12z model discussion - it's gonna get cold...

[nick sussex]

People arent going to be inpressed by tonights ECM....

Good job I think it VERY poor-

Temps current here in Iceland -4C-

Looking forwards to an exciting week......

S

Hi Steve hope you're having a good holiday. Yes that ecm sucks big time so far at 96hrs, the fax chart for wednesday is out and already dismisses the 72hrs ecm data so thats hopefully a good sign, but I agree that ecm is really beginning to get on my wick now!

[Costa Del Fal]

QUOTE(robert @ 4 Feb 2007, 05:54 PM)

The charts are great so far and it is all coming together nicely.

Many more upgrades on the way soon

Enjoy the debating of models *passes cookies and hot chocolate around*

Robert

-----------------

Hmmmm yes the charts are coming together nicely!

*takes a cookie*

[Stephen W]

People arent going to be inpressed by tonights ECM....

Good job I think it VERY poor-

Temps current here in Iceland -4C-

Looking forwards to an exciting week......

S

Agreed! So is it right or wrong?...It seems very determined not to fall in line which is of concern despite the comments re: its accuracy recently...would allow myself more excitement over the week if it was playing ball..Hope you're enjoying the cold and snow in Iceland!

[wellington boot]

with regards tonights ecm, it looks much the same as the last one. Very poor as steve says, but at the same time, we should take heart from the fact that:

1 ecm has been poor recently, and missed last cold spell and also this one which we will have (whether snowy or not)

2 ecm is on its own right now

3 even the ecm could become favourable for cold and snow with fairly minor adjustments to the charts. Its not that far away in terms of synoptics even if it is in terms of the weather we end up with. slightly stronger high. Slightly less aggressive atlantic systems. slightly more southerly tracking atlantic systems

By the way, nice to hear from you in iceland steve. I hope you see some snow!

[Matty M]

I worry, that if it continues like this then our mid-term prospects are going to get screwed over in its favour.

I really wouldn't worry, the model hasnt handled the situation from day dot and not even one gfs ens agrees with it..

It's a muck model at the moment

[MKN]

All im trying to say is some people are going to be dissapointed especaially Northern Ireland i think.

I think scotland has the best chance of something decent this week followed by northern england and the pennines followed then by inland areas further south, the 12z was good for parts of ireland and the south but i feel things are very marginal here so unless things stay the same they could either end up with rain or even worse everything moves further south and no1 gets anything.

[mushymanrob]

No I don't agree.

It's been a dreadful winter with nothing to look forward to if you prefer cold and im of the opinion that if you can't get excited at these charts then you shouldn't bother following the models.

These synoptics don't happen every week unfortunately so I say ramp it up!.

ill get excited when its in the bag dave... exactly like i do in summer when a 30c spanish plume is expected. otherwise ill keep cool.

[Costa Del Fal]

I think scotland has the best chance of something decent this week followed by northern england and the pennines followed then by inland areas further south, the 12z was good for parts of ireland and the south but i feel things are very marginal here so unless things stay the same they could either end up with rain or even worse everything moves further south and no1 gets anything.

Yeah the Republic of Ireland has an ok chance but N.Ireland doesnt faire so well.

Edited February 4, 2007 by Blizzards

[grab my graupel]

I really wouldn't worry, the model hasnt handled the situation from day dot and not even one gfs ens agrees with it..

It's a muck model at the moment

Yeah exactly Matty I'm not too concerned about the ECM either.

Although I wouldn't discount it just yet.

[SNOW-MAN2006]

Just a few charts to post here....

But first i would like to highlight that this is a truely great run for snow lovers. During this period there is the potential for snow anywhere from (drawing a line northwards) bristol eastwards & Snowdonia. The charts reflect the major event of each day and there is a coloured UK map with some rough estimates of any snow amounts

Wednesday

On Wednesday there remains the risk of some light, snow/sleet showers down the eastern coasts. Especially for the Northeast areas. sleety towards the coastal areas these showers will be.

Thursday

Rain approaches from the west/South west but a continuation of those snow showers in the north east which are likely to be more sleety at midday to lower levels due to temperatures approaching 5 degrees.

Friday

This chart shows country wide snow which is looking light and if not showery. Temperatures at there lowest on Friday and snow is more likely to lower levels.

These are rough guidelines (to give an accurate estimate 48 hours before is unlikely so please bear this in mind )

So there is a quick round up of the 12z run from the GFS havent seen other charts yet but GFS is really looking good tonight.

SNOW-MAN2006

Edited February 4, 2007 by SNOW-MAN2006

[PersianPaladin]

Yeah the Republic of Ireland has an ok chance but N.Ireland doesnt faire so well.

I wouldn't rule out some snow showers for the north and east parts of N.Ireland next week.

Edited February 4, 2007 by PersianPaladin

[Michael Winston]

All im trying to say is some people are going to be dissapointed especaially Northern Ireland i think.

Fair point Blizzards. However, I'm going to enjoy the anticipation, model watching and discussions and deal with any disappointment if it arises. I'm sure I'm not alone in this approach - it's never dull!

Enjoy,

Regards,

Mike

[Costa Del Fal]

I wouldn't rule out some snow showers for the north and east parts of N.Ireland later in the week.

yes, i was mainly talking about the main snow in the south on Wednesday/Thursday.

[karyo]

The ECM refuses to show a proper Scandi high and has a strong low pressure system to the North of Scandinavia. This is something that the 12z gfs has also shown. In fact the 12z gfs,despite showing a brilliantly cold and wintry spell, has also downgratedthe strength of the Scandi high as did the 12z UKMO. Yesterday weve seen most models incrase heights to our northeast but today the trend has been reversed.

Karyo

[J10]

I think the ECM should be taken on its merits, not as good for the south at all, but still chances for the north, which basically was the situation a few days ago.

Bear this in mind when considering the potential for this week, as much as most of us want to see some snow (or a lot of it as the case maybe), there are no guarantees that this will deliver any snow.

Possibility of snow very much so, and the models are still generally very positive tonight.

As regarding the build up of pressure to our east, a large deal of uncertainty, by looking at the Pressure Ensembles for London.

http://212.100.247.145/ensimages/ens.20070...prmslLondon.png

[Stephen W]

Hi Steve hope you're having a good holiday. Yes that ecm sucks big time so far at 96hrs, the fax chart for wednesday is out and already dismisses the 72hrs ecm data so thats hopefully a good sign, but I agree that ecm is really beginning to get on my wick now!

Hi Nick - what's your view on this? There's a lot of excitement on here tonight but the ECM is just really not having any of it. I'm holding back becuase of this..

[Nick F]

For anyone wanting a more in depth view of the 12z GFS run up until Thursday - particulalry if they are having to wade through the posts on here, see my post in the technical thread:

http://www.netweather.tv/forum/index.php?s...st&p=910348

12z UKMO and GFS not looking bad for Thursday, UKMO not so deep with low over NW France at t+96, shame about ECM so far, there's always a fly in the ointment for the snow rampers!

[Norrance]

I think scotland has the best chance of something decent this week followed by northern england and the pennines followed then by inland areas further south, the 12z was good for parts of ireland and the south but i feel things are very marginal here so unless things stay the same they could either end up with rain or even worse everything moves further south and no1 gets anything.

Yes it is beginning to look good for favoured 'breakdown'areas in Scotland on Thursday / Friday. Perhaps Perhshire, West Fife, Stirling and inland in the Central belt. May just be too mild near the coast and further South may turn to rain more quickly.

[MKN]

Just a few charts to post here....

So there is a quick round up of the 12z run from the GFS havent seen other charts yet but GFS is really looking good tonight.

SNOW-MAN2006

Good post, im not sure what to make of the chart youve made, i suppose its a wait and see scenario

Edited February 4, 2007 by Nick F
Reduced quote to save space

[nick sussex]

Hi Nick - what's your view on this? There's a lot of excitement on here tonight but the ECM is just really not having any of it. I'm holding back becuase of this..

Well whilst that ecm continues to churn out these operational runs we cant ignore it as much as at present I'd like to nuke it! Theres alot of uncertainty regarding the upstream pattern as noted by NOAA in their discussions relating to shortwave features in relation to the PV over canada, perhaps we might see a blended solution come the time between the 3 major models.

Here first is the NOAA discussions

http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

Check out paragraph 3.

However the ecm 00hrs run was a mild outlier for wed into thursday the crucial time in the models.

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

Everything is very volatile in the models and to be honest I wouldnt look past 72hrs.

[SNOW-MAN2006]

Good post, im not sure what to make of the chart youve made, i suppose its a wait and see scenario

Like i say it is only a rough guide. With the last cold spell my forecast was quite successful so i will be producing an indepth analysis where you can select your region and it will give that area a 5 day forecast

SM06

[J10]

Please try to keep comments weather and weather model related, if not they will be deleted.

Many Thanks

[Stephen W]

Well whilst that ecm continues to churn out these operational runs we cant ignore it as much as at present I'd like to nuke it! Theres alot of uncertainty regarding the upstream pattern as noted by NOAA in their discussions relating to shortwave features in relation to the PV over canada, perhaps we might see a blended solution come the time between the 3 major models.

Here first is the NOAA discussions

http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

Check out paragraph 3.

However the ecm 00hrs run was a mild outlier for wed into thursday the crucial time in the models.

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

Everything is very volatile in the models and to be honest I wouldnt look past 72hrs.

Thanks Nick - appreciate the links which confirm the uncertainty and difficulties which I'm sure all the models are experiencing. I think the motto for this week has to be to take and hopefully enjoy each day as it comes! And as you say, to take anything beyond T72 with model uncertainty in mind.

[frozencamel]

Amazing run. Great for all of us

Apart from the East Midlands...as always

[Evo]

Well whilst that ecm continues to churn out these operational runs we cant ignore it as much as at present I'd like to nuke it!

I think what happens next week will test out DT's medium range forecasting rule number 3:

When the model consensus or majority cluster begins to breakdown… WATCH THE SHIFT TOWARDS the Model A or M.O. solution. Incremental changes towards the M.O. solution will often lead a forecaster to make incremental changes in the forecast usually because of concerns over model uncertainty and consistentency issues. This is often a mistake. Once there is a discernible shift towards the Model A / M.O. solution… it is often wise to make large changes in the forecast that is reflective of the Model A OUTLIER solution.

http://www.wxrisk.com/Meteorology/MRforecasting.htm

This rule has been wheeled out a couple of times, but usually when the consensus is for mild.

IF, and this is a big IF, the model consensus (which at the moment is fairly close) begins to break down, expect something more akin to the ECM solution.

To be fair, I've not even looked at the ECM so I'm relying on how folks are describing it (i.e. rubbish).

I agree with the comments reference not getting too carried away down South. It is going to be marginal for us southerners especially those like me at 0m ASL!

I think the LP was progged too low due to the over-progessive nature of the 12z. My guess is that the 18z will have it back further north again. Nice to be proved wrong though

Experience has tought us not to get too excited down here, hasn't it!

Technically speaking, the less progressive 18z should have the shortwaves further South or cancel them altogether, though I'm still playing catch up with it all today.

Edited February 4, 2007 by Evo