Winter Model Output Discussion - 06Z 09/02/13 onwards

[Barry12]

'dry' doesn't mean no snow...

December 2010 was a dry month.

[igloo]

not to many comments on this evenings GFS run its very grim viewing lets hope its a mild outlier if its not we might as well close the book for this season i was hoping for one last hurra.not this muck

[Severe Siberian icy blast]

not to many comments on this evenings GFS run its very grim viewing lets hope its a mild outlier if its not we might as well close the book for this season i was hoping for one last hurra.not this muck

Agreed the gfs looks as flat as a pancake and as usuall rides everything in from the west . A lovely southwesterly wind at t160

[Eskimo]

'dry' doesn't mean no snow...

December 2010 was a dry month.

He means the air is dry to the low dew points....I think.

[Tim Bland]

Bin GFS 12z IMO. It's got a 940mb low in the Atlantic. Very unlikely to occur. It's a GFS classic of over done depressions having big knock on effects down the line

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=174&mode=0

Edited February 12, 2013 by Tim Bland

[Sussex snowstorm]

Ukmo is not going nothing like the ECM more like the flatten gfs 12z

[Severe Siberian icy blast]

Bin GFS 12z IMO. It's got a 940mb low in the Atlantic. Very unlikely to occur

Agreed , as usual it gives a major Atlantic storm stuck out to see, with something that powerful it would come hurdling over the Atlantic and smash straight into the uk.

The gfs continuously does this and not even worth a second look in fi half the time.

Unless its showing snow of course ! (Joke)

[Backtrack]

Bin GFS 12z IMO. It's got a 940mb low in the Atlantic. Very unlikely to occur. It's a GFS classic of over done depressions having big knock on effects down the line

http://www.meteociel...&ech=174&mode=0

But if we look at the 06z, we see the same low within the same time frame? It's just deepened on the 12z, very possible in my eyes?

(06z left vs 12z right)

Edited February 12, 2013 by Backtrack

[igloo]

Bin GFS 12z IMO. It's got a 940mb low in the Atlantic. Very unlikely to occur. It's a GFS classic of over done depressions having big knock on effects down the line

http://www.meteociel...&ech=174&mode=0

yes it does look unlikely for a 940mb low for late feb but you never know but the UKMO doesnt look great either

[SMU]

If people refer to my post earlier it shows clearly where the GFS goes wrong with its easterly bias.

the GFS solution has credibility in as much as it can happen so we cannot dismiss it totally, however that goes to show that its poor as a forecasting tool because it rarely sees the wood from the trees.

change of GFS varification at 168 ~ 20%

s

[Zenarcher]

A deep Atlantic low can still happen in February we don't have to go far back to see how here is February 2011 that had a 935mb low in the Atlantic,

Also I would add I'm following the UKMO and ECM at the moment as the GFS for the past few days has got a few things wrong in the short time frame and moved over to what the likes of the ECM is saying.

Edited February 12, 2013 by weathermaster

[Cecil Hogmanay Melchett]

less said about gfs / ukmo 12z the better,at least they both look dry,after a dreadful winter here i'll taker dry with open arms.

[rory o gorman]

the gfs 12z takes its time rising heights again. I agree with steve and feel 170-200 hr time frame for sustained blocking .

[doggy123]

Ha ha love how people say bin the model if it does not show want they want to see!

[Rollo]

It is beginning to appear in my opinion the this has been a winter if "Tomorrow never comes",time and again things have looked rosy for cold and other than

the spell in January we have been left wanting, I am not sure where the UKMO is heading bot now we have to cling to perhaps a forlorn hope that the ECMF

follows this mornings path,chart fatigue has definately set in.

[bradymk]

Ha ha love how people say bin the model if it does not show want they want to see!

not necessarily, it is well known that the GFS has a eastward bias and it does tend to over-do atlantic lows just like ECM does tend to over-do easterlies at times. http://www.emc.ncep..../html/acz6.html Day 6 statistics showing ECM and UKMO dominating. Yes GFS does sometimes do better than the others as it is still one of the "top 3" weather forecasting models but ECM has always been consistently better at day 6, especially this winter. So no its not just because its not what we want to see, ECM statistically dominates GFS more times than not and UKMO also seem to prefer ECM and its model over GFS 9 times out of 10. Edited February 12, 2013 by bradythemole

[summer blizzard]

Personally i think the GFS12z is a pretty good run.

Rather than being a trend towards a cold outbreak the clear trend in recent days has been for higher than average pressure over the UK with any real cold being well out.

I suspect many people are looking with rose tinted glasses and whilst it may well evolve into a cold spell i for one am looking forward towards sunshine and dryness.

[Buzzit]

I was looking at the Northern hemisphere charts on the latest 12z GFS - what a load of cobblers - there is low pressure in situ off the coast of Canada for almost the entire 360 hours of the run - ridiculous - I give the GFS operational no creedence past +96 at the moment - pants. And no - it has nothing to do with what weather I want - the fact that the low pressure is sitting there makes the run utterly binnable

In fact : It is almost like the GFS said to itself "I've got all this weak low pressure sitting off Canada and it's not moving anywhere.. sigh.. I know what to do I'll spin up a monster low out of nothing to drive it all away, but hang on, I really like low pressure there so what I will do is make sure another low pressure system reaches the current one before I let the first one go - yeah that will work - I saw it once at the fun fair on the Ghost Train ride"

Edited February 12, 2013 by Buzzit

[Summer Sun]

So we are back to binning runs just because it aint showing cold, I'm sorry but you can't just "bin" a run if its not showing what you want it to. At the end of the day winter is drawing to a cold so you can expect to see some milder runs appearing now

GFS is following what the met office have in there outlooks

Sunday 17 Feb 2013 to Tuesday 26 Feb 2013

Predominantly dry weather is likely to prevail over the UK through much of this period, although sunshine amounts will vary from day to day. East and southeast Britain may also encounter a few wintry showers on occasion

To get the mostly dry weather high pressure will need to build which it does

It also says

northern and northwestern parts of the UK may become somewhat more unsettled with rain or sleet at times

Once again GFS shows this

With an easterly setting up the east could see snow from time to time

East and southeast Britain may also encounter a few wintry showers on occasion

All in all GFS seems to be following a similar path to what the met office's outlooks suggest

Edited February 12, 2013 by Gavin.

[Weather-history]

At the end of the day winter is drawing to a cold so you can expect to see some milder runs appearing

Er...that has nothing to do with it. If the ensembles go for milder runs they will regardless what stage the season is, beginning, middle or end. That is true of any season.

Edited February 12, 2013 by Weather-history

[Blackjack10]

So we are back to binning runs just because it aint showing cold, I'm sorry but you can't just "bin" a run if its not showing what you want it to. At the end of the day winter is drawing to a cold so you can expect to see some milder runs appearing now

GFS is following what the met office have in there outlooks

Completely agree. I have followed this forum for several winters now, and whilst the number of hugely useful posts and knowledgable members has increased, so have the the pointless comments. Mods, will probably delete this, but I'm tuning out for the rest of the winter, as I can just see the amount of model complaining/binning going through the roof in these final few weeks, and sadly this needs to go. Hopefully when I return, the ratio of useful posts to 'I'm binning this chart because it's not showing the next ice age' has increased!

[Tim Bland]

I personally don't buy runs that show hurricanes in the Atlantic in feb. not I

Possible but unlikely. What's more key tho is what the ensembles look like later. Might not be a temperature outlier but I don't expect many of the ensembles to have 940mb low in the Atlantic. If this low is weaker it has large implications. End of GFS run is great for cold and snow but I dont buy the evolution for the above reasons. I'm not disgusting it because of lack of snow as I would gladly bank the whole run for what t shows in FI

Re the above post... The skill of forecasting it to look at the NWP and many other factors / signals and work out what looks right and which doesn't. It frustrates me when people discard models for no other reason than it not showing what they want. All the "bin it" posts this afternoon have given valid reasons...See post below from snow k who is a prime example of a skilled forecaster who knows when a run looks wrong. Steve m is another good example .. when he is following his head and not his heart

Edited February 12, 2013 by Tim Bland

[snowking]

And here in lies the issues with clinging on to every operational run

What is worth bearing in mind is that the ensemble mean signal for some days now has been for a negative NAO signature with HP close to the N of the UK

For as long as this signal occurs, operational runs showing something other than HP over and to the N of the UK can effectively be binned.

However, that's assuming that signal remains the same. As I posted last night, we are looking at a situation inside 72 hours that could alter the fate of this significantly, and so operational modelling will continue to flip-flop.

SK

[Dave Kightley]

Not much different from the Ukmo and GFS then the 00z. Further east with the high and the signal remains for the block to be heading towards Greenland for some runs now. Low pressure can easy be over done and be the high maybe further west like the 00z. Either way high pressure is still there nonetheless. Doesn't matter where it is. It where it ends up I care about and that Greenland.

[Isabellesnanny]

Completely agree. I have followed this forum for several winters now, and whilst the number of hugely useful posts and knowledgable members has increased, so have the the pointless comments. Mods, will probably delete this, but I'm tuning out for the rest of the winter, as I can just see the amount of model complaining/binning going through the roof in these final few weeks, and sadly this needs to go. Hopefully when I return, the ratio of useful posts to 'I'm binning this chart because it's not showing the next ice age' has increased!

I have to agree - as a newbie it is very difficult to actually follow the models and peoples perceptions of them because dependant on people's bias they will find cold or mild whichever is their preference in that model - in fact as soon as you see the name of a poster you can pretty much work out what their post will say It would be a lot easier for those of us who are new on the boards to get a handle on the whole thing if the emotion was taken out of some of the posts and an unbiased opinion given.