Model Output Discussion 5/12/2012 18Z onwards - the one after THAT ECM

[Bristawl Si]

I think he said cold coming by Tuesday with low pressure out to the south west - hinting at potential snow further down the line - not necessarily by Tuesday

Exactly - i think my original post said a threat "from midweek onwards"

[Alex95]

The ECM is as good as last night's up until +168, which is FI in itself really anyway. After that today's looks snowier as the Atlantic pushes in, but from a purely speculative point of view, last night's FI had the promise of the cold spell continuing indefinitely, whereas today's would have the Atlantic winning out. Clearly any breakdown can only be nailed at +72 or +96 ish though so its a bit pointless to speculate about +240.

I'm confident that most of the UK will see some lying snow next week, and some places in the east could well be in store for 6-12 inches of snow depending on who lucks out. Sorry to keep bringing up past cold spells, but I remember people whinging that November 2010 was going to be too marginal, and that we would see a sleet/snow mix, yet parts of NE England to the north of Rothbury in the hills saw as over 30 inches (~80cm), and 10-20 inches was widespread, as well as in some other parts of Eastern England. This time round we have seen people moaning that the flow looks slack, and that there is a chance that Atlantic might try push in after around two hundred and fourty hours from now!

P.S. amazing to think that at this point in 2010/11 the best snow of the winter (by a long shot) in NE England had already fallen! In fact, the very snowy spell culminated in the thundersnow on the 29th November, then an intense band of powder snow on the 1st December. There was more significant snow that winter, but nothing on the scale of November, and certainly no more of note during that particular cold spell.

Edited December 6, 2012 by Alza

[Methuselah]

Just not here despite the MO suggesting it might (no blame to them it was a hard call) in fact its chucking it down with rain, snow on the hill tops above a 1000ft only

I guess that that's what I meant: if snowfall is difficult to nowcast, pinpointing it ten-days' out must be nigh-on impossible. Even computer models can't perform miracles...

[Met4Cast]

Well well.. ECM at T216 backs the GFS, with a hefty low pressure developing in the Atlantic ! But more alarmingly the arm of

Northern blocking from Scandi across to Greenland has collapsed. It just isnt there. And the Scandi High is retreating away

east into Russia on a NW/SE trajectory.. One has to say the runs today are a trend in the wrong direction, and tonights ECM

is a long way removed from the epic ECM of yesterday. All eyes on the Pub run to see if this can provide some kind of back

up to the developing trend from around 8 days out. Cold is still on the cards in the short term, albeit, the NNE winds seem to be

firming up rather than the stiff easterlies shown on earlier runs.

Saying the ECM backs the GFS might be taking it a step too far -

The ECM does show an Atlantic attack, but its at a far, far better angle than the GFS shows. ECM will bring milder air in slowly and I think it'd take a couple of attempts before the cold is pushed away altogether, the surface high developing to the East will help sustain the cold for longer, not to mention the fact the lows energy is heading more Northwards, rather than directly East as per GFS.

Given the background signals talked about by GP for retrogression though, i'd say the current OP output is at odds with the expected development with little sign of retrogression, given this there's a chance we'll see the Atlantic being pushed back in future updates.

[ukpaul]

We are giving some leeway in here as a lot of members are upbeat about the cold spell, however, a few posters seem obsessed with looking for snow and are clogging the thread up with one line comments.

Can those posters please use the other threads and allow the rest of us to enjoy our discussions on the model outputs.

Any silly or off topic posts will disappear.

Thanks all.

Just got in but looked at the models and all still very pleasing to look at, as for the future with the consequences of strat activity to come I don't think we could be in a better position at the moment.

Anyway, apologies if someone already pointed it out in relation to above but the only way to see snow potential is to wait until you start to see fax charts at that range and then the NAE. This far out to ask or to answer about will it/won't it is a fool's game.

Edited December 6, 2012 by ukpaul

[Jan_Bromley]

Ian Fergusson â€@fergieweather

@MattHugo81 GFS all over shop into same timeframe and it's westerly mass-breach of block looks far too optimistic based on prior experiences

The main man speaks

Edited December 6, 2012 by lupiejan

[Iceberg]

Strat Experts:

Is the PV meant to take this long to move to Siberia:

http://www.meteociel...H0-240.GIF?06-0

At 168 it looks like its saying its farewells to the Canadians. Then decides to hang around. I assume something is happening in the strat?

fantastic question, hopefully they can answer this. My view is that there is no chance of the PV setting up Siberia this side of Christmas, as the high below it just far too strong. Its were the models are struggling most, if the PV doesnt go there, then were does it go ?.

[Met4Cast]

Here's Ians forecast, just to clear up what was said on the previous page about Tuesday

http://news.bbc.co.uk/weather/hi/news/newsid_7760000/7760862.stm

[Buzz]

http://www.meteociel...H1-216.GIF?06-0

216

Heavy snow over the Uk from that kink ( in the middle )

VERTICAL advection in the atlantic- I bet the atlantic cant get in-

There could be a HUUGGEEE snowstorm at 240

S

Is it really worth analysing such FI charts? I mean honestly, you and other experts in here discourage others from taking too much notice of FI charts (especially when they are showing mild weather, breakdowns, etc) and now you go and ramp a chart that is 240 hours away and extremely unlikely to verify as shown.

[SMU]

Iceberg-

Chunks of the vortex in the gap between Siberia & Scandi - but no the entire vortex-

I see Ian has put another vote in for the GFS to be consigned to the bin- it will hopefully catch up on the 18z-

S

[PubliusEnigma]

Anyone note the 1065mb Siberian high on the ECM 12Z?

Was just going to post this. Usually its the GFS that touts the highest Anticyclonic pressures from past memory. Wonder what the pub run will place it as ?

[SMU]

Is it really worth analysing such FI charts? I mean honestly, you and other experts in here discourage others from taking too much notice of FI charts (especially when they are showing mild weather, breakdowns, etc) and now you go and ramp a chart that is 240 hours away and extremely unlikely to verify as shown.

Its takes a split second to review a chart- so if they are showing widespread snow- yes.

S

[cooling climate]

An easterly northeasterly airflow for next week is 98% likely now but that is really all we can say.

Each model and each run deals with the lows and energy over Europe differently from as early

as t96 and this has a huge bearing on how cold and snowy the weather may be.

At this rate it may take up to the end of the weekend to answer these questions but I think there

are two things we can be certain of and that is its going to be very cold and there will be snow

around.

Oh and one more point the charts at t240 in a couple of days time will look nothing like they do

now.

[Harsh Climate]

Sorry but you're misreading the 12Z GFS.

The intial E,ly might be slacker but the actual run is better than previous GFS runs with regards to prolonging the cold spell. Exactly the same with the UKMO.

Delighted with the 12Zs so far.

Not in a million years was the gfs 12z run better than previous gfs runs!! I find it even more shocking that the amount of people who actually agree with you.

Just goes to show that on these forums you can tell the less knowledgeable people anything and they will believe you because it's what they want to hear

The 12z gfs offered no snow to almost the whole UK and a return to mild atlantic weather by 204h. At least previous gfs runs had convective snow showers moving into eastern areas next week!

On a lighter note, great ukmo and a good ECM!

Edited December 6, 2012 by Harsh Climate

[January Snowstorm]

Folks last one from me this evening.

I read the charts as I see them

I don't factor in what GP is thinking as this is the model output discussion not the strat thread. (have great respect for GP)

I am not a troll who loves mild

The gfs is well up there and better than ECM in my opinion. For me tonight proves this as ECM is very different from last night's epic (though still cold)

I write all my posts with a general location in mind not imby

Everyone is guilty of imby from time to time

Remember what happens in Cork 9 times out of 10 happens in the UK 24hours later ( I know there are exceptions)

Debate is good I firmly believe, life would be boring on here if all we were doing was congratulating ourselves at how cold the charts look!

So rather than me being childish I think we should welcome open discussion and debate and welcome all views whether it be cold or mild.

Afterall I dont control the weather am only expressing a viewpoint!

[Severe Siberian icy blast]

ECM confirms this evening that the atlantic could well win this battle by next weekend.

We have strong agreement now tonight that heights are not going to retrogress towards Greenland. (though FI at this stage)

I have to say not a bad run for UK, esp the Southeast but for Ireland not great as we are last to see the cold and first to lose it.

We basically get 3 days of severe frost and bitter winds

Saying that, this would apply to all Easterly's, I guess we are more favoured for Northwesterly's.

Last night was EPIC, tonight is back to earth but still good charts

Haha I have to laugh , the ECM confirms the break down?? Come on pal your talking at the LAST frame , a long time away, love to see the verification stats of the last frame coming off, you obviously don't listen to a word the pro's say on hear.

[Alex95]

Not in a million years was the gfs 12z run better than previous gfs runs!! I find it even more shocking that the amount of people who actually agree with you.

Just goes to show that on these forums you can tell the less knowledgeable people anything and they will believe you because it's what they want to hear

The 12z gfs offered no snow to almost the whole UK and a return to mild atlantic weather by 204h. At least previous gfs runs had convective snow showers moving into eastern areas next week!

On a lighter note, great ukmo and a good ECM!

Sorry, but the 12z GFS would certainly deliver thick snow to Northern and Eastern areas, at least to those within about 10-20 miles of the North Sea if no organised troughs form at all. If that's the worst case scenario I'm very, very happy. You can't have -8°C 850s, low thicknesses and an onshore NE/NNE wind without significant snow in my location, and I assume the same is true for many other eastern areas.

P.S. its very hard not to let a bit of IMBY creep in. I'm upbeat tonight as Newcastle nearly always gets at least 2-4 inches of snow per day for the kind of setup modelled for next week, and of course we had 2-3 inches yesterday as well just to get me in the mood. If I hadn't seen any proper snow this winter and I lived somewhere where 1 in 3 easterlies deliver something worthwhile I would be feeling a bit downbeat as a slack easterly or even NNE would be less likely to send snow further west.

Edited December 6, 2012 by Alza

[crimsonp]

so todays models are totally conflicting with yesterdays awesomeness but i saw a vid earlier on the beebs weather thingy and that dude who looks like gordon brown (a bit), phillip avery is it? well he was saying that next week could swing either way, i.e. high pressure from scandi or low pressure from the atlantic. in other words they don't know yet!!! i thought it was a tad pointless them posting it but hey!!

their latest vid shows lots of high pressure coming from scandi over to us well into next week so it seems that the beeb have made their minds up!! obviously they haven't studied todays models hahaha!!

keep your chins up guys and to all those who rant about the ranters, isn't that the premise of all discussion?

http://www.bbc.co.uk/weather/feeds/20634016

[LomondSnowstorm]

Is it really worth analysing such FI charts? I mean honestly, you and other experts in here discourage others from taking too much notice of FI charts (especially when they are showing mild weather, breakdowns, etc) and now you go and ramp a chart that is 240 hours away and extremely unlikely to verify as shown.

Worth analysing yes, worth taking overly seriously if unsupported no.

[london-snow]

All this moaning today yet we are still very much facing a cold to very cold setup get a grip people.

If people want to moan or rant about anything weather related it can be done here -

If you wish to discuss any potential snowfall this can be done here - http://forum.netweather.tv/forum/142-regional-discussions/

I am once again encouraged by the output today which get's us over that first hurdle of the sw tracking and sunk se by 90 hours which is now in the reliable and has shown no signs of taking a different route over the past few days so i can now 99% say that that is nailed on and penned in.

Beyond this is were we can potentially have a very cold setup & possibly snowy. All these details will not be confirmed until at least 48 hours time which is why there is no point in hanging on each run beyond reliability as it will change as the models firms up on what type of easterly we will see & as for experienced members stating ' Dry Run ' ect i think ' Come on how long have you been watching the models for? As you know as well as i that snowfall is unpredictable especially in a easterly flow as connectivity can often come into play'.

For those newbies out there and for those who are seeking answers regarding snowfall there is a learning facility available on n-w which is a brilliant learning tool to use & to gain knowledge.

But for the general rule of thumb you cannot tell no more than 24 hours out in this potential spell where we may well see connectivity from the east coasts then you cannot tell until it happens.

Hope that helps.

L-S

[Harsh Climate]

Sorry, but the 12z GFS would certainly deliver thick snow to Northern and Eastern areas, at least to those within about 10-20 miles of the North Sea if no organised troughs form at all. If that's the worst case scenario I'm very, very happy. You can't have -8°C 850s, low thicknesses and an onshore NE/NNE wind without significant snow in my location, and I assume the same is true for many other eastern areas.

Within 10-20 miles is COASTAL AREAS, hardly widespread snow for east of the pennines like on the previous 2 gfs runs. Can see why you would be happy living in newcastle though

Edited December 6, 2012 by Harsh Climate

[SnowObsessor90]

Oh and one more point the charts at t240 in a couple of days time will look nothing like they do

now.

True, now I can't say I'm not one to have a good whinge but if people say that charts round about the 192-240 hr range can't be taken too seriously if they're showing cold then why can't the same apply now? Double standards methinks.

[johnholmes]

for those wanting a view on what upper air pattern we may be in 6-15 days from now the link below is my view on things and a stab at what the surface may show

http://forum.netweather.tv/topic/75105-model-thoughts-summaries-27th-nov-onward/page__st__40__gopid__2435199#entry2435199

[ukpaul]

Not in a million years was the gfs 12z run better than previous gfs runs!! I find it even more shocking that the amount of people who actually agree with you.

Just goes to show that on these forums you can tell the less knowledgeable people anything and they will believe you because it's what they want to hear

The 12z gfs offered no snow to almost the whole UK and a return to mild atlantic weather by 204h. At least previous gfs runs had convective snow showers moving into eastern areas next week!

On a lighter note, great ukmo and a good ECM!

Not true, you are falling for what the GFS PPN charts are saying and they are far short of the finished article. Nobody knows what the snow risk is until very close to an event, to imagine that you can up to 204h shows a gross misreading of charts. Shortwaves, disturbances, those are not modelled at this far out. surely events from recent years tell people that they should never rule out snow when the uppers, dew points and temps are good enough.

Hopefully people will have the patience to wait and see.

Edited December 6, 2012 by ukpaul

[ITSY]

Liam Dutton, Matt Hugo and other professional forecasters seem to be commenting on twitter that GFS is too progressive, noticed Ian liked the look of ECM surprise surprise!! I would tend to agree given the size of the block we are talking about the the entrenched cold. Either way, the longevity will become clearer over the weekend. For now, it looks like a cold Easterly/NE/SE on the way for many next week bringing with it the risk of some sort of snow for someone, somewhere. How long it will last is as yet unclear. IMO, an excellent start to winter given that the sleety snow is hitting my window outside and that, with only 6 days gone, the E, W and N of England and Scotland have all seen some snow (not for all, but for some).