Model Output Discussion: 12Z (02/12/12) And On...

[A.J]

Good post Gavin, whilst the majority here are looking at the longer term outputs and trends, (and nothing wrong with that by the way) there are some very good synoptics in the shorter term to give many members a 'white surprise' over the next 24-60 hours.....GFS 06z shows a band of rain/sleet/snow moving steadily southwards across the nation giving a covering in many places.....A few charts to illustrate

First of all, T850 temps at 0600, one parameter conducive to snowfall in place, with a pool of colder T850's flooding southwards

Secondly dewpoints at 0600 & 1200z, a second tick in the box for snowfall parameters, again colder dew poimts flood southwards as shown by the snapshot charts

and also the progged preciptation & precipitation type charts for the same time periods

as you can see, snow potential for many parts over the next 24 or so hours, some areas could see substantial accumulations......and we haven't even touched on the potential for thursday night into friday!

[Polar Maritime]

Yes aj, some nice cold -8/-9 uppers getting pulled into the North and Central England during Wednesday

http://imageshack.us...viewimage1.png/

Edited December 4, 2012 by Polar Maritime

[MKN]

Good post Gavin, whilst the majority here are looking at the longer term outputs and trends, (and nothing wrong with that by the way) there are some very good synoptics in the shorter term to give many members a 'white surprise' over the next 24-60 hours.....GFS 06z shows a band of rain/sleet/snow moving steadily southwards across the nation giving a covering in many places.....A few charts to illustrate

First of all, T850 temps at 0600, one parameter conducive to snowfall in place, with a pool of colder T850's flooding southwards

Secondly dewpoints at 0600 & 1200z, a second tick in the box for snowfall parameters, again colder dew poimts flood southwards as shown by the snapshot charts

and also the progged preciptation & precipitation type charts for the same time periods

as you can see, snow potential for many parts over the next 24 or so hours, some areas could see substantial accumulations......and we haven't even touched on the potential for thursday night into friday!

Probably worth reposting in the midlands thread. Only 5 posts in there today given the potential I think people aren't convinced even at +24

[Severe Siberian icy blast]

Good post Gavin, whilst the majority here are looking at the longer term outputs and trends, (and nothing wrong with that by the way) there are some very good synoptics in the shorter term to give many members a 'white surprise' over the next 24-60 hours.....GFS 06z shows a band of rain/sleet/snow moving steadily southwards across the nation giving a covering in many places.....A few charts to illustrate

First of all, T850 temps at 0600, one parameter conducive to snowfall in place, with a pool of colder T850's flooding southwards

Secondly dewpoints at 0600 & 1200z, a second tick in the box for snowfall parameters, again colder dew poimts flood southwards as shown by the snapshot charts

and also the progged preciptation & precipitation type charts for the same time periods

as you can see, snow potential for many parts over the next 24 or so hours, some areas could see substantial accumulations......and we haven't even touched on the potential for thursday night into friday!

But we all no the gfs isn't a short term model, the leading model by a mile for events 24-36 hours ahead is the nae, and what's that showing? Not much , It will be nice to see a supprise , but need to see the nae suggest it , only then will the bbc follow suit.

[Ian Brown]

The METO are talking about wintry showers in far Eastern areas with rain and milder weather at times in the far South and West. Hedging their bets a little but they are obviously see as it being an end of the line easterly at best.

That sort of situation won’t sustain for long and by synoptic implication the block will not be aligned how we then need it to progress an easterly across all parts. We would then have to have the retrogression to Greenland that GP is talking about to keep us on the cold side of the PFJ.

[Dave Kightley]

Haha Funny enough i was talking to a friend about how snowless Poole is as i'm staying there this week. The Gfs is very funny as a blue pixel covers the Weymouth area tomorrow midday. I'm glad i dont live here during the Winter. Being 82 asl is bad enough lol

[AWD]

Place yer bets now;

http://www.wetterzentrale.de/pics/MT8_London_ens.png

In FI we could have uppers as high as +8c or as low as -13c.

Talk about scatter. Could go either way.

[Buriedundersnow]

Although longer term prospects remain uncertain at the moment the next 24 hours will see a band of snow moving down from the eastern side of Scotland right down to Humberside with 5cm to 10cm possible in some parts by Wednesday morning

Moves into Scotland

By 18:00 it extends into Northumberland

By 00:00 the snow is covering north east England right down to Humberside

Now the latest from the Beeb suggests it will turn to rain as it moves further south but this could be one to watch

dont listen to the bbc they said the other night the snow in scotland would turn to rain here the other night and i'm right at sea level and it stayed as snow all night

[stainesbloke]

Good post Gavin, whilst the majority here are looking at the longer term outputs and trends, (and nothing wrong with that by the way) there are some very good synoptics in the shorter term to give many members a 'white surprise' over the next 24-60 hours.....GFS 06z shows a band of rain/sleet/snow moving steadily southwards across the nation giving a covering in many places.....A few charts to illustrate

First of all, T850 temps at 0600, one parameter conducive to snowfall in place, with a pool of colder T850's flooding southwards

Secondly dewpoints at 0600 & 1200z, a second tick in the box for snowfall parameters, again colder dew poimts flood southwards as shown by the snapshot charts

and also the progged preciptation & precipitation type charts for the same time periods

as you can see, snow potential for many parts over the next 24 or so hours, some areas could see substantial accumulations......and we haven't even touched on the potential for thursday night into friday!

Liking those precip charts a lot!!

[Suburban Streamer]

Good post Gavin, whilst the majority here are looking at the longer term outputs and trends, (and nothing wrong with that by the way) there are some very good synoptics in the shorter term to give many members a 'white surprise' over the next 24-60 hours.....GFS 06z shows a band of rain/sleet/snow moving steadily southwards across the nation giving a covering in many places.....A few charts to illustrate

First of all, T850 temps at 0600, one parameter conducive to snowfall in place, with a pool of colder T850's flooding southwards

Secondly dewpoints at 0600 & 1200z, a second tick in the box for snowfall parameters, again colder dew poimts flood southwards as shown by the snapshot charts

and also the progged preciptation & precipitation type charts for the same time periods

as you can see, snow potential for many parts over the next 24 or so hours, some areas could see substantial accumulations......and we haven't even touched on the potential for thursday night into friday!

agree about potential although at this range surely the nmm/nae is a better bet?

[frosty ground]

The METO are talking about wintry showers in far Eastern areas with rain and milder weather at times in the far South and West. Hedging their bets a little but they are obviously see as it being an end of the line easterly at best.

That sort of situation won’t sustain for long and by synoptic implication the block will not be aligned how we then need it to progress an easterly across all parts. We would then have to have the retrogression to Greenland that GP is talking about to keep us on the cold side of the PFJ.

I don't think the Met office are thinking that(but they are obviously see as it being an end of the line easterly at best.), Their thoughts were summed up by Ian F earlier and while the solution to the problem is twofold they back for now the ECM, but both outcomes are entirely possible?

[A.J]

But we all no the gfs isn't a short term model, the leading model by a mile for events 24-36 hours ahead is the nae, and what's that showing? Not much , It will be nice to see a supprise , but need to see the nae suggest it , only then will the bbc follow suit.

The best short term model is the model of opening the window and looking up...lol......I take your point Shaun, but with respect I'd expect the GFS and any mid range model to be more reliable at T24 than T240!.....

Anyhoos, back on topic, my post was more to highight that the potential for snowfall as modelled over the next 24-60 hours has been somewhat overlooked

a quick edit, I did post in the South West regional thread that whilst the 06 GFS output had quite a strong snow signal, the higher resolution NMM downplayed the snow signal, at least in south western parts, but still gives a moderate to strong snow signal for Scotland, Northern England, the Midlands, and the South East (away from the coast) for tomorrow morning

Edited December 4, 2012 by ajpoolshark

[MR EXTREMES]

The METO are talking about wintry showers in far Eastern areas with rain and milder weather at times in the far South and West. Hedging their bets a little but they are obviously see as it being an end of the line easterly at best.

That sort of situation won’t sustain for long and by synoptic implication the block will not be aligned how we then need it to progress an easterly across all parts. We would then have to have the retrogression to Greenland that GP is talking about to keep us on the cold side of the PFJ.

i think you could be right ian i think the setup to the north east and north west is great to see but nothing is coming into the right timeframe i think long distance model watching has put me off.

totally dissapointment nick sussex and others including the met office have step back from the views two weeks ago ive been watching this cold setup for over 3 weeks now and although it is colder theres no sign from the models that things are set to get anymore wintry than they are now.

the gfs ecm and ukmo which i might add has been excellent of late are all clear on one thing after a week or two of colder than average it sets back to a more average setup.

although i teleconnections are pointing towards a shift to colder the models clearly have more input than us and are seeing the teleconnections as not favourable for a more sustained wintry outcome.

i think its a case of close but not close enough i do however feel jan or feb could be better months if colder is what your looking for.

the vortex although weakened has still enforced a strong influence on our wheather this could well be due to its location and strength after all there has also been very little activity in the strat warming but more cooling of the vortex.

[Mark Neal.]

The best short term model is the model of opening the window and looking up...lol......I take your point Shaun, but with respect I'd expect the GFS and any mid range model to be more reliable at T24 than T240!.....

Anyhoos, back on topic, my post was more to highight that the potential for snowfall as modelled over the next 24-60 hours has been somewhat overlooked

a quick edit, I did post in the South West regional thread that whilst the 06 GFS output had quite a strong snow signal, the higher resolution NMM downplayed the snow signal, at least in south western parts, but still gives a moderate to strong snow signal for Scotland, Northern England, the Midlands, and the South East (away from the coast) for tomorrow morning

Good to see you post in here AJ. I did touch on the potential in the SE Thread over the last 12 hours. Could be an interesting surprises, GFS has been consistent on last 2/3 runs for snow here, be good to see the NAE come on board on 12z- but I think it will end up just being a now casting event . Wonder if the front will keep up intensity, I think it will weaken quite a bit with many areas perhaps getting just a dusting.

Time will tell

Edited December 4, 2012 by Mark Neal.

[london-snow]

I don't think the Met office are thinking that(but they are obviously see as it being an end of the line easterly at best.), Their thoughts were summed up by Ian F earlier and while the solution to the problem is twofold they back for now the ECM, but both outcomes are entirely possible?

I however tend to agree with Ian on this one as much as i hate to admit it.

Yes the met may well be sitting on the fence here and judging by the amount of scatter in the ensembles & difference in the models who would blame them to be frank.

What concerns me however is the constant message of threats of attacks from the south west and the threat of milder interludes. Which suggests that colder air cannot become established and embedded to allow a significant cold spell of note to take place. It may well be that in further output things will be edged further west which will allow margin for error but for those saying its a dead cert think again. It also proves that despite all these background indicators being so great and primed to aid us to get the cold weather it does not necessarily mean that we will get it.

Let's hope and prey that it will be a quick solution one way or another for the sake of some.

[Met4Cast]

Good post Gavin, whilst the majority here are looking at the longer term outputs and trends, (and nothing wrong with that by the way) there are some very good synoptics in the shorter term to give many members a 'white surprise' over the next 24-60 hours.....GFS 06z shows a band of rain/sleet/snow moving steadily southwards across the nation giving a covering in many places.....A few charts to illustrate

First of all, T850 temps at 0600, one parameter conducive to snowfall in place, with a pool of colder T850's flooding southwards

Secondly dewpoints at 0600 & 1200z, a second tick in the box for snowfall parameters, again colder dew poimts flood southwards as shown by the snapshot charts

and also the progged preciptation & precipitation type charts for the same time periods

as you can see, snow potential for many parts over the next 24 or so hours, some areas could see substantial accumulations......and we haven't even touched on the potential for thursday night into friday!

NMM Model isn't quite as enthusiastic with the snow risk, neither is the NAE - I'd say a mix of rain, sleet and snow, accumulations to lower levels unlikely

[Cheshire Freeze]

TBH I don't think anyone can dismiss a spell of snowy weather across the UK in the 7-14 day timeframe. Let's look at this holistically for a moment.....

Westward march of cold air across the continent, eastward progression of Atlantic LP systems.....the risk of a battleground scenario certainly there if Scandi high doesn't sink faster than the Titanic. Remember if the cold upper air gets close we only require a slight surface flow from the e/se and the precipitation from any incoming dynamic front will be snow.....especially the further se you are.

Model output doesn't look as good today I'll concede but that means nothing given how much the NWP is changing on a daily basis!

[A.J]

NMM Model isn't quite as enthusiastic with the snow risk, neither is the NAE - I'd say a mix of rain, sleet and snow, accumulations to lower levels unlikely

Hi Dan, see my later post as I commented on this.....simply highlighting the seemingly overlooked potential.....the further east you are, the higher likelyhood of possible accs.....at the end of the day, local variances of , elevation/dewpoints, and wet bulb temperatures will make a difference to who gets a covering whlst 5 miles down the road get an icy mix

[SnowObsessor90]

All this does is reaffirm my personal thoughts from the other night about strong Greenland height rises being the preferred option. We can only hope that conditions at some point will become more favourable for such a setup otherwise I can this winter being full of near misses and marginality with some getting lucky but others less so.

Edited December 4, 2012 by Anonymous21

[Frosty.]

The METO are talking about wintry showers in far Eastern areas with rain and milder weather at times in the far South and West. Hedging their bets a little but they are obviously see as it being an end of the line easterly at best.

That sort of situation won’t sustain for long and by synoptic implication the block will not be aligned how we then need it to progress an easterly across all parts. We would then have to have the retrogression to Greenland that GP is talking about to keep us on the cold side of the PFJ.

Good post terry, kind of sums up where we are, those stonking beasts from the east only exist inside super computers where they remain harmless, never get let out of their cages in reality. I think it will be a cold outlook though, but with little or no snow.

[latitude]

Good post terry, kind of sums up where we are, those stonking beasts from the east only exist inside super computers where they remain harmless, never get let out of their cages in reality. I think it will be a cold outlook though, but with little or no snow.

Except they are very real in Europe? February this year springs to mind, we just missed that. Maybe the models will just tease us with those February synoptics all winter.

Edited December 4, 2012 by latitude

[NO LONGER POSTING]

Liking those precip charts a lot!!

Me too as I live about 2 miles from you lol! But I think it is going to be a bit touch and go TBH..Lamp post watching and radar watching, let's just see what happens, the quicker the cold air can dig in the better.

Edited December 4, 2012 by Surrey

[Frosty.]

Except they are very real in Europe? February last year springs to mind, we just missed that. Maybe the models will just tease us with those February synoptics all winter.

Im very open to upgrades, infact I will relish them because I adore snow and sharp frosts, but terry made a good point, it currently looks like the uk would end up with the dregs of the western limit of the cold as synoptically things have taken a downturn so far today, hoping for changes just like everyone else but we have seen this phony FI promise in the past, but it still looks like a cold outlook is probable with frost and freezing fog although the milder atlantic will probably end up being too close for comfort, at least for the south and west, the north and east might do better as the gfs 00z showed.

[stainesbloke]

Me too as I live about 2 miles from you lol! But I think it is going to be a bit touch and go TBH..Lamp post watching and radar watching, let's just see what happens, the quicker the cold air can dig in the better.

Looks like lamppost watch tomorrow then Unfortunately we live in an area that is often the last place to see snow, we need some really cold air to dig in. It's very possible IMHO, I reckon it's going to be a while longer tho. Still, pretty good charts for the beginning of winter...plus much of Europe now is getting cold.

[SMU]

With the 12s only an hour away we should expect the Easterly- if its coming to at least be moving towards the 168 arena now-

I havent even looked at the 06z suite- however its the 06z, so why worry.

This is a BIG output tonight- expect the big 3 to line up at 120, but possibly not 144!

Expecting ( but also hoping) to cement some foundations today....

S