Model Output Discussion

[William of Walworth]

But have a look at the Ensembles from the 06z...its been similar for a few days now (as mentioned above):

Thanks for that, I should check the ensembles more regularly .....we have to wait and see what transpires, but that looks quite a sharp upward pressure trend after the 24th ... for a short while at least. And those are for Derbyshire too ... what do you think mushy?

Edited July 16, 2009 by William of Walworth

[mushymanrob]

Thanks for that, I should check the ensembles more regularly .....we have to wait and see what transpires, but that looks quite a sharp upward pressure trend after the 24th ... for a short while at least. And those are for Derbyshire too ... what do you think mushy?

not a lot mate.... i dont view the ensembles, not sure why they exist tbh or what their relationship is to the charts. i do think that sometimes you can 'overview' data, which often conflicts thus causing confusion...

...on the other hand i might be just too lazy! :lol: ill stick to the charts, i understand them

[Shiny_Bottom_1]

not a lot mate.... i dont view the ensembles, not sure why they exist tbh or what their relationship is to the charts. i do think that sometimes you can 'overview' data, which often conflicts thus causing confusion...

...on the other hand i might be just too lazy! :lol: ill stick to the charts, i understand them

Hi Rob. Ensembles contain all other members (for example above) on the GEFS run.

For me, they're very good for helping to spot trends, over/under exagerations etc.

Defo good from my POV/interest, and are definately a useful toolkit from NW.

A good example was when I was looking at the NW/GFS forecast for Sunday just gone, and was looking on Friday/Satruday.

The ctrl run (the one we all see on the charts) was showing the rain coming in later and more prolonged than the other members, and also showing a lower pressure.

Based on the other members, it suggested that rain would be gone earlier than the control, and that pressure would not be that low (probably an indication that the low was either in a different position/orientation/tighter isobars compared to most members). The ctrl was wrong, and the other members were correct.

Edited July 16, 2009 by Shiny_Bottom_1

[swebby]

Hi Rob. Ensembles contain all other members (for example above) on the GEFS run.

For me, they're very good for helping to spot trends, over/under exagerations etc.

Defo good from my POV/interest, and are definately a useful toolkit from NW.

Fully agree and well worth getting to grips with if you are yet to take note of them. The ensembles are the first thing i check as it indicates if the GFS output can be taken as reliable and when FI starts. They are also the best indicator of an emerging trend. One member showing high pressure or a -10C T850 can be taken as an outlier but if it is joined by more members in subsequent runs then it is time to start to paying attention.

Cheers

S

[Eugene]

A dire GFS 12Z with only one dry day on monday, rain almost everyday is not normal for July, high pressure cells around the UK have really gone on holiday this July, only ones of note are way to our northwest over greenland and to our west near north america.

http://www.wetterzentrale.de/pics/Rtavn1561.png

[mushymanrob]

well i ought to start looking at them more i guess... they might tell me if its going to be wet or very wet...lol

[Shiny_Bottom_1]

Eugene. Do you take notice of snow fall when forecast by the models? I would guess no.

Be it snow or rain, ppn is probably the most difficult (and most changable) factor when observing model runs.

Lets not get hung up by the ppn forecast, but look for the basic indicators of pressure etc

[William of Walworth]

We should be somewhat cautious about writing off the whole of the coming week for the whole of the UK I think. Ensembles at least are not completely devoid of some chance of a modest improvement later on -- maybe further South, who can be sure?

I find ensembles hard because I never know which suggestions are outliers and which seem more reliable. But still, I'd welcome some input on them from more experienced posters here.

And as far as actual synoptic charts go, are the links that Snowyowl posted earlier -- showing rising presure for some regions by next Saturday -- completely to be discarded, are they out of date now?

Thanks for any help folks .....

Edited July 16, 2009 by William of Walworth

[ANYWEATHER]

Withe the jet going so far south at the moment and judging by the models in the next week or so, im afraid little hope for any Summer weather for us in the UK although there are the exceptions!

[Snowyowl9]

A slightly different variation of azores high coming in late on but the jet looks to ease off on those charts.

As for tomorrow a notable colder day showing even in london.

http://91.121.93.17/pics/Rtavn2417.png

http://91.121.93.17/pics/Rtavn3017.png

Edited July 16, 2009 by Snowyowl9

[Shiny_Bottom_1]

Withe the jet going so far south at the moment and judging by the models in the next week or so, im afraid little hope for any Summer weather for us in the UK although there are the exceptions!

Always worth remembering though, the jet forecast is the same as the ppn forecast, the pressure forecast etc etc.

Its all interlinked.

My comments arent aimed at yourself par se, but a model predicting a jet forecast at t+240 is no more accurate than a pressure forecast at the same time frame. Its all using the same data.

If you get my drift...

[Alex95]

A dire GFS 12Z with only one dry day on monday, rain almost everyday is not normal for July, high pressure cells around the UK have really gone on holiday this July, only ones of note are way to our northwest over greenland and to our west near north america.

http://www.wetterzentrale.de/pics/Rtavn1561.png

I actually agree with you there Very wet weather tomorrow in the NE means that any more heavy rain in the near future would cause flooding Confidence appears to be low however, so with SLIGHT rises in pressure expected to the south we could well end up with a slacker low pressure influence than predicted and therefore more warmth. A high pressure influence is almost impossible in the next week though so there would bound to be showers and thunderstorms so by no means great summer weather.

[bluearmy]

Always worth remembering though, the jet forecast is the same as the ppn forecast, the pressure forecast etc etc.

Its all interlinked.

My comments arent aimed at yourself par se, but a model predicting a jet forecast at t+240 is no more accurate than a pressure forecast at the same time frame. Its all using the same data.

If you get my drift...

very true - but when the mean of 50 ensemble members across 2 different models shows a jet at T240+ , we do need to take it seriously. one would hope that at this time of year the averaging out of the jet strength across so many runs would show the jet to be virtually non existant beyond T240. alas, this continues not to be the case.

http://www.meteociel.fr/modeles/naefs_cart...h=192&map=1

i am encouraged by the fragmentation (albeit temporary) around the 25 - 27th - this corresponds to some ridging in of the AH on the same output which has been shown for many runs now. at the moment, the jet reforms soon afterwards.

[J07]

Withe the jet going so far south at the moment and judging by the models in the next week or so, im afraid little hope for any Summer weather for us in the UK although there are the exceptions!

Makes me wonder where the subtropical jet is in there? Should be around about North Africa.

[Eugene]

I am really shocked by GFS 00Z this morning, i think it is the worse run i have ever seen in the summer, unsettled westerlies followed by unsettled northerlies, best thing about the run is you won't see one as bad as that for quite sometime, even i would say unlikely to come off that bad in the FI stage.

http://www.wetterzentrale.de/pics/Rtavn2641.png

[mushymanrob]

well i didnt think things could get any worse, judging by the 00z i was wrong. this pesky low sits on or nearby for the whole of next week before high presure to our west slowly introduces northerlies.

write off summer?.... well on current outputs i wouldnt bet against it as they have got gradually 'worse' (for 'summer') over the last 2 weeks. after the hope in june of a decent summer, its looking like this july will rival or even surpass july 07 for foul, unsummery, weather.

[Methuselah]

well i didnt think things could get any worse, judging by the 00z i was wrong. this pesky low sits on or nearby for the whole of next week before high presure to our west slowly introduces northerlies.

write off summer?.... well on current outputs i wouldnt bet against it as they have got gradually 'worse' (for 'summer') over the last 2 weeks. after the hope in june of a decent summer, its looking like this july will rival or even surpass july 07 for foul, unsummery, weather.

I have to agree with that, mushy. It looks like I could be in the 'bullseye' for quite a while yet? Thunderstorms look like being the one 'silver lining'!

[Pennine Ten Foot Drifts]

Yes, GFS 00Z Operational is bad. However, neither ECM or GEM paint quite such a gloomy picture in the medium term. I suspect that in the absence of any particularly strong mid-range signals the GFS Operational is simply reverting to type (i.e. Atlantic dominated). Given what GP and Chiono have been saying over the past few days, there is still a posibility of a change as we head towards August, but this is still too far out for models to pick up on. If that change is going to happen, it's not going to be for a while yet before we are likely to see anything concrete within a reliable timeframe (i.e. <T150). So, if you want to depress yourself by believing what GFS is currently showing beyond T150 then carry on, but I for one am viewing any output beyond about T96 with a pinch of salt at present.

Edited July 17, 2009 by Pennine Ten Foot Drifts

[snowingman]

What absolutely awful charts.... the most surprising thing looking towards the next few weeks is the enormous spread of cool temperatures that are setting in, way way below normal across not just us but most of North, West and central Europe.

Surely this model cannot occur, its as if we have move forward 4 months to mid November!! average maximums in the north only around 11 C and in the south 14C,

On the positive, no bad air quality as we will be living in POLAR air!!

Just dreadful... dreadful.. dreadful if you like summer that is

[whitestuff]

Is it me or are the people that are writing off Summer using FI charts, the same ones that constantly say that you can't trust anything past T96 when snow is shown in winter?

Edited July 17, 2009 by whitestuff

[reef]

Quite poor looking models this morning I agree. I absolutely detest heat so these arent too bad for me, but the constant rainfall that comes with it is highly annoying. Already Ive recorded 177% of the monthly expected rainfall at this point and its this fact of almost everyday being wet which I suspect annoys people the most.

The one positive thing is that its very unlikely that this will continue indefinitely. Even 2007 and 2008 had warmer, drier periods.

[MR EXTREMES]

all i can say im not dissapointed with model outputs after all over the last couple of years its become common that more unsettled and perhapes more normal uk weather is taking hold.

im also certain a settled spell will be along at sometime maybe not for awhile yet but at some point of coarse.

as for the jet its safe to say this has been a trend now for a couple of years,

its funny a year or 2 ago watching a program on tv telling why the uk had such a terrible summer,

turning out to be the jets fult but on the other hand its also been made clear the jet was heading futher north year in year out causing us to experience warmer climate,

athough this is not the case now ofcoarse trends now seem to be taking place,

i honestly think this is catching the forecast world out with the jet being far south being a common feature overall.

wether the far south jet movement continues is another theory but it would seem this trend could continue.

also couple this with the weak azores high and no real domination comming from this feature which has been noticable for sometime aswell.

it would seem a decade or more of the hot hot beach weather is now taking a backseat.

but its not all bad because it would seem a more average climate could be on the cards for awhile.

so killer heatwaves not likely but certainly does not rule out nice warm sunny weather which will be back im sure

[William of Walworth]

i am encouraged by the fragmentation (albeit temporary) around the 25 - 27th - this corresponds to some ridging in of the AH on the same output which has been shown for many runs now.

Yes, GFS 00Z Operational is bad. However, neither ECM or GEM paint quite such a gloomy picture in the medium term. I suspect that in the absence of any particularly strong mid-range signals the GFS Operational is simply reverting to type (i.e. Atlantic dominated). Given what GP and Chiono have been saying over the past few days, there is still a posibility of a change as we head towards August, but this is still too far out for models to pick up on. If that change is going to happen, it's not going to be for a while yet before we are likely to see anything concrete within a reliable timeframe (i.e. <T150). So, if you want to depress yourself by believing what GFS is currently showing beyond T150 then carry on, but I for one am viewing any output beyond about T96 with a pinch of salt at present.

Is it me or are the people that are writing off Summer using FI charts, the same ones that constantly say that you can't trust anything past T96 when snow is shown in winter?

Just about the only scope I have just now for not feeling near suicidal about the prospects for late next week and weekend, are the above three posts ......

I'm stubbornly going to ignore all the other contributions for the moment, for my own sanity ..... no offence to the pessimists/realists (delete as appropriate!) but I'm sure you can understand ....

Edited July 17, 2009 by William of Walworth

[swebby]

I am really shocked by GFS 00Z this morning, i think it is the worse run i have ever seen in the summer, unsettled westerlies followed by unsettled northerlies, best thing about the run is you won't see one as bad as that for quite sometime, even i would say unlikely to come off that bad in the FI stage.

http://www.wetterzentrale.de/pics/Rtavn2641.png

Yes, GFS 00Z Operational is bad. However, neither ECM or GEM paint quite such a gloomy picture in the medium term. I suspect that in the absence of any particularly strong mid-range signals the GFS Operational is simply reverting to type (i.e. Atlantic dominated). Given what GP and Chiono have been saying over the past few days, there is still a posibility of a change as we head towards August, but this is still too far out for models to pick up on. If that change is going to happen, it's not going to be for a while yet before we are likely to see anything concrete within a reliable timeframe (i.e. <T150). So, if you want to depress yourself by believing what GFS is currently showing beyond T150 then carry on, but I for one am viewing any output beyond about T96 with a pinch of salt at present.

Morning,

Just looked at the 00z comparisons and there really is now a big difference between the ECM and the GFS/GEFS. Same pattern at around t120-t170 but the ECM has everything shunted about 1000miles further west. While that would not equate to glorious summer it should be ok and a lot better than what we have today. The less said about the GFS output, which has the backing of the ensembles in this time frame the better! Anyone want to take a punt on which will be right or will it be a halfway house between the two?

Cheers

S

[swebby]

The ensembles also tell you when the model programs are screwed