General Model Output Discussion

[snowlover2009]

So if the snow does slam into Wales what depth is likely after the system has passed. Im about 15miles inland and just to the north of Cardiff. The models are looking good asmorning.

No one really knows. For all you know it could be raining buckets, while other places have large amounts of snow, it is going to be hard to say what will really happen.

this is a model out put thread, not asking about snow depths and where we will get it. your contribution to this thread then was 'models look good' i find it annoying when people do that so their posts don't get deleted because they know they are off topic. by saying models look good people must think that if they say that their posts would remain, so people will ask off topic questions

Edited December 26, 2009 by snowlover2009

[Mark Bayley]

According to the verfication stats the GEM does very well.

Still please don't spoil this thread with your wind ups. I know exactly who you are and what your intentions are for posting on this thread.

A very clear pattern emerges with your posts. You always look at the negatives. You always appear at the slightest hint of a downgrade but never appear when the models trend positive. You obviously take great delight in trying to wind members up. This is very sad indeed.

Still don't worry Jemtom I shall be ignoring your future posts!

Correct me if I'm wrong but isn't the GEM model the green line on the model comparisons? Or is it the GME? I think its the GME but I'm not sure. Its doing better than the GFS and UKMO which ever model it is!

http://www.emc.ncep.noaa.gov/gmb/STATS/html/acz6.html

[kev238]

I think many people from the West Midlands/ South Wales area would probably take short term gain over long term ambition at the moment with regards to snowfall seeing as they have had precious little from this cold spell. Certainly where I am at the moment for Christmas (gloucester) would benefit from this short term thinking. It is easy to talk about the long term when your area has had snowfall on the ground and ice days etc but for areas where this has not been the case you can understand the view of take what you can for the short term and leave the long term as just that!

[Cecil Hogmanay Melchett]

I think im going to stop watching the gfs06z and 18z runs,they just overcoomplicate things and are the less reliable runs.Stick to 0z and 12z i think its a good idea.

ecm ens are good,more pls!! :smiliz19:

[nick sussex]

Hopefully the message will come across mate.

One positive this morning apart from the GEM is the ECM extended ensembles.

http://www.knmi.nl/exp/pluim/vijftiendaagse/Data/15DAAGSE_06260_NWT.png

Mean below freezing and room for improvement with regards to the LP.

Yes that early scatter is positive in that the ecm has the low as far north as the top members, the majority have it further south, this means the ukmo is not backed by the ecm operational run or it's entire ensemble suite for the key period.

[Barb]

Correct me if I'm wrong but isn't the GEM model the green line on the model comparisons? Or is it the GME? I think its the GME but I'm not sure. Its doing better than the GFS and UKMO which ever model it is!

http://www.emc.ncep.noaa.gov/gmb/STATS/html/acz6.html

Yes I its the green one. GME is the German model, GEM is the Canadian model. GEM is a very good model these days, should be included with ECM, GFS and UKMO.

[NorthantsSnow]

So if the snow does slam into Wales what depth is likely after the system has passed. Im about 15miles inland and just to the north of Cardiff. The models are looking good asmorning.

Any talk of snow amounts at this stage would be pure conjecture given next week's snow event is FAR from nailed. Wales could equally be soaked in rain or even bone dry.

Keep watching the models and this thread and we should have a clearer idea by Monday.

[East Herts Snow]

My opinion entirely. I think us West Midlanders would take a massive snowfall if it meant we missed out on the inevitable cold, dry weather whilst the rest of the country gets battered!

Secretly I think a lot of people would agree with you.

I think nowadays we are spoilt for choice with the amount of weather charts that we can now access on a whim.

I recall the days when I would be constantly refreshing the teletext weather page on TV! Now I can access up to date pressure, dew point, ground temperature, air thickness levels, upper stratosphere charts at will.

However as the atmosphere is so chaotic, charts that are showing events 96 hours out tend to not happen, or the event turns out to be a watered down version (as is happening for next week). We were originally going to receive a couple of blizzard type events across a large area, but this now appears to be a watered down one snow event for a smaller area.

This is not having a pop at the various meteorological organisations and their computer programmed outputs, what they are trying to calculate accurately are probably the most complicated mathmatical/phyics formulas known to man! The more into the future the projections are, the lot less accurate they will be, i.e a volcano erupting in Indonesia can totally change the worlds weather patterns almost instantly.

I tend to now only concentrate on charts up to a maximum of 5 days (apart from snow forecasts which I only look up to 24 hours), anything after 5 days I use as a rough guide only.

Also look out for regular postings from the more senior technical posters (I refer to them as the Old School mob), AKA John Holmes, Glacier Point, Steve Murr, Nick Sussex, Kold Weather, The Eye in the Sky, Blast from the Past). They mix their technical skills with good old previous experience. I sometimes find the experience helps more with these cold set-ups than possibly deciphering the many technical charts(although I have learnt so much from the above posters that I can now form my own basic weather forecasts for IMBY).

NB - Apologies if I have left anyone out from my Old School list of posters!

Edited December 26, 2009 by North Londoner

[Mark Bayley]

Yes I its the green one. GME is the German model, GEM is the Canadian model. GEM is a very good model these days, should be included with ECM, GFS and UKMO.

Thanks, i always seem to get those two mixed up :smiliz19:

Yes does seem a good model, not be totally dismissed! Were still at a time frame were changes are going to happen. Lets hope these changes are for the good!

[Barb]

I think many people from the West Midlands/ South Wales area would probably take short term gain over long term ambition at the moment with regards to snowfall seeing as they have had precious little from this cold spell. Certainly where I am at the moment for Christmas (gloucester) would benefit from this short term thinking. It is easy to talk about the long term when your area has had snowfall on the ground and ice days etc but for areas where this has not been the case you can understand the view of take what you can for the short term and leave the long term as just that!

Same for me, gimme my blizzard early next week. It can do what it wants after that.

[Stu_London]

I think it has to be of concern that the 0z GFS introduced a quick breakdown from the SW and the 06z has backed it up from a position yesterday where all the operational runs for all models showed a prolonged cold period.

I feel the 12zs tonight will be very informative on how long we are likely to be cold for.

That said, some very interesting patterns remain with cold air never far away which will definately make for interesting model watching and hopefully make for interesting weather watching.

[swfc]

Secretly I think a lot of people would agree with you.

I think nowadays we are spoilt for choice with the amount of weather charts that we can now access on a whim.

I recall the days when I would be constantly refreshing the teletext weather page on TV! Now I can access up to date pressure, dew point, ground temperature, air thickness levels, upper stratosphere charts at will.

However as the atmosphere is so chaotic, charts that are showing events 96 hours out tend to not happen, or the event turns out to be a watered down version (as is happening for next week). We were originally going to receive a couple of blizzard type events across a large area, but this now appears to be a watered down one snow event for a smaller area.

This is not having a pop at the various meteorological organisations and their computer programmed outputs, what they are trying to calculate accurately are probably the most complicated mathmatical/phyics formulas known to man! The more into the future the projections are, the lot less accurate they will be, i.e a volcano erupting in Indonesia can totally change the worlds weather patterns almost instantly.

I tend to now only concentrate on charts up to a maximum of 5 days (apart from snow forecasts which I only look up to 24 hours), anything after 5 days I use as a rough guide only.

Also look out for regular postings from the more senior technical posters (I refer to them as the Old School mob), AKA John Holmes, Glacier Point, Steve Murr, Nick Sussex, Kold Weather, The Eye in the Sky, Blast from the Past). They mix their technical skills with good old previous experience. I sometimes find the experience helps more with these cold set-ups than possibly deciphering the many technical (although I have learnt so much from the above posters that I can now form my own basic weather forecasts for IMBY.

NB - Apologies if I have left anyone out from my Old School list of posters!

Post of the winter,either take this advice or stick to the fax charts as i will be.

[cold snap]

As for people waiting for met office to update and see what model and outlook there going with.

The irish met office have done this already and it good news.read the extract below.

At this stage, it looks as if that rain and sleet, will slide away into Wales and the south of England early on Wednesday, so that it will be a cold, and still a breezy day countrywide, with a fresh and GUSTY NORTHEAST BREEZE . Most places dry with sunny spells, but a few wintry showers are likely along the east and possibly also on parts of the north and northwest coasts. Thursday, New Year's Eve, and Friday, New Years Day will both be very cold and frosty with icy roads and pavements in many places. Scattered wintry showers in coastal areas also.

[snowlover2009]

As for people waiting for met office to update and see what model and outlook there going with.

The irish met office have done this already and it good news.read the extract below.

At this stage, it looks as if that rain and sleet, will slide away into Wales and the south of England early on Wednesday, so that it will be a cold, and still a breezy day countrywide, with a fresh and GUSTY NORTHEAST BREEZE . Most places dry with sunny spells, but a few wintry showers are likely along the east and possibly also on parts of the north and northwest coasts. Thursday, New Year's Eve, and Friday, New Years Day will both be very cold and frosty with icy roads and pavements in many places. Scattered wintry showers in coastal areas also.

good news for cold, but nothing much in the way of snow

[Frosty.]

GFS op is one of the mildest runs in FI.

Hardly mild though, less cold yes. A very wintry 6z for the north especially, northern and eastern coasts would be prone to snow showers but not much inland penetration, FI shows the atlantic trying to attack from the southwest but that just strengthens the roar cold SE'ly flow across the BI with snow for the north and sleet/rain in the south. Probably some data issues which will be cleared up by tomorrow.

[clark3r]

Post of the winter,either take this advice or stick to the fax charts as i will be.

looking at the fax charts wednesdays poss snow event will prob not happen now as it looks to be outbreaks of light patchy rain sleet maybe snow clearing south! the good news is the low will be much further south allowing the cold air to kick in! this how i see the fax chart for wed anyway!

[snowingman]

extended charts show us returning to mild weather past the new year... shame really considering the charts on Xmas day.... I guess it is inevitable!! saying that the jet is still way south.. very unlike our winters of late

[snowking]

I recall the days when I would be constantly refreshing the teletext weather page on TV! Now I can access up to date pressure, dew point, ground temperature, air thickness levels, upper stratosphere charts at will.

Now your talking! The good old nowcast page on ITV teletext and the current conditions table updated hourly on BBC Ceefax.....classic days

In terms of the output I think people need to learn to take a broader look at the output and stop trying to look at specific snowfall forecasts from 4 days away! I was unfortunately struck down with a stomach bug yesterday (I do pick the day of all days!) so I hadnt got a look at the models in about 36 hours, and to be honest they are now following the mid-term teleconnection trends which have been showing for some days prior to the recent NWP upgrades

For people in discussion about long term cold vs short term snowfall i can absolutely sympathise with those wanting one big dumping but please heed the warnings offered by nick and dave this morning. The issue is that there isnt even any guarantees from this range that there will be much snowfall depending on shorter term development of warm sectors and rather marginal conditions dependant upon dew points and thicknesses etc. we dont really want to be back to the bad old days of 24 hour cold snaps leaving many disappointed

SK

[mezzacyclone]

extended charts show us returning to mild weather past the new year... shame really considering the charts on Xmas day.... I guess it is inevitable!! saying that the jet is still way south.. very unlike our winters of late

The tripole`s intact & the NAO & AO twins couldn`t forecast any lower?

the only thing thats "inevitable" is that the factors for prolonged cooling are all on board.

As one of the old boys said recently - look at the bigger picture across the states & western atlantic grid, namely the 500mb NHEM Heights hereand you`ll find alls well?

[snowking]

Met Office update is out

On Thursday there is a risk of further sleet and snow in the south and east before it moves away southeastwards. This will allow a cold northeasterly flow to develop across the UK with wintry showers in northern and eastern areas. Some central and western areas enjoying drier, brighter spells. Staying frosty in many areas overnight. Friday and the weekend period look like being in a cold northerly flow with snow showers affecting many areas, especially northern and eastern areas. This will lead to a widespread and sharp frost. The following week looks cold especially in the north with wintry showers here, and possible rain, sleet or snow encroaching from the southwest at times. Overnight frosts are likely to continue.

Very similar to yesterdays to be honest, no backing away just yet from extended cold

SK

[bluearmy]

the meto update is an upgrade on yesterday. no talk of rain except second week battleground encroachments.

i think we should wait for tomorrows output with full datasets to resume before making too many judgements on the mid to long term. not saying that current output is faulty but there is always a questionmark against xmas day data.

[Craigers]

You got to admit if the GEM model came true then that would be amazing! the bigger picture is always the key for better events

[cold snap]

The charts this morning showing show Mr mild taking a massive chunk away from greenland.its kind of caught me by suprise.however this can go back on track later.

What is intresting to note is how many Januarys have not been to good for us in recent winters?

I call January a key month.i just pray to god.we get back on track.

Mr mild does always figures out an area overlook by cold spread to sneak in.its up to Mr cold to block this .hence we might see this later on.

We dont a two week southerly creeping into January please god.however thats in f1 and not set in stone yet.

On a positve not tv forecasts talking very cold.its us that maybe worrying to much.but the once bitten twice shy quote comes to mind.and how many times have we be bitten

Just seen the met office update its SUPERB.

So to end with if you dont understand models and just read written updates you will be very happy.

Sometimes i think we have to much to look at that

Edited December 26, 2009 by cold snap

[Matt12]

For people in discussion about long term cold vs short term snowfall i can absolutely sympathise with those wanting one big dumping but please heed the warnings offered by nick and dave this morning.

I think that most people would prefer a good dumping simply because we can't be sure that good synoptics (more than 5+days away) will bring about a prolonged cold spell. In modern times, good synoptics have nearly always ended in major disappointment.

Also, to be be totally honest, I don't think a even larger teapot is capable of producing a cold spell of more than 7 days or so - anywhere in England anyway. At least it hasn't in my lifetime, and I'm 27 now.

I would take a good short-term cold snap - with a good dumping - especially as where I live in the south east of England always seems to be too sheltered for the worst of the snowfall - we only got 2 inches recently, despite the south east being battered by snowstorms!

Either way, I hope everyone gets the snow you want. Here's to keeping our fingers crossed.

[rich1]

Met Office update is out

Very similar to yesterdays to be honest, no backing away just yet from extended cold

SK

I tend to find these updates tend to be a few datasets behind however. Sometimes the forecaster just chucks the output in the bin and backs their instincts, but most of the time they tend to follow the models rather than the models following the written update, if you know what i mean

expect a 'turning milder in the new year' update tomorrow even if/when the models swing back cold again, prompting panic and wrist slitting and nonsense talk about 'cool' snaps all over again but all the same, the cold air is never too far away and feel that once we get a full set of runs after today we may have a better idea than the xmas runs which can 'go off on one' from time to time due to data issues of varying kinds