Winter Model Discussion - The Hunt For Cold - 10th Dec

[Froze were the Days]

Nice to see even in FI we see a short wave in the same location (Norwegian Sea) which dismayed us all pop up once again, strikes me we're going absolutely no where with this synoptical pattern - even up to the run up for xmas and what cold was trending in the lowish-res has now gone.

[pyrotech]

Well this is the first time in days that snow is shown in Wales on Thursday (GFS 12z). So it looks marginal looking at the 850mb and obviously temporrary, but those looking for a little snow and cold can take this as a upgrade. This moves North effecting many areas, but perhaps less Snow on this run for Scotland. Every run seems to be a slight upgrade to me for this weekend, albeit a pointless one to a large extent as it will soon wash away. However an hour or two of snow would definitely be welcomed by me. I do realise that GFS can back track from this to an all rain event, but positive that it shows some snow. Further upgrade for longer spells or more areas are not out of the question.

[Frosty.]

A little high Frosty I'd say. Average for December is 6/7, for Jan 5/6 as maxima

Thanks for correcting me snowmaiden, actually 5 or 6c or 6 or 7c feels pretty darn cold in a strong wind, added chillfactor makes it feel closer to freezing.

[Cheshire Freeze]

Nice to see even in FI we see a short wave in the same location (Norwegian Sea) which dismayed us all pop up once again, strikes me we're going absolutely no where with this synoptical pattern - even up to the run up for xmas and what cold was trending in the lowish-res has now gone.

It does feel like we're going nowhere fast!

I did have some optimism yesterday as things appeared to be slowly heading in the right direction for another attempt at an easterly around 192 hrs. Since this point we appear to have taken another step back unfortunately. I haven't looked at SST profiles recently but I'm wondering if that warm patch of water off the east coast of Canada is still there and wonder how much it's aiding with the pattern of energy perpetually being spat at us despite the PV being advertised to reside across the other side of the hemisphere.

[Snowly does it]

Thanks for correcting me snowmaiden, actually 5 or 6c or 6 or 7c feels pretty darn cold in a strong wind, added chillfactor makes it feel closer to freezing.

Definitely. Average weather for the winter in the UK is chilly, quite windy, sometimes wet with frosts on clear nights.

We need a little extra for it to be white

[Paul T]

The energy in the Jet fed by a potent mix of extreme temperatures from Canada and Eastern America and is at the forefront of the projected zonal pattern.

From 14th to 20th Dec I expect relentless South Westerlies unless this set-up changes fairly significantly.

In better news, the models are starting to indicate some frontal snow @69hrs for a fair swathe of England.

[Snowly does it]

It does feel like we're going nowhere fast!

I did have some optimism yesterday as things appeared to be slowly heading in the right direction for another attempt at an easterly around 192 hrs. Since this point we appear to have taken another step back unfortunately. I haven't looked at SST profiles recently but I'm wondering if that warm patch of water off the east coast of Canada is still there and wonder how much it's aiding with the pattern of energy perpetually being spat at us despite the PV being advertised to reside across the other side of the hemisphere.

The potential for the cold to be drawn over us at days 8/9 is still there. The trend at the moment for this time is for the Azores to be throwing a ridge up and the Atlantic system to move. With that trend we will see cold and mild outcomes over the next 3 or 4 days. Ensembles should give a flavour of the more likely outcome.

[Chess01]

I think its all about how the models deal with the movement of the vortex . While i know its fi the vortex moves to siberia which leads to cool weather in the uk but when you go through a days the vortex seems to seep into scandanavia . This seems key that we need to keep that vortex out to siberia to get some cold from that block to our east otherwise it will just be sitting there wasting away

[Bradowl]

This is the latest chart from the beeb for the end of the week

That ties in nicely with GFS's 12z run tonight

This set up reminds me of some of charts in late 70s and early 80s, quite a few of severe cold snaps came from occluded fronts strung across to north of UK and very slowly worked there way back southwards.

[snow drift]

Splitting hairs. I think we know what I mean by mild in this instance.......upper air not supportive of snow (except maybe the highest UK peaks),of Atlantic origin and brought about on a brisk wind.

Hi CC. I think your pre winter thoughts were for a fairly "normal winter". I get the feeling that your posts have this bias which is a shame because in previous years I have found your input brilliant. You seem keen to talk up normal and reluctantly comment when cold is shown, all tho this is your preference I believe. Please revert back to the post style you used to use. I mean no offence with this but miss your more objective posts without the "mild" slant which seems to be used to back up your pre winter thoughts

.

[Summer Sun]

This set up reminds me of some of charts in late 70s and early 80s, quite a few of severe cold snaps came from occluded fronts strung across to north of UK and very slowly worked there way back southwards.

The chances of anything like that this time appear slim unfortunately

Edited December 10, 2012 by Gavin.

[The PIT]

A return to average temperatures for the weekend with rain and showers and a stiff breeze too look forward too. Not even anything decent in FI to get excited about. Suspect a large possible NO event later this week.

[Froze were the Days]

It does feel like we're going nowhere fast!

I did have some optimism yesterday as things appeared to be slowly heading in the right direction for another attempt at an easterly around 192 hrs. Since this point we appear to have taken another step back unfortunately. I haven't looked at SST profiles recently but I'm wondering if that warm patch of water off the east coast of Canada is still there and wonder how much it's aiding with the pattern of energy perpetually being spat at us despite the PV being advertised to reside across the other side of the hemisphere.

Yep very warm SST's off the eastern seaboard, must be promoting cyclogenisis, interesting to note Norwegian sea is colder than average (should this correlate with shortwave formations - I'll have to look into the tuition forum on them).

I'd like to be more optimistic but this could be the first bout of real mobile Atlantic conditions eventually occurring once the 'buffer' of the Siberian High has been displaced, looking back after the last week or so I really can't help thinking we've been unlucky, the long wave patterns have been favourable along with SST's, Teleconnections but the Atlantic has awakened at precisely the wrong time, opportunities missed.

Only positive I can make is that I thought it would start to trend milder after mid-month (in my December CET forecast). - I would rather have been wrong.

Edited December 10, 2012 by Froze were the Days

[Peter H]

This set up reminds me of some of charts in late 70s and early 80s, quite a few of severe cold snaps came from occluded fronts strung across to north of UK and very slowly worked there way back southwards.

Indeed, though I think on this occasion they're now fairly confident the mild weather will win out.

Not much sign of anything really cold materialising up to Christmas now.

[Downburst]

This set up reminds me of some of charts in late 70s and early 80s, quite a few of severe cold snaps came from occluded fronts strung across to north of UK and very slowly worked there way back southwards.

Yes, very interesting chart. I think very indicative of the blocking.

[IDO]

V. good synchronicity:

http://modeles.meteo...ndres&runpara=0

Looks like a locked in pattern for the next 7/8 days with static LP close to the UK.

The GEFS mean at T192:

http://modeles.meteo...21-1-192.png?12

At T288:

http://modeles.meteo...21-1-288.png?12

The block is on the retreat east. As it does, the zonal flow ramps up. The downstream pattern is well defined, stubborn block, possibly heading very slowly east. This is unlikely to change. We therefore need the upstream to trigger ridging. The mean at T300:

http://modeles.meteo...21-1-300.png?12

This shows the US also under a huge block (HP) with an under cutting trough. To me this looks harder to model than the saga we have been through regarding the easterly. I suspect there are shortwaves causing mayhem with the upper flow.

My view is the upstream is fluid enough to maybe lend favourably to the UK, or maybe not. Whats for sure is that there could be lots of variable op runs as to the Atlantic, and its eventual flow, after T240. The scatter highlights this:

http://modeles.meteo...22-1-240.png?12

At T384:

http://modeles.meteo...22-1-384.png?12

It may take a week before the Christmas weather is sorted. All to play for.

Edited December 10, 2012 by i'm dreaming of...

[Isolated Frost]

A snapshot at D5 of the US 850 temps outlook- pretty notable arctic air as cold air is whipped into the mid-latitudes as a result of the relocating vortex energy- this excess energy in turn fuels the succession of atlantic low pressure systems that quash any attempted build up of a mid-atlantic ridge; something I recall GP touching upon.. the result is generally high pressure to the south-west and to the north, with a mean trough to the west of the nation and cyclonic S/SW winds dominating-

Another one of note will be a pulse of notably lower geopotential heights that develop over the temperature difference between the remote Ural high and mountain energy over Mongolia- this should move into Scandinavia/C Europe at D9/D10 with associated sub -15c 850 air temps- as this passes, expect the tint of the blocking heights to rotate over western Russia and allow a E/SE airflow to enter much of Europe- the cut-off being an extended low pressure system over Britain

[cyclonic happiness]

Indeed, though I think on this occasion they're now fairly confident the mild weather will win out.

Not much sign of anything really cold materialising up to Christmas now.

I think this is a good thing, I don't want to keep chasing cold spells that are only every in FI, so that we have a seemingly endless stream of lows and south westerlies makes me think that a cold spell will just 'sneak up on us' when we least expect it, like say...around Christmas and New Year?

We've been lucky that past few years in that we've had alot of cold early and it's sort of made the back end of the winter a write off.

This year could be amazing, but the best winters in history have always happened after Christmas.

[Cheshire Freeze]

Hi CC. I think your pre winter thoughts were for a fairly "normal winter". I get the feeling that your posts have this bias which is a shame because in previous years I have found your input brilliant. You seem keen to talk up normal and reluctantly comment when cold is shown, all tho this is your preference I believe. Please revert back to the post style you used to use. I mean no offence with this but miss your more objective posts without the "mild" slant which seems to be used to back up your pre winter thoughts

.

Hi Snowdrift, preference doesn't come into my posts (true I'm a coldie), it can't do otherwise objectivity is thwarted (did Sociology at uni so know all to well about this sort of thing). The reason why it may seem that I'm 'bigging up' the mild scenario is because this is the scenario I championed back in October (fairly mobile Nov and December). Due to this and the charts that we see before us from the NWP serves to increase confidence in my original thoughts so therefore I see no necessity to 'chase' down cold charts.....it would prove both fruitless and pointless to do so.

You'll recall I actually got invested into what the charts were showing a few days back though,as ever, remained cautious and rightly so....I even sent a PM to Ian Brown suggesting I wasn't completely sold on the idea though had reasonable enough confidence on the easterly situation occurring.

The issue is it's hard to be objective on this forum because for every one person who appreciates the time spent through analysis of the models, two people take umberance to what is suggested because they have a bias of a mindset over what they WANT to see vs what is likely to happen in reality. For example I'd LOVE to see raging easterlys and -20 upper air over the UK from now until March and I could wax lyrical on how likely this evolution is and how we're about to see widespread snowy disruption......though back in the real world we all know deep down that this (sadly) isn't the case!

[Frosty.]

Suspect a large possible NO event later this week.

No I think a large snow event for northern hills and especially scottish higher ground with Easterly gales is looking highly likely with drifting, also some trancient snow for most areas soon turning to heavy rain as fronts are driven north across the uk. Eventually the fronts clear through northern scotland and less cold uppers cover the uk but many areas retaining some cold at the surface so cold rain and windy by the weekend I think with a slow thaw for the hills by then, the mountains probably remaining sub zero. It's a real shame the cold snap can only last a few days, so many knowledgeable people on here put up an excellent defence for a prolonged very cold spell to become established and it's all come to nothing sadly.

Edited December 10, 2012 by Frosty039

[snowmadchrisuk]

85% Of the 12z GFS Ensembles go for Mid Atlantic or Greenland pressure rises at +240 ,, thats a large percentage and something to watch ,

[nick sussex]

Look west not east!

Start hoping for some amplification in the eastern USA, the limpet trough isn't going to sink without that.

The chances of a long draw easterly are low but the ridge to the east can impart some forcing on the trough if it has some help, that way you might get a shot of colder air as the trough sinks.

The Azores high needs to retrogress and slow down the Atlantic thats what we're looking for.

Edited December 10, 2012 by nick sussex

[Summer Sun]

12z ensemble are out

There's still a chance of something colder again from late next week, after peak around the 15th the ensembles then take a drop slowly but surely maybe better luck later next week just in time for Christmas?

Edited December 10, 2012 by Gavin.

[Frosty.]

85% Of the 12z GFS Ensembles go for Mid Atlantic or Greenland pressure rises at +240 ,, thats a large percentage and something to watch ,

Yes those wonderful ensembles that led us all up the garden path in the last few weeks only to implode, but the law of averages says we will strike it lucky at some point.

[Polar Maritime]

Well the Easterly has been pushed away as we all know, and reading through this thread amazes me that so many can write cold weather off for the next few weeks.

Just look how the models have performed over the last 3 weeks... terrible !. With the Polar Vortex so unstable, the models really are struggling.

So i would say anything after the weekend is all to play for,

As Frosty posted early'er, Cold can appear on the models as fast as they can drop it. And battleground snowfall can pop up within hours.

Still all to play for in my opinion. We are 10 days into Winter..

Edited December 10, 2012 by Polar Maritime