Model Discussion Thread - January 13th

[bluearmy]

Yes I'm beginning to wonder whether the guys on holiday and has just set them for the week!

The ECM ensemble mean at 168hrs is solidly behind the operational run and I thought you'd like this at 192hrs!

http://www.meteociel...=1&map=1&type=2

actually, the ecm ens mean at T216/T240 are worse than the 00z run. whilst thing look pretty secure on the ens T144/T168/T192, beyond that there are a few options on the table. the good thing is the upper and surface trough n italy day 10..

[Earth Wind and Snow]

Weather chat amongst the Pros from Twitter over last hour:

"Yes EC looks tasty!" ....."If this comes off then there'll sure be a risk of decent snow across the UK"......."Cold again after 20th Jan..." and finally

"If this comes off most of N Europe and the UK would have caught a cold by Sunday Jan 22nd".

I think that just about sums up the Pros' thoughts right now.

ECM - top shelf

GFS - Bin

Regards

The Irish Met in their 7pm forecast said it will turn milder next Tuesday and Wednesday and then 'high likelihood of turning much colder from Thursday onwards with cold north-west winds veering to a bitterly cold north-east flow for next weekend. Usually they only forecast 4-5 days ahead so for them to put their neck on the line this early indicates they are very confident probably beacuse of the ECM ensembles today all steadfast behind the operational.

I hadn't looked at the 12z ECM at that stage and then looked to see the cold has been even upgraded from the 0z run plus support from other models of similar pattern

Judging by some of the comments on here you would think these charts are showing a mild south-westerly

http://www.wetterzentrale.de/pics/Recm1681.gif

http://www.wetterzentrale.de/pics/Recm1921.gif

http://www.wetterzentrale.de/pics/Recm2401.gif

The GFS is on its own tonight just like it was last weekend when it was showing screaming easterlies for this weekend

It could still be right but the chances are reducing drastically - thats 7 ECM runs in a row showing the same pattern with ensemble and other model support

EWS

[nick sussex]

And more maps!

This is the forecasters view of the USA at day 7:

http://www.hpc.ncep.noaa.gov/medr/day7nav.html

Given the low to the west of Greenland and its orientation, then look at this:

http://www.meteociel.fr/modeles/ecmwf.php?ech=168&mode=1&map=1&archive=0

If you look at the ECM operational run, its ensembles spreads regarding dispersion suggest room for the PV to be a little further to the nw with higher pressure further into the Greenland, the area of higher heights clustering edges towards Iceland:

http://www.meteociel.fr/modeles/ecmwf.php?ech=192&mode=1&map=1&type=2

I promise thats the last of the maps!

[nick sussex]

actually, the ecm ens mean at T216/T240 are worse than the 00z run. whilst thing look pretty secure on the ens T144/T168/T192, beyond that there are a few options on the table. the good thing is the upper and surface trough n italy day 10..

Yes thats why I urged caution earlier regarding the post 168hrs period, troughing into the UK is solid but its the sinking of the trough that isn't, but the mean as we know can be skewed by some wild options either way.

[bluearmy]

Copy & paste Copy & paste LOL

'copy and paste' !! thats why JH likes them so much - consistency. actually, that 8/14 is a big improvement away from nw europe on last night. the surface ridges holding hands across greenland and the 6/10 dayer is much better with the atlantic high retrogressed a long way west allowing a mean northerly. thats says northerly followed by mean euro troughing across us. as stewart would say - brrrr.

[Zakos]

18z GFS or at least its ensembles should hopefully lean towards the ECM. One things for sure, were going to see large changes in the output in a relatively short time range from the either the ECM or GFS. My view is that GFS will lean towards cold, although perhaps the real outcome may not be as cold as the ECM is showing.

[Paul]

Just a quick reminder - there's a report button for any posts anyone thinks are off topic or likely to be troublesome in some way - it really helps the team when you use it as we are notified straight away.

If you choose not to report a post you think is a problem & respond to it, you're only likely to inflame any potential problems so please don't do it.

And don't forget we have the model chat thread open (was model moods) for more chatty/bantery type posts about/around the models, so please take a moment to decide where your post is best suited to (this thread should be for more detailed, reasoned discussion).

http://forum.netweather.tv/topic/72172-general-model-chat/

Thanks

[BLAST FROM THE PAST]

Don't expect on 'hanker' on any run falling in line. On Monday the 144/168 range will be 72/96....then we'll see where we are. With RJS theory and GPs teles and 500mb showing solid 'signal' for ECM evolution....I'll stick with that. My method?..........

GFS for me is good at times in picking up trends way out, but generally falls behind the other big two.

BFTP

Edited January 13, 2012 by BLAST FROM THE PAST

[nick sussex]

The ECM ensemble maps are interesting tonight as they give an idea of possibly two ways forward.

http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!168!pop!od!enfo!enplot!2009112700!!/

Its trough sinking with high pressure cell to the north, or trough held near the UK with low pressure forced to cut se through the UK.

Either option is certainly better than whats been on show for most of the winter, I think the modelling can't decide where to split the energy from the PV past day 7, ne keeping high pressure intact to the north supported by low heights over Iberia, or se through the UK.

This would then result in that mean of the ECM. The main thing initially is to get the PV split and the troughing se and worry about the rest later.

Edited January 13, 2012 by nick sussex

[ChartViewer]

Don't expect on 'hanker' on any run falling in line. On Monday the 144/168 range will be 72/96....then we'll see where we are. With RJS theory and GPs teles and 500mb showing solid 'signal' for ECM evolution....I'll stick with that. My method?..........

GFS for me is good at times in picking up trends way out, but generally falls behind the other big two.

BFTP

That could really light the blue touch paper Blast but hey its Friday night.....Good luck to coldies with the GFS 18Z the NH charts are in your favour with the ensemble mean and also ECM ensembles rock solid...However im not convinced and will only say yes I got this wrong when the gfs comes on board which idont think it will and suspect the opposite...

Regards

Edited January 13, 2012 by ChartViewer

[danm]

Absolutely, the METO mid and extended forecasts updated daily have been superb for the last couple of years after previously attracting derision - not least from myself.

They have access to what has been described as 'super' data and today they chose to ignore the ECM ensembles and support the GFS output by implication in calling a changeable period from next weekend with rain. I don't see any rain on the ECM charts from T168 or weather that would be changeable by most peoples defintion of the word.

Let us see what the 18z brings, though it hardly matters in compared to the 0z runs tomorrow. Those who ha- ve written the GFS off - I will put the humble pie in the oven for the time being.

You keep talking with absolute certainty that the Met have ditched the ECM and followed the GFS for their extended outlook - do you have any evidence to back this up other than your own personal interpretation of what was written in their outlook?

Many other people interpret their outlook as one of hedging their bets, not siding wholly with either the ECM or GFS - whereas you claim with absolute certainty that they are ignoring the ECM ensembles.

[danm]

Well I suggest you read the forecast and make up your own mind - the ECM ensembles members this morning were all cold or very cold for De Bilt, the METO did not even mention the possibility or 'low probability' - one of their favourite phrases - of cold E/NE winds from next weekend.

I have read it, and I have made up my own mind - that the Met were (at the time of writing) sitting somewhat on the fence due to the complete divergence between the ECM and its ensembles and the GFS. I cannot state with any kind of certainty that they are disregarding any model and it's ensembles - a claim which you have consistently made today with regards to the Met IGNORING the ECM ensembles.

[Paul]

Well I suggest you read the forecast and make up your own mind - the ECM ensembles members this morning were all cold or very cold for De Bilt, the METO did not even mention the possibility or 'low probability' - one of their favourite phrases - of cold E/NE winds from next weekend.

This is way off topic, and really don't want to be drawn into it on here, but since you refuse to let it lie, I guess I may as well in the hope we can then return to the model thread.

The problem with making cold forecasts in the current climate is hype - if the met remark on the probability of cold and snow when it is still highly uncertain, then the likelihood is it'll be splashed all over the press within 24 hours and hyped to oblivion. I would suggest that is one possible (and in my opinion, highly likely) reason for them not mentioning it, and although (like you) I'm not party to inside info on that front, it's as realistic in my view as the possibility they're ignoring the ECM output for operational reasons.

Time will of course tell, but conjecture and/or wild stabs in the dark about it aren't really going to get anywhere - particularly in the model thread so can we please return to the subject in hand and perhaps continue any meto related talk in the meto thread:

http://forum.netweat...to-30-forecast/

[JP1972]

Back on topic I'm assuming I have chosen probably the worst time to start model watching!!!

The word 'confusing' doesn't even touch the sides!!!

Having 'watched' for the past couple of winters I always got the impression that model scatter and uncertainty was a good thing from a cold weather pov but this curent stand off is testing everyones patience now surely.

[Frosty.]

I think tonight's very encouraging ecm for cold potential has given the meto more to think about, they are keeping their powder dry at the moment but both ecm runs today have a lot more snow potential than their update is indicating but another similar ecm tomorrow could tip the balance and a more wintry update should follow by tomorrow or sunday, this current mexican standoff between the gfs and ecm will be resolved this weekend.

[saintssupporter]

i think the ecm will be right as it has been saying that cold has been coming for the past 5 days now whilst the GFS is saying thing one minute and another run something else. so ill think ill go for the more consistant run at this period in time

[bluearmy]

looking through the naefs 12z and no surprise there isnt too much synergy with ecm ens mean. infact, the two charts are outside each others spreads next weekend over most of the uk. either the two outputs have to trend towards each other over the weekend or it will be clear that the ncep model suites do not seem have the resolution (either horizontally but more likely vertically) to cope with the upcoming pattern. looking through the postage stamps T168 ecm, there are various placements of the troughing but the general theme is pretty clear cut. nevertheless, it would be wrong to just dismiss out of hand an entire model suite at a range greater than 6 days.

[JonMillar]

Hi all

I am a complete rank amateur and generally only a lurker, However as there is so much debate about the GFSvECM I thought it would be interesting to track the GFS and ECM 500hpa and SLP runs in a spreadsheet so that we can see the general trends of how these two will eventually come together. I've started by using the last three ECM runs from the 20th onwards (as there is general agreement roughly up to that point).

If you think this will be useful I could keep this updated for the next few days (although the file may get a little too large after a while).

See what you think

JM

(The file doesn't contain any macros and is virus checked)

2012-01 500hps + SLP GFS-ECM Comparison.xls

[danm]

ECM ensembles not quite as good as previously:

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

[Grimsby Snow Lover]

ECM ensembles not quite as good as previously:

http://www.knmi.nl/e...agse/index.html

Perhaps not but they look ok for as far as next weekend which going by what we have had for the last 7 weeks is a start in my book. Lets get the cold first and then start worrying when it will end.

[Catacol]

Currently nothing is nailed on, but there are growing numbers of respected posters and analysts who are seeing an amplified pattern backing west as we approach February.

Edited January 13, 2012 by Paul
Removed met office related comments

[Tim Bland]

ECM ensembles not quite as good as previously:

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

Oh dear! Not much support for the ECM OP. squeaky bum time folks! Where's GP? Would be good to hear his take in things long term

[bluearmy]

ECM ensembles not quite as good as previously:

http://www.knmi.nl/e...agse/index.html

that tick up of the mean towards the end of the second week is a constant on the extended ecm ens over the past couple of days. what is interesting to me is that more than a week ago, the ecm ens mean temps for london in the second week were showing around average/cool but did have a small mean uptick around the 17/18th jan. now we come to verification, we do indeed get the rise in temps on these dates. no cold period should be expected to go on without the odd incursion of less cold. even dec 2010 had a day or two with uppers above zero after the first week. of course we have no idea where the model is headed after week two except the 32 dayer was bullish for a noreaster into feb. we would maybe need another trough to drop through to give us that with its transient warming ??

[ChartViewer]

Oh dear! Not much support for the ECM OP. squeaky bum time folks! Where's GP? Would be good to hear his take in things long term

Reason being ECM is flattening the ridge.....So temps are soon to match GFS....At T74 gfs holding firm to its flat azores ridge mast

Regards

[Grimsby Snow Lover]

Oh dear! Not much support for the ECM OP. squeaky bum time folks! Where's GP? Would be good to hear his take in things long term

It is worth remembering that the De Bilt ensembles are only really useful for our part of the world if the flow is a direct Easterly, the fact that the ECM is showing more of a NEly could suggest why the temperatures don't look bilterly cold.