Winter Model Discussion 18Z 19/2/13 onwards.

[Suburban Streamer]

What happened to the returning SW flow you and Matt were tweeting about Ian [tweets are so uninformative IMO as they are just one liners so one can't really grasp any depth from it]? Was that just what a model/mogreps was showing? If so is that model in tune with the others showing retrogression or a different outcome.

BFTP

I think people should stop copying tweets into this thread. It's like Chinese whispers.

Either follow people on Twitter and read all the tweets or just give Twitter a skip

[nick sussex]

Todays Cat Litter award goes to the GFS lower resolution output!

I'd ignore that and concentrate on the higher resolution, I think it simply boils down to how much energy heads se into the Med and phasing of energies.

Because the jet is tracking quite far south then if you get no phasing or this happens much further east then theres a case to be made for spring on hold for the UK, if you get the energy phasing to the west of the UK then its likely to turn much milder.

Theres not a great deal of middle ground here so it will be interesting to see which model has called those shortwaves correctly.

[legritter]

Just a quick one from me ,past 168 hrs i feel there is still a possible chance out there of some thing wintry but im hoping todays Met update might give us a few clues as they have far more info in front of them .pressure to our very far n/west looking quite high in further charts on ecm ,so lets hope tonights run starts to firm up in earlier frames .i think the picture will become clearer by midweek and a change on GFS i feel is imminent lets hope its in our favour ,dont get throwing the towell in just yet ,march can be cruel ,cheers

[snowmadchrisuk]

It's a case of can't win with the 6z , Any Milder air that does come is coupled by very wet and windy weather. No sign of Mild air and Sunshine on any of the milder runs.

[johnholmes]

The differences between 00 and 06z GFS sums up perfectly the utter waste of time it is in following every run.

Just what some expect I am not sure.

At its furthest reaches it goes from sub 1000mb to better than 1030mb-says it all really!

[Panayiotis]

I think the ECM 00z is a million times better than yesterdays runs, it gets rid of the energy over southern Greenland,compare:

I was looking at this trend yesterday and on every run since Saturday the energy has decreased every run for the 4th March, I will be looking out for this also on the 12z.

[skifreak]

I'm uploading March 2001 forecasts at the moment and ECM and GEM 0z op runs in their latter stage look March 2001ish

Googles 'fat powder skis' ! Given the excellent and extensive base, March 2001 followed by April 2012 and May 2012 would be absolute dreamland for the Scottish Snowsports areas!

The big scatter in the GFS ensembles for Aberdeen were something I seem to recall being a feature of winter 2010, with gradually more and more going cold until another bought of colder weather arrived.

[No Balls Like Snow Balls]

Not many cold runs in the GFS 06z ensembles. Is it quite safe to say that the worst of winter is over and are we more likely to see spring warmth showing on future model runs rather than arctic blasts or Beasts from the East!!!

[nick sussex]

Looking at the UKMO further outlook it does highlight several key aspects of the current modelling.

Largely dry through this weekend. Variable amounts of cloud, with the best of the sunshine towards the north and west of the UK. Some rain possible in the far north, and perhaps some wintry showers into northeastern areas later Saturday and into Sunday. Breezy at times in the south, especially the southwest, and feeling cold in that northeasterly breeze. Rather cold in the south and east, but nearer normal temperatures in the north. Into next week, probably becoming more unsettled and windier from the southwest, and still a few wintry showers possible in the northeast. Mainly dry conditions may persist across central areas well into next week. Temperatures may recover to nearer normal in the south with time, but rather cold elsewhere with further frosts.

Those possible wintry showers in the ne are in relation to a shortwave tracking e/se from around Iceland which might bring that briefish colder upper air.

In terms of that unsettled weather moving in from the sw that's likely given the trend from the models, in terms of central areas of the UK perhaps hanging onto drier conditions that would suggest that theres more trough disruption with energy sliding away.

Unsettled weather in the sw with northern areas drier is generally associated with an east/se surface flow ahead of low pressure so its really whether that flow will be sourced over the Med or from eastern/ne Europe.

I think their suggestion at the moment is from the Med otherwise they would have mentioned that unsettled weather bringing a chance of some snow.

We'll see over the coming days whether that remains the case, if the ECM trend gathers pace expect to find a more wintry tone to that outlook.

If the GFS is right with that phasing of energies to the west of the UK then that's likely to mean milder weather, certainly I'd wait a few more runs to see which trend is correct. Its getting late in the season but whilst some unseasonable cold looks to be developing to the east and ne my interest remains.

[Summer Sun]

The reason behind this current weather is a huge area of low pressure causing a whirlpool effect the met office are expecting this to last for quite some time, of course the exception to the cloud is Scotland, Ireland and at times Northern England but for Yorkshire south this week is cloudy and chilly

[Man With Beard]

If low heights in Iberia get established they could stay there quite some time - this would probably result in southerly based winds and eventually mild (dare I say warm?) weather reaching the south of the UK - though significant cold weather may also result from such a set-up if there is a link-up with low heights to our east. So in the 7-14 day range I'm expecting an easing of the cold and eventually mild/very mild, but still a small chance of very cold. An all or nothing scenario.

[Frosty.]

It's a miserable cloudy, dry and cold feeling week with a nagging nely breeze, not cold enough for snow anymore but still on the cold side, looks similar all week long, scotland and n.ireland doing nicely for sunshine but even the far north tending to cloud over during wednesday as the high across the north changes shape and winds change from sswly to westerly, most of scotland will be sunny on wednesday though and feeling pleasant in the light winds with temps of 7-8c, for the southern half of the uk though it really is a week to endure with hardly any sunshine, grey and overcast with a chill breeze and a little drizzle or light rain here and there thanks to that whirlpool low over mainland europe. There is some uncertainty about the weekend but probably the dry, chilly and rather cloudy pattern will persist but perhaps with a front across the far north bringing some rain to the n.isles and n.mainland of scotland and a risk of wintry showers spreading down into shetland and orkney during the weekend.

[Peter H]

Glorious day here today. Wall to wall sunshine and not really cold. Just a little bit of a nip in the air. This would have been a great set up in July or August.

I do think winter is pretty much over bar the shouting now. Too late in the season for snow to lie for any length of time due to the strength of the sun.

Some models were predicting a plunge of very cold air next week, but that scenario seems to have dissipated for now

[phil nw.]

Closing this in a few minutes-ready for the 12`s folks.

[phil nw.]

OK locking this now-new thread for the 12z runs here.