Model Output Discussion

[Frosty.]

Well the ecm 12z is a flop as far as an E'ly next week is concerned so i'm afraid the model confusion begins again with several still onboard but the ecm going for a swim.

[nick sussex]

Looking through the model output I think we can see that actually theres a split between the models, the ECM, GEM, NOGAPS all take a piece of energy into a shortwave se'wards, the GEM and NOGAPS take this further sw so are lower risk, the ECM looks very dodgy and could go wrong as it takes the shortwave more ese towards the UK. The GFS, UKMO and GME don't develop the shortwave, that then leaves the JMA which doesnt want to know at all and just runs over the block.

So given all this its just a mess basically because of the uncertainty, I always believe that the longer and more complicated the road to cold the more likely that the next variable will be one hurdle too far, the best route is the quickest.

[Cumulonimbus Tower]

Well the ecm 12z is a flop as far as an E'ly next week is concerned so i'm afraid the model confusion begins again with several still onboard but the ecm going for a swim.

ECM 12z looks very much like its 00z to me. Nothing much has changed then except for one or two of the cannon fodder models coming on board

[nick sussex]

ECM 12z looks very much like its 00z to me. Nothing much has changed then except for one or two of the cannon fodder models coming on board

Unfortunately theres quite a large difference in terms of the complexity of the pattern. The shortwave thrown off the main trough could become a real pain, the GEM is fine as it takes this well to the sw, the ECM drives this into the UK and then we have to rely on things going right after that, so basically more time for things to go wrong. In terms of cannon fodder yes generally the NOGAPS is that but the GEM definitely isn't, i was just trying to show what all the models had to offer overall.

However its just one operational run so i don't want to cause a major prozac drama but trying to show that theres still alot of uncertainty and that any easterly is by no means a foregone conclusion.

[Frosty.]

ECM 12z looks very much like its 00z to me. Nothing much has changed then except for one or two of the cannon fodder models coming on board

I thought the ECM 00z was better but I could be wrong, anyway, the gfs 12z gave us a heart shaped high but on the ecm it's gone very pear shaped. There is still a chance it could happen with the gfs,ukmo,gem all for it but losing the ecm is a hammer blow although it will probably look completely different again in the morning with FI around T+96.

[PubliusEnigma]

To be honest if the ECM is showing the colder outlook I tend to go with the model, Otherwise, my monies with the GFS when it shows the

colder solution, so for me this evening, the GFS is the one to go by.

[weather eater]

I think the problem now, as opposed to Christmas time, is that we are now chasing the cold, its the old story of fantastic synoptics showing up with far to much time for them to change to something less potent or disappear altogether. All standard model stuff, the small changes in the near time frame are making a big difference in the crucial time period. There's also the usual amount of premature back slapping going on and criticism of those members who urged caution or dared to suggest something else might occur, which given the model output at the time was fair comment, indeed given the uncertainties and timescales it would still be fair comment.

Also worth keeping in mind when talking about the NAO or AO etc is mistaking the word, projected, as cut and dried will happen, The phase NAO or AO is projected to go negative appears often in the model thread, projections of this kind seem as subject to change as any climate modelling.

To be honest if the ECM is showing the colder outlook I tend to go with the model, Otherwise, my monies with the GFS when it shows the

colder solution, so for me this evening, the GFS is the one to go by.

Sounds to me like you will follow whichever model has the coldest evolution, fair enough, but I foresee a fair amount of disappointment coming your way if you always follow that philosophy.

[Eugene]

I think the problem now, as opposed to Christmas time, is that we are now chasing the cold, its the old story of fantastic synoptics showing up with far to much time for them to change to something less potent or disappear altogether. All standard model stuff, the small changes in the near time frame are making a big difference in the crucial time period. There's also the usual amount of premature back slapping going on and criticism of those members who urged caution or dared to suggest something else might occur, which given the model output at the time was fair comment, indeed given the uncertainties and timescales it would still be fair comment.

Yeah we're chasing the cold i guess the snow risk tomorrow for southwestern UK is too far ahead for you and air frost tomorrow night

Yes the cold weather fans are such back slappers it's not like the mild crew are like that is it

No change from me, a change to colder conditions looks favourite if you go on the runs tonight overall instead of concentrating on single mild outliers

[mcweather]

The ECM ensembles will be interesting especially if the operational is a milder run as it was on yesterdays 12z.

[SP1986]

The NAO/AO is a good tool for following where the models might go though, I find they pretty much follow the NAO/AO trend. 3 days ago the NAO/AO trend was followed by a GFS runs showing fairly deep cold and an easterly, since the NAO/AO has shown a neutral turn which the ECM may have picked up on. I'm not 100% sure how it works but it might have some bearing on the models runs, not necessarily the actual outcome.

I suppose it helps if the NAO/AO settles on a stable pattern.

[weather eater]

Yeah we're chasing the cold i guess the snow risk tomorrow for southwestern UK is too far ahead for you and air frost tomorrow night

Yes the cold weather fans are such back slappers it's not like the mild crew are like that is it

No change from me, a change to colder conditions looks favourite if you go on the runs tonight overall instead of concentrating on single mild outliers

Dear oh dear, I think you well know I'm talking about a proper meaningful cold spell not just tomorrows rather marginal event.

And just who are the mild crew that slap each other on the back, the vast bulk of members on NW are coldies, as I am, just some are more objective than others.

Thirdly I never just base my thoughts on one run, never have. Why is it that some members simply cannot abide anybody suggesting that cold synoptics are not a foregone conclusion every time they show up, its tedious and boring.

[Cecil Hogmanay Melchett]

The NAO/AO is a good tool for following where the models might go though, I find they pretty much follow the NAO/AO trend. 3 days ago the NAO/AO trend was followed by a GFS runs showing fairly deep cold and an easterly, since the NAO/AO has shown a neutral turn which the ECM may have picked up on. I'm not 100% sure how it works but it might have some bearing on the models runs, not necessarily the actual outcome.

I suppose it helps if the NAO/AO settles on a stable pattern.

have you got a link to these nao/ao neutrel values ste?

[SP1986]

Aye, theyre neutral in the sense of averaged out if you know what I mean...

From this the AO is perhaps below average overall.

I'm not sure what a neutral NAO and slightly negative AO would produce in terms of pattern, although of course as we know these forecasts change alot and are as productive as the models themselves

[Cecil Hogmanay Melchett]

Aye, theyre neutral in the sense of averaged out if you know what I mean...

<snip>

thanks ste that nao plot is nowhere near as negative as yesterdays plot.

maybe explains ecm's refusal to bring anything of note.

Edited January 19, 2010 by shuggee

[Jason T]

Load up on de-icer. Its going to get very cold.

[winterof79]

Sorry for the off topic post,never used de-icer,just another excuse not to do anything physical like scrape it off.The vast cold pool will visit our shores before long.The models do not toy with things like this without credence.Nice to see them have to deal with something different these days,even if they struggle.One thing is for sure,next year when this occurs the data input from this year will help stop the massive sway in outputs

[Jason T]

Sorry for the off topic post,never used de-icer,just another excuse not to do anything physical like scrape it off.The vast cold pool will visit our shores before long.The models do not toy with things like this without credence.Nice to see them have to deal with something different these days,even if they struggle.One thing is for sure,next year when this occurs the data input from this year will help stop the massive sway in outputs

point taken. apologies.

[Skyhi]

with ice as stubborn as it was a week ago, you needed a chizel let alone elbow grease!!

[aspire27]

with ice as stubborn as it was a week ago, you needed a chizel let alone elbow grease!!

Please back to the model output.

[weather eater]

Sorry for the off topic post,never used de-icer,just another excuse not to do anything physical like scrape it off.The vast cold pool will visit our shores before long.The models do not toy with things like this without credence.Nice to see them have to deal with something different these days,even if they struggle.One thing is for sure,next year when this occurs the data input from this year will help stop the massive sway in outputs

Sorry chap I might have to rant at you a little as this is the third time I've said this to different members. The models do not use past data in their calculations; here is a link that explains how they work.

Edited January 19, 2010 by weather eater

[Skyhi]

Please back to the model output.

apologies, new here and still learning..

[shotski]

ECM Looks like it could bring in a south westerly at +192 ? GFS Looks good for cold ? ECM performed best last time round.

Hope i'm wrong.

[Ben_Cambs]

De Bilt ECM ensembles now out, not too bad seeing that ECM 12z threw a wobble. Dont forget, around the New Year it predicted a milder breakdown and look what happened.

ECM Ensembles: http://www.knmi.nl/e...M_06260_NWT.png

Edited January 19, 2010 by Snowman0697

[winterof79]

Point taken Weather Eater.cheers.

[snowmadchrisuk]

The ECM ensembles show that the Operational was about the mildest run until deep into FI . Now on to the 18z .