Model Output Discussion:

[kold weather]

Carry on here, remember keep respectful of each others views and STAY ON TOPIC, thanks!

[MAF]

i am reposting this as there was no reply in the previous thread :lol:

so how far out are you guys placing FI?? seems to me that not much has changed in the "uncertainty" stakes.

(there are still a lot of people saying "wait until the weekend to verify" )

yet FI is been talked about as been a lot further out than it was a few days ago

[NorthNorfolkWeather]

i am reposting this as there was no reply in the previous thread :lol:

so how far out are you guys placing FI?? seems to me that not much has changed in the "uncertainty" stakes.

(there are still a lot of people saying "wait until the weekend to verify" )

yet FI is been talked about as been a lot further out than it was a few days ago

My comment would be that FI is somewhere between T120 and T144 as the models are all pretty much in agreement up to there. During this last week I'd have said that at one point FI was between T48 and T60

[Tristrame]

i am reposting this as there was no reply in the previous thread :lol:

so how far out are you guys placing FI?? seems to me that not much has changed in the "uncertainty" stakes.

(there are still a lot of people saying "wait until the weekend to verify" )

yet FI is been talked about as been a lot further out than it was a few days ago

To the seasoned model reader-FI varies depending on how accurate the models have been and how many flip flops they have had in recent weeks etc.

To me hard FI is always post 120hrs but if things are really uncertain then it's post 96hrs.

Outside of that,it's a case of looking for trends and agreement.

Another point to consider is that even avid model watchers and high post count users here can get caught out by believing a trend that makes it all the way from far FI into sub 120 only to be snatched away again by the models or more accurately by mother nature herself.

The most potent example of this was in mid january 2007 when people here and else where were getting all excited about snowmageddon charts only for all models to flip flop inside a week and for it not to happen.

So while looking at models and imagining what might happen is enjoyable-do bear in mind that they can flip flop and this has been all too common in recent months.

You will also notice that peoples definitions of FI change as they get more confident but a flip flop is still always possible so it's safer to add caution to everything you say and then theres no major disappointment

[cheeky_monkey]

dont know if this is relevant..but could help somewhat..i have notice of the last 2 winters that cold spells in the uk seem to correspond with mild spells in western canada and the prairies...when it was cold over new year 08/09 and earl Feb 09 it was very mild in these regions...just b4 xmas and the early part of Jan it was mild here in fact it was well above zero when it should be -10c..and again they are predicting a sharp warming with temps above freezing at the same time it is showing the cold spell arriving in the uk...coincidence?

[nick sussex]

dont know if this is relevant..but could help somewhat..i have notice of the last 2 winters that cold spells in the uk seem to correspond with mild spells in western canada and the prairies...when it was cold over new year 08/09 and earl Feb 09 it was very mild in these regions...just b4 xmas and the early part of Jan it was mild here in fact it was well above zero when it should be -10c..and again they are predicting a sharp warming with temps above freezing at the same time it is showing the cold spell arriving in the uk...coincidence?

Yes you're right its to do with the ridge/trough placement, often if theres an amplified pattern across the USA and Canada which helps with getting colder set ups over Europe you'll find a ridge over the west with troughing over the east, at the moment the ridge is keeping low pressure from moving far enough east into western Canada and so its hard for the cold to tuck into that region, over in the east troughing is allowing cold air from the north into that region.

I see Whistler is still getting some snow from time to time but the winds are generally west to sw as low pressure seems to be heading ne skirting with that area instead of being able to clear eastwards.Hopefully things will be okay for the Olympics although lower down its looking a bit marginal.

If the ridge can either move east a little or further west then that might just help, the former might just allow some colder air in if the lows can get a little further east, or the latter will bring some cooler drier conditions with a se flow from the interior.

[cooling climate]

Well I for one am really looking forward to what should be a cracking afternoon

and evening model outputs. Similar to or better than this mornings outputs will

do nicely.

Not asking much is it.

[cheeky_monkey]

Yes you're right its to do with the ridge/trough placement, often if theres an amplified pattern across the USA and Canada you'll find a ridge over the west with troughing over the east, at the moment the ridge is keeping low pressure from moving far enough east into western Canada and so its hard for the cold to tuck into that region, over in the east troughing is allowing cold air from the north into that region.

I see Whistler is still getting some snow from time to time but the winds are generally west to sw as low pressure seems to be heading ne skirting with that area instead of being able to clear eastwards.Hopefully things will be okay for the Olympics although lower down its looking a bit marginal.

If the ridge can either move east a little or further west then that might just help, the former might just allow some colder air in if the lows can get a little further east, or the latter will bring some cooler drier conditions with a se flow from the interior.

Thanks thats very interesting..as a side issue here environment Canada are projecting the warm spell to be somewhat short lived 3-5 days(although they have been predicting this warm up for a while now) before it becomes colder again...dont know what kind of bearing that will have on the UK??

[karyo]

dont know if this is relevant..but could help somewhat..i have notice of the last 2 winters that cold spells in the uk seem to correspond with mild spells in western canada and the prairies...when it was cold over new year 08/09 and earl Feb 09 it was very mild in these regions...just b4 xmas and the early part of Jan it was mild here in fact it was well above zero when it should be -10c..and again they are predicting a sharp warming with temps above freezing at the same time it is showing the cold spell arriving in the uk...coincidence?

The same applies with Greece! When we have cold weather here, it is mild there and vice versa! My mother said it's been an uneventful winter so far in Greece with only short lived snow spells!

It was similar last year too!

Karyo

[nick sussex]

Well I for one am really looking forward to what should be a cracking afternoon

and evening model outputs. Similar to or better than this mornings outputs will

do nicely.

Not asking much is it.

A positive start from one of the lesser models that was halfhearted this morning, the GME clears the shortwave se'wards without leaving any residual energy behind which is a good sign.

[Blizzard_of_Oz]

A positive start from one of the lesser models that was halfhearted this morning, the GME clears the shortwave se'wards without leaving any residual energy behind which is a good sign.

Keep them coming please, I have several cigarettes burning in the ash tray a.t.m.

[nick sussex]

Keep them coming please, I have several cigarettes burning in the ash tray a.t.m.

OK the GME upto 108hrs is a big upgrade from this morning and moves towards the ECM/GFS/UKMO. The GFS upto 48hrs looks fine, shortwave clears se. The GFS upto 72hrs is good similar to the 06hrs run so far, now here comes the shortwave sinking south out of Scandi.

[kold weather]

Well I for one am really looking forward to what should be a cracking afternoon

and evening model outputs. Similar to or better than this mornings outputs will

do nicely.

Not asking much is it.

Yeah, to be honest the evolution looks likely to evolve into cold of some sort its just a matter of whether we get the full works or a light meal instead really, but the models are quite amazingly different from those of just 3 days ago thats for sure!

Yep Nick, airflow from Europe by 84hrs for the east of England from the SE.

[cooling climate]

OK the GME upto 108hrs is a big upgrade from this morning and moves towards the ECM/GFS/UKMO. The GFS upto 48hrs looks fine, shortwave clears se.

Great start to the afternoon's preceedings, lets hope the 12z follows the 06z and we get the

cold and the snow. If it does then hopefully the UKMO and the ECM will follow.

[Eugene]

Yes yesterday FI was around T+72 hrs but with another almost identical GFS 12Z run around that mark it has increased to around T+120 hrs onwards now.

[kold weather]

Looks like the easterly starts to work its way in by Sunday, probably see temps come in a little below average and I'd imagine temps will only reduce from then onwards if we get any sort of decent easterly flow.

Also looks like the evolution is pretty solid now, the most uncertain part now is whether the cold pool over Scandinavia can work its way far enough west to really bring home the much colder stuff.

[nick sussex]

Great start to the afternoon's preceedings, lets hope the 12z follows the 06z and we get the

cold and the snow. If it does then hopefully the UKMO and the ECM will follow.

Yes its looking very good, IMO its all systems go! warp drive initialized! Very close now folks to being able to get really excited but we need to see the ECM and UKMO remain consistent.

[Optimus Prime]

Looks like light falls of snow Monday night into Tuesday into the East and South East maybe.

[Harsh Climate]

http://cirrus.netweather.tv/gfsimages/gfs.20100204/12/96/h850t850eu.png Text book stuff and within 96h! .

Hmmm how come I dont see any more winters over, 18C this friday posts??

Like I said the other day during those awfull runs, all the signs are there for much colder easterly type weather around 9/10 februrary

[k19]

Looking like that cold air might sweep across the uk by mid next week according to GFS and UKMO a good call by the meto.

Curiously, what set up caused the 23rd december cold spell for the north west?

[kold weather]

Pretty good evolution out to 120hrs, as OP has just said instablity starts to increase overnight into Tuesday as well as the upper low feature developing to our east which will hopefully drag in the proper deep cold stuff. Anyway will be interesting to see where this run ends up going, worth watching to see if the jet undercuts the upper high over Iceland.

[PB22]

UKMO 12Z looking good so far as well:

[nick sussex]

Good news from the UKMO, upto 96hrs very similar to the GFS at that timeframe.

[Bartlett Low]

Looking like that cold air might sweep across the uk by mid next week according to GFS and UKMO a good call by the meto.

Curiously, what set up caused the 23rd december cold spell for the north west?

That was originally a North-Easterly which turned Northerly and then finally North Westerly. Irish sea snow streamers.

[Harsh Climate]

UKMO 12Z looking good so far as well:

http://www.meteociel...96-21.GIF?04-17

Sure is. And this time theses a deep cold pool just to the east