Winter Model Discussion 12Z 22/1/13 onwards.

[J10]

Latest Skiing Blog now out

http://forum.netweat...h-january-2013/

Containing the usual synoptic analysis, admittedly not so much uncertainty this week.

Edited January 25, 2013 by Jackone

[Summer Sun]

The ECM short ensemble shows a gradual cool down later next week most of the members stay above zero we may however see more below when the full ensemble is out shortly

The full ensemble is now out

More members do trend below zero in the long run so we should certainly see temps back to average by later next week

Edited January 25, 2013 by Gavin.

[Frosty.]

Yes frosty it was certainly fun last time watching the models torturing themselves with ridiculous mild output when we all knew it was going to turn cold.

I for one can't wait for another Ian Brown wtf run.

Yes i'm hoping lightening can strike twice, feb is usually the coldest winter month with the sea temps nearing their coldest levels and we will be unlucky not to have some cold snaps or one decent prolonged spell, at least temps should be dropping after midweek.

[BARRY]

I no this isn't model related but can someone explain why it's raining in the midlands when it was forecast heavy snow?? Thanks..

maybe the dew point is to high or the temps are to high that's why, the models may predict snow but if your local temps are warmer then that's part of the normal scatter of temps

[Polar Maritime]

Yes i'm hoping lightening can strike twice, feb is usually the coldest winter month with the sea temps nearing their coldest levels and we will be unlucky not to have some cold snaps or one decent prolonged spell, at least temps should be dropping after midweek.

Yes Frosty, Feb has delivered some of the most severe cold spells in the past, the models are already hinting a cool down after the brief milder spell next week, some promising signs already, i think the models are still struggling with the effects of the SSW, plenty of scope yet, and this cold spell has not even finished yet, some of the heaviest snow i have seen falling now here..

Edited January 25, 2013 by Polar Maritime

[Frosty.]

Yes Frosty, Feb has delivered some of the most severe cold spells in the past, the models are already hinting a cool down after the brief milder spell next week, some promising signs already, i think the models are still struggling with the effects of the SSW, plenty of scope yet, and this cold spell has not even finished yet, some of the heaviest snow i have seen falling now here..

Yes PM... 1000 feet up you should get 15cm at least, i'm glad this cold snap has gone out with a BANG instead of a whimper, roll on the next freeze.

[Ice Day]

Quiet in here tonight! Well, perhaps a tentative attempt at some heights building at 132 towards Greenland?

[Continental Climate]

Quiet in here tonight! Well, perhaps a tentative attempt at some heights building at 132 towards Greenland?

Extremely tentative

[Ice Day]

Well it's still trying REALLY hard at 150

[Panayiotis]

The lack of posts for the 18z GFS reflects how uninteresting things are atm, however at 141hrs there may be sign of relief as the low coming out of America,is perfectly tilted to shoot those heights towards Greenland and is a great upgrade compared to the 12z, will this thread shoot back to life as the GFS rolls on?

[Beaufort12]

I don't know an awful lot about reading models but at 156 is it just me or does it look like the greenland high and atlantic high are trying to elope?

[Panayiotis]

At 159hrs the low to the SW of Greenland has stalled (which is really good news!), as this helps with WAA into Greenland which sustains the heights in that area. The 0C line kissing the south of Greenland (we want this to go as north as possible), and with those weak heights to the NW/W and low pressure to the east we are in a northerly flow.

[matty40s]

really strange here tonight, I hope the mods move this elsewhere and do not delete as I am witnessing something I hae not seen before in the uk and is prevalent in the us, an ice storm.

The snow started about 8pm, but it was ice crystals mixed with snow, the road surfaces were immediately white as the ice and snow intermingled.

I am seeing a previously unfrozen canal stretch turn to a slush puppy and the TV signal give up.

Now I have torrential rain/hail mix. The models give some strange short term forecasts, with heavy flooding a possibility again, which is not good for us boat owners in the uk.

[Panayiotis]

And if by magic it happens, now look at the cold return after a week of leaving! Could this ridge in the Atlantic become a Scandi ridge?

[Panayiotis]

Shortwave at 186hrs, west of the high (the one 'riding' on it) should be watched, it could send heights into favourable positions!

[Ice Day]

This is a very encouraging trend, big differences from the 12z. As several posters mentioned earlier, the models are definitely starting to try to build heights towards Greenland. Let's hope this trend gathers pace tomorrow.

[damianslaw]

Whilst the immediate output looks rather unpalatable if you are after either dry settled conditions, or cold conditions, in the medium term i.e. as we move into February the models are hinting at increasingly likelihood of amplification in the atlantic flow which will in time aid those crucial height rises in the mid atlantic which will set up the opportunities for more settled conditions and most likely of the cold variety. All depends on the behaviour of the Canadian Vortex, there are indications that it will intensify and build westwards which again would enable mid atlantic height rises and more importantly the chance for the arctic heights over the other side of the Pole to build southwards towards Greenland and therefore the possibility of a link up.

From a personal perspective, I don't mind the prospect of a wet windy spell as long as it is shortlived, remember the ground is saturated and a sustained wet spell is the last thing we need - it is high time we see a lengthy settled spell, the chances of such spells increase markedly as we move into February - preferably the cold freezing variety, a greenland high would be perfect!

[Panayiotis]

Can anyone see the resemblance between todays 18z and yesterdays?

[bradymk]

JMA ensembles for 1 month period updated today continue theme of signal for HLB to our NW as we progress through February with low heights over Scandinavia. A lovely 18z run, shortlived atlantic, then cold, dry and frosty under a chilly NW wind before the high starts to retrogress towards Greenland. After 384, we would see some lovely charts, shame it stops at 384 and i know its F.I but there is big support for such a set up.

Edited January 25, 2013 by bradythemole

[SnowObsessor90]

It doesn't look like it's going to make it on this run but as the saying goes the trend is your friend and all that.

Edited January 25, 2013 by SnowObsessor90

[Cumulonimbus Tower]

The lack of posts for the 18z GFS reflects how uninteresting things are atm, however at 141hrs there may be sign of relief as the low coming out of America,is perfectly tilted to shoot those heights towards Greenland and is a great upgrade compared to the 12z, will this thread shoot back to life as the GFS rolls on?

Sorry to be off topic but i think the lack of posts may be to do with the masses of snow piing up outside this evening rather than the search into deepest FI-land for more.....

UKMO looks like it may be onto something at 144 btw. It's been quite good of late hasn't it?

Ned

[Panayiotis]

To end this brilliant run (IMO), we end with this, and if it went further you find us back in the freezer! Just remember my prediction in my signature.....

Edited January 25, 2013 by Panayiotis

[bradymk]

Sorry to be off topic but i think the lack of posts may be to do with the masses of snow piing up outside this evening rather than the search into deepest FI-land for more.....

UKMO looks like it may be onto something at 144 btw. It's been quite good of late hasn't it?

Ned

haha yes you might have a point, but no snow here, im currently nearly flooded in here in West Wales, we have had severe problems all around here tonight with snow melt + very heavy rain cutting some places off, very bad. GFS 18z is a superb run as is UKMO 144 chart and the ECM at 240 is also ok. Also, notice the gradual cooldown on the EC ENS becoming cooler and cooler every run now and the control puts De Bilt straight back into the freezer at the end. ECM 32 sticks with its output which may explain the sudden change once again in the MetO outlook. Strange and confusing how its changed so much last few days. Im happier tonight.

Our saviour low may well indeed be the break we're looking for to land the first punch , still a few rounds to go but at least its a start.

Thanks Nick, you have invented some lovely sayings this winter for sure saviour low the newest to add to the list. Edited January 25, 2013 by bradythemole

[nick sussex]

Some positive signs this evening that the mild weather will be shortlived.

The trend is to amplify the upstream pattern a bit more, I think it will take some time before we can think of a return to snowier conditions but what we want to see is pressure falling in central/southern Europe to stop the Azores high trying to edge ne into that region.

We want it going nw or west to allow pressure to fall to the east.

Earlier the GFS 18hrs looks similar to the UKMO with its amplitude of that troughing. I know I must sound like a broken record but the key to the fightback against the imminent mild mush is the deep low crossing the USA.

You'll note that the better ensembles and operationals all develop that and phase it with the PV lobe in northern Canada, the more amplified this is the better the downstream pattern will become because this will help pull the Azores high away from its favoured location.

Our saviour low may well indeed be the break we're looking for to land the first punch , still a few rounds to go but at least its a start.

[cooling climate]

The ECM was looking a lot more amplified by t240 and again the 18z GFS does the same. Would not be

at all surprised to see the models build on this now with more and more runs showing an even more

amplified pattern t 216 and onwards over the coming runs.