Model Output Discussion:

[danm]

T+144:

http://www.meteociel...1-144.GIF?04-12

More snow for the southeast...cold and frosty elsewhere.

sinker? looking great otherwise.

[Lewis]

I think, the ECM is playing catch up with the other models, GFS and UKMO has an agreement with something very notable with regards the strength of the flow and the blocking holding. ECM is an upgrade from it's earlier run, so i expect an upgrade tomorrow.

Game on

[Eugene]

http://www.meteociel.fr/modeles/ecmwf.php?ech=168&mode=1&map=1

[Matty M]

Basically the small problem with the ECM is that little shortwave that forms east of Greenland at T96hrs, a less developed feature

and a more extensive easterly across the region.

[Guest North Sea Snow Convection]

sinker? looking great otherwise.

Not at 168 it isn't. The north easterly train rumbles on...

[kold weather]

168hrs looks much better for at least the southern portion of the UK though the upper high is IMO somewhat close to the UK still...

Still at least we keep a cold flow going upto 168hrs just as it looked like it was going to be cut off by the ECm at 144hrs.

[TEITS]

+168 will surprise a few.

Despite an excellent +168 chart im happy to continue with the UKMO/GFS/GEFS mean because of the excellent agreement between these models. I will add I would say the same whatever the ECM shows for the rest of the run.

[danm]

http://www.meteociel...68&mode=1&map=1

A beasterly forming? Th north atlantic and siberian highs look to be joining.

[Snowaddict]

Basically the small problem with the ECM is that little shortwave that forms east of Greenland at T96hrs, a less developed feature

and a more extensive easterly across the region.

Whilst the ECMWF 12Z Operational Evolution is not as fantastic for Eastern Ireland as the 12Z UKMO/GFS Operationals, I still think it's quite good indeed. There would be a risk of snow showers between T+90 - T+120/125. Severe cold once again possible, even likely at night with penetrating frosts & a renewed risk of light snow showers towards T+168. I think it would be fine still for the Southeast.

Worth noting though that ECMWF brings in the cold air quicker than any other source of NWP Guidance tonight so it might just be a little too progressive.

Very solid out to T+168 & it would require only minor tweaks to become much better.

[Southender]

+192 to show the high over the top of us?

Or something more interesting I wonder....

[Matty M]

Whilst the ECMWF 12Z Operational Evolution is not as fantastic for Eastern Ireland as the 12Z UKMO/GFS Operationals, I still think it's quite good indeed. There would be a risk of snow showers between T+90 - T+120/125. Severe cold once again possible, even likely at night with penetrating frosts & a renewed risk of light snow showers towards T+168. I think it would be fine still for the Southeast.

Worth noting though that ECMWF brings in the cold air quicker than any other source of NWP Guidance tonight so it might just be a little too progressive.

Very solid out to T+168 & it would require only minor tweaks to become much better.

Yea i think it is being too progressive, i don't believe its evolution tbh.

[John Snow]

Safe to say a very cold and likely very snowy spell next week is 90% nailed on now that all of the big 3 are on board

Things seem to be upgrading by the day so I think that a spell of severe weather is coming that will make Dec/Jan seem tame

[Geordiesnow]

http://www.meteociel.fr/modeles/ecmwf.php?ech=168&mode=1&map=1

Trying to redevlop the easterly flow so should keep some people happy at least.

I still prefer the UKMO/GFS runs mind you, easterly is more likely to last longer on these runs than the ECM imo.

I don't understand some saying the snow risk will only be in EA and the SE, it last the longest in these locations but other places in the east of Scotland, England and perhaps Ireland will also benefit from snow showers albeit the window of convective activity would not last as long as the GFS/UKMO.

In summery, good run for cold/snow fans but not as good as the GFS/UKMO imo.

[Iceberg]

ECM will almost certainly go on to from a retrogressing GH from that 168 chart, allow another NE blast a little later.

[SMU]

+192 to show the high over the top of us?

Or something more interesting I wonder....

I think the Pattern will back further East on the 192 Chart-

the siberian high is beginning to retrograde west & all it needs to do is suck that small icelandic pressure belt NE a little & bingo- roaring easterlies again-

thats my punt for the 192-

S

Edited February 4, 2010 by Steve Murr

[bluearmy]

Agreed that ecm doesnt fling the norwegian shortwave at us as ukmo and gfs. but it didnt on the 00z either. i would nt discount this evolution yet.

at T168 we're starting to run out of cold to our east!! a reload please via more undeructting and a scandi trough would be fine.

[kold weather]

ECM will almost certainly go on to from a retrogressing GH from that 168 chart, allow another NE blast a little later.

Yep just like you and Steve I think thats probably the most likely evolution, we need it because the sort of flow the ECM progs tends not to stay very cold for all that long, generally like to see a reload after 72hrs of that sort of flow kicking off.

192hrs chart out, shows a flabby easterly flow with a fairly strong upper high over Iceland, need a little shortwave to drop down the eastern flank of the upper high,

Edited February 4, 2010 by kold weather

[Snowaddict]

Ireland would not get snow out of the ECM, heights are too high and the flow is slack.

Actually it would, 850mb temperatures at T+96 - T+120 are -7 widely across the country. In addition, towards T+168, there would be renewed chance. T+168 is very similar to the the pressure readings in January which delivered snow showers at 1025 - 1030mb - giving 5cm in several places in the East of Ireland.

Granted it's not as good as UKMO/GFS, but it certainly would deliver snow showers into the East, albeit light in nature, on some occasions between T+72 and T+168.

[Thundery wintry showers]

GFS/UKMO is obviously better for cold/snow lovers but the ECMWF charts, with the flimsy high pressure over the north and a slack north-easterly type on its southern and eastern flank, are reminiscent of the 6th-8th January this year. I recall that snow showers were still quite widespread on that occasion despite the relatively high pressure and slack airflow.

I also think the ECM evolution is perhaps a more likely scenario, GFS and UKMO may well be providing an exaggerated version- certainly the snowiest case scennario- but only time will tell on that one.

Nonetheless a clean sweep of cold and, for many, snowy operational charts from GFS, UKMO, GME and now ECM.

[SMU]

I will take that- Ice days & snow for the South & SE- dry & very cold with a severe frost in the North & NW-

S

[ITSY]

Living in the East of England, I don't really mind the choices from the big 3 tonight. However, ECMWF is not AS GOOD as UKMO or GFS for large swathes of the country.

With GEM still running against the whole idea - i'd say that we are currently 70% likely to see the very cold weather arriving at some point during the next 5 days, with snow then for the middle half of next week. Still 30% of me undecided. Yes, a very precise figure

The volume and amount of snow we get is obviously still up for grabs yet - and most probably will be until Monday/Tuesday at the earliest.

Haven't seen more than 2/3cms of snow here in Cambridgeshire, since the fall we had on the 18th December (when we had an amazing 14cms of level snow and 20-40cm drifts).

Here's to a fun week ahead.

I hope.

[Eugene]

All i`m gonna say is we would of killed for this run on tuesday night, just shows you what just one days of excellent runs does to people, makes them super fussy overanalysing every single detail

[PB22]

Anyone want a northerly after the easterly?

[cooling climate]

I think it certainly helps to look at the northern hemisphere charts on Meteociel.

There was never a hint of a sinker in the evolution from t144 onwards, to much

high pressure around to the north and east.

[SMU]

More snow for the SE-- Bitter everywhere-

Reload from the NW of Norway coming through-- Atlantic shortwaves heading towards Azores & on towards africa...

S