Model Output Discussion 19th January 2014-18z onwards.

[Paul White.]

Steve - if the JMA is correct why do the metoffice not buy it? I'm all for optimism but to say the professionals are wrong is a step too far IMO

Hi Tim With all due respect and I promise I don't want to offend you. But what is the point of looking at models and reading this fine thread if people keep on defaulting back to Met office further outlooks they do get it wrong.

[Cleeve Hill]

Steve - if the JMA is correct why do the metoffice not buy it? I'm all for optimism but to say the professionals are wrong is a step too far IMO

Don't poo poo it. We're getting ready for a snow fest. Gotta love Steve for his bullish forecasts !

[SMU]

Steve - if the JMA is correct why do the metoffice not buy it? I'm all for optimism but to say the professionals are wrong is a step too far IMO

 

Hi Tim- no one is saying anyones wrong, so for clarity-

 

I could sit here day in day out & post up a summary of what the models show at say day 6-10 then put that into words on here -

Gibby & others does that, & for many that's enough -

 

In terms of professional forecasting its all about the consensus & how that relates to the overall probability of the outcome verifying, All the plausible outcomes ARE considered from all of the data available- however without exception the UKMET will take the consensus view of all the models.

That being at this time no overwhelming support for any cold.

 

I do 2 things differently, Im not always interested in the consensus>- why because the available data for us-

GFS, ECM, UKMO & JMA is different to the UKMET with

 

ECM + ENS, UKMO, MOGREPS & APARGE - + the long range GLOSEA 5 & ECM DET 32..

 

If you look above the critical thing missing for us is the MOGREPS & ECM cluster ensembles- with this info it gives you a much better tool for consensus forecasts.-

 

Because we only get the GFS ENS & snippets of the ECM the consensus for us is heavily skewed by the GFS & Ensembles - which are often worthless, so basing a forecast on our information is not as good as the data available to UKMET.

 

So some different interpretations have to be made, & for me that includes the possible impacts if the models are wrong & the effects, particularly when it comes to cold.

if you look I don't really say its 100% going to turn cold or theres a bitter spell on the way, merely point out whats required for cold from what we are seeing from the outlooks, If I don't post there is essentially ZERO cold on the way.

 

Take today -

Consensus forecast is at best polar northwesterlies oscillating between mild South westerlies with the odd COL thrown in all the way out to day 10-

 

Where as extracting the potential model bias will show that post day 7 we have our greatest chance of cold this year with the arctic high- however its not yet fully into accuracy range where the model bias is less intrusive.

 

so Im not knocking the METO forecast as its correct to the current data available, however if things change watch their wording slowly change to accommodate that -

 

Remember we have carte blanche what to write - the professionals are more bound towards using the best data available not discounting data without reasonable assumption & unfortunately the model bias approach is simply not consistent enough to overall any consensus because its as often wrong as it is right.

 

I do like the way posts because with his summary he usually covers off the consensus with the probability of the other solutions arriving as well.

Which is how its been thus far this winter- ensemble streams saying 20/25% cold the rest mild.- exactly how we sit tonight..

 

S

 

PS run the JMA & see the NH tropospheric response to the Arctic high

 

A full reversal of zonal winds starting over Eastern Siberia, then to Central Siberia, onto Russia, then to Eastern & northern Europe & finally onto the UK-

 

A similar theme to Dec 78.

Edited January 20, 2014 by Steve Murr

[Tamara]

The next well anticipated phase of upstream development is going to plan . The burst of westerlies programmed from next weekend (which as suspected they might do) are giving some members who visit this thread a lot of trepidation and an inevitable feeling that we are returning to the extreme flat, fast zonal pattern of the first part of the winter and are even preparing post mortems just past the half way interval and the refreshment oranges 

 

However I must say I've been looking forward to this   We've seen the start of the improvement with the easterly attempts and almost getting the cold nearly to our back door, which actually has very slightly exceeded my initial expectations to be honest. There is enough on display already this evening alone to suggest the obvious that we are into an even further different world giving a next stage of acceleration and clear blue water from those flat zonal days..

 

Trough disruption upgrade phase 2 starting (phase one the attempted easterlies) Troughing digger further south into Europe and, this time as we know, arctic high pressure present

 

 

 

Yep, I know...day 10 and jam and all that....

 

However, stratospheric forecasts support vorticity to eject out from NE Canada into our atlantic sector, and weaken the parent blob thereafter *forecast disclaimer*....Now if that tropical forcing signal to retrogress and amplify the atlantic high can actually get a move on, come real and verify with that arctic high sitting there and shove the whole lot south ....

 

As bluearmy posted earlier today, longer term ECM ensemble data has pointed to the atlantic retrogression signal arriving that we are looking for to amplify and unlock the pattern. This could be considered tentative, provisional and likely anticipatory at range, and the MJO forecasts have been proving slow and a real party pooper - so we might understandably take this signal right now with a pinch of salt to avoid hopes being raised too much.  In that sense we need to approach FI synoptic output with some caution. But time is pressing on, wavelengths are ever changing and we look towards more stratosphere ammunition into early February (we have a zonal wind gap to bridge there)

 

These factors if they can come together increase signifcantly the pressure for the dam to break. The results in the circumstances with a formidable vortex finally vanquished could be quite dramatic and spectacular...*If* the timing proves right and we call in the atmosphere for the favour it owes us after the winter so far, then could we be the ones to benefit?

[Troubleatmill]

If the ECM output was early winter it would be okay, high to the ne forcing the jet se, not desperately cold but some wintriness. Okay to fill a bit of time whilst you wait for better synoptics to arrive, because of the lack of cold and snow thus far and time ticking on its a lesson in frustration because the high is well placed to the ne if you didn't have the PV from hell firing at you relentlessly.

 

Whilst you don't see a clearance of energy between troughing near the UK and the PV theres no chance of any decent cold, unless you have the pattern much further west which at this stage seems unlikely so that's really what it comes down to here.

 

Clearance=cold

 

Non-clearance=average to cool, okay for the mountains

 

This is the energy that is the decider here:

 

ECH1-192.gif

 

Whilst you have those low heights attached to low pressure near the UK then you won't be able to get any real cold uppers in, if that clears the Arctic high could extend further sw, then the next low ejected by the PV will be forced more se to the west of the UK.

 

If of course someone orders a huge westward correction you don't mind the phasing upstream because you'll be on the colder eastern flank of low pressure but that's very unlikely so as it stands its down to the clearance of energy.

 

The ECM at T240hrs finally gets a clearance but its still too close for comfort and you have to factor in that this only happens because the Arctic high remains strong, I wouldn't trust the ECM with that, indeed any model at that range so I think we need a much earlier clearance of energy.

If the ECM output was early winter it would be okay, high to the ne forcing the jet se, not desperately cold but some wintriness. Okay to fill a bit of time whilst you wait for better synoptics to arrive, because of the lack of cold and snow thus far and time ticking on its a lesson in frustration because the high is well placed to the ne if you didn't have the PV from hell firing at you relentlessly.

 

Whilst you don't see a clearance of energy between troughing near the UK and the PV theres no chance of any decent cold, unless you have the pattern much further west which at this stage seems unlikely so that's really what it comes down to here.

 

Clearance=cold

 

Non-clearance=average to cool, okay for the mountains

 

This is the energy that is the decider here:

 

ECH1-192.gif

 

Whilst you have those low heights attached to low pressure near the UK then you won't be able to get any real cold uppers in, if that clears the Arctic high could extend further sw, then the next low ejected by the PV will be forced more se to the west of the UK.

 

If of course someone orders a huge westward correction you don't mind the phasing upstream because you'll be on the colder eastern flank of low pressure but that's very unlikely so as it stands its down to the clearance of energy.

 

The ECM at T240hrs finally gets a clearance but its still too close for comfort and you have to factor in that this only happens because the Arctic high remains strong, I wouldn't trust the ECM with that, indeed any model at that range so I think we need a much earlier clearance of energy.

Great post Nick, looking at it on wetter at 240 we have the only clearance in the northern hemisphere which is what we need to bring it this way, high pressure always wants to head south and if ours is the only door open, its will kindly come for tea

[cooling climate]

Looking at the ECM,and GFS t192 charts and the JMA at t168

the similarities are obvious. There are of course some differences

which you would expect at the 7 to 8 day range but with a Arctic

high sitting over the pole and an Azores high wanting to ridge north

I woul not bet against the JMA tonight.

[Yarmy]

JMA Verification for up till November 2013. Quite impressive:

 

acc_z500_recent_week_nh.png

 

Have you got a link for that? Why does it only go out to last November?

[mulzy]

Looking through the various models, it's obvious why the Met Office are making their current calls for the medium term.  Not saying that they will continue to be right, but so far this winter they have been pretty much spot on in the 6-15 day range.

 

Kudos to them - well done!

Edited January 20, 2014 by mulzy

[SMU]

Not forgetting the risk for Thurs eve for snow

 

http://expert-images.weatheronline.co.uk/daten/proficharts/en/2014/01/20/basis12/ukuk/rart/14012318_2_2012.gif

http://www2.wetter3.de/Animation_12_UTC/78_35.gif

S

Edited January 20, 2014 by Steve Murr

[IDO]

Have you got a link for that? Why does it only go out to last November?

Hihttp://ds.data.jma.go.jp/tcc/tcc/products/model/verif/1mE/index.htmlI assume they do their own verification, unlike the other models, so it takes a bit longer. They are also compiled as a monthly package not rolling daily like NOAA, and are based on their weekly anomaly charts rather than the daily runs. Edited January 20, 2014 by i'm dreaming of...

[nick sussex]

Hihttp://ds.data.jma.go.jp/tcc/tcc/products/model/verif/1mE/index.htmlI assume they do their own verification, unlike the other models, so it takes a bit longer. They are also compiled as a monthly package not rolling daily like NOAA, and are based on their weekly anomaly charts rather than the daily runs.

Theres also this link which is good to have an easy comparison between the main global models including the JMA:

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/12Z/

[chionomaniac]

Just catching up with the models (before reading this thread), but what I have noticed with the ECM is that when clicking between T+ 168 > T+192 to T+216 the evolution jumped wrt to the Atlantic low moving east between the latter two, so much so that I assumed that I had not clicked correctly and missed a day out. What I had expected to see was more in line with the JMA. So I think that there could be some surprises in store in this respect.

 

Also, another thing to take note of is that the JMA Atlantic ridge pattern follows it's own MJO forecast, which is different from all the other models as the JMA shows the MJO entering phase 8 whereas all the other models stall in phase 7 - 

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

 

The strat disruption is certainly leading to a more disrupted tropospheric vortex pattern and I believe that this will only increase when the FI strat forecasts are taken into consideration. I am certainly not as downbeat as some on here today, though having viewed the JMA MJO forecast I am slightly circumspect about how quickly an Atlantic ridge will disrupt the trough, no matter how 'wrong' the latter evolution of the ECM looks. One to check the ensemble mean later for any clues I think.

[Mucka]

Not one but two brilliant posts on one page from Steve M and Tamara and not that anybody asked me but I wholeheartedly agree with both the points of views expressed and the model interpretation. Not that there aren't others who provide great analysis and insight, there are, but Tamara and Steve M are two of the most popular posters for a reason and I really am not one to gush over other people. 

Still that is the beauty of this thread, you can have page of relatively emotional uninformed outpourings followed by insightful and well crafted posts and most of us are capable of both at various times. It's all part of the theatre IMO and the Mod's are always on hand to tidy up any more spillage. 

 

I think Steve M explains a constant point of conflict within this thread perfectly which usually revolves around those who try to give analysis beyond what the models simply show and what that means on the ground and those who consider such things fanciful. Also his breakdown of the differences between a professional organisation and the constraints their forecasts are bound by and the enthusiast who has no such constraints was spot on.

 

Plenty to play for with end of Jan and Feb still up for grabs with a little extra interest in the closer time-frame thrown in.

 

Edit.

 

And then Chino weighed in too! Good stuff about JMA moving the MJO to phase 8 while the other models stall in phase 7.

Edited January 20, 2014 by Mucka

[Mucka]

Not forgetting the risk for Thurs eve for snow

 

http://expert-images.weatheronline.co.uk/daten/proficharts/en/2014/01/20/basis12/ukuk/rart/14012318_2_2012.gif

http://www2.wetter3.de/Animation_12_UTC/78_35.gif

S

 

Yes I asked Ian about that earlier as he didn't mention any snow risk for Thursday. Hopefully he will update later or tomorrow.

[Paul_1978]

Hi Tim With all due respect and I promise I don't want to offend you. But what is the point of looking at models and reading this fine thread if people keep on defaulting back to Met office further outlooks they do get it wrong.

I don't think it's the Met's Further Outlook he's referring to, more Ian F's (paraphrasing) "there will hardly be any snow, but there is a concern over rain, and then we're back to westerlies". But on the other hand he did say that the Met really respect the JMA (we already knew that from him saying the same last winter). So with the JMA being quite bullish, then it's all a bit confused.com. At least we have the whole of Feb and 10 days of Feb. I make that 5 weeks.......but don't forget what happened last March!

[SouthernSaint]

 

GFS 8 day snow totals. Apologies if posted elsewhere. 

[Snow Grain]

Looking through the various models, it's obvious why the Met Office are making their current calls for the medium term.  Not saying that they will continue to be right, but so far this winter they have been pretty much spot on in the 6-15 day range. Kudos to them - well done!

Strongly disagree, Since their very poor long range forecasts of the past they decided to play safe and sit on the fence. A big freeze has to be set in stone before they make announcements. Most of the more experienced members on nw could do a 6-15 day forecast based on data available. The met office have to be cagey because they are open to ridicule whereas nw members are not under the same scrutiny when they announce a raging easterly that doesn't materialise!

[ANYWEATHER]

Strongly disagree, Since their very poor long range forecasts of the past they decided to play safe and sit on the fence. A big freeze has to be set in stone before they make announcements. Most of the more experienced members on nw could do a 6-15 day forecast based on data available. The met office have to be cagey because they are open to ridicule whereas nw members are not under the same scrutiny when they announce a raging easterly that doesn't materialise!

And A big Welcome to Netweather...

[TSNWK]

Strongly disagree, Since their very poor long range forecasts of the past they decided to play safe and sit on the fence. A big freeze has to be set in stone before they make announcements. Most of the more experienced members on nw could do a 6-15 day forecast based on data available. The met office have to be cagey because they are open to ridicule whereas nw members are not under the same scrutiny when they announce a raging easterly that doesn't materialise!

Boom. Straight in there.. Welcome.

[Snow Grain]

Boom. Straight in there.. Welcome.

Sorry, I've been lurking for a while but not posting. Anyway thanks for the welcome, I'll try to be constructive and not fall into the groaning category. I'll just say its forgivable for the current despondency as we have been wishing the westerly regime away since November. Things are looking up now for the coldies!

[SMU]

& the updated ensembles for ECM.

 

Operational is the MILDEST run.

 

http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png

 

In short. The best set of short ensembles of the year with the -20c scale being used of the first time.S 

[Yarmy]

Theres also this link which is good to have an easy comparison between the main global models including the JMA:

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/12Z/

 

Cheers, often look at the 0z stats, but didn't realise the 12z stats had the JMA on it. Currently, on a par GFS and better than GEM but trailing the Euros.

[Captain Shortwave]

Well the ECM ens have a NW/SE tilt on the jet, but with the pattern too far east so it's a generally west/north westerly flow. I'm guessing the op is in the minority in getting the Arctic ridge to push towards Greenland and instead transfer in to the north east of the UK, reinforcing the Scandi high and forces near enough all the Atlantic energy south east. Well we finally might get a decent Euro trough.

Simply put it's not great at face value for the UK, but it would not take much to become epic.

De Bilt looks rather chilly

Atlantic ridge... where art thou???

Edited January 20, 2014 by Captain shortwave

[KTtom]

Just catching up with the models (before reading this thread), but what I have noticed with the ECM is that when clicking between T+ 168 > T+192 to T+216 the evolution jumped wrt to the Atlantic low moving east between the latter two, so much so that I assumed that I had not clicked correctly and missed a day out. What I had expected to see was more in line with the JMA. So I think that there could be some surprises in store in this respect.

 

 

 

 

Lol, did exactly the same....for those wondering what were on about, here is the +144, look at the orientation of the low exiting Canada, heading NE, WAA up western Greenland screaming for an Atlantic ridge: 

 

 

Then it suddenly does a 90 degree turn and heads east!

 

[shaky]

& the updated ensembles for ECM. Operational is the MILDEST run. http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png In short. The best set of short ensembles of the year with the -20c scale being used of the first time.S

steve I seriously dont think this is over yet!!I have been analysing the charts over the past couple of hours and all it needs is a 100 mile or 200 hundred mile shift at t96 to make a good snow event!!see what the 00z runs bring and if it still shows the same then maybe a give up but not yet!!