Model Output Discussion

[swfc]

Another move away from an easterly towards the northely.Notice the stronger pressure over greenland tho which may come more into play later.The blocking gets stronger and stretched.

Edited December 12, 2009 by swfc

[johnholmes]

I'll udpate my blog for the coming week tomorrow evening.

[multi cellular thunderstorm]

http://www.wetterzentrale.de/pics/Rtavn1081.png

In terms of wed/thu easterly this run is rubbish, not what i wnated to see.

Lovely 18Z, showing a stream of snow showers packing into Fife and Dundee overnight Wednesday into Thursday, with perhaps similar accumulations to the 2nd February here, which gave 2-3 inches

LS

Just shows how two people in different areas can interpret the models so differently!

Not sure whether to see it as an upgrade or not for me, looks better early but the flow is soon cut off and the showers stop for N England northwards.

What will happen with the northerly I wonder?

[TEITS]

Latest +96/+120 fax charts disagree with the UKMO raw output.

The +120 isn't as extreme as the ECM but far better than the UKMO. I would say similiar to the 18Z actually.

http://www.meteociel.fr/modeles/ukmo2.php?ech=120&carte=2000

[Harsh Climate]

-10 isotherm making land around yorkshire and the north east thursday ,with precipitation,and people still are not satisfied.I am quite frankly asstounded

At this point any precipitation will be rapidly dying out though, as pressure builds...

[PB22]

-10 isotherm making land around yorkshire and the north east thursday ,with precipitation,and people still are not satisfied.I am quite frankly asstounded

And given the fact that it will change again tomorrow, I really cannot understand the hysterics accompanying every model run nowadays. To be seeing these synoptics in mid-December are very rare indeed, and that alone should be enough to please everyone. As John Holmes has tried to explain many times, details for snow potential, etc. can not really be studied until around 48 hours beforehand.

[mickpips]

Dont post often but after all this weeks hype and unbeleivable charts , i somewhat feel disheartened by some of the output over the last 24-48 hours .... The GFS was giving us some outstanding runs and more impressive was how consistent they were , even bringing onboard the UKMO and others , then little backtracks turned into bigger ones etc ..... Which TBH is usually the case anyway having been here year after year and seeing huge petential only to be kept at arms length run after run ( Great but not within the reliable ... ALL the time !!

I still beleive we'll see a major cold spell setting up from wednesday , but dissapointing to see the Met Office site showing nothing but rain showers on and off on their site for my location right through to thursday !!

[paul tall]

Because if you had read every run so far the timescale of the easterly is getting shorter and shorter , the depth of the cold taking longer to get here and sometimes not at all. People are concerned that it's going to be a blink and you'll miss it affair or be pushed into the med!.

See?

Yes, I see.

So, it's the usual then.

[Paul Sherman]

Considering some of the Charts we have seen this is an absolute Stinker!

Not much in the way of Snow around maybe a little bit for the North East and Scotland on Wed-Fri with nothing values further South and West.

Dont like the look of the way this is going and it looks to be trending towards the Ukmo, if the ECM Backs down on the OOz then goodnight Vienna, or should that be the Cold will be going to Vienna

[Neilsouth]

Yes, I see.

So, it's the usual then.

Pretty much! , Hence why i'm waiting till monday . It's a little bit fustrating , one run looks good another bad then it swaps around though saying that i wasn't expecting hail and sleet today!. Hopefully it upgrades through the week

To be fair Paul, synoptics will not please me. Synoptics are just squiggly lines. What will please me is deep, deep snow.

Agreed or just good snow , i am NOT interested in cold dry weather. If i want cold i'll open up my freezer!

Edited December 12, 2009 by neilsouth

[paul tall]

And given the fact that it will change again tomorrow, I really cannot understand the hysterics accompanying every model run nowadays. To be seeing these synoptics in mid-December are very rare indeed, and that alone should be enough to please everyone.

To be fair Paul, synoptics will not please me. Synoptics are just squiggly lines. What will please me is deep, deep snow.

[Cecil Hogmanay Melchett]

Worrying 18z!!

Minima of 2 and 3 degrees fri night.Thats going to be RAIN .

Lets hope this sinking high doesn't suddenly start becoming a trend.

[Geordiesnow]

Nothing has changed in that i think that we may have to wait until tomorrow morning before we know whether the ecm is just a one off run or not.

Although the 18Z could be alot better, i will settle for this run for now even if it does not really excite me alot.

[Harsh Climate]

Dont post often but after all this weeks hype and unbeleivable charts , i somewhat feel disheartened by some of the output over the last 24-48 hours .... The GFS was giving us some outstanding runs and more impressive was how consistent they were , even bringing onboard the UKMO and others , then little backtracks turned into bigger ones etc ..... Which TBH is usually the case anyway having been here year after year and seeing huge petential only to be kept at arms length run after run ( Great but not within the reliable ... ALL the time !!

I still beleive we'll see a major cold spell setting up from wednesday , but dissapointing to see the Met Office site showing nothing but rain showers on and off on their site for my location right through to thursday !!

I completly agree with you. In the last 24-48 hours even FI hasnt even offered up much, no deep cold pools nor something to get your teeth into. I think what was great potential is now getting ebbed away into something ordinary. Im yet to come to a conclusion but this easterly on wed/thu is begining to look pretty tame (snow wise) and any following northerly is nothing to get excited about unless ya live in scotland or a north sea coast...

Edited December 12, 2009 by Jed Bickerdike

[AtlanticFlamethrower]

Dreadful!

The closer it gets, the more it downgrades. At minimum we need light blues but it's going toward the greens with each run. This Monday and Tuesday once had light blues... now greens.

I think SSTs have something to do with this and the model struggles to take account of SSTs until closer to the time... when new data - warmer than expected - is fed into the models.

North Sea presents an 11C warm barrier. If the cold pool is slow moving we'll not guess the best of it and what we do get won't hang around.

[PB22]

To be fair Paul, synoptics will not please me. Synoptics are just squiggly lines. What will please me is deep, deep snow.

Then, with all due respect, you are living in the wrong country - move to Norway or Russia.

18Z GFS, for what its worth at this range, shows the northerly developing by T+156:

http://www.wzkarten.de/pics/Rtavn1561.html

[yamkin]

Skuse my ignerunce Yamkin, but what is COAMPS?

Worzel - get some cider in side her.

(Coupled Ocean/Atmosphere Mesoscale Prediction System)Used operationally by the US Navy for short-term numerical weather prediction for various regions around the world.

[winterof79]

And given the fact that it will change again tomorrow, I really cannot understand the hysterics accompanying every model run nowadays. To be seeing these synoptics in mid-December are very rare indeed, and that alone should be enough to please everyone. As John Holmes has tried to explain many times, details for snow potential, etc. can not really be studied until around 48 hours beforehand.

Agreed Paul,sometimes it is difficult to post on here for fear of being realistic.The models show no atlantic threat at all just a biting easterly which will probably be diplaced by a chilling northerly IN DECEMBER.It is like wanting more money,once you have more it is never enough

[dvdfjojo]

re the two posts below

BBC follows the UKMO output for it forecasts hence why Darren Bett said a few days ago it will turn milder with SW'lies when the UKMO produced that one off run on it's 144 hour chart. I think they use the ECM output for it's long range forecasts for the website but i don't think they have ever used the ECM output for the TV forecasts. And they certainly do not use the GFS!

Let me clear this confusion up.

The Met O fax charts are not just based on the UKMO model because they also take into account the ECM ensembles. Now the BBC will use the Met O fax charts as will ITV, not sure about Sky. I also think im right in saying that the Met O brief the BBC forecasters on a daily basis.

I have explained before just what they use but to repeat for those who are not long on this site.

UK met do brief the BBC and ITV media presenters(such as Ian Fergusson) and obviously their own forecasters, usually on BBC TV, are part of this briefing. Indeed they may add their own view if they feel strong enough that the technical discussion sent out by the senior forecaster at Exeter needs a tweak here and there. They are rarely if ever allowed more than a tweak!

As to what they use-they have access to every model in the world and will use whatever the senior forecaster decides is going to give the more accurate idea over day 1 out to day 16, so not always the same model for any issue. ECM is used just as any other model is used. They have their own large scale (world model), more localised and their Fine Mesh with a grid-I think-Ian Fergusson may have the most up to date idea-of about 10km, an output from MOS (Model Output Statistics) and others whose names escape me at the moment.

So they have a huge amount to assimilate every 6-12 hours for their updates, usually twice a day, sometimes 4x daily.

Hope that helps.

Ian if I've missed anything out or said something not now correct please feel free to correct it.

Thanks for that John - I'd not seen you say that before so it's worth repeating every now and again. It's interesting how the human touch of forecasting still has the major input and why they are the ones who tend to get it dead right.

[January Snowstorm]

I think it's perfectly reasonable for people to be a tad upset at recent charts

It's very true that the real cold is being constantly put back into lala land

Indeed it's a worry that even with a greeny high we still dont get the goods.

Yet again I have egg on my face as I was telling everyone expect a major cold spell

Both Met Eireann and UKMET suggested mainly dry and cold and they were right on the button I fear. Guys it's obvious to me that the pro's only keep a very distant eye on the charts we follow on here. In fact you would wonder are we better off at all having access to them.

Listening to the beeb is proving far, far more accurate

[swfc]

Given is the 12th of december and we have a virtually dead atlantic and major blocking towards greenland then i think some comments and despair are a bit ott.

[Whether Idle]

Anyone agree with me that East Anglia and the South East could see some sleet/snow tomorrow afternoon/evening? Temps a tad high at 5-6c maximums but under PPN I would expect it to fall and with -5 uppers I would say there is certainly a half decent shout for some wintry stuff in those areas I just mentioned.

I'm surprised no ones making more of it.

Yes, tops of the hills in Kent could get wet snow tomorrow afternoon/evening.

[Geordiesnow]

I was feeling okay but now i am starting to think that it is a poor run, the only positive i can really take from it is that it does not trend with the UKMO.

I really do hope the ECM is onto something but seeing as this model not been performing all that well, i am not that hopeful but it could happen.

Lets hope tomorrow morning runs will upgrade things but we need upgrades to come quick otherwise it will be a blink and you miss it affair.

[pj cov]

I completly agree with you. In the last 24-48 hours even FI hasnt even offered up much, no deep cold pools nor something to get your teeth into. I think what was great potential is now getting ebbed away into something ordinary. Im yet to come to a conclusion but this easterly on wed/thu is begining to look pretty tame (snow wise) and any following northerly is nothing to get excited about unless ya live in scotland or a north sea coast...

for me,,you typify one of many that only see the negative of what is obviously a very rare,, and very cold set up,,

for those of you that struggle with reading the models etc,,stick to reading the posts of the more experienced

and more intelligent posters...

[TEITS]

You have to laugh at the T+144hr, which beautifully demonstates how the UK can manage to tap into relatively mild air despite a strong Greeny high and a southerly tracking Jet - you couldn't make it up really, but you'd be a brave person to bet your mortgage against it's eventual development given the emerging trend!

Worzel - get some cider in side her.

One of the first things I learn't as a youngster is wind direction doesn't bring the weather, airmasses do. Click on the +144/+168 chart and note how we are changing from a continental airmass to an Arctic (Polar) airmass.

http://www.wetterzen...s/Rtavn1442.png

http://www.wetterzen...s/Rtavn1682.png

Just because we have a Greenland HP, Sly tracking jet doesn't instantly bring you cold weather. In this case you have to wait until the LP moves S and introduces the Arctic (Polar) airmass.

I really can't understand why some are moaning. We have already seen with the ECM that the end of the week isn't certain. Also the potential beyond the E,lys is upgrading with every run.

Im off to shoot some people on Modern Warfare 2 before I become really annoyed!

Edited December 12, 2009 by THE EYE IN THE SKY