Model Output Discussion - January 11th.

[swilliam]

Ensembles are out http://www.wetterzen..._London_ens.png

Mean dips significantly below the average, change due to take place on the 19th of Jan.

Op not an outlier, but certainly at the mild end of the pack, especially towards the end.

I only post this because some said the ensembles where poor, when they're really not.

I think they are (poor) in comparison to earlier runs. Any significantly colder weather has been pushed back to the 19th Jan (over a week away and in FI) and there is good agreement for this. Nearly all of the very cold runs have disappeared. So maybe not raging mild zonality but a major shift.

Edited January 11, 2012 by swilliam

[ukpaul]

Just by chance I'd left the wetterzentrale graph of the GFS 00z London ensembles on my computer screen this morning, I updated it to the 12z ones and there was barely any change as I could see. Getting colder with some nice cold uppers from 192h on on a number of runs, some runs that put us into something very much at the opposite mild end such as the GFS 12z op.

Just thought I'd mention that there is some consistency, just that the consistency is to have a wide spread from a week out.

[Zakos]

I think they are (poor) in comparison to earlier runs. Any significantly colder weather has been pushed back to the 19th Jan (over a week away and in FI) and there is good agreement for this. Nearly all of the very cold runs have disappeared. So maybe not raging mild zonality but a major shift.

I agree that they have been downgraded.

However, most ensembles never went below -5 until 19th of jan anyway. This run has simply eliminated the cold outliers that did.

Its certainly a mild shift, ill give you that. But there's nothing to suggest it wont shift back to cold though is there?

Edited January 11, 2012 by Zakos

[ukpaul]

A quick model related question, are the different models reacting to the same data (and the lack of it, where that exists)?

If so are the chops and changes at the moment because they are reacting to inconsistent signals which they are all getting at the same time? We see many times where models diverge and I've always presumed that this is because of how they use the data differently, if they are using different data however that would make cross model consistency in quick turnarounds more credible. Just wondering what the ups and downs are a result of.

[swilliam]

I agree that they have been downgraded.

However, most ensembles never went below -5 until 19th of jan anyway. This run has simply eliminated the cold outliers that did.

Its certainly a mild shift, ill give you that. But there's nothing to suggest it wont shift back to cold though is there?

No - I just think any major cold has probably now been put back to beyond the 19th Jan whereas we had a chance of getting this earlier. There still could be shift in the medium term as well but this seems unlikley - I am just saying what is showing on the last run and how it has changed compared to previous runs.

[VillagePlank]

GEFS analysis, London, 12z output,

[sebastiaan1973]

In my opinion the same as GFS and UKMO at 120h.

Too bad.

[IDO]

The recent output from GFS and to an extent the other models remains pointless beyond five days. GFS are failing to persevere with a pattern for more than two runs. Not only that but after each change it is a flip rather than a gentle progression. Do the variables change that much? It fuels incongruity within the weather conflabs and heightens my distrust, for when there is any constancy within the output, as the runs are, in the main, seemingly disingenuous. I have noticed experienced members saying that there is a meteorological event horizon around the 15th, when the weather Gods will decide our fate, and I assume this is why the outcomes are so widely different? Is it therefore the case that GFS (and coincidentally ECM) have changed the variables (in the 12z) to expound on the poorer pattern that is possible on that day,and thus the reason the Easterly is tossed into the abyss? Conversely the 06z was likely a reflection of variables favouring the better scenario from the 15th? Surely for the sake of mathematical integrity and for the peace of mind of the franchised there should be an addendum, where the input is explained so we can then extrapolate the results without the necessity of a medium.

This may sound naive but I am just trying to understand the vagaries of model watching.

[Zakos]

No - I just think any major cold has probably now been put back to beyond the 19th Jan whereas we had a chance of getting this earlier. There still could be shift in the medium term as well but this seems unlikley - I am just saying what is showing on the last run and how it has changed compared to previous runs.

oh I see, your referring back to a few days ago when there was an easterly modelled to occur pre jan 19th, and has now been at least delayed.

Yes im agreeing with this. Sorry my mistake.

All i was saying was that the ensembles arent that bad.

Edited January 11, 2012 by Zakos

[Matty M]

ECM somewhat better than the UKM and GFS but will not be as good as this morning due to decent changes over Arctic regions.

[Gowon]

The ECM looks different to the GFS at 120, there's less energy pushing out East of Greenland and more energy going South in the Atlantic.

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2012011112/ECH1-168.GIF?11-0

Good chart-

High about to link over svalbard-

upper air cold pool moving west over Europe & a ridge thrown out to Greenland should see that system go under the scandi block ready for 192..

S

[ChartViewer]

At T168 ECM has Azores ridge stretching Northwards similiar to other models......Not what you want to see at this range to be honest. Jet and PV doing its worst?

Could all turn out ok longer term but sorry this aint as good a run so far.

http://www.meteociel...H1-168.GIF?11-0

Good chart-

High about to link over svalbard-

upper air cold pool moving west over Europe & a ridge thrown out to Greenland should see that system go under the scandi block ready for 192..

S

Steve but thats at T168 which is now in realms of FI.....and with an Azores ridge going north over UK temps are worse for cold...Ok longer term that maybe better but again your looking at FI not in T96 to T120

[Southender]

And this is why noobs get confused!

Mr Murr & Chartviewer post two different views on the same chart!

Edited January 11, 2012 by Shrimper

[winter watcher]

I think the latest ECM is a lot better than the GFS but in terms of what it showed this morning maybe if anything its more of a half way house and possibly a lot more realistic as the real cold for mid to late month has been suggested for a while.

[TEITS]

The GFS/UKMO might be disappointing but this isn't over by a long way yet. I reckon we shall see many more ups&downs in the model output over the next few days and even into the +96 timeframe. Some of the old fogies like myself, OON (lol) will remember how difficult E,lys are to predict and caused many inaccurate forecasts in the 1980s.

My main gripe with the model output is the lack of consistency with regards to the positioning of the HP, PV, and the track of LP systems spining off the PV. Until this is resolved at the +144 timeframe the lack of consistency will continue.

[ukpaul]

At T168 ECM has Azores ridge stretching Northwards similiar to other models......Not what you want to see at this range to be honest. Jet and PV doing its worst?

Could all turn out ok longer term but sorry this aint as good a run so far.

Steve but thats at T168 which is now in realms of FI.....and with an Azores ridge going north over UK temps are worse for cold...Ok longer term that maybe better but again your looking at FI not in T96 to T120

That's exactly how things were at 168 on the 00z. Look at the Northern Hemisphere view for an overall perspective.

[ChartViewer]

And this is why noobs get confused!

Mr Murr & Chartviewer post two different views on the same chart!

Because cold lovers are continually looking at the FI right now not what it shows up to T144.....which is a consistant sign from all 3 models tonight which is an Azores ridge edging North due to a jet and strong PV......Sure you might get a hooking of both highs but it is at T168 onwards which is def FI right now

Regards

[Duane S.]

At T168 ECM has Azores ridge stretching Northwards similiar to other models......Not what you want to see at this range to be honest. Jet and PV doing its worst?

Could all turn out ok longer term but sorry this aint as good a run so far.

Steve but thats at T168 which is now in realms of FI.....and with an Azores ridge going north over UK temps are worse for cold...Ok longer term that maybe better but again your looking at FI not in T96 to T120

I said a few days ago when it was mild mild mild on the charts that this period was still up for grabs , to expect wild forecast flucuations, well we had them and there could still be a lastminute.com dramatic swing but the door is getting closer to being shut and I suspect we will soon have to start focussing on the next window/bite of the cherry which will be in about a 7-8 days time.

[winter watcher]

To be honest i would bank a chart like this a cool and cold outlook with night and morning frosts where we don't get cloud cover in the reliable time frame. And high chances into a progression to much colder conditions as we move into the final third of January which ties in well with GP'S and Roger J Smith forecasts. It was always a slim chance that we would see a easterly and i would not be surprised to see it shown on future runs but i think we would need a few bites of the cherry and eventually it will come.

[Gowon]

Because cold lovers are continually looking at the FI right now not what it shows up to T144.....which is a consistant sign from all 3 models tonight which is an Azores ridge edging North due to a jet and strong PV......Sure you might get a hooking of both highs but it is at T168 onwards which is def FI right now

Regards

Sorry mate your being contradictory. You used the T168 chart and said that's not what we want to see at that range but then accused SM of looking at FI.

Edited January 11, 2012 by Higrade

[Duane S.]

ECM 192-216 seems progressive, read into that what you will! Suspect 240 will look good and 266 would look even better!

[ukpaul]

Looks like model watching has returned to normal now, looking deep into FI for some hope

Think it's time to turn off the lights for a few days!

ECM isn;t pretty and 3 models tonight quite close at T144hrs

This is misleading, just look where the PV goes, a 'proper' cold spell, rather than anything that tried to get there on a wing and a prayer too quickly has been at around 23rd January for a while and that's continued to be the point of interest as it moves closer.

Arctic high not as widespread later on which changes the later part of the ECM run.

EDIT: although not the eventual outcome which gives a variation on the 00z 240h.

Edited January 11, 2012 by ukpaul

[Frosty.]

LOL at "different coloured blobs, floating back and forth" - that's about where I'm at!! Blue - good, yellow - not good!!! Learning every day tho!! H.

I like the white blobs best but not much sign of them on the gfs 12z today,

[Harsh Climate]

Looks like model watching has returned to normal now, looking deep into FI for some hope

Think it's time to turn off the lights for a few days!

ECM isn;t pretty and 3 models tonight quite close at T144hrs

When will people learn??

3 days ago any easterly looked certain not to happen, 1 day later epic easterlies where shown, yesterday it looked bleak again, then this morning it looked good again and now not so good... :wacko: So you getting the picture yet??

Many ups and downs to come, I think the chances of an easterly before the end of January is currently at around 40%. It could go either way

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In the end a pretty good result from the ECM, shows many possibilities

Edited January 11, 2012 by Harsh Climate