Model Output Discussion - 21st - 28th November

[Iceberg]

Some good divergency on the models upstream this morning. ECM is much more progressive with HP development on the pacific/US west coast.

AT T168 ECM has a 1040mb high, GFS a 1024mb high, this translates as we move though the time periods with ECM moving a strong ridge (1035mb) into Alaska, where as GFS keeps pressure at 1004-1008.

ECM then produces a Major block, 1045mb in places from the arctic to the central pacific down through western Canada.

What this screams from ECM is Major intense amplication upstream with the building blocks at T168.

The Arctic is not in any shape to keep the Blocking however if it happens, it would probably be enough to provide the first shot of cold winter weather eventually to our shores.

[Frosty.]

Here comes the (phantom) Siberian High that GP was talking about last night. The Gfs 00z shows a colder feeling day tomorrow as a brief NW'ly arrives with showers spreading southeast, wintry showers across the far north. Saturday looks much milder but also windier with heavy rain in the northwest, pushing east and south, sunday looks stormy across the far northeast and windy further south, also turning colder again but with temps only back to the seasonal average. Next week there is potential for winds to turn Northerly as the complex trough edges east but it's a slow process, indeed next week is looking very unsettled with heavy rain for most areas (welcome rain for the south!) as another low develops over southern britain and with the air slowly turning colder, there is the chance of some wintry ppn but scotland seems most favoured for snow to low levels from midweek, a messy looking pattern..next week looks a lot more wintry than the gfs 00z yesterday at least.

Edited November 24, 2011 by Polar_ Low

[wolvesfan]

Morning all,

Far reaches of fi albeit but we could be looking at early modelling of the elusive scandi high which i'm sure is going to set this thread on fire as winter progress's(if it varifies).

[Gibby]

Good morning. A bit busy still this morning so just a quickie from me. The big three models continue to show a changeable theme for the next few weeks. There are variations between all the models but the general message of a fairly mobile Atlantic spell of weather remains with the most wind and rain for the North. GFS does indicate cooler conditions at times with some occasional wintry precipitation for the hills in the North while ECM looks less progressive than last night's 12z. There still remains no indication of any harsh wintry weather anytime soon with any FI charts suggesting such in the ensembles too far out and sparse currently.

Edited November 24, 2011 by Gibby

[WhiteFox]

No disrespect to Nick S and his wanting the snow for the well being of the ski industry - but I think there is a much larger downside, economically, to Christmas shopping and the economy in general when we get the kind of disruptive snow in the UK and NW Europe that has been the calling card of (not so much last year) but the previous two - and I'm talking also about 'missed days at work' and the damage to roads/infrastructure as well as the commercial aspect.

I always take issue with news reports about losses to business caused by bad weather! A couple of days of snow does not cause the economy to grind to a halt; business catches up and even if there is a prolonged spell of weather which causes a disruption to figures we nearly always see a catch up in subsequent periods.

Also, the way we measure economic activity, damaging weather is actually good for economic activity. Repairing infrastructure and replacing damaged items actually contributes to GDP growth (whether you agree with how it's measured or not). It's like the old story about how a car accident contributes to GDP through money paid to recovery workers, mechanics etc...

Let's just be glad we don't live in a climate which has genuinely dangerous weather on a regular basis like parts of the US!

Anyway, looking at the ensembles this morning, I'm happy to see a nice variation in temperatures at the 850 level indicating low pressure systems coming closer to the UK. I know many (or most) are looking for prolonged cold and blocking, but I'll be happy just to get some variation in the weather with more active warm and cold fronts crossing the UK.

[nick sussex]

No disrespect to Nick S and his wanting the snow for the well being of the ski industry - but I think there is a much larger downside, economically, to Christmas shopping and the economy in general when we get the kind of disruptive snow in the UK and NW Europe that has been the calling card of (not so much last year) but the previous two - and I'm talking also about 'missed days at work' and the damage to roads/infrastructure as well as the commercial aspect.

That said - I love snow, but I can't help feeling that the real building blocks are not yet in place for now - tight PV, flat jet etc., but it does look like things are gradually shifting. I think I'm with the pilot who compared our 'now' with the early autumn/late summer that we're used to. We're just coming into late autumn and our winter will start towards the end of December. It's like there's been a 'phase shift' of the seasons and we're at least a month behind the norm - and have been for the second half of the year.

I was more emphasising the chances of snow for the mountains of Europe which doesn't need terribly cold air, a PM incursion wouldn't result in a great deal for the UK away from the far north and higher ground.

In terms of economic impact of course last December wasn't good for the UK but those months are very rare, much of the problems were due to people being clueless on the roads, airports not having enough snow clearing equipment and just the general inability of the UK to cope with a centimetre of snow.

This isn't only reverved for the UK, try being in Vancouver when it snows! It's down to cost ratio, given how infrequently snow falls in the UK is it worth governments spending huge amounts on combatting this.

Do bear in mind that the snowsports industry is crucial for the Alps and Pyrenees and hence my concerns about the current pattern.

Going back to that another day and another set of disappointing model runs for cold lovers, the inability of the trough to clear eastwards and failing to dig se'wards suggests more tears will be shed in the ski resorts.

My skiing delayed yet again and I'm in a rather irritable state of mind.

[willinkent]

I am heading to Denmark 8th December. Looking like my going to Denmark is influencing weather again. Last year I was due to go to denmark on 2nd December.....couldnt catch train/taxi/bus as had 8inches of snow here in Faversham...... hoping not going to happen again.... stansted was open but my flight took off, M25 chock a block with jack-knifed lorries..... ooppps.... hopefully see some snow in Denmark though with those charts if they came off.... long way ahead but so little snow as of yet in scandi.... hopefully it'll be more seasonal through early/mid december.... eager model watching over next few weeks....

[nick sussex]

The problem across the output is the orientation of that Atlantic troughing, its actually digging sw'wards and even the NAEFS has shifted to that trend this morning, eventually if the limpet high ridges back in rather than having a feed of se'rlies its more like to be a south to sw flow.

It's likely that as the trough fills out we'll see yet more troughing to the sw, as I said yesterday you have to have the trough running se'wards so that the angle the limpet high builds in at is more favourable down the line.

I'm not going to be saying any more about ski prospects as I'm sure I've bored everyone to tears by now, I might start a separate thread, called Operation Save The Skiing Season!

[johnholmes]

I've put my latest ideas on how the upper pattern may eveolve and why in the technical thread-as usual for my convenience its a pdf file. Don't be alarmed by where its been posted, its in what I hope is my usual easy to read and understand text and charts.

As to worries about the Alps ski season. Obviously its going to be a later start than usual, certainly than last year. However, I do not see the need to become worried to the extent some folk sound. I'll be very surprised if Santa does not deliver the white stuff to fairly low levels in time for Christmas in the Alps!

[ITSY]

GfS 06 interesting with a devlping easterly during FI. Too early to deliver the goods really - and the fetch isn't long enough - but it creates either at or below average temps widely in England and Wales and largely below average in Scotland. A new devlpmnt?

[Gavin Hannah]

The GFS for the the next 5 days has been fairly consistent I feel. I do think that out in FI, it's hinting at a possible cold shot developing. The jet also looks like taking a detour through spain for a short while at least.

[nodrog]

I know im against the grain here as most are snow lovers, but this Extratropical system expected to hit as low as 944mb tonight!

Models show is between Iceland and North West Scotland in the Atlantic... over the Faroe Islands will be 'battered' with ave gusts 50 -80 mph WSW.

Looks wild for the begining of the week also... nice!

[nick sussex]

Some nice eye candy for cold lovers in the depths of FI.

Again though so unlikely to verify that it hardly warrants much discussion.

Back on earth in the higher resolution output this follows the NAEFS with that trough slowly filling out. the ECM is unlikely to verify as shown because of what it does with a shortwave at 120hrs, the UKMO and GFS phase this with the main trough moving east out of Canada, the ECM separates this and runs it out into the Atlantic.

This causes a big difference near Greenland and hence anything after this will develop differently.

Theres still a level of uncertainty because of these disagreements, also exactly how that trough will fill out near the UK and what will happen to the upstream pattern in the medium term.

[legritter]

morning all ,just had a look at charts and other forums , things could get very interesting next week onwards . looking foreward too tonights chat on here . some interesting developments in northern hemisphere at the moment , euro high beware , mother nature could send you packing south ,or replace you with a beast of a relative . we just need a singing from the same hymn sheet , from the models . i think we have a FAIR chance of something more wintry on its way ,regards till later ,legritter .

[johnholmes]

I know im against the grain here as most are snow lovers, but this Extratropical system expected to hit as low as 944mb tonight!

Models show is between Iceland and North West Scotland in the Atlantic... over the Faroe Islands will be 'battered' with ave gusts 50 -80 mph WSW.

Looks wild for the begining of the week also... nice!

yes its rather sad that with a storm being predicted so close that there is no mention in this thread.

Too involved with snow prospects I'm afraid. I will have a look but I suspect that the other thread has most things covered. It will not be long before its going to be basic forecasting as the low gets into areas with data. 24 hour forecasts do not need models for predicting things, well not in the old days!

[BLAST FROM THE PAST]

I think the progression is looking good. A More wet and windy set up with gales in places and temps up and down. What to look for as we advance into Dec. Lps digging further south and pressure rises probably to our NE, not SE or NW. Early dec looks like a chance of gales for many. Models have shown/are showing this in varying form and 2-4 Dec looks another period to concentrate on. Certainly the benign weather is shoved on. 3rd week of Dec I reckon before we get what folk call 'cold' weather but some decent 'weathery' weather before that to be had.

BFTP

Edited November 24, 2011 by BLAST FROM THE PAST

[lorenzo]

That storm is certainly the story of today. Am thankful it is not further south tbh.

Not often rapid cyclogenesis is shown in the satrep charts. http://www.knmi.nl/data/satrep/archive/ZAMG/MANU_20111124_0600.html

Shipping forecast at 1130 highlighting hurricaine force winds. http://www.metoffice.gov.uk/weather/marine/shipping_forecast.html#All~Faeroes

Not a day for the Fishing.. !

[Gavin Hannah]

There was def a sniff of HP evolving over Scandi out if FI. A step in the right direction perhaps.

[November13]

I think winter gales is about the best we can hope for in the short term. No sign of any cold at all. This recent 2-3 months has been the worst Autumn early winter in a long time. No snow not even a drop for the whole of November in Scotland other than a few showers on the high tops. I think people become obsessed with snow because winter is about frost and snow. We can get gales or storms any time of the year.

[johnholmes]

I think winter gales is about the best we can hope for in the short term. No sign of any cold at all. This recent 2-3 months has been the worst Autumn early winter in a long time. No snow not even a drop for the whole of November in Scotland other than a few showers on the high tops. I think people become obsessed with snow because winter is about frost and snow. We can get gales or storms any time of the year.

not correct as the link below will show-brief but it did happen

http://www.winterhighland.info/pix/pixalbum.php?pix_id=734

[weatherobsuk]

Behind this Cold Front overnight the GFS is keen to introduce a northerly plunge across Scotland all throughout Friday, with a slight minimal risk including the Lake District into Saturday aswell. Short-term the models are giving some wintryness even if FI has little in the way of consistency as of yet.

[johnholmes]

not correct as the link below will show-brief but it did happen

it also snowed quite well down Cairngorm on 7 October

http://www.winterhig....php?pix_id=734

[Gavin Hannah]

Overall tho, I think we can all be chuffed that for the next week at least, we will see some "weather". I think the past 3-4 weeks were the slowest in terms of weather patterns developing that I can ever remember. At least with some variability in the patterns, there is a chance that the real cold can develop out of thin air.

Edited November 24, 2011 by MadSnowboarder

[November13]

not correct as the link below will show-brief but it did happen

http://www.winterhig....php?pix_id=734

Was that snow not October? It was November I said had no snow!

http://www.bbc.co.uk/news/uk-scotland-highlands-islands-15596782

Edited November 24, 2011 by November13

[Osbourne One-Nil]

Wrong thread - general winter discussion please. This is for model discussion.