Model Output Discussion

[PubliusEnigma]

Greeny High there on every 6 hours from T0 to T384 for the entire run, = a southerly tracking jet. Most likely synoptics,

the awful summer north of the midlands goes on. MOre of the same for the southern half of the country, although never more than 2 warm summery days here before the high ridges scoot east. 30oC highly unlikely for the remainder of July. POssibly peaking at 25oC. Just August to look forward to for a summery month. Modern summer Augusts have been notably poor over the last 4 or 5 years. My instinct tells me we will have to wait to early mid September for the next lengthy late summer spell.

[azores92]

So many people talking like the monsoon rains are finally lifting from the country when many parts are still well below average rainfall up to date for this year! Imo more rain is only welcome round these parts despite the fact it is summer, as the ground needs it. Anyway, back on topic and the GFS is not too bad in the outlook, with HP keeping closest to the south, with therefore the driest and brightest conditions here. More of the same really.

[Derp Patrol]

Greeny High there on every 6 hours from T0 to T384 for the entire run, = a southerly tracking jet. Most likely synoptics,

the awful summer north of the midlands goes on. MOre of the same for the southern half of the country, although never more than 2 warm summery days here before the high ridges scoot east. 30oC highly unlikely for the remainder of July. POssibly peaking at 25oC. Just August to look forward to for a summery month. Modern summer Augusts have been notably poor over the last 4 or 5 years. My instinct tells me we will have to wait to early mid September for the next lengthy late summer spell.

There's still 2 months to go and you're writing of the rest of summer pretty much? wow. Not to mention September is warmer than May and you can still see 30C right up untill the end of September. I don't know whether you were referring to your area but I doubt that we've seen the last 30C.. we achieved 33C for June which is pretty good for June, and we are not even in the hottest part of summer yet... All it takes is any form of plume or high pressure dominated scenario and 30C is on the cards.

(SE post) I think that it will be pleasant for the next few days, a bit cool relatively speaking though as 20C is 3C below average, however there will be sunny spells as we are not in a terrible pattern like some people seem to think so it will feel warm in the strong sun.

Edited July 6, 2011 by robthefool

[Mark Burton]

Greeny High there on every 6 hours from T0 to T384 for the entire run, = a southerly tracking jet. Most likely synoptics,

the awful summer north of the midlands goes on. MOre of the same for the southern half of the country, although never more than 2 warm summery days here before the high ridges scoot east. 30oC highly unlikely for the remainder of July. POssibly peaking at 25oC. Just August to look forward to for a summery month. Modern summer Augusts have been notably poor over the last 4 or 5 years. My instinct tells me we will have to wait to early mid September for the next lengthy late summer spell.

If the Greeny High does persist, then I agree with you that it will be more of the same. I think this summer is proving a mixed bag for everyone - high temps/ storms/ cooler interludes, for me, very interesting - I've got no complaints.

Edited July 6, 2011 by Mark Burton

[johnholmes]

Hello All

With the GFS op run not looking great I thought it would be a good time to share the NCEP ensemble products and the great 'training' page they have provided to assist with better understanding of the output. Even though the training page is old the data is up to date showing the weather to remain average or below average for the foreseeable...

http://www.weather.g...pc/index6.shtml

http://www.esrl.noaa...light/12012001/

thanks for those links I would imagine well worth a read when I get chance

rob, i know that quite a few posters like to use these charts. however, i am 99.9% certain that these are a mean representaion of the operational 500mb pattern for days 8 through 10. therefore, if the op is out of line with the ens at this timescale (often the case), the charts can be a bit misleading. JH makes a fair point that even though the surface pressure may be quite different, the 500mb flow is less likely to vary too much between the op and ens. i think it much better to wait for the NOAA cpc output around 9pm. again 500mb but with forecaster input mon thru fri, a much better indicator of where we're likely headed. the only downside for this output is that it doesnt include the most recent ecm 12z run in its workings.

yes I did make the point that one needs to use all 3 outputs, ECMWF, GFS and the NOAA output. IF all 3 are pretty close and that is how they have been for 3-4 days its a pretty fair bet, over 70% I would suggest that the upper air pattern will be close to what they show.

Of course one then has to work out which of the various surface charts allied to the 500mb are most likely to happen.

That is, to some extent, why the major weather centres employ fairly expensive humans as well as the incredibly expensive models.

Just to say that in any 7-15 day outlook I issue, when I did them on Net Wx , and now on my own web site, by far the greatest input comes from these 500mb anomaly charts. There is other teleconnections used but at the 7-15 day time scale those rarely directly affect the output.

In that time scale I have mostly managed about a 70%+ accuracy so they do give good guidance when used as I've suggested.

[johnholmes]

And to follow up re the comments from ba about NOAA

The link below shows their chart for the 8-14 day period, very similar to ECMWF and GFS from this morning.

http://www.cpc.ncep....14day/500mb.php

Would anyone suggest any length of settled spell with a high level of warmth during the period covered on that chart?

I doubt it and the 'tale' has been the same from the 3 outputs for a good many days, certainly at least a week since I got back off a short holiday.

The link provided earlier about NOAA(apologies to who posted it-forgot your avatar) and a 'teach in' on ensemble forecasting and how it can help forecast in the 3-15 day time scale should be well worth reading I for one will read the links closely.

the thanks are to buzzit

Edited July 6, 2011 by johnholmes

[shedhead]

Greeny High there on every 6 hours from T0 to T384 for the entire run, = a southerly tracking jet. Most likely synoptics,

the awful summer north of the midlands goes on. MOre of the same for the southern half of the country, although never more than 2 warm summery days here before the high ridges scoot east. 30oC highly unlikely for the remainder of July. POssibly peaking at 25oC. Just August to look forward to for a summery month. Modern summer Augusts have been notably poor over the last 4 or 5 years. My instinct tells me we will have to wait to early mid September for the next lengthy late summer spell.

The latest outputs certainly add weight to your comments. With the first week of July already behind us and nothing to suggest anything resembling a pattern change, this month is already looking like a write of if dry, hot and sunny weather is your bag. Clearly August is still capable of delivering some protracted fine, settled weather, but again as you point out the last few Augusts have been very disappointing and it frankly would not come as any real surprise to me to see the current pattern extending well into next month, perhaps even dominating it.

Should this happens I suppose all will quickly be forgiven/forgotten if a cold, blocked winter follows, but if we get to November and high pressure takes up residence over central Europe and wafting SW'erlies envelop the UK for weeks on end there will be some seriously unhappy campers on here... me included!

Edited July 6, 2011 by shedhead

[lorenzo]

Greeny High there on every 6 hours from T0 to T384 for the entire run, = a southerly tracking jet. Most likely synoptics,

the awful summer north of the midlands goes on. MOre of the same for the southern half of the country, although never more than 2 warm summery days here before the high ridges scoot east. 30oC highly unlikely for the remainder of July. POssibly peaking at 25oC. Just August to look forward to for a summery month. Modern summer Augusts have been notably poor over the last 4 or 5 years. My instinct tells me we will have to wait to early mid September for the next lengthy late summer spell.

Great example of one run being ring fenced, lifted and commented on - the end result being similar to Inception.

This thread as an observer over the last few days has gotten a little snipey in regards to folk slating the SE ( where majority of members - no pun intended) are and IMBY posts.

This post model followers is a Troll post - look at tomorrows 12z run and see if the exact predictions mirror this to T384... then look at MJO activity and the fact that it updates from Ncep on Monday well within 384, look at the ECM as the highest res short range run for closer forecasting where the GFS liftts trends more quickly.

Look at teleconnections and the MJO poised on a knife edge..

And finally Its not a clear North South divide on here whether model watching or not, for weather or opinions.

We are an Island planked in the atlantic ocean influenced by 2 blocking patterns to our NE and NNW and the massively convected ocean to our west... thats just for starters.

This thread is here for folk to learn from people - read the models and be honest with what you see.edit add chart

http://raleighwx.americanwx.com/MJO/JulyPhase2500mb.gif

Who is to say this composite is final round the corner for remainder of July ...

Edited July 6, 2011 by lorenzo

[feb1991blizzard]

Great example of one run being ring fenced, lifted and commented on - the end result being similar to Inception.

This thread as an observer over the last few days has gotten a little snipey in regards to folk slating the SE ( where majority of members - no pun intended) are and IMBY posts.

This post model followers is a Troll post - look at tomorrows 12z run and see if the exact predictions mirror this to T384... then look at MJO activity and the fact that it updates from Ncep on Monday well within 384, look at the ECM as the highest res short range run for closer forecasting where the GFS liftts trends more quickly.

Look at teleconnections and the MJO poised on a knife edge..

And finally Its not a clear North South divide on here whether model watching or not, for weather or opinions.

We are an Island planked in the atlantic ocean influenced by 2 blocking patterns to our NE and NNW and the massively convected ocean to our west... thats just for starters.

This thread is here for folk to learn from people - read the models and be honest with what you see.

I dont see what is wrong with PE's post, yes no one can guarantee what the weather will be like for the next 2 months granted but at the moment the met office agree with PE that the North will be colder than average and showery, and August has been cold and showery for the past few years so that is the form horse, i predicted a CET of over 18c for July but i have to admit now that is looking unlikely and around average is looking the likely outcome.

[PompeyFC]

can someone explain why that greenland high has been there for weeks on end yet in winter when we (I mean cold lovers) all crave it we get a transient 2-3 days worth before its blown away ????

its really giving me the hump this summer

Edited July 7, 2011 by PompeyFC

[Weather-history]

can someone explain why that greenland high has been there for weeks on end yet in winter when we (I mean cold lovers) all crave it we get a transient 2-3 days worth before its blown away ????

Have you forgotten the last two winters?

Still looks unsettled, by the way.

Edited July 7, 2011 by Mr_Data

[mushymanrob]

rob, i know that quite a few posters like to use these charts. however, i am 99.9% certain that these are a mean representaion of the operational 500mb pattern for days 8 through 10. therefore, if the op is out of line with the ens at this timescale (often the case), the charts can be a bit misleading. JH makes a fair point that even though the surface pressure may be quite different, the 500mb flow is less likely to vary too much between the op and ens. i think it much better to wait for the NOAA cpc output around 9pm. again 500mb but with forecaster input mon thru fri, a much better indicator of where we're likely headed. the only downside for this output is that it doesnt include the most recent ecm 12z run in its workings.

thanks for that

There's still 2 months to go and you're writing of the rest of summer pretty much? wow. Not to mention September is warmer than May and you can still see 30C right up untill the end of September. I don't know whether you were referring to your area but I doubt that we've seen the last 30C.. we achieved 33C for June which is pretty good for June, and we are not even in the hottest part of summer yet... All it takes is any form of plume or high pressure dominated scenario and 30C is on the cards.

... there isnt two months of summer left, there one and a half! :lol:

how many times in recent years has 30c+ been reached in august? or even july this side of '06? ... its rare... the point is that its highly unlikely that a hot spell will develop out of nothing. weather prediction deals with whats 'most likely' given the predicted data. the predicted data does not show any scope for a plume, high pressure, heat, outside of an odd ridge day (or two) here and there. until the teleconnections suggest a pattern change the chances of anything hot is extremely remote. so viewing the output, taking in to account that pattern changes often take a while to establish, then 'writing off' summer at this stage (in terms of a decent hot spell), half way through, looks a fair bet... unfortunately!

...and this mornings output makes poor viewing, gone are the fi teases, and theres nothing other then 'ordinary' 'average' british summer conditions, even perhaps below average at times.

[Downpour]

Good post by Lorenzo above - I have often wondered why it is considered heresy to talk of the benign weather prospects in the SE, yet doom wrist slitting and talk of monsoon rains in the NW is apparently fair game. As 30m people, about half of the entire UK live in the SE quarter of the island, you'd think that talking about the SE would be welcomed!

Well it is only 7 July so there IS two months of summer left, save seven days. This is if you slavishly adhere to the Met Office summer- many of us still consider early and mid September as summer (warmer than May) and are traditionalists who say the first day of Autumn is September 21. Outlook looking benign and pleasant in the most populous regions of the UK, as the reasonable SE summer rolls on.

[Gibby]

UKMO shows the Low pressure centred over the UK currently drifting away NE very slowly over the weekend with a weak ridge moving east into Britain by Tuesday. So further heavy showers today, tomorrow and for Northern and Eastern regions through the weekend while the South and West see less showers with time and dry weather by Monday extending to all parts by Tuesday with better temperatures and some sunny spells.

GFS this morning shows the same path to next Tuesday as the ridge moves east. After that Low pressure quickly follows in from off the Atlantic bringing a return to cooler and changeable conditions with rain or showers at times for all. The remainder of the run maintains the very changeable theme with rain and showers winning out over the shortest of drier spells in the south as weak ridges pass by.

ECM shows a different evolution than the other two developing the situation shown last night with high pressure developing to the NW on Monday/Tuesday bringing a dry, quiet period there while Low pressure developed over France is close enough to Southern England to influence the weather here with cool east winds and rain near the south coast on Wednesday/Thursday. In the final days of its run slack low pressure remains over Southern Britain and Europe with a high pressure ridge eventually toppling south over the UK by day 10 hopefully introducing more settled and warmer conditions to the south and more unsettled, windy conditions further North.

In Summary the big three continue to show an improvement for early next week. However, ECM is continuing to show a diversion into showing Low pressure near South and Southeast Britain midweek with the risk of rain there while GFS shows any improvement as short lived with the Atlantic coming back in control quickly after midweek. Until the resolution of how the incoming ridge interacts with the exit of the current showery regime is answered I think there will be more scenarios shown in the coming runs but whatever happens it is fairly certain that there is no easy path to any sustained warm and sunny conditions anytime soon.

[VillagePlank]

[London] ensembles min/max/mean:

Looks like quite good agreement out to the 11th and then diverging quite rapidly from thereon in. Strong agreement way out after the 20th for a reasonably large hike in 850hPa temps. Unusual, perhaps? Summer to restart after the 20th?

Edited July 7, 2011 by Sparticle

[UV-RAY]

Good post by Lorenzo above - I have often wondered why it is considered heresy to talk of the benign weather prospects in the SE, yet doom wrist slitting and talk of monsoon rains in the NW is apparently fair game. As 30m people, about half of the entire UK live in the SE quarter of the island, you'd think that talking about the SE would be welcomed!

Well it is only 7 July so there IS two months of summer left, save seven days. This is if you slavishly adhere to the Met Office summer- many of us still consider early and mid September as summer (warmer than May) and are traditionalists who say the first day of Autumn is September 21. Outlook looking benign and pleasant in the most populous regions of the UK, as the reasonable SE summer rolls on.

Mathematics and Geography are not two of your strong points I see.

Back to the models and not much as changed, big block over Greenland preventing any sustained heat building over the UK. A few nice warm sunny days for some, followed by spells of rain/showers. for all. Basically I would say that's the pattern set for the next two weeks, will August deliver anything different?

[Downpour]

Mathematics and Geography are not two of your strong points I see.

You really ought to read my posts and check your facts before making yourself look silly by calling me out on something. I said the SE quarter of the UK. London has 8 million, SE 8 million, East Anglia 5.5 million. Add in bits of other regions that also fall into that SE quadrant and you reach 30 million easily, surpassing it probably. It's a statistic you and others would do well to remember when calling "poor and unsettled" on the models when the reality is a decent average summer for the populous SE quadrant.

[UV-RAY]

You really ought to read my posts and check your facts before making yourself look silly by calling me out on something. I said the SE quarter of the UK. London has 8 million, SE 8 million, East Anglia 5.5 million. Add in bits of other regions that also fall into that SE quadrant and you reach 30 million easily, surpassing it probably. It's a statistic you and others would do well to remember when calling "poor and unsettled" on the models when the reality is a decent average summer for the populous SE quadrant.

Whatever! This is a UK model thread not an IMBY thread, your post are growing tiresome as they are predictable. Here's an idea try and post something about the whole of the UK.

[Downpour]

Whatever! This is a UK model thread not an IMBY thread, your post are growing tiresome as they are predictable. Here's an idea try and post something about the whole of the UK.

As I and others have said, attempting to post about the whole UK is pretty pointless as west Scotland and West London are a million miles away in climate terms. As there are no regional model threads the only place to discuss the likely medium term prospects for the SE are on here. If you don't like my posts, just ignore them.

[Radiating Dendrite]

can someone explain why that greenland high has been there for weeks on end yet in winter when we (I mean cold lovers) all crave it we get a transient 2-3 days worth before its blown away ????

its really giving me the hump this summer

As Mr. Data said, I suggest you look at the winter 09/10 and 10/11 archive charts.

The main thing is summer is that the polar vortex disappears so the high can more easily form.

[shedhead]

The overnight runs show decent agreement on a slow imorovment from the southwest this weekend as the low drifts away, then as we move into the early part of next week all three go for a spell of relatively decent weather, albeit from

differing synoptics. Thereafter the jury is out, but with ECM singing from a rather different hymnsheet than both UKMO and GFS at T+144hrs my money is on GFS from midweek, with another attack of Atlantic low pressure being the

most likely evolution.

[95 Degrees]

I see almost everyone is in summers over mode again, forgetting of course that hot spells can occur out of nowhere for example the late June hot spell we had over a week ago, It feels like pressure will never drop over Greenland but it really only takes one day for a dramatic change to take place on the models, and unless we're still here in Early August in the same situation then there is no need for these summer's over posts, when there is over a month of high summer left!

[A.J]

As I and others have said, attempting to post about the whole UK is pretty pointless as west Scotland and West London are a million miles away in climate terms. As there are no regional model threads the only place to discuss the likely medium term prospects for the SE are on here. If you don't like my posts, just ignore them.

hmm...so can I infer from that, that you find Gibby's excellent and well constructed daily UK model analysis & summary 'pretty pointless' then?....not sniping, just curious

Can't comment on the 00zGFS as the 06z is just starting to churn out thus can't see the 00z archive....The 00z ECM is interesting as it throws up a pot-pourri of weather....It suggest showers for most parts of the UK for the next 48 hours, then heights build as a ridge moves down from the north west giving northern parts of the UK some respite from all the recent wet weather they've endured, I would surmise that the vast majority of the UK could enjoy a couple of pleasantly warm days with a light easterly breeze...Further south on tuesday/wednesday, pressure drops over France with a shallow LP developing, looking at the elongation of the LP centre, I would guess pulses of thundery rain push across the English Channel as opposed to plume/thunderstorm scenario, meanwhile the run shows a shallow LP approaching the NW of scotland filling as it does which would introduce showery rain into Scotland and perhaps Northern Ireland, whereas over Southern & SE parts of the UK dry up as LP drifts away to the SW and disspates, the run concludes with the AH ridging across the UK giving the potential of some pleasant weather to most parts, the exception being Western & Northen Scotland which may see cloud & drizzle from a frontal system associated with a LP to the north of the British Isles..

Now I wouldn't like to hazard a guess at how accurate this summary is, or even if I'm reading the charts with only a modicum of understanding, but the point is, a forecast for the entire UK based on a model run in just a few sentences with no 'IMBYism'

[Iceaxecrampon]

The latest outputs certainly add weight to your comments. With the first week of July already behind us and nothing to suggest anything resembling a pattern change, this month is already looking like a write of if dry, hot and sunny weather is your bag. Clearly August is still capable of delivering some protracted fine, settled weather, but again as you point out the last few Augusts have been very disappointing and it frankly would not come as any real surprise to me to see the current pattern extending well into next month, perhaps even dominating it.

Should this happens I suppose all will quickly be forgiven/forgotten if a cold, blocked winter follows, but if we get to November and high pressure takes up residence over central Europe and wafting SW'erlies envelop the UK for weeks on end there will be some seriously unhappy campers on here... me included!

Myself included.

Yes the irony of it all.

Devon and Dorset beaches for us from the 1st of August.... No heat for the forseeable.

[Downpour]

hmm...so can I infer from that, that you find Gibby's excellent and well constructed daily UK model analysis & summary 'pretty pointless' then?....not sniping, just curious

Can't comment on the 00zGFS as the 06z is just starting to churn out thus can't see the 00z archive....The 00z ECM is interesting as it throws up a pot-pourri of weather....It suggest showers for most parts of the UK for the next 48 hours, then heights build as a ridge moves down from the north west giving northern parts of the UK some respite from all the recent wet weather they've endured, I would surmise that the vast majority of the UK could enjoy a couple of pleasantly warm days with a light easterly breeze...Further south on tuesday/wednesday, pressure drops over France with a shallow LP developing, looking at the elongation of the LP centre, I would guess pulses of thundery rain push across the English Channel as opposed to plume/thunderstorm scenario, meanwhile the run shows a shallow LP approaching the NW of scotland filling as it does which would introduce showery rain into Scotland and perhaps Northern Ireland, whereas over Southern & SE parts of the UK dry up as LP drifts away to the SW and disspates, the run concludes with the AH ridging across the UK giving the potential of some pleasant weather to most parts, the exception being Western & Northen Scotland which may see cloud & drizzle from a frontal system associated with a LP to the north of the British Isles..

Now I wouldn't like to hazard a guess at how accurate this summary is, or even if I'm reading the charts with only a modicum of understanding, but the point is, a forecast for the entire UK based on a model run in just a few sentences with no 'IMBYism'

Well maybe pointless was too strong a word mate, but my point is that more detailed regional posts are of great value and I'm not sure where they can go if not in the model thread. Fair enough if there was a London & SE thread as in winter, but that no longer exists sadly.