Winter Model Discussion - Cold Hunting -12Z 03/01/13

[Weathizard]

Am I the only one finding people mentioning last months failure really irritating? It is absolutely not the same in any way. Look back at the threads, yes we had odd fantastic runs (that ECM) but generally when we had very cold GFS runs it wasn't supported and the ens were very unimpressive. This time we have -AO, destroyed vortex, warm stratosphere all over the pole, more favourable MJO.

Find it strange people keep referring back, its like judging a new partner because you've been scarred in the past. Anyone I'm off to Brighton vs Newcastle now, have a nice afternoon guys.

[bluearmy]

London ens

Temperature:

A cold set of ensemble members there, with the majority trending to 6c or colder. ECM was a colder option, but not unsupported. GFS follows the mean well.

Wind;

Not much to say really, both EC & GFS well supported and a spread as you would expect in FI.

Precipitation;

Slightly wetter than yesterday's, with the GFS taking a wetter route compared to the drier ECM. With these ensembles being a bit wetter & colder than yesterday's, this could suggest that with time, pressure to the north could retrogress's far enough away from the UK, but still keeping the colder air over us, allowing for precipitation to fall, increasing the probability of snowfall.

Awd, the blue line is gfs op. the red line is ecm op. the grey lines are the 50 ecm ens members. I wouldnt be taking any notice of the blue line after day 8.

[AWD]

Awd, the blue line is gfs op. the red line is ecm op. the grey lines are the 50 ecm ens members. I wouldnt be taking any notice of the blue line after day 8.

I know? My post stated that didn't it? Or have I missed something?

[lorenzo]

ONLINE!!

Glad to see that, our most passionate cold hunter will be around as the strat serves up some monster action, would not have been the same without Cobra or Stellar runs getting ramped.

06z looking very good, the Pacific high at 192 feeding heights will into the Arctic with a strong flow, the Greenland high looking to establish at 300 mark. Another run with the NH gyre as GP so explicity described as pancaking the tropopause, a post cited elsewhere as weather pornography and would be inclined to agree, again showing in later frames of low res.

Wave 2 worth tracking down over the next 5 days, this the current peak on ECM, will it increase towards verification again and bring in cross polar activity sooner, and another favourite chart, this time, Heat flux..

Too much eye candy!!

[Cloud 10]

Amazing that the last two GFS +384 charts from the 00z and the 06z are so similar.

A very rare occurrence in the very deepest reaches of FI!

[Summer Sun]

Hello everyone.

New to Netweather although I have followed the discussions on here for quite a while. I find the informative posts on here really interesting and hope to learn from you guys over time.

Self confessed bias towards preferring cold weather, but to be honest a general fascination with all types of weather. In my opinion we should consider ourselves very fortunate to live in such a varied climate. That's what makes the model watching so fascinating.

Can anyone suggest a good link for me to a site that provides all the model updates.

Thanks.

Welcome to Netweather the main 3 models can be found here (GFS, ECM and UKMO) - http://www.jp2webdes...o.uk/ds/gfs.htm

Additional models plus the main 3 can also be found here - http://translate.goo...tes.php&act=url

Edited January 5, 2013 by Gavin.

[Froze were the Days]

Not to sure I liked that 06Z run - looks very complex, notice how we depend on a stronger Iberian High to link up with the rather 'flabby' looking northern HP close to the UK and then maybe draw in some continental air. Still really not sure we'll see anything significantly cold before mid-month, prospects do look good in the longer term but can't help feeling that the Iberian High could put a clanger on us and draw the 'potential' High being too far south which fails to link up with the Greenland position later. Just thoughts, and maybe looking at the synoptics with a glass half empty.

Edited January 5, 2013 by Froze were the Days

[nick sussex]

Not to sure I liked that 06Z run - looks very complex, notice how we depend on a stronger Iberian High to link up with the rather 'flabby' looking northern HP close to the UK and then maybe draw in some continental air. Still really not sure we'll see anything significantly cold before mid-month, prospects do look in the longer term but can't help feeling that the Iberian High could put a clanger on us and draw the 'potential' High being too far south which fails to link up with the Greenland position later. Just thoughts, and maybe looking at the synoptics with a glass half empty.

As long as you get an amplified trough to the west then the high will be forced northwards ahead of it. The evolution is something we've seen in recent years.

Of course at this time its hard to say how far north the pattern will be and this will effect cold advection into the UK. I think its looking like the first chance of an easterly pre 144hrs is going to be difficult because the model trend is to not disrupt enough energy se'wards.

We will though have to deal with a shortwave likely to be forced se through the UK after that time as the energy splits over the UK.

[Kentish Snowman in Yorks]

Being slap bang under a high pressure in early January is no bad thing though so even if the 6z verifies it would feel very seasonal with widespread frost and fog and hopefully some sunny crisp days to boot....lovely!

[Ian Brown]

Am I the only one finding people mentioning last months failure really irritating? It is absolutely not the same in any way. Look back at the threads, yes we had odd fantastic runs (that ECM) but generally when we had very cold GFS runs it wasn't supported and the ens were very unimpressive. This time we have -AO, destroyed vortex, warm stratosphere all over the pole, more favourable MJO.

Find it strange people keep referring back, its like judging a new partner because you've been scarred in the past. Anyone I'm off to Brighton vs Newcastle now, have a nice afternoon guys.

I see what you mean with regard to last months failure - but there are many ways for it to 'fail' and those of us who have been around for a long time have seen many failures.

This looks promising here :

http://www.wetterzentrale.de/pics/archive/ra/2001/Rrea00120010131.gif

Er maybe not :

http://www.wetterzentrale.de/pics/archive/ra/2001/Rrea00120010202.gif

Oh no :

http://www.wetterzentrale.de/pics/archive/ra/2001/Rrea00120010204.gif

Never count your chickens.

[Iceaxecrampon]

Weighing in with the Cumbrian ensembles looking at the near time frame big single day drop progged around the 8th and 9th then a good mean trend downwards bottoming out around the 19th.

Ian

[bluearmy]

the 06z gefs are more blocked week 2 and the troughing to our east finds it harder to influence (in general terms). still, better than mobile and if this a swing of the pendulum in the wrong direction, those seeking cold will be happy enough with the outcome.

EDIT: the further they go, the less i like the suite. i rather hope the trend of the 12z in week 2 is a tad different. (someone check we haven't had a solar flare overnight!)

Edited January 5, 2013 by bluearmy

[ghrud]

SnowTornado, on 05 January 2013 - 10:36 , said:

I knew someone would mention the stratosphere. Warming there that's set to occur are still forecasted warmings. So if the forecast for that to happen is wrong then the implications to our weather towards a colder outlook may not happen. People always seem to think stratospheric warming and AO Nao and all the other teleconections GP talks about are guarenteed. They are still all forecasts. And as with the weather forecasts they don't always occur

And, why not 'mention the stratosphere'?

You are right enough about NAO and AO, however: they are nothing more than indices that are derived from what the synoptic models are predicting...The state of the stratosphere, in contrast, has enormous potential as a forecasting tool; which, IMO, fully justifies the current interest in it...

Yes I agree it is okay to mention the SSW as is part of the weather systems and will have an impact. I think the point being made though is that too much hope is being pinned on an event that may well have no effect at all in this part of the world. It’s being treated as a panacea for all our cold winter (lack of) woes. Let’s talk about it, but not like it's the answer to the world the universe and everything.

Edited January 5, 2013 by ghrud

[winterof63]

Welcome to Netweather the main 3 models can be found here (GFS, ECM and UKMO) - http://www.jp2webdes...o.uk/ds/gfs.htm

Additional models plus the main 3 can also be found here - http://translate.goo...tes.php&act=url

Thanks for the link.

[Frosty.]

Really don't know why some are harping on about Dec because what is now occuring in the Stratosphere is a different kettle of fish. We all realise what could go wrong and don't need telling every 5 mins.

Yes TEITS the strat was cold and now it's warming up nicely, totally different to before. We have had rubbish weather over christmas but the models are now firming up on a much colder pattern which is entirely due to the strong stratospheric warming event and i'm really optimistic about the outlook now.

[That ECM]

As long as you get an amplified trough to the west then the high will be forced northwards ahead of it. The evolution is something we've seen in recent years.

Of course at this time its hard to say how far north the pattern will be and this will effect cold advection into the UK. I think its looking like the first chance of an easterly pre 144hrs is going to be difficult because the model trend is to not disrupt enough energy se'wards.

We will though have to deal with a shortwave likely to be forced se through the UK after that time as the energy splits over the UK.

Hi nick.

Firstly, many thanks for all your imput, especially considering your locality. Your imput for our area is much appreciated. Looking at it from your area, it's is looking really good and if this was showing over us, most would not be able to curb their enthusiasm.

Lets hope that the high pressure, currently modelled to be over or near us, can drift north west and the finger of cold uppers can be come a bit more crooked and drag some over us.

Many thanks again fella.

Regards.

That ECM

[MR EXTREMES]

very cold to the east northeast and running through france pushing west gem t144 looking good.

ukmo t144 ofcoarse all thease have diffrent low heights in diffrent places but once again cold pushing east south east trend sametime scale close to the same depth of cold deep cold in much of eastern and western europe nearly there getting close already.god only knows what the second and 3rd warmings will do but good coldie stuff going on.

gfs fair bit slower to evolution but at t192 hrs again cold surge moving east to west and again europe freezer.

gfs i think has been outstanding but not top of the verification list.

ecm top of the verification list at same time frame as gfs bigger push west and bingo streamers anyone loving this and it also in the next two frames does show a rise in temps and 850hpa but screams reload from northeast.

but must remember surface cold get underestimated in any cold setup so all good from ecm.

jma t192 slower but same evolution different setup but still cold surge east to west.

gefs t180hrs same evolution cold surge east west or slightly more sw either way another good sign.

no gaps t144 again looking good and this is updating right this minute so its only up to t144 right now but hey looks good aswell even though this is a lesser model even so still has the weather data to be a weather pridiction model.

looking good across the board we could pick out the bad but lets get the cold there first and then pick and choose but overall lots more to look forwards to for coldies and good to see steve murr back hope things go right because i could not handle another gutted episode from the sm coldie camp lol.

and well done to all those that have contributed to a fantastic sometimes frustrating and rollercoaster ride on net weather.

[MR EXTREMES]

Weighing in with the Cumbrian ensembles looking at the near time frame big single day drop progged around the 8th and 9th then a good mean trend downwards bottoming out around the 19th.

Ian

i dont see a big fail happening here i also see massive swing towards cold alot more so that before christmas and this is from one warming event.

i dont see any reason to see that this chart is a fail the length of the cold spell will always be something hard to pin down until its happening but the chart you posted has same look to it as 2009/2010 winter and im confident its right.

[Iceaxecrampon]

i dont see a big fail happening here i also see massive swing towards cold alot more so that before christmas and this is from one warming event.

i dont see any reason to see that this chart is a fail the length of the cold spell will always be something hard to pin down until its happening but the chart you posted has same look to it as 2009/2010 winter and im confident its right.

Yes such a strong ensemble agreement in the near time frame by all members 4 days from today - as for failing - it hasn't to..! - I have a decent "outing" planned for the 22nd...

Heres hoping

Ian

[AWD]

Not bad clustering for something far more seasonal in the 2m temps;

[ITSY]

The only thing that concerns me amongst some excellent output today is the number of ens members that either flatten or develop the HP directly over the UK - far more than those that produce the excellent synoptics we are after. Still, like I have said before, early days and much potential to work with. If you look through the strat charts theres also no sign of it getting at all back to normal even at +384. Lots of time yet.

[phil nw.]

Not bad clustering for something far more seasonal in the 2m temps;

Yes showing colder days and nights will be with us from around Weds/Thurs next week with night frosts becoming a feature again.

That`s before any feed of cold upper air from the east arrives probably starting next weekend.

[MR EXTREMES]

The only thing that concerns me amongst some excellent output today is the number of ens members that either flatten or develop the HP directly over the UK - far more than those that produce the excellent synoptics we are after. Still, like I have said before, early days and much potential to work with. If you look through the strat charts theres also no sign of it getting at all back to normal even at +384. Lots of time yet.

there is this risk that i pointed out yesterday to jh but all things considering i think just getting the cold set in is the first step in the right direction.

my feeling would be a settled cold to start with then hopefully we can get low heights running southeast below us into france or even better southern france or spain to suck the colder air east to west.

this would be aided by the jet stream which ive not really taken much notice of but if u have blocking over us or to the north the most likely outcome would be any low heights going southeast under the block or if not running up against the block helping build blocks futher north.

[IDO]

I think the pressure ensembles show how much scatter there is:

Relative agreement for 5/6 days, with a lowering of pressure, as the HP sinks. A general consensus by the members that pressure will try to rise again, but by D8/9 the members diverge. Some keep HP over the UK and some suggest we will be influenced by a trough, with different timing and length. The ens temp mean does suggest a cooling trend though either way:

[nick sussex]

Hi nick.

Firstly, many thanks for all your imput, especially considering your locality. Your imput for our area is much appreciated. Looking at it from your area, it's is looking really good and if this was showing over us, most would not be able to curb their enthusiasm.

Lets hope that the high pressure, currently modelled to be over or near us, can drift north west and the finger of cold uppers can be come a bit more crooked and drag some over us.

Many thanks again fella.

Regards.

That ECM

Thanks thats very nice of you.

It's hard to say at this point how cold any flow will be into the UK because of the uncertainties regarding where any high centres.

Of course the current trend in terms of set up does favour continental Europe and south and se parts of the UK but if you get retrogression of the pattern it would then look better for the majority of the UK.

Things are still evolving and so its best to still be sceptical of any detail shown at this timeframe.