Model Output Discussion 12z 04/12/2012

[Stoxs]

All the swings and the like was the start of SACRA because we all thought it was going to happen others belived us and it didnt.

most vivid memony was sat at pc on this forum watching radar of a low heading into southern England that would have produced snow, The one and only Mr Holmes was here also and he was predicting it to pass right through southern England , this was within 12 hours. It completely missed the whole U.k and gave Paris one of their biggest snow falls ever.

It was that time i realised noting could say what the weather would do , except your eyes and the window and a lampost.

[AWD]

The 18z ensembles have definetly trended colder. Far more colder members than there are less cold;

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=479&y=4

Good ensembles IMO with the Op & control never too far away from the mean.

[johnholmes]

All the swings and the like was the start of SACRA because we all thought it was going to happen others belived us and it didnt.

most vivid memony was sat at pc on this forum watching radar of a low heading into southern England that would have produced snow, The one and only Mr Holmes was here also and he was predicting it to pass right through southern England , this was within 12 hours. It completely missed the whole U.k and gave Paris one of their biggest snow falls ever.

It was that time i realised noting could say what the weather would do , except your eyes and the window and a lampost.

ah another eggy face for me!

[london-snow]

I seem to remember it being the other way round unfortunately, west then further east.

I beg to differ there WE,

A poster a few nights showed us various examples of how the models paint the picture further east however within time and into the realiable westward correction was evident on a good few occasions.

May have my wires crossed but that's how i see things at the moment. Westward correction in the models is the way forward for me.

Time will tell.

[Mark Neal.]

The 18z ensembles have definetly trended colder. Far more colder members than there are less cold;

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=479&y=4

Good ensembles IMO with the Op & control never too far away from the mean.

Great News! Lets hope the 00z runs continue a colder trend and we see more model agreement on an easterly ( would be good!).

Anyway the day started with caution when it seemed as if it may go pear shaped, now we are back in a good outlook; still caution remains. Enjoy what is on offer and let's hope we so finally get the BFTE

Mark

[Stoxs]

ah another eggy face for me!

For us all John, not your fault it was just an eye opener to what can go wrong at such a short time frame.

this must have been 5 years ago at least, Models and the like are great for trends but thats it. the rest is now casting .

[fergieweather]

Ok: hot off press: based on new UKV, which represents quite a marked escalation, we are upping snowfall issues to 5cm plus in areas N of London, especially Herts, Bucks, Beds, across Chilterns to Oxon. Concern now re potential disruptive impacts tomorrow AM.

[weather eater]

I beg to differ there WE,

A poster a few nights showed us various examples of how the models paint the picture further east however within time and into the realiable westward correction was evident on a good few occasions.

May have my wires crossed but that's how i see things at the moment. Westward correction in the models is the way forward for me.

Time will tell.

I hope you are right and I'm wrong, but that’s my memory from the last few years. We will have to agree to disagree for now; personally I just hope tomorrows runs give the 18z some backing.

[Stoxs]

Ok: hot off press: based on new UKV, which represents quite a marked escalation, we are upping snowfall issues to 5cm plus in areas N of London, especially Herts, Bucks, Beds, across Chilterns to Oxon. Concern now re potential disruptive impacts tomorrow AM.

Now thats the most profesional RAMP i have ever seen , M4 corridor then AGAIN lol

[london-snow]

Ok: hot off press: based on new UKV, which represents quite a marked escalation, we are upping snowfall issues to 5cm plus in areas N of London, especially Herts, Bucks, Beds, across Chilterns to Oxon. Concern now re potential disruptive impacts tomorrow AM.

Hi Ian,

I realize you are a very busy man right now however with you mentioning snow over the north london region how about south london or will it be a bit too marginal with more chance of rain than snow?

Thanks in advance.

[Severe Siberian icy blast]

Ok: hot off press: based on new UKV, which represents quite a marked escalation, we are upping snowfall issues to 5cm plus in areas N of London, especially Herts, Bucks, Beds, across Chilterns to Oxon. Concern now re potential disruptive impacts tomorrow AM.

Anything pointing to anything more substantial further west or is it the same?!

[fergieweather]

Can't reply to anymore queries re what-where as it would require posting UKV mapped output!! Stress innumerable uncertainties remain given variants of UKV, MOGREPS-R, NAE, GM & EC output on snow areal coverage. However the eastern bias looks more firmly set. 18z UKV a quite marked escalation re potential to N - NW of London and hence tricky forecast issues re possible impacts.

[Severe Siberian icy blast]

Can't reply to anymore queries re what-where as it would require posting UKV mapped output!! Stress innumerable uncertainties remain given variants of UKV, MOGREPS-R, NAE, GM & EC output on snow areal coverage. However the eastern bias looks more firmly set. 18z UKV a quite marked escalation re potential to N - NW of London and hence tricky forecast issues re possible impacts.

Thanks for all your help Ian , your a great help.

[swilliam]

Anything pointing to anything more substantial further west or is it the same?!

If you bug him with will it snow in backyard questions every times he posts then the result will be that we will not get this inside info.

[peterf]

i want an hour on Ian's pc lol.

[Snowy Easterlies]

Ok: hot off press: based on new UKV, which represents quite a marked escalation, we are upping snowfall issues to 5cm plus in areas N of London, especially Herts, Bucks, Beds, across Chilterns to Oxon. Concern now re potential disruptive impacts tomorrow AM.

thats a big upgrade, i wasn't expecting anything tonight or tomorrow apart from maybe a flurry or two

Edited December 5, 2012 by Snowy Easterlies

[Pixel]

http://www.metoffice...Time=1354644000

(-;

[WhiteFox]

Anything pointing to anything more substantial further west or is it the same?!

It's a case of now casting. According to netweather radar there are currently two chunks of moderate snow: just to the west of Birmingham and just to the West of Leicester, both heading in a SE direction. I've verified both by looking at traffic cams on the M1 and M5. Not much settling by the looks of it at the moment, but given colder air digging in chances increase if it strikes at the coldest time before dawn. The other question is whether the PPN intensifies or not. At the moment it doesn't look like the radar echoes would deliver 5cms, so there may be some indication of intensification given the met forecast.

[Snowy Liverpool]

Anyone know where this front is coming from? Is it the one thats bringing ppn over the midlands/southwest England or is there one further North?

[Vince]

You should have been around a few years back just after Xmas If i remember rightly, GFS Nailed an Easterly to it's Mast within T72, And it completely vanished, that was one of the worst pendulem swings on here EVER!

the biggest turnaround in 24 hours was back in Feb 2009( around the 6th or 7th) , GFS had many ensembles around the -10 mark apart from one of the 20 peterb's and that solitary one was right . on this occasion the UKMO was the only model saying no to a severe cold spell and it was proved correct .

[Met4Cast]

Anyone know where this front is coming from? Is it the one thats bringing ppn over the midlands/southwest England or is there one further North?

I think it's a bit of both

[Cheshire Freeze]

Anyone know where this front is coming from? Is it the one thats bringing ppn over the midlands/southwest England or is there one further North?

I suspect its that precipitation expanding slightly westwards just south of Durham on recent radar returns. Stretches E-W with the western end of it over NI

[CrimsonSunset]

Greetings from Cork where it rarely snows! Been lurking here for a while now and ye have helped me learn a lot about charts and weather watching in general It is quite disheartening though knowing how difficult it is to get any snow at all here, too marginal for both easterlies and northerlies, although we did get a couple of inches Jan and Dec 2010. Still useful and fun to keep up to date with this thread though as to even begin thinking about getting the right conditions here it pretty much needs to be widespread in the UK.

I do like the trend of the models this winter so far though and in the last few days in particular, despite the chopping and changing, but things seem to be firming up for some sort of cold outbreak sooner rather than later IMO. While model watching and winter hopes in general often seem more punishing than rewarding for us all in this part of the world, be glad that ye are always far more likely to get interesting winter weather than us across the water.

Anyway, bring on the 00z!

Edited December 5, 2012 by CrimsonSunset

[Bonjangle]

Greetings from Cork where it rarely snows! Been lurking here for a while now and ye have helped me learn a lot about charts and weather watching in general It is quite disheartening though knowing how difficult it is to get any snow at all here, too marginal for both easterlies and northerlies, although we did get a couple of inches Jan and Dec 2010. Still useful and fun to keep up to date with this thread though as to even begin thinking about getting the right conditions here it pretty much needs to be widespread in the UK.

I do like the trend of the models this winter so far though and in the last few days in particular, despite the chopping and changing, but things seem to be firming up for some sort of cold outbreak sooner rather than later IMO. While model watching and winter hopes in general often seem more punishing than rewarding for us all in this part of the world, be glad that ye are are always far more likely to get interesting winter weather than us across the water.

Anyway, bring on the 00z!

Welcome to you , ups and downs in here for well over a 2 month but we love it , well i do for sure

[The watcher]

Greetings from Cork where it rarely snows! Been lurking here for a while now and ye have helped me learn a lot about charts and weather watching in general It is quite disheartening though knowing how difficult it is to get any snow at all here, too marginal for both easterlies and northerlies, although we did get a couple of inches Jan and Dec 2010. Still useful and fun to keep up to date with this thread though as to even begin thinking about getting the right conditions here it pretty much needs to be widespread in the UK.

I do like the trend of the models this winter so far though and in the last few days in particular, despite the chopping and changing, but things seem to be firming up for some sort of cold outbreak sooner rather than later IMO. While model watching and winter hopes in general often seem more punishing than rewarding for us all in this part of the world, be glad that ye are always far more likely to get interesting winter weather than us across the water.

Anyway, bring on the 00z!

Hi there Crimson, head on over to the Ireland thread in the regional section and have a look in, we have a few "Corkies" on here, we look forward to your input and updates.

The Watcher