Model Output Discussion

[swfc]

Sorry but can someone explain the parallel run to me please.???

[SP1986]

Forget the UK, look how much cold goes into Greece on the 18z - that's astounding! In my opinion if the high pressure is going to occur, this is pretty much how it'll play out (in terms of pattern, not severity), and at one point the FI shows -24C in Northern Greece. It's all fairy tale stuff in terms of severity and has little to no chance of being that severe if it occurs but in terms of what it shows, it's quite entertaining!

[Paul]

Sorry but can someone explain the parallel run to me please.???

It's the new version of the GFS - they run it in parallel prior to the upgrade, which is taking place on the 15th.

[kold weather]

I agree Stephen it looks quite a possible set-up, ironically for cold if we do get a block that doesn't quite make it I'd rather have the block sitting just to the SE of us rather then the NW, as any easterly without substance will be a murk fest and probably not really that cold, whilst a SE drift would be a good deal colder overall I suspect.

18z GFS control run looks to be close to the ECM at 216hrs.

[NorthantsSnow]

could there be something better on the ensembles though?

Keep an eye on P5.

[Cal]

It's all moves in the right direction, to see such models runs with so much cold air being moved westwards in the 'christmas pudding' so early on in the season is very encouraging, whether the UK taps into the very cold airmass is another matter , be nice for a change to see the whole of the UK involved instead of a few isolated corners!

[keithlucky]

this is my feeling dont get me wrong i luv this,

and i wait with fingers toes everything crossed,

but we coldies might have a breakdown tomorrow so im going for this as a phantom runs lol.

but by god i hope im wrong,

white christmas i never seen one of them in my llife so it would be something very special,

but i just dont trust the models there to erratic and very unrealistic in my opion.

Where ever you look all weather sites are predicting a cold and wintry christmas thats frightning .

[snowking]

What I am also noticing in the model output is the fact that we get into a continental flow from around t150 as the surge of warm air moving towards iceland-

Not exactly the beast from the East- however not to be sniffed at

I think its also important to think back to last winter and the rather cold run we had in the lead up to the snowy spell in early february - it meant that generally not only was modification not that much of an issue but also snow settled pretty easily. Given the rather above average autumn we've just had any sort of cooler pattern would be welcome. As long as it didnt impact on our chances later (and i realise that is pretty likely if it were to occur) i'd settle for an inversion from a bartlett

SK

[NorthantsSnow]

Chart of the day for me would be P10.

http://91.121.94.83/modeles/gens/run/gens-10-1-336.png?18

Doubt anyone can top this!

[cooling climate]

PTB 17 t324 onwards.

Yes please.

[Megamoonflake]

Hmmmm GFS and parallel run choose a different road to the other ensembles! http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=306&y=141&ville=Londres

[swilliam]

Keep an eye on P5.

I think 10 is going to win and 12 is the big loser

[snowmadchrisuk]

PTB 17 t324 onwards.

Yes please.

To be honest the Ensembles are ok at +180 but at +240 there are more milder ones than cold. But It is way to far in advance to worry about , although pressure remains high over the uk on all the ensembles.

[SMU]

Hmmmm GFS and parallel run choose a different road to the other ensembles! http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=306&y=141&ville=Londres

thats got to be corrupt- theres one run with -14c in london-

S

[NorthantsSnow]

To be honest the Ensembles are ok at +180 but at +240 there are more milder ones than cold. But It is way to far in advance to worry about , although pressure remains high over the uk on all the ensembles.

Yes I think with my serious head on for one moment the best way to describe the ensembles this evening, in one word; subdued.

[Megamoonflake]

thats got to be corrupt- theres one run with -14c in london-

S

This is only up to 180, good to see how some of the runs evolve after this time frame. It will be interesting to see the full ensembles when they come out!

Edit here you go http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=306&y=141&ville=Londres

Edited December 4, 2009 by Megamoonflake

[kold weather]

Remember though in the set-up that we could see higher 850hpas that look mild on the face of it actually could be very cold at the surface with a cold inversion. From what I've seen of the ensembles so far they are fine, I'd say for now the models are suggesting cold is quite possible, whether or not its the beast type cold though is something very uncertain..I'd say odds still agianst it but early days still.

[Duane S.]

The models have swung back dramatically in favour of a cold spell over the past 24 hours or so. With this in mind remember that it will NOT now be a progressive countdown to T-0 whereby every subsequent run is as good or better than the last! It could easily go very pear-shaped, I struggle to see it ending up being a blowtorch but we are asking a bit of a favour of the old enemy (the Euro high) here

We have to prepare for some serious downgrades and not get disheartened when, inevitably, they hit. The word you can't use enough when viewing charts in 'trends', nothing else counts for much and what we have been seeing is a trend for HP retrogression (how often do we see that happen?), Cold air to spill out of the Arctic and into Europe (Note I said Europe and not the UK ) and the jet to act very favourably in due course.

I stick by my original belief that we are going to get a short-lived relatively cold blast in 8-10 days time but it will be a precursor to a bigger one 4 to 7 days after that.

Get your bets on for a white Xmas. Obviously still much more likely that it won't snow but there haven't been many early December periods of late when things have looked this promising for a Xmas day flurry.

Edited December 4, 2009 by s4lancia

[swilliam]

PTB 17 t324 onwards.

Yes please.

Yes probably wins in terms of (cold) intensity but I think 10 might deliver more snow. Anything remotely approaching these would be welcome though

Nice bit of fun.

[Paul]

I often think an indicator of a cold shot, or at least a near miss arriving is a big spread on the ensembles - I think it's fair to say we have this tonight (in the latter part of the run at least):

http://www.netweather.tv/index.cgi?action=ensviewer;sess=

[karyo]

Forget the UK, look how much cold goes into Greece on the 18z - that's astounding! In my opinion if the high pressure is going to occur, this is pretty much how it'll play out (in terms of pattern, not severity), and at one point the FI shows -24C in Northern Greece. It's all fairy tale stuff in terms of severity and has little to no chance of being that severe if it occurs but in terms of what it shows, it's quite entertaining!

If it happens, I'll take some time off work and go to stay with mum for a week!

Karyo

[Snowstorm1]

GFS 18z was missing critical data tonight. Bin it IMO.

http://www.ftp.ncep.noaa.gov/data/nccf/com/gfs/prod/gfs.2009120418/gfs.t18z.updated.status.tm00.bufr_d

[Cloud 10]

Can't help but look at the moscow ensembles,control and operational both well off the bottom of the chart.

[Paul]

GFS 18z was missing critical data tonight. Bin it IMO.

http://www.ftp.ncep....tus.tm00.bufr_d

Lol, we had enough of this last winter - there is always something or another missing from a run, it's seldom relevant though - if there are data issues you will see it here:

http://weather.noaa.gov/tgstatus/

The messages you're linking to are technical bulletins and generally aren't relevant to the validity of the output.

[kold weather]

No don't bin it at all!

The data its missing is the Qscat and somethying else....however the Qscat data has been gone for at least a good week now and we've had many many model runs without that data now...

FWIW the Qscat is simply a Sat. that measures surface winds and whilst very useful for us who watch developing hurricanes, for the UK I bet the difference it makes is no more then 0.2% to be honest, there are many more vital things we could lose then that, granted it was a little depressing to see it gone given my keen interest in Tropical systems, but on the global scale, its not all that important on the grand scheme of things, no reason to bin it anyway!

As I said, the models have ALL been missing that data for a week now, and we are not going to get it back for years since its finally failed.

Edited December 4, 2009 by kold weather