Winter Model Discussion - The Hunt For Cold - 12th Dec

[Ladyofthestorm]

Looks like game over for a cold spell this side of Christmas, the NAO MRF has gone positive. I hope no-body gave the bookmakers any money for a white christmas.

[bradymk]

Looks like game over for a cold spell this side of Christmas, the NAO MRF has gone positive. I hope no-body gave the bookmakers any money for a white christmas.

remember the NAO forecasts are purely based on what the operational models are showing.

[cold snap]

Look without moaning or giving out as there's a thread for that ,best way I could describe the pattern upto 190 hours is not going as one would like

[Gavin Hannah]

https://twitter.com/BigJoeBastardi/status/278921720159694848/photo/1

Global temp anomaly up to 21 Dec.

[SnowObsessor90]

Its early days but you have made a fair few points. Re winter as a whole there's nothing to answer yet. Re models backtracking to major cold......very unlikely in neartime for Dec.....but the synoptic pattern is moving well away from what was/is anticipated.

BFTP

Still think that your 'descending winter' scenario is in with a fair shout? as I'd gladly take that now.

[Matty M]

I am struggling to find a potential route to cold, can anybody on here point to a route to cold on the models in the next 240hrs?

I just think we're snookered right now. Everything is just too flat to get us out of this. We need to get some ooomph somewhere. The Azores High ridging at around T120hrs is a highly highly unlikely possible route to cold. I

Anything more realistic out there?

[bradymk]

https://twitter.com/...9694848/photo/1

Global temp anomaly up to 21 Dec.

up to 21st? I think the chart shows 21st to 28th and this chart can change instantly depending on operational output like it did a few days ago.

[Gavin Hannah]

up to 21st? I think the chart shows 21st to 28th and this chart can change instantly depending on operational output like it did a few days ago.

Oh is it?? I thought it said up to 21st. And yes it can change at a drop of the hat, but this is what it's showing atm.

[cooling climate]

Ah - but hang on.... I also (a) pointed out in my original post how we pay little attention operationally to the seasonal models, nor cite in wider public message (they're far too experimental.... EC32 is as far as we'll employ with better confidence, at least of sorts, and it's done well into early Dec) and also ( crucially, you can't compare the UKMO seasonal modelling of a few years back to what's being synthesised now. The new version, as explained in a fascinating recent (Sept. 2012) paper, has been 'retro-run' to re-evaluate the 09-10 winter predictions, with much better success versus the original, and it's worth reading the outcome of this work undertaken at Exeter - because it's important when making any reasoned assessment of their current seasonal forecast effort and offers some balanced insight into their eventual validity. Note also how the essentially average/zonal dominated winter this year was also signalled, broadly at least, in the EC & NCEP seasonal outlooks as well as the last ones from UKMO. Nonethless, the current suite of seasonal models remain very much embryonic in this area of science. Liz Bentley's comments in the BBC sidebar below say it all, really.

Anyway - for those interested, see - -

See: http://iopscience.io...326/7/3/034031/

And more accessible explanation at http://www.bbc.co.uk...onment-19584302

Only a week and a half ago while watching the weather on telly the weather

girl said that they expected more northerly type weather during the winter

(not just December) with a higher chance of frost,ice and snow.

Then suddenly the long range models and ens members flipped to a much more

zonal and milder outcome(nowt to do with inter planetary magnetic fields

and invisible J rays from Jupiter)why?.

It could of course be inactivity of the MJO or the QBO or both or the fact

that the likely hood of a re immerging La Nina in January which would of

course mean a quieter MJO more in the way of mid latitude high and the dreaded

(from a coldies point of view) southeast rigde.

If this is the case then the models could possibly have over reacted and also

any SSW if there is one would have a unforseen impact I would have thought.

[Snowman.]

I'm liking this run its moving the PV to Russia with heights increasing over the pole this is also keeping the PV from establishing its self over Greenland.

[Panayiotis]

No cold within 240hrs on this run, but there is still potential, if the low near Newfoundland became rounder, it would do a much better job at ridging the Azores into Greenland.Example of this was in the 12z.

http://cdn.nwstatic....180/h500slp.png

Edited December 12, 2012 by panayiotis

[Matty M]

GFS FI is awful locally but hemispherically there is PV disruption and movement of PV to Russia.

I think we need to step far back and start looking at things from Day 10-20 and mark the period from now to Christmas off our cold list.

[TEITS]

Only thing im going to comment on is the significant difference in the modelling of the PV compared to the 12Z.

[Snowman.]

This has also stopped them dreaded lows spawning over US.

[nick sussex]

Only thing im going to comment on is the significant difference in the modelling of the PV compared to the 12Z.

http://modeles.meteo...nh-0-336.png?18

Yes its all over the place, as long as it doesn't land in Greenland then thats at least something to be thankful for!

[bradymk]

GFS FI is awful locally but hemispherically there is PV disruption and movement of PV to Russia.

I think we need to step far back and start looking at things from Day 10-20 and mark the period from now to Christmas off our cold list.

Yes thinks this sums it up well, doesn't look too bad hemispherically and a lot better than some GFS FI charts have been showing over the last few days. PV over Siberia with a weaker area over Canada (i think). I think any cold this side of Christmas is going to require some amplification of the pattern which just isnt showing at the moment. ECM ensembles about my only straw left for cold this side of christmas.

[Swave Snow]

The pub run has changed dramatically in the far reaches of FI GFS 12z was showing raging south westerlies now its showing a low more over the UK. Hopefully some changes starting to show. Although its the Pub run it does sometimes pick up on an emerging pattern and does indeed at the end bring a north easterly/northerly. Some crumbs or straws who the hel knows?

[weather_it_will]

Christmas day on the beach in heavy rain then, not too unlike the Aussies but with added rain, instead of sun.

http://modeles.meteo...fs-9-300.png?18

It can of course all change as that is the nature of FI. RIP Winter 2012

Straw clutching will continue......

Edited December 12, 2012 by snow is falling

[cold snap]

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=372&code=0&mode=0&carte=1

She got there in the end lol

[bradymk]

Latter charts of GFS FI show what could happen with more amplification of the pattern. For me, FI looks a lot better with the PV in a better position with it over Siberia with weaker area over Canada. (I think )

[crimsonp]

FI on the GFS has been very very messy over the past few days....... never say die, i say!

[SouthPennine88]

GFS FI is awful locally but hemispherically there is PV disruption and movement of PV to Russia.

I think we need to step far back and start looking at things from Day 10-20 and mark the period from now to Christmas off our cold list.

I would want to hold in my thoughts until perhaps Sunday before accepting we have a no cold period coming up.

The reason I say this is that there is potential out there to say a brief northerly may salvage out the blue as we have seen before in the past ... although having said that, it's most probably going to just become a piece of history in a few days and be swept up by the relatively strong atlantic.

Edited December 12, 2012 by SouthPennine88

[cold snap]

Latter charts of GFS FI show what could happen with more amplification of the pattern. For me, FI looks a lot better with the PV in a better position with it over Siberia with weaker area over Canada. (I think )

I might be wrong but the end result your standard toppler

[TEITS]

Yes its all over the place, as long as it doesn't land in Greenland then thats at least something to be thankful for!

Im just glad mate that the recent awful GFS trends in distant F.I have been halted with regards to the modelling of the PV.

During this period im going to be following CH excellent Stratosphere thread even more intently over the next few weeks.

[nick sussex]

My optimism rating has now rocketed from 5 to the dizzy heights of 5.125/10 !

Before we throw in the towel for the Xmas period we should remember that at least the PV might be on the move, it could still all end in tears but at least this might kick some life into the pattern.