Winter Model Discussion 12Z 15/02/13 onwards.

[Harsh Climate]

240 ain't bad

[Summer Sun]

T240

-8 uppers over Ireland

Dry for just about all and chilly

[Cheshire Freeze]

This is a particularly strange chart. Atlantic energy still going under a sinking block whilst the PV encroaches from the N. Feasible.......Not.

Edited February 15, 2013 by CreweCold

[SMU]

http://www.meteociel.fr/modeles/ecmwf/runs/2013021512/ECM1-240.GIF?15-0

ECM ends mouthwatering for the SW & Southern Ireland- If anyone thinks it wont be snow then look at how the 850 drop in decending air in 24 hours - down to -8c.

If you want further clarification look up Jan 1982.- 50cms of snow over Ians corner-

^^ thats a SW blizzard waiting to happen

S

[UV-RAY]

T240

-8 uppers over Ireland

Dry for just about all and chilly

Dry, cloudy and chilly I would say.

[Mucka]

Big upgrade from the ECM with the high better orientated at 192hrs and 216hrs, great news you guys might stay in the cold a while longer.

If people put aside the worries about the upper air the ECM 12hrs synoptically is much better than the 00hrs.

For the SE. ECM 12z would bring about a boring spell of cold weather for the NW.

The models have seemingly moved away from retrogression in the mid range and we aren't seeing a cut off Greenland high being modelled at all.

Could be a good spell for the S/SE but unless there is some retrogression we will struggle to see anything worthwhile in NW England.

[Met4Cast]

No denying it's a fairly good chart syoptically and no, you might not need deeply cold upper level temperatures when winds are coming in from the continent, BUT..

- Convective potential is LOW, winds coming mostly from the SE are not going to generate massive amounts of showers I'm afraid

- Undercut is decent, but probably a little too far South, snow might scrape the far South but certainly nothing widespread

Unless I'm missing something, this is a largely dry albeit very cold run. The only snow risk comes right at the end of the run

Edited February 15, 2013 by Daniel Smith

[Ian Brown]

Some similarities between the output tonight and Feb 47.

I find it hard to believe that people are looking at synoptics at days 7-10 and posting 'mainly dry' IMBY charts.

Edited February 15, 2013 by Ian Brown

[Summer Sun]

Now ECM is over here is tonight's GFS ensembles

Just about bone dry to the 27th which is when the uppers start to rise

The Aberdeen ensemble is that same as above

A cool down from the 19th to 26th looks likely after which the uppers start to rise its likely to be a fairly dry cold spell as well according to the GFS ensemble

Edited February 15, 2013 by Gavin.

[UV-RAY]

Some similarities between the output tonight and Feb 47.

Heights were further North in 47 Ian, leading to a much better orientation for the UK. I can only see this being a cold, dry and cloudy affair for most of the UK.

[bradymk]

Little bit frustrating reading this thread last 20 minutes. Great ECM run, and i repeat what others are saying, you do NOT need -8 uppers to get snow when you have a flow like the ECM is showing. ECM is much better for prolonging the cold than this mornings run. Some saying that it is only good for the south east, this is also incorrect, as Steve says, the west would be gearing up for a blizzard if the 240 chart was to verify. A bitter run for all.

Some similarities between the output tonight and Feb 47.

I find it hard to believe that people are looking at synoptics at days 7-10 and posting 'mainly dry' IMBY charts.

This reinforces my point ;-) When Ian B says this, you know the models are looking great!

Edited February 15, 2013 by bradythemole

[Purga]

ECM 240 - Just like 'A question of sport' - what happens next??

Edit: with nothing in the Med (LP) to support the HP it would sink and then finito cold spell.

Edited February 15, 2013 by Purga

[kent]

Wish I could share some peoples optimism but 2 days ago ECM was showing a greenland block now its down to dry air and snow wise nothing to get excited about. Still things can change in another 2 days. I hate easterlies, never deliver from IMBY STANCE.

[SMU]

Dorset could be in a very good position. in this scenario

[Mair Snaw]

Little bit frustrating reading this thread last 20 minutes. Great ECM run, and i repeat what others are saying, you do NOT need -8 uppers to get snow when you have a flow like the ECM is showing. ECM is much better for prolonging the cold than this mornings run. Some saying that it is only good for the south east, this is also incorrect, as Steve says, the west would be gearing up for a blizzard if the 240 chart was to verify. A bitter run for all.

This reinforces my point ;-) When Ian B says this, you know the models are looking great!

Agree with this post and many others re uppers, how many times do we see posts saying lets get the cold here first and then worry about the other bits after. so lets get the cold here before we start saying its not good enough etc.

[Cheshire Freeze]

Wish I could share some peoples optimism but 2 days ago ECM was showing a greenland block now its down to dry air and snow wise nothing to get excited about. Still things can change in another 2 days. I hate easterlies, never deliver from IMBY STANCE.

A GH was always the prefered option, by me at least. We could get all sorts of disturbances running down in an unstable NE flow. The ECM would be predominantly dry away from some southern and perhaps SE areas.

By no means a run to moan over though!

[nick sussex]

For the SE. ECM 12z would bring about a boring spell of cold weather for the NW.

The models have seemingly moved away from retrogression in the mid range and we aren't seeing a cut off Greenland high being modelled at all.

Could be a good spell for the S/SE but unless there is some retrogression we will struggle to see anything worthwhile in NW England.

Yes I think the slight disappointment is something I alluded to over previous days regarding convective potential and why it does seem like pulling teeth this winter to get a decent window of opportunity for that from an easterly.

In terms of the ECM there is an opportunity to retrogress the high but this doesn't occur on the operational however at least theres a chance compared to the 00hrs which had no chance.

The trough disruption at 168hrs is much better than the earlier 00hrs, its still a developing situation so there could be more changes.

[LomondSnowstorm]

Heights were further North in 47 Ian, leading to a much better orientation for the UK. I can only see this being a cold, dry and cloudy affair for most of the UK.

We don't know the orientation as on every run it changes slightly, making a big difference to the uppers advecting westwards. At face value yes the ECM is far from the best run I've seen for northern and central parts but looking at the bigger picture it gives us 5+ days of a continental/easterly flow of some variety and with no breakdown right through to +240.

And they were not always further north in 1947, most of it came from southeasterlies with merely a 'wedge' directing the undercut:

A slightly better upper cold pool and more in the way of heights towards Greenland and this winter could well have gone in that kind of synoptic direction:

[Cheshire Freeze]

ECM 240 - Just like 'A question of sport' - what happens next??

Edit: with nothing in the Med (LP) to support the HP it would sink and then finito cold spell.

It's hard to tell....With the LP to the SW and the trough pushing down to the NE, the high may be severed in two, allowing a wedge to reside around Iceland or the whole thing may sink, letting the Atlantic back in.

[Ian Brown]

Cold with snow chances for many sums things up Wednesday to at least next Sunday.

If anyone is unhappy then I will happily refer them to the late eighties, much of the nineties and much of the noughties winters.

[Jason M]

No denying it's a fairly good chart syoptically and no, you might not need deeply cold upper level temperatures when winds are coming in from the continent, BUT..

- Convective potential is LOW, winds coming mostly from the SE are not going to generate massive amounts of showers I'm afraid

- Undercut is decent, but probably a little too far South, snow might scrape the far South but certainly nothing widespread

Unless I'm missing something, this is a largely dry albeit very cold run. The only snow risk comes right at the end of the run

No, your not missing anything.

It will be very cold, but to my eyes its bitter but dry for most. I'm not even sure the SE would get much in the way of snow from that.

850s are irrelevant largely in this type of flow for ground level temps. I'd not be suprised to see a couple of ice days from the ECM run, but decent 850s are very relevant for convective snow.

I personally don't agree that the 850s should be off limits to discuss either. It's the model thread and comment should therefore be valid.

It's worth noting though that other models are giving us better prognosis and within the GEFS tonight there are some really good cold snowy runs. Nothing is settled, the 850s may look better tommorow but your entitled to point it out (and brave given some of the preceeding posts in here).

Jason

[goosey007]

Now ECM is over here is tonight's GFS ensembles

Just about bone dry to the 27th which is when the uppers start to rise

The Aberdeen ensemble is that same as above

A cool down from the 19th to 26th looks likely after which the uppers start to rise its likely to be a fairly dry cold spell as well according to the GFS ensemble

věry misleading gavin london and aberdeen are 150 & 400 miles away from my location ....so of no relevance to mě and many others .....paricularly with the chance of channel lows!!!!!

[Tim Bland]

I think the optimism varies depending on where you live. Great for the SE especially kent and possibly south of the m4. There's no getting away from te fact the ensembles are overwhelmingly in favor of spring to arrive on que I welcome in March

[Weather-history]

There's no getting away from te fact the ensembles are overwhelmingly in favor of spring to arrive on que I welcome in March

Yes but a couple of days they were suggesting an early start to Spring as early as next week. I feel no lesson has been learnt here.

[Mucka]

Yes I think the slight disappointment is something I alluded to over previous days regarding convective potential and why it does seem like pulling teeth this winter to get a decent window of opportunity for that from an easterly.

In terms of the ECM there is an opportunity to retrogress the high but this doesn't occur on the operational however at least theres a chance compared to the 00hrs which had no chance.

The trough disruption at 168hrs is much better than the earlier 00hrs, its still a developing situation so there could be more changes.

Agreed, it is only one run and it will change but we can only analyze the output we get.

As you pointed out we were seeing much keener retrogression previously which is the disappointment.

Hopefully the models can move back in that direction and give us a little more interest.