Winter Model Discussion - The Hunt For Cold -12z 14/12/12

[AWD]

At least the GFS is showing a rather seasonal feel to Christmas now rather than double digit temperatures;

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=216&mode=1&carte=1

[Panayiotis]

There we go it moves east and most of the UK is in -5C uppers just in time for Christmas! http://cdn.nwstatic.co.uk/gfsimages/gfs.20121216/12/204/h850t850eu.png

[The Northern Ramper]

Bank

[Zenarcher]

What's the chances of the GFS over deepening that low though?

Rather high if I know the GFS.

Looking at the GFS gust charts on NW Extra shows 75mph over Southern England. We all must bear in mind this is 1 week away and yes the GFS is widely known for overdoing low pressure systems.

[Frosty.]

We definitely are 'getting closer'; the question is: to what?

christmas

models are still struggling with this week, some parts of scotland could have snow with good undercut from gfs 12z.

[Weathizard]

An ouch run for us on the south coast, pummeled by rain. Won't happen though. Very uncertain beyond even t72

[kev238]

The trend today is definitely a favourable one... if it continues it could be game on., Certainly for where i shall be over xmas (gloucestershire and near the river severn) i fear it may be a wet one!

[Paul T]

Every single day of the high res GFS run has snow forecast for some part of Scotland. Deffo moving into a colder outlook.

[Methuselah]

Blimey! That's not just one the way-of-the-pear, it's stripped the entire orchard bare!

[SMU]

http://www.meteociel.fr/ukmo/runs/2012121612/UN144-21.GIF?16-17

If the UKMO moved to another day then a more southerly undercut looks possible- sadly its way out on its own at the moment- but with the GFS flailing around its probably worth more than that run.

S

[Jonan92]

Another Vortex Split in FI

[Zakos]

the models really overpowered the Atlantic a few days ago.

The atlantic was predicted to be far, far stronger than this a few days ago, with South Westerlies right across Scandinivia.

A complete change in the jet angle over Europe.

A very large turnaround from the GFS. Very good to see. That said, as you can see from the above charts,this pattern is very complicated, and the uncertainty is very high for the Christmas- new year period. Those who are writing off cold for xmas are wrong, and the runs today show exactly why. The setup is very complicated and big changes can and most probably will happen

The GFS is clearly having trouble and as usual reverts to default.

Edited December 16, 2012 by Zakos

[Panayiotis]

In Fi we started to go back to zonal (GFS default?) but the Arctic high i have been talking about saves the day, causing the split vortex and pushes away the PV to Russia.This then links up with the Azores helping us get the ridge into Greenland and we are left in northerly winds. http://cdn.nwstatic....384/npsh500.png (Fi however but there is a trend for an Arctic high)

Edited December 16, 2012 by panayiotis

[mcweather]

You have to laugh at the GFS its almost as if its looked at what it put out on the 00z run extended range and scared itself to death and run off into the corner to hide and say it wasn't me that did it honest.

[SnowObsessor90]

How are things currently looking strat wise?, I notice there hasn't been an update from the likes of Chio etc yet.

Edited December 16, 2012 by Anonymous21

[Zakos]

anything beyond 180 hours is useful only for spotting trends IMO.

worryingly, the GFS does show a trend for high pressure to build to our south.

However another trend is for the Polar Vortex to undergo significant distortion]

Amazing Polar setup. Not so good for the UK, although I think the High is trying to ridge into Greenland at the end of this run...

[Frosty.]

I bet the metoffice experts will be scratching their heads in disbelief (or maybe not) but the models have been indicating trough disruption and things are becoming even more interesting now. Also, our scottish friends will be twitching with excitement with snow in the north becoming a real prospect, semi reliable timeframe now.

[AWD]

How are things looking strat wise?, I notice there hasn't been an update in the strat thread yet.

Still looking good;

http://cdn.nwstatic.co.uk/gfsimages/gfs.20121216/12/240/npst30.png

http://cdn.nwstatic.co.uk/gfsimages/gfs.20121216/12/384/npst30.png

Interestingly starting to feed over to the Canadian side of the vortex in FI, which wouldn't be a bad thing for us.

The Strat doesn't flip around like the NWP output does in FI. The Strat FI is far more reliable than the NWP FI output, although not inflammable of course, so there isn't really a need for daily Strat updates, as not too much of any relevance changes daily.

Edited December 16, 2012 by AWD

[snow1975]

I bet the metoffice experts will be scratching their heads in disbelief (or maybe not) but the models have been indicating trough disruption and things are becoming even more interesting now. Also, our scottish friends will be twitching with excitement with snow in the north becoming a real prospect, semi reliable timeframe now.

Yes, I've just come in and looked at the 12z runs. Todays GFS/MetO 12's look like yesterday's GEM/JMA.

[Derbyshire_snow]

Is this the Major change in the models that you were talking about yesterday Matty H?

[Cloud 10]

Still looking good; The Strat FI is far more reliable than the NWP output, although not inflammable of course,

Maybe not inflammable,but certainly looks to be warming up.

[Liam J]

All this jumping about within the outputs is really starting to grate on me, Dear models - please can we have a more clear idea of what may actually be happening over the next 7 days, if thats not too much to ask..... Thanks

[Rollo]

I fear this will it won't it situation will last for some time yet, we certainly do not know what the outcome is going to be and I fear neither do the computors. My gut reaction is that eventually we cold lovers will get what we crave.

[Derbyshire_snow]

Is this the Major change in the models that you were talking about yesterday Matty H?

[snowmadchrisuk]

Yes, I've just come in and looked at the 12z runs. Todays GFS/MetO 12's look like yesterday's GEM/JMA.

This will be the second time this Month the smaller Models picked on a change first , They also predicted our Mild spell with the Atlantic winning , why the big 3 were still showing a blocked Greenland. Only concern for me is , we do usually get there with Northerly's but timing usually get's pushed back a few days , or even a week from where it fist shows on the Models.