, one over the weekend one also suggested a weakening of the upper trough, but this is the first forecaster analysed forecast to suggest this. I will be awating the next update tomorrow, to see if today's run is supported or if it is a blip.

 

It was more of a response to some of the earlier comments, who suggested no changes despite no evidence to the contrary.

 

In terms of simplistic, it is better than a most of the analysis in this thread.

Edited June 17, 2013 by Jackone

[Milhouse]

ECM 12z mean looks supportive for a substantial pressure rise from the southwest by day 10. The difference between this and last summer is quite evident with a quick return to settled conditions for the southern half of the uk being indicated by the ECM after a very unsettled weekend. Still no sign of greenland high pressure forming, in complete contrast to this time last year.

[Tony27]

it looks like the unsettled spell at the weekend will be short lived, high pressure is shown for next week on the ECM op and mean, but then again another low will probably pop up and flatten the ridge. now the 18z is about to come out and probably give us an extreme run of either summer 1976 style synoptics or june 2012 synopitcs, it might be sober tonight though

Edited June 17, 2013 by Tony27

[bluearmy]

as expected the ecm mean and naefs looking a better bet for a less unsettled outlook. we're some way from converting that to settled though. stay positive and hope for the 'flattening jet pendulum' to stay on a ne track rather than destination nw europe as it has so far for most of the past six weeks. 

[DTHFCJ]

I have been tracking the NOAA upper charts for days, and they have been consistent in having troughs over us, however the latest updated in the 8-14 day range is the most positive for over a week.

 

6-10  day charts

610day.03 17.gif

Trough bang on top of the UK

 

8-14 day charts

814day.03 17.gif

Trough gone from UK and High Pressure edging in from west.

with some support from these too......

http://www.meteo.psu.edu/~fxg1/ECMWF_12z/test8.gif

[Thundery wintry showers]

Looking over the current model outputs I am revising my opinion of the next fortnight's weather to "statistically near-average" rather than "wetter and cloudier than average".  The next couple of days look like being mostly dry with increasing amounts of sunshine and rising daytime temperatures.  Indeed Wednesday looks like it could well be a hot day in the south-eastern corner of the country with the ECMWF backing up the GFS in showing the 15C 850hPa isotherm moving over and generating max temperatures of around 30C. 

http://cdn.nwstatic.co.uk/gfsimages/gfs.20130617/18/48/ukmaxtemp.png

 

Late Wednesday and Thursday may see a thundery breakdown in the south, but Thursday looks like being grey, wet and cold in northern parts of England.

 

The models have sped up the frontal system on Friday/Saturday so there's an increased chance of the frontal rain passing through overnight with sunshine and showers to follow, though in these cyclonic situations slow-moving fronts sometimes turn up and bring more organised rainfall, so I'm not too confident of the "sunshine and showers" assessment at this time range.  The GFS is currently suggesting significant convective/thunderstorm potential for the 23rd and 24th as the low pressure fills and retreats, but the ECMWF version, with pressure building more quickly from the west, would probably not bring much heavy shower/thunderstorm activity.

 

"Less unsettled" sums up the likely outlook for days 8-15 quite well IMHO- there is strong agreement on pressure being relatively high to the south and west of Britain, but not close enough to prevent disturbances from moving around its periphery and giving Britain relatively changeable, but not especially wet, conditions.