Model Output Discussion 17th Dec.2013-12z onwards.

[Ali1977]

Greeny heights showing on several Ens members at T192, Scandy heights not showing as much though...

[Purga]

BA is one of the most knowledgeable on here, he is describing/looking for the small changes in the Northern Hemisphere due to the predicted stratt warming. Very interesting to see these changes take place, and someone you may learn a thing or to off !

I am always open to learning things from many sources so please do not patronise. My main point is that, at the moment, I cannot see any indications from the NWP that there is likely to be any proper cold weather for the bulk of the UK in the foreseeable future. I may very well be wrong and I hope I am actually. You may not like what I say and many who like cold weather won't and I won't get many 'likes' for expressing my opinion as truthfully as I can. I do really love extreme cold and snow but only see unsettled zonal weather in the NWP.

 

The 12z just endorses this

UKMO at 144hrs

 

GFS throughout th entire run

 

End of high res

 

Best chart and very fleeting cold shot from low res run

End of Low res run

This is model discussion and that is what the models show.

Edited December 29, 2013 by Purga

[Cecil Hogmanay Melchett]

GFS12Z really ramping up that strat temp profile pretty much directly to our north.

Hopefully some kind of effect on that PV which,to be frank,is getting right on my nerves now!!

[Polar Maritime]

My main point is that, at the moment, I cannot see any indications from the NWP that there is likely to be any proper cold weather for the bulk of the UK in the foreseeable future.

 

My point was you have exhausted your point.

 

And belittled BA.

Edited December 29, 2013 by Polar Maritime

[Mucka]

GEM is so dreadful I can't bring myself to post it.

The output hasn't been good today really but if we don't assume each Op is right at day 10 (and since they are all different they can't be) and look at the bigger picture we should slowly get a settling down of the Atlantic as we progress through January. Maybe not as quickly as I had hoped but TWT on that. Otherwise we should see the probability of colder incursions increase in the second week of January and I'm still hopeful of seeing snow falling to low levels in Northern England rather than just Scotland and  on hills though even temporary accumulations seem unlikely based on today's output.

 

Tons of scatter by day 10 and a multitude of options which only just takes us into the second week of Jan so no point in looking beyond the Hi res section for me and even there is plenty of divergence between output. I don't think this a time to make snap decisions for how January will turn out either way.

Edited December 29, 2013 by Mucka

[IDO]

GEM is a zonal fest from start to finish and ends a long way from anything resembling cold:

 

T240:    

 

The vortex remains the driver for the NH despite weak polar heights. The GEFS at T300 are about 65% zonal with a mix of other options, none of which are worthy of being classified as a cluster:  http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=300

 

The obvious call is to stay with the current zonal outlook to mid January, but there is still potential, and until we establish inter run and model support I will remain hopeful.

[Summer Sun]

A lot of rain to come over the next 10 days but from Jan 6th to 14th it eases off

 

[Jason M]

One or two very good ensembles, but as usual they are out beyond 10 days.

Tbh we have made zero progress in the last 10 days and it looks like things will stay pretty much the same for the next 10 days at least.

[Mucka]

GFS ensembles SE England (cooling signal through second week)

 

http://www.meteociel.fr/cartes_obs/gens_display.php?x=292&y=127&run=12&runpara=0&type=3&ext=1

[2810lollypop]

A lot of rain to come over the next 10 days but from Jan 6th to 14th it eases off

 

Then what happens ? Please say snow !

[Joe Levy]

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=309&y=142 (South-East England)

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=263&y=1 (Northern England)

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=188&y=176 (South-West England)

 

The ensembles for the 12z GFS. An overall downward trend in 850 temps towards the end, as with the 6z. A more notable presence of cold, rather than cool, runs. Still in the minority, but perhaps the effects of various warmings and other signals are now starting to become more obvious in the output. Keep watching.

[winterof79]

Not as bad as some make out really

http://www.meteociel.fr/ukmo/runs/2013122912/UW144-7.GIF?29-18

http://www.meteociel.fr/ukmo/runs/2013122912/UW144-21.GIF?29-18

 

GFS FI is  quite the opposite to the 06z as i am sure the ensmbles will show.The effects of the warming will be interesting to see unfold.

Edit: I see some have already posted them.

Edited December 29, 2013 by winterof79

[Radiating Dendrite]

A bit of straw clutching going on at the moment I feel.

We look like being stuck in the zonal pattern for at least another week and anything being predicted after this is pure guess work.

Fingers crossed......but it is like pulling teeth this winter!

[Frosty.]

Another stormy Gfs 12z run, no sign of settled weather on this run or the latest met office update and the good news is the experts still think we have a chance of significantly colder weather during the second half of January. In the meantime it's more stormy weather ahead with low after low sweeping in off the atlantic bringing heavy rain and gale / severe gale force winds and briefly milder temps but soon followed by colder and showery conditions with wintry ppn on higher ground, it also looks cold enough at times for sleet and snow to low levels according to this run with some incursions of arctic air and generally, temps never much better than average for most of the time. Again it's the ongoing risk of disruptive winds and heavy rain which will grab the headlines for the next 7-10 days but there are signs of more pronounced colder incursions by the 2nd / 3rd week of Jan with wintry ppn, ice and frosts with the jet axis tilting nw / se...one thing we can say about the current pattern is it ain't boring.

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2013122912/ECH1-168.GIF?29-0

 

In the midst of a tepid day of model runs the 168 ECM shows huge promise-  Kumchatka ridge & Scandi trying to meet in the middle-

 

The atlantic trying desperately to push through....

 

S

 

EDIT 192

 

http://www.meteociel.fr/modeles/ecmwf/runs/2013122912/ECH1-192.GIF?29-0  mild for the UK but the picture may well look good at 216

Edited December 29, 2013 by Steve Murr

[lassie23]

Storm after storm is the message of the models. However, they will be taking a different route towards the UK leading to brief northerly outbreaks and maybe some of the white stuff.

[johnholmes]

and to follow our cold optimist mr SM, a 'possible' late Christmas present from jh for the coldies on here

note I said POSSIBLE

 

Musings on some changes showing on at least one 500mb anomaly centre charts-29dec13.pdf

[Mucka]

http://www.meteociel.fr/modeles/ecmwf/runs/2013122912/ECH1-168.GIF?29-0

 

In the midst of a tepid day of model runs the 168 ECM shows huge promise-  Kumchatka ridge & Scandi trying to meet in the middle-

 

The atlantic trying desperately to push through....

 

S

 

Not too dissimilar from this mornings GEM.

It has certainly been a day of any ridging signals being quickly overridden as the Canadian section of the PV spits purple globules of doom our way.

Even though that signal is quite strong and has cross model support I won't be convinced it is right until tomorrow evenings output shows something similar.

ECM still offers a little light at the end of the tunnel as does JMA so tomorrow could still turn out quite different trend wise.

 

[LomondSnowstorm]

As Steve suggested - a more interesting chart for +216 with yet more hints of amplification upstream. That combined with the emergence of the Arctic High in the modelling and it's simply wrong to say that either there's no 'northern blocking' or that there's no medium term potential - clearly there is both, just that currently the former isn't likely to come good for our little bit of land just yet.

Edited December 29, 2013 by LomondSnowstorm

[Carl46Wrexham]

Then what happens ? Please say snow !

 

Snow doesn't settle on flooded ground sorry. I love snow but I would gladly settle for a spell of dry weather when this rubbish spell finally ends.

[Grimsby Snow Lover]

The AO is still forecast to go negative after in the new year, although the NAO looks to remain positive for the near future.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

[Joe Levy]

An interesting chart at 240 hours on the ECM. Still way earlier than I am expecting any significant cold to appear in the output, but interesting nonetheless. The vortex over Western Greenland and Eastern Canada is strong here, which is why a warming would be welcome. I'd be interested to know what all of you make of this chart

Edited December 29, 2013 by Joe Levy

[Captain Shortwave]

Very happy to draw a line in front of tonight's output and wait for the 00z runs. Very little consistency between any of the models and the runs within the specific models. Very little confidence going forward. 

[Dancerwithwings]

Snow doesn't settle on flooded ground sorry. I love snow but I would gladly settle for a spell of dry weather when this rubbish spell finally ends.

It does if it freezes But i do see your point

[lorenzo]

Looks like on balance we are going to have to endure the massively tricky model watch involving -   how much of the vortex remains in it's Greenland home  fuelling the Atlantic train of depressions.

 

Just as within the ensembles there are zonal, varying degrees of interaction with the Arctic high, Azores lingering about - as for nothing at all showing signs of cold, yes it's one of the ensembles, but it's there.