Winter Model Discussion 12Z 15/1/13 onwards.

[snowice]

From my basic model knowledge, it looks like Northern Ireland could gain little from these updated charts.

Am I correct?

I think we have been forgotten over here to much excitment across the water?

Edited January 16, 2013 by snowice

[russell k]

GP went for this in the winter forcast, we just missed out in dec. and now on the doorstep of a significant event, brilliant, hats off to GP, go back and review, even if it rains snows IMBY many are going to be happy.

Thanks

[Orpingtoniceagedec10]

Has anyone else noticed all that energy coming up through Germany in a NNW direction . If our storm on saturday is timed right , the wrap around easterlies could well invite it to the party . Any thoughts ?

[Panayiotis]

Can anyone confirm if this fax means it will be rain over the UK on Sunday away from North East Scotland ? The Damn 528 line is off the east coast and strong southerlies will see temps at the surface increasing. In fact ive just checked the met o outlook 3-5 dayer and it says snow on friday then milder weather.

Is that it then ? 1 day of snow, then a thaw and rain.

Now i know the ECM 12z is showing a colder prospect again on tuesday but will we have lost the cold pool over us by then.

making any precipitation marginal south of he m4 ?

I've read some posters SMurr i think talking of -20oC and snow fields - is that based on the fact the fax charts are wrong. Having read

from the professionals here - Eye in the sky - that they are one of the most accurate/reliable.

Have I got this right as im still learning, or are we in for a weekend of snow ?

Any help appreciated thanks.

Lottie.

Youve read the charts right, just to show you I think this is where you might have been wrong; the southerly winds are coming over a fairly cold UK, and bearing in mind the winds are coming from France (which is much colder than us as its connected to Europe and not fully surrounded by the sea) the air isnt as warm as one would think, also the air is coming from the continent this means the air is drier and therefore dew points are lower, low dp (below 0C)means there is a high chance for snow if the uppers are below -4C (which in this case they may very well be).

For example this the chart for Sunday from the GFS, it shows a low to the west bringing in a southerly wind, but because cold has been with us more than a week by then, the uppers stay cold.

So I would think past Saturday, snow is still a possibility away from the far S/SW.

Edited January 16, 2013 by Panayiotis

[Severe Siberian icy blast]

Mini tiger re the fax.

The fact it's southeasterly winds means the due points are very low, the fronts are pulling away to our southeast , what you are looking at it a very snowy but yet equally worrying and dangerous weekend, I'm been serious people, this is getting serious, I love snow, I live and breath it , but take care , and only go out if you have to .

[pages]

Thank god for the 216 http://www.meteociel.fr/modeles/ecmwf/runs/2013011612/ECH1-216.GIF?16-0!! I think by then we will all need a break dry but cold that chart, nice winter sunshine!

The 216 is awful if you want an end of the cold, look at the northern hemi charts the arctic high is coming, by t264 height will be strong from Greenland to scandie, low undercuts and the country is in serious danger of being hit by record breaking uppers.

People will say I am ramping but run the northern hemi charts from t192 through to the end and you will see

[Isolated Frost]

48-168 was probably the best 5 day period I have seen on the EC since November 2010's prospects.

And the reload potential from the NE after 168... is monster, the injection of polar energy into Scandinavia, the retrogressive motion completing over the GIN corridor, and the Azores high ridging into Greenland (MJO phase 7, ta)... cold bottling up for release is extraordinary.

And the most extraordinary thing about is that the most extraordinary stuff is at D2-D7... from frontal to convective to frontal to convective to a bit of both, basically all of Scotland, England and parts of Wales are in for a snow-fest... combine that with the incredibly low temps over the snowfields.. wow.

People have analysed the early part of the run enough... hemispherically, this is awesome

[Frosty.]

Very little to add that what has already been said.

What is clear from the 12Zs is the GFS seems lonely tonight yet again. The UKMO/ECM both suggest another spell of snow on Mon/Tues and then its a case of looking NE.

It looks like we will be looking east and then north and then east again in the next few weeks, truly epic turnaround to this winter

on a serious note, driving will be very dangerous and look out for the elderly and feed the birds.

[Staffordshire]

Just imagime the temps over the snowfields at night! they will be phenominal!

[Weather Boy]

I don't think this snowfest ECM run can be discounted. GFS aside (which seems to have lost a lot of credibility in this spell with its unrealistic breakdown run after run) the models have all been more than hinting at a cold snowy evolution in the medium term, with the METO leading the way. This is not an out of the blue upgrade (although doubtless it will be altered between now and T+0).

Also worth pointing out that in more routine times, this sort of timescale (day 6) this would be regarded as at least semi reliable. Hard to ignore the GFS, but it has little credibility right now and surely shouldn't be favoured.

[IDO]

Mini tiger re the fax.

The fact it's southeasterly winds means the due points are very low, the fronts are pulling away to our southeast , what you are looking at it a very snowy but yet equally worrying and dangerous weekend, I'm been serious people, this is getting serious, I love snow, I live and breath it , but take care , and only go out if you have to .

I think the problem is that even BBC London no longer than 10 mins ago said that London and the SE will turn milder on Saturday and the snow will turn to rain. Lots of contradictions so reason for scepticism. Hard to know as all models are still not on the same hymn sheet even 36 hours out.

[Snowman.]

If that ECM came off we will colder than Greenland!

240 Shows the start of some kind of cold can't really show anything else I suppose.

[Cloud 10]

The last three fax charts for Saturday make for interesting viewing,i look forward to tonight's!

last night..

this morning..

this evening..

[ukpaul]

Youve read the charts right, just to show you I think this is where you might have been wrong; the southerly winds are coming over a fairly cold UK, and bearing in mind the winds are coming from France (which is much colder than us as its connected to Europe and not fully surrounded by the sea) the air isnt as warm as one would think, also the air is coming from the continent this means the air is drier and therefore dew points are lower, low dp (below 0C)means there is a high chance for snow if the uppers are below -4C (which in this case they may very well be).

For example this the chart for Sunday from the GFS, it shows a low to the west bringing in a southerly wind, but because cold has been with us more than a week by then, the uppers stay cold.

So I would think past Saturday, snow is still a possibility away from the far S/SW.

This does mean that the south coast is also very marginal throughout next week, with uppers of -2 and -3, as per the ECM, from Monday afternoon through to Wednesday. I'm not one normally to put a downer on things but, with the front on Friday now decaying earlier than was progged yesterday on the WRF, those of us near the South East corner are going to need the system to push through and pivot in the way that the 12z GFS did if we are not to be looking enviously 100 miles further North by this time next week.

Of course the front may push through, as per the UKMO and NAE, it may pivot and dump on us again on Saturday and the 850s for next Monday and so on may become higher as the block remains stronger and pushes that system further South.

Glass half full/Glass half empty? You choose......

Edited January 16, 2013 by ukpaul

[weatherjay]

quick question regarding ECM/UKMO longer term! if these 12z runs were to verifiy, would there be snow melting away from the far west and south west after fridays event!? or would it likely stick around till further potential snow events, such as monday?

[pages]

I am seriously worried if this verifies upto T240 we are in serious trouble, weak vortex, strong arctic high, pool of -20 uppers heading across Europe, that low is going to send energy under and we know the rest!!

[cj114]

I think the problem is that even BBC London no longer than 10 mins ago said that London and the SE will turn milder on Saturday and the snow will turn to rain. Lots of contradictions so reason for scepticism. Hard to know as all models are still not on the same hymn sheet even 36 hours out.

I know! It was the same last night as I said then. Nowcasting will be the order of the day I think. I am also worried about my Gas Bill, Old people, Birds etc and having a Car Crash. Other than that it looks great!!

[TheHumph]

I think the problem is that even BBC London no longer than 10 mins ago said that London and the SE will turn milder on Saturday and the snow will turn to rain. Lots of contradictions so reason for scepticism. Hard to know as all models are still not on the same hymn sheet even 36 hours out.

BBC South have it snow free all day Saturday and yet the five day forecast shows it snowing here on saturday! I cannot believe that anywhere in the South (apart from perhaps Cornwall) will have rain over the weekend especially with temps dropping because of lying snow. I bet if you watched each region's forecasts side-by-side it would be a right mish-mash of information. In a nutshell - I agree with you!

[dbaloo]

hi i'm still learning how to read models, but where on monday would the snow affect if indeed it does arrive?im in south east wales and am wondering what parts of the country will be affected as im working in the midlands monday and need to travel there and back!

[Mini tiger]

Hi Lottie

The FAX chart you show is last night's 120 chart and will be updated again later this evening. I suspect it will show a better picture for snow, although the chart you posted was still very good.

I'm not a big expert but as I understand it, the 528 DAM line is not so important in set ups like this, where frontal snow is forecast to meet cold uppers.

The ECM tonight is a very snowy chart and I don't think marginality would be an issue there.

I'm sure someone far more knowledgeable than me will correct me if I'm wrong, but it all looks good to me!

Exciting times to be model watching!

Thanks for your reply .. I thought 528 dam air meant the air was cold up there, and if it was higher

than 528 dam, then it wasnt so cold higher up ?

sorry for the question.

[Tom D]

hi i'm still learning how to read models, but where on monday would the snow affect if indeed it does arrive?im in south east wales and am wondering what parts of the country will be affected as im working in the midlands monday and need to travel there and back!

Impossible to say for sure. Wait for Met Office warnings. They're paid professionals at what they do.

[Mini tiger]

Youve read the charts right, just to show you I think this is where you might have been wrong; the southerly winds are coming over a fairly cold UK, and bearing in mind the winds are coming from France (which is much colder than us as its connected to Europe and not fully surrounded by the sea) the air isnt as warm as one would think, also the air is coming from the continent this means the air is drier and therefore dew points are lower, low dp (below 0C)means there is a high chance for snow if the uppers are below -4C (which in this case they may very well be).

For example this the chart for Sunday from the GFS, it shows a low to the west bringing in a southerly wind, but because cold has been with us more than a week by then, the uppers stay cold.

So I would think past Saturday, snow is still a possibility away from the far S/SW.

Hi Panyotis.

I feel much more at ease now. That makes a lot of sense. Its just the Met office forecast says milder on sunday with rain, so i figure they are not as up to date

with the latest charts as you guys.. Fantastic..Ive never built a snow man, i am off work on Sunday, so just have to sit back and wait to let it snow...

Whooppeee ...

[Duane S.]

BBC South have it snow free all day Saturday and yet the five day forecast shows it snowing here on saturday! I cannot believe that anywhere in the South (apart from perhaps Cornwall) will have rain over the weekend especially with temps dropping because of lying snow. I bet if you watched each region's forecasts side-by-side it would be a right mish-mash of information. In a nutshell - I agree with you!

BBC will likely still be working off previously supplied data that very had it for as a snow to rain event (for many in the West and South at least) as the front bulldozed it's way through. Things have evolved a bit since then and (I would guess) would filter to the BBC etc as time goes on.

After the near time-frame faxes earlier on, tonight's fax updates are going to be fascinating!

[ChartViewer]

CMA 12Z T72...Yum

Bye bye jet

Edited January 16, 2013 by ChartViewer

[pages]

JMA shows the same evolution as ECM.