Model Output Discussion

[snowmadchrisuk]

Thanks chris

I think we really are in for a cold spell, not sure of the magnitude or duration yet but from past memory, all the good cold spells start in a similar way with hp building through the uk and heading towards scandi, and we will have plenty of very cold air to tap into when the time comes...lets just sit back and watch the drama unfold

Exactly , forget all the model drama , and the winter is over comments , let's just sit back and let the high do it's work :ph34r:

[Cloud 10]

The gfs parallel run comes up trumps yet again.

[snowmadchrisuk]

The gfs parallel run comes up trumps yet again.

Shame it is after +240 but nice to see all the same. I am going for a Frost here in Leicestershire Friday morning taking at least 2 degrees off this Morning's GFS temps for Friday. Light Winds , Clear Skys , Early Night's. It's all there .

[azores92]

what we seem to be looking at imho, is a fairly mild/changeable regime until the latter part of next week, when temperatures may start to tumble thanks to the introduction of high pressure moving up from the south, and the longer it sticks round, the more likely the chance of cold coming in from the continent is. who cares whether we get faux cold or not, or whether the majority of the cold goes to greece. i believe you should be thankful for what you get, a couple of degrees above freezing, with clear blue skies and proper frosts is wintry by my standards, and thats a brilliant place to start. anything away from wretched atlantic weather and 12/3 degrees by day, and exacerbating the shortness of the days sucks.

definitely welcoming this seasonal anticyclonic weather with open arms for the time being, let the north/east of us get cold, and then pull out the plug when we reach christmas and beyond

Edited December 6, 2009 by azores92

[weather eater]

I hear what people are saying but at the end of the day this is a model discussion thread, there is only a chance of cold in the ECM maybe bits of cold in GFS beyond 240Z, but this isnt supported by the ensembles atm.

So from this apart from whey out in FI with little support, there isnt anything in the models to get too excited about, however there was on Thursday and Friday.

It's not doom and gloom, but lets not pretend that a cold and snow are on the horizon yet.

Can’t say I'm worried about cold and snow, firstly I'd like the rain to stop. As for the ensembles, any read through the model thread on any day of the year demonstrates that these chop and change as often as the operational runs, whatever they show today is like to be something different tomorrow and the so on. They do not stand alone and need to be viewed as part of a bigger picture, ensembles, operationals, teleconnections, etc; even then an open mind should be kept.

[Shunter]

Interesting european ensembles for gfs 6z...

The operational run is a cold outlier for Paris and a warm outlier for Reyjavic. Moscow and Athens both show a warming trend but Helsinki and Oslo appear well clustered.

This combined would seem to indicate a scandi high pressure cell becoming the overiding factor in the next week or so.

On to the 12z's...

[johnholmes]

further to my post No 420 about 1020 this morning-

the trough over America I was commenting on is indeed the one, around the dates I gave, to set up the change in type, changing the major wave length pattern across the area of the northern hemisphere of particular relevance to the UK.

It creates a wave length downwind of its own trough of a twin upper trough with upper high in between, tending towards the 'Omega' pattern type. The distance between the two troughs is about 70 degrees longitude which is just about that which was usually looked upon, pre model days, as likely to be slow to change or move.

[SMU]

I hear what people are saying but at the end of the day this is a model discussion thread, there is only a chance of cold in the ECM maybe bits of cold in GFS beyond 240Z, but this isnt supported by the ensembles atm.

So from this apart from whey out in FI with little support, there isnt anything in the models to get too excited about, however there was on Thursday and Friday.

It's not doom and gloom, but lets not pretend that a cold and snow are on the horizon yet.

ECM ensembles are certainly cold......

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

S

[kold weather]

I suspect the ensembles are not really a worry, they aren't as good thats for sure but I'd bet they probably don't have a good enough resolution to nail that shortwave, this wil lbe a case of the ensembles following the op runs, the ECM ensembles show that point very nicely I think!

Anyway, I see nothing wrong with the 06z, evolution doesn't suggest the beast from the east as there may be a little too much energy...however we shall see.

Looks to me like the high may be fairly cloudy at first looking at the GFS...but I never put much stock into these forecast till closer in. Plus, the longer the high sticks close by the colder those temps will become.

Edited December 6, 2009 by kold weather

[Cecil Hogmanay Melchett]

I hear what people are saying but at the end of the day this is a model discussion thread, there is only a chance of cold in the ECM maybe bits of cold in GFS beyond 240Z, but this isnt supported by the ensembles atm.

So from this apart from whey out in FI with little support, there isnt anything in the models to get too excited about, however there was on Thursday and Friday.

It's not doom and gloom, but lets not pretend that a cold and snow are on the horizon yet.

To be fair thats cherry picking.

Have you looked at ukmo T144 and the ecm sensembles ?Hmmm,the poster,sorry antagonist

is no longer online to answer to my post.

Edited December 6, 2009 by happy days

[492]

further to my post No 420 about 1020 this morning-

the trough over America I was commenting on is indeed the one, around the dates I gave, to set up the change in type, changing the major wave length pattern across the area of the northern hemisphere of particular relevance to the UK.

It creates a wave length downwind of its own trough of a twin upper trough with upper high in between, tending towards the 'Omega' pattern type. The distance between the two troughs is about 70 degrees longitude which is just about that which was usually looked upon, pre model days, as likely to be slow to change or move.

I understand that if the wavelength is of sufficient length retrogression of the longwave pattern will occur. Is 70 degrees longitude the length at which this can start to occur ?.

[johnholmes]

it does sometimes occur but not always, one to watch, 70+ is about the length for not moving much but retrogression can and sometimes does occur

[kold weather]

One more thing to add, I wouldn't be too upset if we do not get the cold blast directly into our location because as long as it reaches central Europe and as long as we can keep the high nearby with a slight continental airstream then we will get very cold conditions one way or the other.

Indeed a SE drift like that would probably be colder overall then a pure easterly flow at this time of year due to the north Sea.

[osmposm]

To be fair thats cherry picking.

Have you looked at ukmo T144 and the ecm ensembles.....

Despite my length of time as member here, I'm still rather ignorant about some of the models and where to find them.

I think I've got the GFS sorted, but could somebody tell me where to find the two above....especially this longer UKMO which I always thought only went out to +120 hours?

Thanks, Ossie

[Frosty.]

further to my post No 420 about 1020 this morning-

the trough over America I was commenting on is indeed the one, around the dates I gave, to set up the change in type, changing the major wave length pattern across the area of the northern hemisphere of particular relevance to the UK.

It creates a wave length downwind of its own trough of a twin upper trough with upper high in between, tending towards the 'Omega' pattern type. The distance between the two troughs is about 70 degrees longitude which is just about that which was usually looked upon, pre model days, as likely to be slow to change or move.

I like the sound of an Omega pattern, I also like the latest meto update which is going with a cold SE'ly to E'ly flow with frost/fog but they don't think it will last too long before milder air wins, hopefully that will change in the coming days and we finally get a cold wintry spell worth remembering!

[Cecil Hogmanay Melchett]

Despite my length of time as member here, I'm still rather ignorant about some of the models and where to find them.

I think I've got the GFS sorted, but could somebody tell me where to find the two above....especially this longer UKMO which I always thought only went out to +120 hours?

Thanks, Ossie

If you go to wetterzentrale and click on ukmo it goes out to 144hrs.

Hmm just looked at GEM,and that didn't inspire me! Anyway,i still say tomorrow before this low pressure

around Iceland will be handled so i guess verything is up in the air.

meto outlook 15 dayer talks of mild south westerly flow at the end of the period! Sinking HP into Europe

i would imagine,and i dont like those breakdowns,they result in an extended period of zonality from my

experience.

[osmposm]

If you go to wetterzentrale and click on ukmo it goes out to 144hrs.....

Ah yes, thank you, it is there ( http://www.wetterzentrale.de/topkarten/fsukmeur.html ). And yet the Netweather version only goes to +120...

[kold weather]

Yeah Happy Days, I think they probably go with a very similar evolution to the 06z GFS. Still I'm not sure the models will have a good grip beyond 180hrs yet alone quite a bit after that so plenty of things could happen yet that the models aren't quite keying into.

As for the GEM, its not as bad as it co0uld be, I'd have thought we would stil lget a decent drift in from Europe and that'd be cold still.

Models moved closer to a cold spell with HP over the top of us, but further away from a big easterly IMO.

[reef]

A new thread here:

This one will be closed in a few minutes.

Thanks :lol:

[The Eagle]

Whilst individual models diverge around 120 - 144hrs to different outcomes I think overall we are very close. Just not quite there yet. We need further weakening of the stubborn ridge from the South after 120hrs and an undercutting LP to get things going. Hopefully the Jet Stream will begin to play ball. It is going South but does not have the punch yet to get a shortwave into the Med from the Atlantic.

Edited December 6, 2009 by The Eagle