Winter Model Discussion 18Z 12/2/13 onwards.

[Cloud 10]

Quite a shift in the 12z gfs ensemble mean at 168 hrs compared to the 00z,quite a jump

towards the ecm.

00z.. 12z..

[SMU]

GFS ensembles coming round- expect a few stray cold runs now-

PTB 3,PTB 4,PTB 5,PTB 6 ( nearly),PTB 12,PTB 18-

The rest slide the Euro shortwave SSE instead of SW...

Expect another 36 hours of this GFS nonsence.

[Frosty.]

The Gfs 12z has improved for the third time today in latching onto the ecm 00z pattern a little earlier on each run, it now shows sunday in single digits celsius whereas the 00z was 12c on sunday, it goes on to show temps nearer 7c early next week compared to 11-12c on 00z so it's synoptically improved but then the rest of the run is utterly forgettable, small steps in right direction though during the early part of the run.

[cooling climate]

name='rjbw' timestamp='1360775019' post='2608141']

Thanks for that Ian, tbh if you saw today's T0-T48 in isolation you'd be thinking SW'lies for the following period would be a good bet but something strange has been happening since early Jan, northern blocking seems determined to reassert itself over and over. Another shot at cold must be the favourite now that UKMO and ECM seem to singing the same story at T144

There is nothing strange happening at all. Have you missed all the posts both in this thread and

also in the strat thread of the SSW back in early January.

Should be another very good run from the ECM tonight with the GFS slowly oh so slowly coming on

board. Couldn't give a monkeys what Mogreps, ECM 32 dayer etc show they have been pants this

winter judging by the snippets posted in here. Do not see why posters get so hung up over them to

be honest.

[Frank Trough]

once again then the MOGREPS suite a fair mile away from the ECM & UKMO OPs-

Havent seen any post from Ian all winter that suggests they are any good- always following rather than leading-

S

i remember IF posting in the lead up to the December easterly that never was that MOGREPS never really bought it and that because of it the METO were unsure of the level of easterly influence...which as it turned out was precious little...

[The PIT]

Latest model scores GFS actually been the top dog in recent days however the graph shows over all ECM has less bad days.

[Cheshire Freeze]

Latest model scores GFS actually been the top dog in recent days however the graph shows over all ECM has less bad days.

GFS actually 3rd with .885

UKMO 2nd with .892

ECM 1st with .902

NOGAPS was above GFS at one point. Though last couple of days all models seem bunched together in terms of verification. This can't be the case now though as they're all going for differing outcomes

Edited February 13, 2013 by CreweCold

[Glacier Point]

Quite a shift in the 12z gfs ensemble mean at 168 hrs compared to the 00z,quite a jump

towards the ecm.

00z.. 12z..

Indeed, GEFS mean height anomalies broadly reflective of ECM EPS and UKMO 12z output, as well as state of global teleconnectors.

Day 6-10 H5 anomaly

Day 11-15 H5 anomaly

That's a very plausible and smooth transition going on there from Scandinavia to southern Greenland and likely back again. We would be looking at the back door for cold pools coming westwards and to the south-west for possible channel low type scenarios. The T850s aren't anything special at the moment according to the GEFS but that might change.

Either way, still looking like a below average February.

[fergieweather]

i remember IF posting in the lead up to the December easterly that never was that MOGREPS never really bought it and that because of it the METO were unsure of the level of easterly influence...which as it turned out was precious little...

That's true, but quite honestly, anything post-T+144 is not really of great consequence to us/UKMO in day-to-day forecasting and I'd struggle to name many colleagues who even bother looking in any depth further than that range in the models. Experience has taught them not to bother getting headaches over it all!

[london-snow]

Indeed, GEFS mean height anomalies broadly reflective of ECM EPS and UKMO 12z output, as well as state of global teleconnectors.

Day 6-10 H5 anomaly

Day 11-15 H5 anomaly

That's a very plausible and smooth transition going on there from Scandinavia to southern Greenland and likely back again. We would be looking at the back door for cold pools coming westwards and to the south-west for possible channel low type scenarios. The T850s aren't anything special at the moment according to the GEFS but that might change.

Either way, still looking like a below average February.

Yes but a far cry for a sustained period of cold weather.

[chionomaniac]

Sometimes when you miss the days output it is great to catch up to a few surprises. The first was unexpected snowfall on the way home. The second is a great UKMO this evening. How great it is to this model showing the charts it does for T+120 and T+144. The UKMO has been close to the mark all winter and it will be no surprise to see it's output backed up by the ECM and eventually by the GFS. I suspect that winter has quite a final fling up it's sleeve and that will be delivered with the last burst of negative mean zonal wind anomalies in the 6-10 day timeframe.

And this could be the best due to the shift in vortex posistioning since the start of the SSW.

[Snowman.]

I remember a couple of years back that having the UKMO model on board for an easterly was a necessity...numerous times I can remember the GFS going for easterlies in the 5-7 day range but the UKMO didn't and on most, if not every, occasions the UKMO was nearer the mark. I'm not sure how the models have progressed since then, but I'd still feel happier seeing the UKMO showing an easterly rather than the GFS. Nonetheless it will be fascinating to see how this period pans out.

This actually happened in December.

Interesting...

[Frosty.]

That's true, but quite honestly, anything post-T+144 is not really of great consequence to us/UKMO in day-to-day forecasting and I'd struggle to name many colleagues who even bother looking in any depth further than that range in the models. Experience has taught them not to bother getting headaches over it all!

Yes, just leave the headaches for us enthusiastic amateurs looking for our next snow fix, might not have long to wait for it either.

[chris55]

EC looking fine at 72,

[chris55]

At 96 and a little more energy heading south east than the UKMO for the same time,

[Snowman.]

i remember IF posting in the lead up to the December easterly that never was that MOGREPS never really bought it and that because of it the METO were unsure of the level of easterly influence...which as it turned out was precious little...

MOGREPS can be just as wrong as any other model?

What makes you think that it will always be right?

[chionomaniac]

Yet again ECM and UKMO similar at T+120, with the GFS odd man out.

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2013021312/ECH1-120.GIF?13-0

Great chart- just 12 hours slower than UKMO- so on inspection its not so great to the eye, it will be very soon.

S

[Ian Brown]

http://www.meteociel...H1-120.GIF?13-0

Great chart- just 12 hours slower than UKMO- so on inspection its not so great to the eye, it will be very soon.

S

Touch and go as to where that energy goes Steve.

[fergieweather]

MOGREPS can be just as wrong as any other model?

What makes you think that it will always be right?

It's not! Just as pear-shaped as any other output at that range. Sometimes right, sometimes way-off.

[Mucka]

Touch and go as to where that energy goes Steve.

Looks like SE/NW so should be a very good 144, especially if the trough develops on the Eastern flank.

I typed that before the 144h honest!

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2013021312/ECM1-144.GIF?13-0

A tad slower & a tad further East-

S

[Summer Sun]

T144 is slightly further east

Edited February 13, 2013 by Gavin.

[Mucka]

http://www.meteociel...M1-144.GIF?13-0

A tad slower & a tad further East-

S

Compared to? A tad better than UKMO and the ECM 00z with better alignment and trough distuption to the SW.

Cancel that, I was comparing to yesterdays 12z.

Still surprised at the 168h though, thought it would be better.

Edited February 13, 2013 by Mucka

[chionomaniac]

Great T+168

Edited February 13, 2013 by chionomaniac