Model Output Discussion - January 12th.

[Tom Montalbano]

Although way out in FI of that 18z run quite a few of the members end with an attempt to build heights over Scandinavia.

Havnt seen them in graph form yet but would expect quite a few members showing a dip in 850 temps near the end of the run, esp to our east.

Anyway fascinating model watching again today, drama and suspense up a notch.

What will tomorrow bring.......whoops now today!

Regards,

Tom

[Zakos]

I hope so, I was hoping the winter would make up for such a dire year of weather bar April and the heatwave in late September.

The ensembles have runs going down to -10. They don't really surprise me, as they are probably northerly topplers, if they were cold snowy runs, we would be seeing the ensembles showing -10 for a long duration. Like 2 days ago for example when the outliers were going down to -15 etc. Where as the cold runs just dip to -10 for a few hours, so you can take it they are just cold topplers or from a cold northwesterly.

Yes most of them are topplers and i agree with what you said about how everyone looks forward to them but they rarely deliver etc.

Dont give up hope! lol. I have a good feeling about this February.

I would say the models should clear things up tommorow, but many including myself have said this, and often quite the opposite happens!

If the ECM sticks to its guns this would be a very good signal regardless of other models.

[SnowBallz]

Last post from me tonight. Whilst I bemoaned the GFS in my last post - what I have noticed with GFS is how on occasion it often plumps up a synoptic way beyond the reliable timeframe and sticks to these on a few runs, but then wildly ditches it to something completely different only to go back to the original synoptic within or just beyond the reliable timeframe.

It tends to do this when there is a major pattern change as we are seeing now. So take some comfort here you cold snow lovers, i.e. the southerly tracking jet and easterlies with major northern blocking it was showing a couple of days ago beyond the 240 hr timeframe could very easily resurface on its runs in the next few days but this time within the reliable timeframe and therefore supporting the ECM evolution.

The ECM on the otherhand for a good few days has been showing the same synoptics i.e. a weak PV and propensity for airstream from the east.

Yep, it definitely does this - was very evident the last couple of winters, especially the last. That's mainly why I tend to completely ignore it; I'll view its output, but I give it no credibility whatsoever. My MRF tool of choice is, and always will be, the ECMWF. For me, that model consistently verifies to a degree which deserves respect. I think it has shown that it has a better handle on the 'local' atmospheric dynamics far better than GFS does.

That's not to say that it's always right - no model is. But form is a long term average, and the ECMWF outperforms every other model; hedge your bets on it, and you won't be too wrong, too often.

[Cheshire Freeze]

Ok I'll hedge my bets.....I fully expect to see an ECM backtrack come morning. Night all.

[HotCuppa]

http://www.meteociel...H1-216.GIF?12-0

Heavy Snow showers moving across the UK from the NE :bomb:

S

which pretty much guarantess bugger all in the north west of england..never liked easterlies because they deliver nothing here..so im looking and hoping we see something favourable with the synoptics from the north west, which tends to deliver more snowy conditions down this side.

Just not sure yet what is going to happen with these models lol

[David-kig]

gfs upto 78h looks the same as the 18z. maybe p.v slightly further west if a little? doesnt look good already!!!!!! cant see much change from the gfs upto 120h diffrent. urghhhhhhh

Edited January 13, 2012 by David-kig

[David-kig]

oh il say slightly better by 144h but that p/v is annoying. still nothing like ecm. gfs is playing a slow catch up and i mean slow. something around greenland is going wrong or the jet. the experts will know. 150h the easterly is nearly there but missing us totally. azores high looks like it wont move. diff problem. could be a good end????

nice ridge at 180h a northerly? later output becomes mixed..trend towards the ecm at 240h though p/v strong again on this run. more confusion? at least gfs gives a cold dry week. then a nice northerly then cold zonality???????? not a bad run if u look at it? Ecm though is still better longer term i can imagine

Edited January 13, 2012 by David-kig

[Brum Watcher]

oh il say slightly better by 144h but that p/v is annoying. still nothing like ecm. gfs is playing a slow catch up and i mean slow. something around greenland is going wrong or the jet. the experts will know. 150h the easterly is nearly there but missing us totally. azores high looks like it wont move. diff problem. could be a good end????

somethings happening at t192 potentiallyyyy

oooohhh god GFS trying to take the ECM TO THE CLEANERS. t252. in a positive way.

[David-kig]

somethings happening at t192 potentiallyyyy

oooohhh god GFS trying to take the ECM TO THE CLEANERS. t252. in a positive way.

yh a nice fl . easterly did try to get going at 192h. better then the 18z anyway. short term lets see if the ecm sticks to its output

Edited January 13, 2012 by David-kig

[Brum Watcher]

GFS possibly trending towards the ECM around 240 252. last few show the standard as u were. strong PV, HP to the SW.

GFS possibly trending towards the ECM around 240 252. last few show the standard as u were. strong PV, HP to the SW.

and I Quote. The first time this winter I have seen a -10 all through the heart of the Country to London. b4 u all start, i know fi and this and that. the trend and persistency is the main focus now. VERY IMP ECM TODAY aswell as ensembles.

[weathe20]

Personally I think the 00z is an improvement. The cold out east is right on our doorstep at 192 rather than being over Russia as per the 18z run >

Also the GFS continues the theme of N / NW attack in FI as per GP.

Edited January 13, 2012 by weathe20

[David-kig]

ecm 12z and gfs 00z at 192 dont seem far apart. the only issue\ difference seems to be the p.v from what i can see.

Edited January 13, 2012 by David-kig

[Great Plum]

The problem with the GFS 0z, much like its previous runs is the way that the vortex doesn't really stay out west and reforms again by the end of the run...

http://www.wetterzentrale.de/pics/Rtavn1201.png

West of Greenland - good!

http://www.wetterzentrale.de/pics/Rtavn1681.png

Over Hudson bay... This is where a number of people and the good folk of NOAA expect it to be around this time... Whilst I suspect subsequent frames are FI, look what it does:

http://www.wetterzentrale.de/pics/Rtavn2881.png

The ensembles also show a warming of the 850s at the end of the run back towards the mean.

http://www.netweather.tv/index.cgi?action=charts;type=ens;sess=

Now, I understand that much of what I have written concerns FI, but thought this is a way of showing what we probably don't want to happen if we are looking for snow...

Also, sorry for lack of northern hemisphere charts, but I'm on my phone and I can't remember the links... (8 month old woke up again!)

Edited January 13, 2012 by Great Plum

[winterof79]

http://www.meteociel.fr/modeles/ecmwf/runs/2012011300/ECH1-168.GIF I have to say i was a little aprehensive awaiting the ECM beyhond 120z http://www.meteociel.fr/modeles/ecmwf/runs/2012011300/ECH0-168.GIF But i will take that. Edited January 13, 2012 by winterof79

[Isolated Frost]

And the ECM 00z continues the support for an easterly, by bringing it closer at 192. Lack of substantial northern blocking however shows the need of another strat warming.

[winterof79]

Oh my word....i think i need to sit down http://www.meteociel.fr/modeles/ecmwf/runs/2012011300/ECM0-192.GIF That is a special chart and if it were to verify would make anybody forget the very average start to winter.

If i had to be super critical,Yorkshire looks to be a little warmer than elswhere but thats probably due to it bucketing down with snow.

Edited January 13, 2012 by winterof79

[Snowmadsam]

What a run from the ECM so will the GFS turn back on itself or continue its idea of winter?

Find out....after the break :lol:

Edited January 13, 2012 by Snowmadsam

[KTtom]

Stunning ECM again, which has this @+168

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

Compared to this from the GFS

http://www.wetterzentrale.de/pics/Rtavn1681.png

Something has to give today surely...worth noting that GFS doesn't even correlate to the +120 fax chart.

[Isolated Frost]

You are joking ??? I presume

No. The rebuilding of the PV alerts the causes of another needed strat warming... the strat cools quickly and near it's original intensity and position by D10/D11 and so another douse of the fire would hopefully finish it off, accompanied by another one. The ECM 240 shows the pv working back towards greenland, and into the arctic... with only the aleutian-siberian block holding our own in the east. It would lead to a good easterly outbreak, but then we would need something else to prolong it, or gain more substantial blocking to the north as we enter feb, which can last longer with a less active pv/atlantic situ.

Of course the gradual fall in angular momentum helps this all, and it's the hope we have on that that can get us another cold spell wo/ strat warmth.

A nice chart nonetheless from the 216 ECM at 500mb. -8c uppers digging into england with the upper trough aligned ne-sw across norway to s england.

What I will however say is that the ECM builds a much calmer pv into baffin, nunavut and greenland at 240, something that despite potentially damaging for sustained cold, is not as strong as could be, and so a strat warming soon would be very beneficiary.

[Grimsby Snow Lover]

Correct me if I am wrong here but the 00Z ECM/GFS runs come out at midnight and are only relieased at the times we see them. If that is the case and haveing read the 3-5 day outlook on the metoffice site for my region the ECM model would seem to be more inline with their thoughts up to Tuesday anyway. They mention a cloudier day with the chance of rain later. The GFS chart for Tuesday looks very settled with a huge high on top of the country so I would think rain would be hard to find, however the ECM chart on Tuesday shows a more unsettled chart with the high getting squashed by an approaching system for the Atlantic. So hopefully we could get a better mid range forecast today if my thoughts are correct.

[Radiating Dendrite]

Oh my word....i think i need to sit down http://www.meteociel...00/ECM0-192.GIF That is a special chart and if it were to verify would make anybody forget the very average start to winter.

If i had to be super critical,Yorkshire looks to be a little warmer than elswhere but thats probably due to it bucketing down with snow.

Its not that special. Snow would be marginal with those uppers, especially near the coast.

[VillagePlank]

London, GEFS 00z analysis,

[Jayces]

Oh my word....i think i need to sit down http://www.meteociel...00/ECM0-192.GIF That is a special chart and if it were to verify would make anybody forget the very average start to winter.

If i had to be super critical,Yorkshire looks to be a little warmer than elswhere but thats probably due to it bucketing down with snow.

Its not that special. Snow would be marginal with those uppers, especially near the coast.

I am no expert so apologies if I am wrong but looking at the current GFS run from this morning at T+0 it shows uppers of -4 to -8 across much of Northern Europe and precipitation of snow across the same region.

So why would it not be snow from the ECM 192 chart? What's different?

[Paul]

Those meteociel charts colours are a bit scewed and do tend to make it look a touch colder than it is, but even so -6c @ 850hpa is generally pretty reasonable for snow.

Looking at the differences between the models this morning, even at 96 hours they're diverging, which goes a long way to explain the very different outcomes on offer by the time we reach 168 hours plus!

Taken from the model comparison page:

http://www.netweathe...modelcomp;sess=

[WhiteFox]

I am no expert so apologies if I am wrong but looking at the current GFS run from this morning at T+0 it shows uppers of -4 to -8 across much of Northern Europe and precipitation of snow across the same region.

So why would it not be snow from the ECM 192 chart? What's different?

On the continent, you can get snow with higher 850 temperatures. When I was in the US we would look for 0oC at the 850 level as the cut off for snow, particularly during frontal events. In our climate perched on the western edge of the continent with a large ocean nearby we need lower temperatures to gurantee snow. Also, continental climates have a higher threshold for thickness; again in the US 540dm is generally used as the upper limit for snow, whereas in the UK we're looking for 528 or below.