Model Output Discussion - 26Th Dec 21:25-->

[arnott]

exactly-you cant say widespread snow when its just for the south! consider and give input for the whole country surely??

[Dingwantssnow]

As a newbie this is getting ridiculous, reading the posts regarding this run its a disaster, improvement, upgrade, downgrade, etc etc etc. I know its ll about opinions but come on. Is there somewhere that summarises each models output, rationally without any regional bias.

I 2nd that. Far to Much IMBY stuff going on. Also when people are mentioning northern parts of the country what is really ment is southern scotland...which is another country all together.

It would probably mean alot of work for some one . But couldnt one of the more senior on here maybe post a summary in a sticket after the run Like ralphie suggests?

[nick sussex]

As you say a big if not huge improvement on UKMO, but just to keep our feet on terra firma the GFS throws the milder air even farther north on this run, with snow now pushing right up to the Borders and down here in the far south seeing temps on a par with yours in SW France. Would really love to see the GFS be wrong, but we've been here many times before and history has shown us when you want it to be wrong it has an uncanny knack of kicking you square in the teeth.

IMO now the ukmo has gone with the ecm ensemble trend then it's game up for the gfs, have you seen it's latest verification over the last few days? nosedived! i fully expect the ecm to prog the same pattern as the ukmo this evening and wouldn't be surprised to see it show an easterly in it's later output.

[West is Best]

Err thats the low that was coming up from the south west then swings back south west then south east. You'll also be compairing the 12 oz to 06 oz of the other models unless the ecm has sneaked out early. UKMo is pretty close at T96 so not a large differance as you make out. Haven't got the t120 yet.

Anyway West howz it hanging you ain't around much these days.

It's such a bizarre pattern though, no? The low splitting, the first main one is already off the coast of East Anglia at T96, and then a new depression retrogressing back into the Atlantic? Maybe these are just extraordinary synoptics.

It's a fantastic GFS run but I really don't have confidence in it at the moment. For me UKMO Fax, ECMWF, GEM, UKMO main focus for me at the moment.

I'm doing ok. Had a pretty rough tail end of 2009, to put it mildly, but still here.

Edited December 27, 2009 by West is Best

[MKN]

Is there somewhere to view the gfs latest verification?

[Yeti]

As you say a big if not huge improvement on UKMO, but just to keep our feet on terra firma the GFS throws the milder air even farther north on this run, with snow now pushing right up to the Borders while down here in the far south temps are on a par with yours in SW France. Would really love to see the GFS be wrong, but we've been here many times before and history has shown us when you want it to be wrong it has an uncanny knack of kicking you square in the teeth.

I'm not at all convinced this is true. Normally it is the ECM that is the kick in the teeth and refuses to back down whilst the others follow and the GFS carries on its delusions. When the GFS is against the ECM, UKMO and GEM I would never, ever place money on it being true.

[chionomaniac]

As you say a big if not huge improvement on UKMO, but just to keep our feet on terra firma the GFS throws the milder air even farther north on this run, with snow now pushing right up to the Borders while down here in the far south temps are on a par with yours in SW France. Would really love to see the GFS be wrong, but we've been here many times before and history has shown us when you want it to be wrong it has an uncanny knack of kicking you square in the teeth.

Interestingly Worzel, the GFS is showing similar characteristics that it showed prior to the previous vortex split earlier in the month. With another one modeled for around 6 days time we are seeing the GFS struggling with the intermediate synoptics. I commented earlier in the month for the previous split that the GFS got the modeling of the split right but not so the intermediate projections. With a split in the vortex it is akin to knowing an answer before we know how to get there. For instance if the answer is 10 this can be arrived at by either adding 5+5 or 7+3 but the answer is still 10. The time frame around T+200 the GFS looks like it is getting to the solution that the underlying teleconnections are suggesting but perhaps modeling the Scandinavian ridge too far east. It seems to me that it is the bit in between where surface synoptics are differing.

[Cecil Hogmanay Melchett]

If i was in the midlands i'd be warning family members etc of whats coming.

Some places could see silly ammounts of snow,Birmingham etc.

[MR EXTREMES]

GME 108h as well Steve :cold:

thats the type of chart which intrests me this in my eyes is classic.

and i can understand why most get so excited by marginal battle ground events this is my point thats not good because it could swing in the oposite direction of what your wishing for.

ofcoarse dry clear cold air might not be what people are looking for but it does not matter as long as deep cold pooling is present over europe ie not just to our east i can remember when i was a child looking at scandi temps and temps over into france right down to paris.

because enriched cold was there so every direction apart from west or sw was a source of cold.

but the gme chart is a thing of beauty.

ukmo is a little better aswell lets hope the ecm brings on the mother of all cold lol:drinks:

[snowlover2009]

ukmo is a huge improvement as is gfs. thanks god for this lol.

who would be in the firing line if ukmo came off?

would i still be at risk?

[Cecil Hogmanay Melchett]

ukmo is a huge improvement as is gfs. thanks god for this lol.

who would be in the firing line if ukmo came off?

would i still be at risk?

not really,its all further south from us on ukmo.

[cooling climate]

The GFS out to t144 is nonsense. It is completely on its own out to t72 and the way that

low just hangs off the Danish coast is highly in-probable but by doing so it keeps all the

really cold air further north.

What this means is that instead of a strong east n/easterly airflow we are left in a slack airflow,

this I think is highly in-probable and has no backing from the latest UKMO run and I am certain

it will have no support from the ECM model.

The rest of the run is epic but I think it would be even more so as the very cold and wintry weather

would be set in a lot sooner than the GFS 12z shows.

[Nick L]

If i was in the midlands i'd be warning family members etc of whats coming.

Some places could see silly ammounts of snow,Birmingham etc.

:blush:

I am surprised at how little is being made of this in here, I think most are concentrating on the long-term prospects, which will be stressful with the way the models are at the moment!

I mean, look at this from the UKMO 12z:

http://www.meteociel.fr/modeles/ukmo2.php?nh=&carte=1594&ech=60

That would bring quite a lot of snow for Wales and the west Midlands, in a line say from Birmingham northwards.

[cyclonic happiness]

If i was in the midlands i'd be warning family members etc of whats coming.

Some places could see silly ammounts of snow,Birmingham etc.

:blush:

To be honest we could do with a bit of snow as we've had next to none so far, as regards to the 12z, what a weird weird looking run, I don't think i've ever seen anything like that even in FI???

I still think the GFS has got a hang over after all it's christmas parties but think that it will start to fall into line over the bext couple of days.

But, If the synoptics it shows in FI do come to pass, we could be in for one of the most extraordinary winter that we've seen.

[snowmadchrisuk]

Is there somewhere to view the gfs latest verification?

Yes GFS last for boxing day . http://www.emc.ncep.noaa.gov/gmb/STATS/html/graphics/acz6.gif

[Guest North Sea Snow Convection]

Back from shopping and nice to see a really good UKMO! Those really cold temps to the north east have taken another step closer. We still need the GFS to fall in line, but assuming that the ECM is consistent again tonight, then surely it must fall in line afterwards.

[NorthNorfolkWeather]

The UKMO 12Z run is incredible up to T120, a fantastic evolution of an Omega block with considerable WAA to our northwest, then the T144 just looks wrong from this evolution to T120 to a final T144 which I don't "get"

Edited December 27, 2009 by NorthNorfolkWeather

[rmc1987]

UKMO saves the day yet again for the Midlands with -5 maintained tonight and the warm front not getting North of London.

LOL....typical for here really! ;-(

[john mac]

Greao see the UKmo coming up with the goods, IMO the gfs has taken a small step towards the euro's as long as the ECM comes up trumps the we will see the GFS moving into line with the other models :blush:

[aspire27]

Is it possible for the ECM and GFS to be different all the way? If so, what forecast can be given, or is that a stupid question?

Do they have to be roughly the same?

[kent]

LOL....typical for here really! ;-(

Saved the day? Havent seen a snowflake here on the south coast in poole and looks like another massive disappointment. It seems no matter how peoplke say this is outstanding, incredible and stunning etc it just keeps on raining here.

[nick sussex]

Yes I have seen the recent verification stats and GEM hasn't done half bad of late either has it...

I also think you are right regarding ECM backing the latest UKMO solution later this evening, but despite all of this I will still feel a good deal more relaxed when GFS jumps off this milder and milder merry-go-round. It might be incorrect, but it's still un-nerving nonetheless.

The GEM just out is very good aswell and looks similar to the UKMO at 144hrs, so for the moment the gfs is isolated, i still think we'll see further changes in the output but its key that we can get some agreement at T-96hrs, as i was saying the other day small differences at this timeframe can cause a big difference later given the current set up.

[snowmadchrisuk]

Is it possible for the ECM and GFS to be different all the way? If so, what forecast can be given, or is that a stupid question?

Do they have to be roughly the same?

Usually the different models should all be about the same out to 3 days out. After this they all have there different ideas and when we start to see the models trending to the same sort of setup we have more confidence in an outcome. In the Case of the Snow Tuesday/Wednesday the argument is how far North the warm sector of the low get's with all models showing the mild air not getting North of London except the GFS which is still pushing the mild air up into Northern England. Maybe when you say your hering about upgrades downgrades at the same time it is because people are talking about different models as the evening run's all come out around the same time.

[whitestuff]

If i was in the midlands i'd be warning family members etc of whats coming.

Some places could see silly ammounts of snow,Birmingham etc.

:blush:

I just looked at the snow risk maps and can't see this. Can you tell me where it shows we in brum might at last get some decent snow

[Guest North Sea Snow Convection]

Worth noting on the UKMO 12z that the greenland High is more east based than previously towards NW Iceland again and that is going to help the cold air advection from the north east get towards the BI on a more south westerly track rather than the westerly track that was indicated yesterday that meant that the cold air was taken too far north.

That is a very good sign imo - and hopefully if the ECM shows similar to that timeframe then the evolution could be very interesting in terms of an easterly that may be indicated. It will alter the approach of the further lows suggested by the models after t144 and mean that a proper undercut into europe is made much more likely and possible and that non marginal snow events should occur .

Edited December 27, 2009 by North Sea Snow Convection