Winter Model Discussion 06Z 10/01/13>

[johnholmes]

Totally disagree - with respect to Stewart and the METO - both were wrong in December and the METO did a quick volte face.

I'm surprised the METO are talking about snow early next week, I thought the 6-15 dayer would stress the uncertainty. The GFS must be a huge elephant in the room at Exeter right now.

I have to admire you Ian-I think!

How about in the quieter thread you give a detailed explanation of why you think this.

It would also be interesting if Ian F could spare time to drop in the senior man's comments as to why they feel so confident this morning?

I will drop that in that thread as well-pages will soon cover this post

[Methuselah]

Long time lurker but first time poster-

It seems to me that the models may be hinting at some form of middle ground solution. The jet is certainly tilted better on the 06z than the 00z run.

Welcome aboard. Huw. Enjoy the fun!

[492]

Totally disagree - with respect to Stewart and the METO - both were wrong in December and the METO did a quick volte face.

I'm surprised the METO are talking about snow early next week, I thought the 6-15 dayer would stress the uncertainty. The GFS must be a huge elephant in the room at Exeter right now.

Statistically third week in January is slightly more likely to be dominated by high pressure to our east or even north east. The Altantic will often quieten down during the second half of January. The effects of the turmoil in the stratosphere may act in our favour. Over the last few years mainly short severe spells have been occurring so it is reasonable to expect unusual events to continue to occur. If the next fortnight results in normal zonality we have to reconsider the teleconnections that we currently believe to be a useful tool in forecasting in our latitude.

[johnholmes]

what on earth Ian has the averages over any time period got to do with the here and now. Are you trying to tell us that 'now' is like the milder winters most of us have experienced when we look at the total confusion being caused recently by model differences, NONE of them show truly mild by the way, not even GFS.

[Methuselah]

Latest MJO update shows things moving swiftly through phase 5 at a reasonable amplitude. This I believe equates to more MLB as we move to phase 6.

http://cawcr.gov.au/...Last40days.html

I see the Meto have just released their first warning of Snow for the SW on Saturday...and also an updated MRF suggesting colder weather to become more embedded, seems they must have reasonable confidence for this, despite the GFS differences.

Current Hadley CET for January stands at 7.6c up till 9th. If this were continue it would beat the all time record for January of 7.5c set in 1916 I believe. I would therefore think that any future movement to a milder synopsis this month is on the law of probability highly unlikely.

http://www.metoffice..._info_mean.html

Unfortunately, when it comes to current real-time situations, computer models and airmasses don't concern themselves with any 'law of averages'??

Edited January 10, 2013 by Rybris Ponce

[fergieweather]

Totally disagree - with respect to Stewart and the METO - both were wrong in December and the METO did a quick volte face.

I'm surprised the METO are talking about snow early next week, I thought the 6-15 dayer would stress the uncertainty. The GFS must be a huge elephant in the room at Exeter right now.

I have to admire you Ian-I think!

How about in the quieter thread you give a detailed explanation of why you think this.

It would also be interesting if Ian F could spare time to drop in the senior man's comments as to why they feel so confident this morning?

I will drop that in that thread as well-pages will soon cover this post

Their 6-10/15d assessment is already nearly 2hrs later than normal and that says it all about the high stakes being carefully considered at Exeter before they make any pronouncement.

[EML Network]

Something that hasn't been mentioned yet is the control run on the GFS...in terms of over the past 6 runs it has done the same thing...it has gone along with the Operational, but dived quickly back down again this time yesterday it was showing what could only be described as pure snow mageddon bliss post 192

And whilst this mornings control run isn't quite the snow tastic run it has been over the past 6 runs, it's STILL trending back towards cold after a short lived mild blip.

So this seems to be the trend, IF the GFS has indeed got it right for early next week, I wouldn't be at all suprized to see a relatively quick return to something cold again by next weekend.

[SMU]

If people have read some of the things that I have intimated over the years & what ian has confirmed in his posts over the weeks-

* The GFS has poor handling of high pressure systems to the NE- it always has-

* The GFS has a strong atlantic bias- particular on the 06z & 18z suite- especially the ensembles- ie to much energy

* Exeter, whilst viewing the 06z dont take any stock really, all they do however is use it to determine confidence- I have NEVER seen the fax chart modified to the GFS away from UKMO/ECM

* The ECM ensembles & mean are a LOT keener on a the shortwave dropping south than the GFS-

* The fact that the METo have updated next week to ignore the entire GFS shows there is zero confidence-

* THe ARPEGE info MUST be strong-

here is the 12z predictions

UKMO- no change

ECM- westward correction to the UKMO with respect to mondays low-

GFS- a big SW correction & 50% of the ensembles move to the EURO solution.....

S

Edited January 10, 2013 by Steve Murr

[Iceberg]

I think it favours the ECM/UKMO quite strongly, there is going to be no mid-point anyway.

The 06z ensembles are the strongest yet to back the solution that the OP has shown for 6 consecutive runs. Surely this can't go on much longer and the ECM will change tonight.

You've been saying surely ian for days now. The models will not surely go one way or another.We have a time of incredibly heighted model variability and yet people expect the models to suddenly agree at day 4 or day 5.

NOAA, the METO, EC, EC EPS and MET GM, BOM, GEM might all be wrong they almost certaintly are, but that almost certaintly wont make the GFS and its ENS right.!

[garbagebags]

Bit of a left field question here, but do the guys who program the ECM talk to those who program the GFS and so on?

[Duane S.]

Latest MJO update shows things moving swiftly through phase 5 at a reasonable amplitude. This I believe equates to more MLB as we move to phase 6.

http://cawcr.gov.au/...Last40days.html

Forecast to be in P6 in a few days, thereafter some differences between models as to where it goes (slows in P6 or edges towards P7). To my mind this should enhance Mid-Atlantic ridging going into next week. Maybe certain models just a bit slow on the uptake...

[bluearmy]

Their 6-10/15d assessment is already nearly 2hrs later than normal and that says it all about the high stakes being carefully considered at Exeter before they make any pronouncement.

they could be expected to sit on the fence ian. another 24 hours wont make any difference. there seemed to be a lot of spread to the west on ecm so its not unreasonable for them to 'sit tight'.

[Frosty.]

Have to agree Frosty the stratospheric profile last month is nothing like what have going on now. Ian, the models caught everyone out last time, but the writing was on the wall due to the stratosphere not being primed for lasting cold, the dynamics are complete opposites to what we have now, so your views on how the MetO and all the models except the GFS being wrong is a little misleading. Off course we can't ignore the GFS, but it seems an unlikely option.

Yes things are a lot more in our favour this time and the meto, with all the extra forecasting tools they use, are surely calling this correctly, if they thought the gfs solution was more likely, they wouldn't keep saying it's going to be a cold outlook, indeed, today the 6-15dayer is an upgrade for snow compared to yesterday.

[Troubleatmill]

Just regarding SSW, is there a definitive link to that and cold in the uk or is it another....mountain torque, MJO, -NAO ect, as in its another peice of the jigsaw and in itself means or should i say determines nothing? not argumenting against it in anyway, just asking ,

[BLAST FROM THE PAST]

If people have read some of the things that I have intimated over the years & what ian has confirmed in his posts over the weeks-

* The GFS has poor handling of high pressure systems to the NE- it always has-

* The GFS has a strong atlantic bias- particular on the 06z & 18z suite- especially the ensembles- ie to much energy

* Exeter, whilst viewing the 06z dont take any stock really, all they do however is use it to determine confidence- I have NEVER seen the fax chart modified to the GFS away from UKMO/ECM

* The ECM ensembles & mean are a LOT keener on a the shortwave dropping south than the GFS-

* The fact that the METo have updated next week to ignore the entire GFS shows there is zero confidence-

* THe ARPEGE info MUST be strong-

here is the 12z predictions

UKMO- no change

ECM- westward correction to the UKMO with respect to mondays low-

GFS- a big SW correction & 50% of the ensembles move to the EURO solution.....

S

Nice to see Big Steve, cards on the table as per norm.

BFTP

[Weather of Mass Disruption]

I would say that's boils down to the sheer matter of probability.

The governing algorithms will have a set of values that influences synoptic probability, in much the same way that you'll need to instruct an algorithm as to how the Earth rotates on its axis, and therefore what the prevailing (W~>E) pattern is. There'll then be thresholds which adjust prevailing probability, based on phenomenon such as SSWs.

However, I think understanding of SSWs themselves perhaps isn't established enough yet. In order to accurately mathematically model, using computational fluid dynamics, you'll really need to be quite sure of the data relationships involved, as - in an algorithm - if there's a high degree of doubt, it'll exponentially spoil. I would imagine that the boffins at Reading (ECMWF) are busy running developmental code, which would layer phenomenon such as SSWs into the operational algorithm. But there really does need to be a lot of research done into cause:effect, before you unleash a variable which - potentially - is very influential.

I wouldn't say it's so much a matter of money, but more a matter of scientific knowledge and geophysical understanding. Some of these relational processes and phenomenon are relatively new, and it takes time to carry out the proper audit of their scientific plausibility. What is important though, is the supercomputing ratio between Operational and Development. My understanding is that ECMWF are really exhausting their Developmental capacity, as Operational introduces more and more variables - net result being: less time to test and develop code. Ideally, you'd want a 70:30 ~ 80:20 split, but apparently it's now at a fairly critical 90:10.

All of that points to a fairly major upgrade in supercomputing power in the very near future, and - considering the high degree of success of ECMWFs NWP models - they make a very strong case for it. The JMA invested a staggering amount of money recently in a new supercomputer, and that's partly as to why UKMO have a high degree of respect for them, aligned to the fact that it runs the UK-UM base platform. The next UKMO upgrade is circa. 2015, and I wouldn't be surprised if there was even closer tie-in with ECMWF when this comes about.

Hope that's helpful?

SB

Hi Snowballz Many thanks for the response, all of which was most useful and certainly helps with my understanding. Although I have to be honest, much of it is a little above my head, probably should have concentrated more in my maths lessons. Still never to late to learn. Much appreciated :-)

[Summer Sun]

when does the ECM 12z come out?

All model output times can be found here -

[SE Blizzards]

Just been catching up on all the latest models etc etc, and i like many am very confused. Models are still all over the place. I really thought that by today we would all have some idea on how this weather pattern would verify, but instead we are all left scratching our heads more than ever

Interesting as to what simon keeling has to say about it all, he seems to be favouring the GEM!? Hmmm!?

http://www.weatherweb.net/wxwebtv2.php

Edited January 10, 2013 by SE Blizzards

[Paul]

getting packed with one liners again annoying ! (mods delete this)

Hello, we're not your personal slaves!! If you think something will need to be deleted then don't post it, don't expect someone else to follow behind you clearing up your mess on demand. You'll also notice a delete button on your own posts, feel free to click it.

[mcweather]

The outlook was done at 11.30 so what u meaning.

I think Ian F is refering to the internal 6-10-15 day model guidance for the forecasters at the meto rather than the public website update.

[bluearmy]

Looking through the gem ens, its clear why naefs still looks reasonable !! we have had this kind of situation before but never with the stakes so high for any number of reasons !!

[bradymk]

Looking through the gem ens, its clear why naefs still looks reasonable !! we have had this kind of situation before but never with the stakes so high for any number of reasons !!

GEM Ens good again today, and for me, the GEM might end up being the most consistent model to come out of all this. Also, a meteorologist who I rate highly is Simon Keeling and he thinks GEM will be the most likely solution as it handles the atlantic ridge "better" but the uncertainty continues.

[AGAL]

Thanks Ian - I wasnt aware of that... past posts had suggested that GFS was pretty much a non feature at discussions in Exeter. Thanks for the clarity.

That may be so Exeter not using GFS but it was that model that started to rapidly disolve the December cold spell -so it got that spot-on. Sorry to seem a tad contentious but ignoring GFS because UKMO doesn't use it and no doubt driven by the desire of nearly all of us to see something a little bit special in cold weather terms, is colouring our logic possibly. I feel GFS done it again with my only hope being the huge SSW currently inplay throwing a spanner into the computers logarithms meaning they*all* are throwing out wild speculative options ?

Edited January 10, 2013 by AGAL

[Troubleatmill]

ECM ensembles are a peach compared to the GEFS will a solid agreement for a continuation of cold, the opposite to the GEFS who have a just a few cold members the ECM has just a few milder members, this is at T168

Edited January 10, 2013 by Nick JB

[nick sussex]

I've discovered yet more upstream data to inflict on this thread!

Here is the SREF, this is the ensemble system for the NAM.It's basically the USA version of the UKMO NAE .

Enjoy its view of the upstream pattern versus the GFS ! this is from the 03hrs run, still waiting for the 09hrs , that will be interesting as it will be the latest data available from the USA before the evening model runs come out.

These are the respective charts to 03hrs on the 13th:

SREF

GFS

Edited January 10, 2013 by nick sussex