Model Output Discussion

[reef]

A new thread.

The other thread was perhaps the largest collection of off-topic posts, slanging matches and opinionated nonsense Ive ever seen. 28 pages in a few hours is impossible for the team to keep in check. Any off topic posts in this one will simply be removed without warning.

Any trolling and baiting and those responsible will find themselves on a vacation. Sorry to be harsh but it was next to impossible for anyone to understand whats actually happening when you read through the old one.

Thanks.

[Liam J]

18z going for a more atlantic based influance, and not without back up, make the must of this cold snap it may be short with nice clear arctic air and snow showers for a few ( more normal for us) and added to the last cold at the begining of january all in all a good winter..

looking like frontal snow next week as the atlantic trys to take control.

[NorthantsSnow]

Definitely think the control run should be binned. Just been through every single ensemble and not one of them supports the easterly it shows at T180.

Utter nonsense and not to be taken seriously.

[Mark Bayley]

GFS ensemble mean looking good with an east/south easterly flow

T144

Compared to the ECM and UKMO

GFS seems on its own tonight (out of the big 3) Will the 0z be the final nail in the coffin? As ever we shall have to wait and see

[Lewis]

a lot of armchair forecasters on here tonight that think they can call it (when the models are still arent decided)

Bye bye

Reef asks just one thing, and one thing only, to stay on topic, and the first post is the opposite, stop trying to wind people up!

18z as i said earlier is good short range, mid range is when it starts to go cuckoo, hopefully come Monday we shall have more of an idea.

[Ian Fergusson]

"......it was next to impossible for anyone to understand whats actually happening...."

Yup: an adequate (abstracted) summary in a mere 12 words.

Doutbless replicated at the various national forecasting centres too.... hope the sense of humour can return on this new thread.

[dave79]

I've a question for the expert model watches on here.

Is it possible to see charts from events gone past, say feb 91 before the event actually happened, back then the charts must have gone backwards and forwards before finally agreeing on the final outcome. Hense these type of charts must give us an indication of what may happen now. I'm a newbie but I do agree that the small details in weather change the outcome of an actual event happening.

[mushymanrob]

i dont think i can remember when there was such a protracted uncertainty with the models at such a close time.... fi must begin at about 48 hours.. forget anything after that.

[PB22]

From the previous thread, I would like to know how the FAX charts can be classified as an outlier?? I've heard some things in my time, but I have never heard of the FAX charts being called an outlier! The FAX charts have human input, and not just any old input, but input from professionals at the Met Office. They have looked at all the data and have gone with what they think is the likely outcome. They don't go and draw up an "outlier"!! In any case, I bet it wouldn't have been called an outlier if it was showing a cold easterly!

[LomondSnowstorm]

The ensembles have improved in the medium term also, so not all doom and gloom by any means. http://91.121.94.83/...21-1-138.png?18 Into FI and the mean is still pretty cold http://91.121.94.83/...21-0-252.png?18

LS

Edited January 30, 2010 by LomondSnowstorm

[Snowyowl9]

GFS still at this timeframe showing northern blocking and a undercut so we are none the wiser what`s going to happen going by all the models today,they are not handling the blocking pattern to the north at all well which is to be expected.

http://www.wzkarten.de/pics/Rtavn1201.png

http://www.wzkarten.de/pics/Rtavn12017.png

[Tom D]

I've a question for the expert model watches on here.

Is it possible to see charts from events gone past, say feb 91 before the event actually happened, back then the charts must have gone backwards and forwards before finally agreeing on the final outcome. Hense these type of charts must give us an indication of what may happen now. I'm a newbie but I do agree that the small details in weather change the outcome of an actual event happening.

http://www.wetterzentrale.de/topkarten/fskldwd.html

Select a date, then tick the boxes and click 'Ziegen' again and you can view the 850hpa temps and 500hpa thickness I believe.

Doesn't really matter if you can't read German, most of the words are quite obvious anyway

Edited January 30, 2010 by Tommyd1258

[nick sussex]

The GEFS ensembles upto 180hrs for London just confuse the issue even more, for the key time period upto 144hrs theres only one ensemble member out of 20 that brings any milder air in. The operational run is at the top end of members from the 3rd Feb. Given that the gfs 18hrs has newer data one would think if there was a very strong signal to take more energy eastwards that it would have picked up on this as the major divergence begins at 72hrs!

[PB22]

Further to my previous post, the ECM London ensembles are out:

http://www.meteogrou...e_forecast.html

Whilst the ECM was at the top end of the temperature scale, it was not an outlier. As a whole, the ensemble suite is the mildest set for several runs.

The T+120 FAX for February 4th is similar to the ECM T+120 output, and a look at the ensembles shows the operational was not an outlier for this time, hence the reason the pro's have come up with that FAX chart.

18Z GFS ensembles for London:

http://91.121.94.83/...ndres&runpara=0

Edging ever further away from a deep cold trend.

Edited January 30, 2010 by Paul B

[swilliam]

The 18Z GFS ensemble is not telling us much really except that the OP was top of the range for most of the run and the control was bottom. There now seems to be a rise in the mean between the 8-12th due I think to that big low that develops in mid Atlantic.

As a general comment there have been some very silly posts in here tonight. Why do people have to look at the models and then make pronouncements about what is going to happen (e.g. game over for the cold, definitely mild now etc.) when clearly it is not yet decided.

[Mac_SE]

What was it the Mod asked for at the top of the thread?

This forum's actually OK when there's not an easterly about, but when it is, boy, it's just too painful for words.

Less personal justification, more model chat please...

[January Snowstorm]

The ensembles are every bit as fickle as the models.

Perhaps we give them too much credance.

Height rises over Greenland look a certainty, I shant be swayed yet.

Imo the gfs ruled the roost with the last cold spell including the breakdown.

[Secret Society]

Further to my previous post, the ECM London ensembles are out:

http://www.meteogrou...e_forecast.html

Whilst the ECM was at the top end of the temperature scale, it was not an outlier. As a whole, the ensemble suite is the mildest set for several runs.

The T+120 FAX for February 4th is similar to the ECM T+120 output, and a look at the ensembles shows the operational was not an outlier for this time, hence the reason the pro's have come up with that FAX chart.

18Z GFS ensembles for London:

http://91.121.94.83/...ndres&runpara=0

Edging ever further away from a deep cold trend.

as per the reply on two from the met, the met 15 day is done on the 00z. the faxes were not taken into account earlier today.

until it changes the easterly is still on

[igloo]

stormer of a control run http://www.meteociel.fr/modeles/gefs_cartes.php more cold ensemble members than mild also

[NorthantsSnow]

Clearly now they feel that with the ECM (operational) on board they have the confidence to back their own model, So the odds are weighted against the GFS but I would rather see the 0zs before being as bullish as Paul B and Stephen P.

With respect, these posters are always bullish about a less cold trend when it emerges.

Not a criticism, especially as most of the time they tend to be right, however like you I prefer to keep an open mind until we have something approaching agreement in the +96-120 timeframe, and since we don't have that yet, we cannot be sure of what will happen after.

[PB22]

as per the reply on two from the met, the met 15 day is done on the 00z. the faxes were not taken into account earlier today.

until it changes the easterly is still on

I was talking about tonight's FAX charts which came out an hour or so ago and were based on tonight's 12z ECM, i.e.

http://www.meteociel.fr/ukmo/fax/fax96s.gif

http://www.meteociel.fr/ukmo/fax/fax120s.gif

Nothing to do with the 6 to 15 day forecast on the Met Office website which is beyond the range of the FAX charts anyway.

[Tomomcd]

Would be careful with the ensembles when things are so complicated

There low resolution is likely to over simplify things imo

[NorthantsSnow]

stormer of a control run http://www.meteociel.fr/modeles/gefs_cartes.php more cold ensemble members than mild also

Yes but the control run had zero support. Literally not one ensemble member looks anything like it at T180.

Let me clarify that: I'm not saying no other ensemble member produces an easterly at some point, but those that do introduce it in an altogether different way and not until much later in the run.

[kent]

Massive high pressure building over siberia, will try to push its intense cold east over our shores. The mighty Atlantic squaring up to push it back. Who wins? Simples, nobody knows yet.

[West Sussex Kate]

is that huge low in the atlantic to blame for all this ?