Model Output Discussion - Tuesday 20:25 -->

[Snowaddict]

This 06Z run is a thing of pure beauty...

What would we have all given to see such synoptics during the past winters, at any time!

For those who cherish cold and wintry synoptics, from T+120 onwards these runs are something to truly behold.

Don't worry about the finer details...

The main evolution is shaping up very well with the HP cell cut off by T+102 - Not deep in FI, but T+102 which is amazing.

Snowfall will be a great bonus but to see these synoptics is simply fantasitc.

Oh and did I mention that the Parallel run has widespread cold uppers across the British Isles @ T+132

http://www.meteociel...ode=1&runpara=1

This is simply astounding stuff guys, cherish these runs

Edited December 9, 2009 by Snowaddict

[Just Before Dawn]

Slower , but the same result , Trend over the last few runs has been to move that really cold pool of air to the North East towards the Uk , and that is why it is slower as it is taking a SW route to the Uk instead of moving directly Westwards towards us. This is all very good because air as cold as what is heading towards us will take some shifting , and the Atlantic would have to make several snowy attempts before it even stands a chance of winning the battle.

Indeed - and the Speed by which we get cold air will chop and change over the next few days - this run is nice if you take it at face value because the SW track the cold air takes means a longer sea track over a warmish North Sea, so you'd expect convective showers to be fairly impressive. It'll change, of course.

Edited December 9, 2009 by Just Before Dawn

[snowmadchrisuk]

Seems my post was deleted for posting on the 06Z in the model discussion thread.

Anyway as I said in my deleted post the cold is delayed but the longer term potential was better. However even at +144 we are going to see many more changes but the general pattern remains intact which is good news.

What a snowfest in F.I.

Yes I think reef is on one this morning, You sit here waiting for comments on your post then you realize it has been deleted. I have looked and looked again and you are right, with that sort of flow it would be Snow just getting deeper and deeper. London wouldn't handle it. I have a great deal of respect for you TEITS because I don't know if you remember but you predicted this 3 weeks ago .

Chris

[Richie V]

Time to put the razor blades away chaps, It WILL get much colder with a real treat instore towards the end of 170h. Just relax and enjoy, give yourselvs a 12 hr break from the models. I'm not coming back until at least the 18Z today

[TEITS]

[quote name='snowmadchrisuk' date='09 December 2009 - 11:39 ' timestamp='1260355141' I have a great deal of respect for you TEITS because I don't know if you remember but you predicted this 3 weeks ago .

Chris

Edited December 9, 2009 by THE EYE IN THE SKY

[West is Best]

The 06z is a remarkable run. Absolutely outstanding. My big concern at the moment is the high pressure link up at T114 onwards. We HAVE to see the Greenland high hoovering up 'our' one to create the true holy grail for cold setups: northerly blocking. Don't care if that kind of evolution gives people the jitters because serious snowfall in this country will nearly always come off that sort of setup which sees incursions from the south into the block. The 6z is absolute holy grail territory, and matched by an increasing number of other model outputs. I'm still going to remain cautious because we've seen failed link-ups before, almost at the last minute. Want to see this one come inside T48 for the real snowgate potential to be opened up.

Do you think someone has a sense of humour? I mean, perfectly timed for the climate change conference or what?! Wouldn't it be a thing of great wonder and beauty if the delegates were all snowed in at Copenhagen

Edited December 9, 2009 by West is Best

[Cecil Hogmanay Melchett]

I love 06z,what an FI,some places would se snowed in of that came off.

Have to say though the forecast from a certain bbc presenter for next week was NOT what i was expecting to hear.

Wind and rain,WTF?EDIT:it was D.Brett on 5live,talking about the Atlantic breaking

through the high pressure building over the country.

maybe we should be a tad more concerned about that ukmo run than we thought.

Edited December 9, 2009 by happy days

[Stu_London]

06z GFS delivers maybe the run of the decade with the closest to a Jan 1987 event I've seen on model output

Shame it is +252 - but a cold spell of sorts and maybe some snow now looks likely.

[snowmadchrisuk]

Parallel is Fantastic yet again , and once the cold air get's here on Friday night it leaves it over us until the end of it's run at +384 . And the arrival of the First -5's will be in the 48 hr charts tomorrow , so there is very little way out of a cold spell now.

[Methuselah]

Yes I think reef is on one this morning, You sit here waiting for comments on your post then you realize it has been deleted. I have looked and looked again and you are right, with that sort of flow it would be Snow just getting deeper and deeper. London wouldn't handle it. I have a great deal of respect for you TEITS because I don't know if you remember but you predicted this 3 weeks ago .

Chris

Please guys? Try and remember that we are trying our best to keep posts confined to the relevant threads...I realize that our decisions may appear to be arbitrary on occasions; but, you'll all be doing yourselves a favour by posting in the right place...

Either that or, come the first snowflake, we'll all be in mayhem! :blink:

Help us to help you? :blink:

[reef]

Yes I think reef is on one this morning, You sit here waiting for comments on your post then you realize it has been deleted. I have looked and looked again and you are right, with that sort of flow it would be Snow just getting deeper and deeper. London wouldn't handle it. I have a great deal of respect for you TEITS because I don't know if you remember but you predicted this 3 weeks ago .

Chris

For your information I havent removed anything. However if people actually posted stuff that was on-topic then maybe it would stay where it is? The team are working overtime at the moment in an effort to keep the threads clear of rubbish which makes them confusing to pickany information up on.

[snowmadchrisuk]

Please guys? Try and remember that we are trying our best to keep posts confined to the relevant threads...I realize that our decisions may appear to be arbitrary on occasions; but, you'll all be doing yourselves a favour by posting in the right place...

Either that or, come the first snowflake, we'll all be in mayhem! :blink:

Help us to help you? :blink:

Fair enough and sorry , I just disagreed with him on some posts, when you are trying to discuss the 6z you can not keep flipping from thread to thread it get's confusing . Will personally try and make sure I stay on topic from now on anyway , and no offence was intended to reef .

[Frosty.]

Cheers mate im glad someone remembered. I can smell an E,ly in a force 10 gale.

What I love about the current model output including the GFS parallel is the astonishing charts are appearing at +120 and not +384 like we're used to seeing. Now of course the detail isn't sorted i.e flow ENE,ly, NE,ly etc or how and when the cold airmass reaches our shores. However the general theme of blocking to our N remains intact and within the accepted reliable timeframe.

Hopefully come this evening the UKMO will trend towards the ECM/GFS and todays 0Z was just a one off.

Seems I have quoted my own post. How I did that I don't know!

Why is darren bett saying it will turn milder next week then?

Amazing GFS 06z, simply astounding, gobsmacking run and now we have the GFS and ECM and GEM and NOGAPS to name but a few of the models which are going full on for a siberian blast developing during the course of next week, too early to start guessing about snow amounts but there will be plenty of snow to share around if these charts verify.

Edited December 9, 2009 by Frosty039

[Methuselah]

Fair enough and sorry , I just disagreed with him on some posts, when you are trying to discuss the 6z you can not keep flipping from thread to thread it get's confusing . Will personally try and make sure I stay on topic from now on anyway , and no offence was intended to reef .

Thanks Chris. Much appreciated! :unsure:

[NorthantsSnow]

The 06z does have a "classic British winter" feel about it. Reminds me of some of the great winter charts from yesteryear that people dig up from the archives every now and again. The synoptics looks pretty much perfect on this run for delivering widespread cold & snow and for a lengthy period as well. Not marginal either with increasingly cold uppers as the run progresses. (admittedly it takes a while to get going properly)

The ECM seems to have similar ideas this morning. The UKMO is definitely the weak link of the models with a disappointing output today, so we'll have to see if there are any changes to their LRF later or whether they still favour a colder solution as they did yesterday.

[SMU]

The 06z is a remarkable run. Absolutely outstanding. My big concern at the moment is the high pressure link up at T114 onwards. We HAVE to see the Greenland high hoovering up 'our' one to create the true holy grail for cold setups: northerly blocking. Don't care if that kind of evolution gives people the jitters because serious snowfall in this country will nearly always come off that sort of setup which sees incursions from the south into the block. The 6z is absolute holy grail territory, and matched by an increasing number of other model outputs. I'm still going to remain cautious because we've seen failed link-ups before, almost at the last minute. Want to see this one come inside T48 for the real snowgate potential to be opened up.

Do you think someone has a sense of humour? I mean, perfectly timed for the climate change conference or what?! Wouldn't it be a thing of great wonder and beauty if the delegates were all snowed in at Copenhagen :unsure:

I cant really add much to the comments of the net weather fanatics this morning- although I must just add this one chart in-

I doubt Lakeside & bluewater will be busy with XMAS eve sales this year-

http://www.wetterzentrale.de/pics/Rtavn37217.png

Minus 4 MAX-

Steve

[ISAAC]

GFS has a brillaint FI, T120 not as good as the cold uppers backs off again, any precipiation will be of a wintry mix of best on monday to wednesday morning.

Cold but no deep cold scenario from that chart in the reliable timeframe.

[Tom Montalbano]

That little low moving down the north sea takes its time but it is like a finger stuck in a dyke and it unleashes some big cold and a ferocious north easterly gale behind it!! Of course it is not going to go exactly like the 06z suggests, but next week looks very interesting indeed to say the least!

Was that an intentional pun Tamara! :unsure: The 850 -5 isotherm seemed to be held over Holland for what seemed like an eternity before it finally moved westward from the Dykes! The low actually takes about 2 days from the Norwgian coast to Belgium, probably under pressure from everybody shouting "Move South".

If that run verifies I would expect a rain to snow situation from the east.

http://charts.netweather.tv/gfsimages/gfs.20091209/06/168/h850t850eu.png

http://charts.netweather.tv/gfsimages/gfs.20091209/06/180/h850t850eu.png

http://charts.netweather.tv/gfsimages/gfs.20091209/06/168/prectypeuktopo.png

http://charts.netweather.tv/gfsimages/gfs.20091209/06/180/prectypeuktopo.png

We then get another low drop SW, with more widespread snow, which is then absorbed by the main low over the Bay of Biscay.

Then bitter easterly for the whole U.K and as the wind drops out some severe frosts would occur combined with snow cover. Hint of a re-load northerly towards Xmas day.

Stop! I'm getting way ahead of myself there but that has to be one of the best ever runs I've seen on the net.

No doubt its going to get colder and drier than it has been lately, no need to be specific about the fine detail, says he, having done just that!

A word of caution, its not in the bag yet, I will be more confident if these sort of runs are still occurring come Friday/Saturday. Its that t96 thing from past experience.

Regards,

Tom

[Barb]

500's: http://91.121.94.83/modeles/gfs/run/gfs-0-180.png?6

Wow, just look at all that cold to our E/NE. The only thing we need is to tap into it and with such strong Northern blocking it's difficult to see how we could not (knowing this country it'll probably find a way). Once that cold is over us then we're in business. Any atlantic incursions such as what UKMO +144 is showing will not move that mass out of the way - the likely result would be megablizzards. So much potential showing, of course it's still just potential I'm not going to start planning for my igloo construction just yet.

Edited December 9, 2009 by Barb

[nick sussex]

The gfs 06hrs run maintains the balance between block and lows to the sw very well, so for the most part the uk stays very cold with some wild snowy weather towards the south.

This however is one of those situations where progging how far lows will come north is extremely difficult, so if you're in the far south you never know will the low head too far north, if i was still living in Sussex i'd prefer a strong ene flow with snow showers simply because i won't be nervously watching how far lows get.

On the opposite side you do indeed get the heaviest and most prolonged snow with cold/mild battles. If the ukmo does come on board then you want the trend to remain an elongated area of lower heights to the south the further east into the med the better.

[cooling climate]

For your information I havent removed anything. However if people actually posted stuff that was on-topic then maybe it would stay where it is? The team are working overtime at the moment in an effort to keep the threads clear of rubbish which makes them confusing to pickany information up on.

Charming, although I do understand what you and the other mods are saying.

ECM extended ensembles in case it has not been mentioned are again very good. Apart from the control and

a minority of others they are going for a protracted cold spell.

Edited December 9, 2009 by cooling climate

[Duncan McAlister]

Am I right in using this formula for working out the thicknesses?

Say the pressure is 1020 and colour corresponds to 528dam on the chart on the right of the map.

1020-1000 = 20

20*0.8 = 16

528 - 16 = 512dam.

[SMU]

This is the formula to work out thickness-

Roughly 500 height-((SLP-1000)*0.87

Steve

[reef]

Certainly very interesting synoptics on the GFS 6z, which if they came off would give a noteworthy snow event to much of the UK. The problem I have with the run is that small low pressure over the North Sea at T+168. These little features are notoriously hard to forecast and often end up much further North than the GFS is showing.

One bonus though is that this run would lead to a white christmas in places.

[NorthantsSnow]

GFS has a brillaint FI, T120 not as good as the cold uppers backs off again, any precipiation will be of a wintry mix of best on monday to wednesday morning.

Cold but no deep cold scenario from that chart in the reliable timeframe.

Even in the reliable timeframe I could plausibly see snow flurries for the SE with -5 air flirting with the SE corner and an LP close by. It's after that that things start to get really interesting for all of us, as the floodgates open from the NE and the coldest air converges on us. :unsure: