Model Output Discussion 12z 07/11/2012

[fergieweather]

That chart screams blocking to the north

Yup: as on the pressure anomaly output I'm looking at now. Strong signal. We shall see. Anyway I'm sure it's all been gawped at on here before so apols for any duplication!

[Cheshire Freeze]

Yup: as on the pressure anomaly output I'm looking at now. Strong signal. We shall see. Anyway I'm sure it's all been gawped at on here before so apols for any duplication!

Your input is much welcomed

[bluearmy]

Yup: as on the pressure anomaly output I'm looking at now. Strong signal. We shall see. Anyway I'm sure it's all been gawped at on here before so apols for any duplication!

matt tends to give us the info on the strat thread re the ecm 32 day updates ian. we only get to see the odd chart (as you posted) when something dramatic is shown. i get the feeling that the ecm 32 dayer, being restricted, generates some discord in Reading when its posted on forums such as this. given that we pay for much of it via our taxes, i'm happy to see it rather than just hear about it !!

[Cheshire Freeze]

matt tends to give us the info on the strat thread re the ecm 32 day updates ian. we only get to see the odd chart (as you posted) when something dramatic is shown. i get the feeling that the ecm 32 dayer, being restricted, generates some discord in Reading when its posted on forums such as this. given that we pay for much of it via our taxes, i'm happy to see it rather than just hear about it !!

Completely agree, technically we have paid for it through taxation....but let's not slide into that debate

[Cloud 10]

Yup: as on the pressure anomaly output I'm looking at now. Strong signal. We shall see. Anyway I'm sure it's all been gawped at on here before so apols for any duplication!

Don't worry about duplication,you won't see many EC 32 charts being posted!

[Snowman.]

No, it would appear you're looking through cold-tinted glasses. The NAO forecast is not 'neutral at best', on the first graph* all members point to a moderately positive outcome for the next week, later trending towards neutral but with just four of them opting for varying degrees of -NAO.

Further down the line, that can of course all change - EML isn't suggesting that November mildness (which earlier you were denying as being likely!) guarantees any sort of weather further down the line. It's rather the stratosphere's November weather, rather than the UK's weather, which is (strongly) indicative of the UK's weather further down the line, though of course still doesn't give anything close to definite.

*I've never paid attention to the three graphs below, no matter what they're showing. What exactly is the difference between them and the top graph, and why are they showing fairly different outcomes?

edit: I do think there's a tendency in this forum to jump on anyone who suggests/points out the possibility of mildness, as if they're suggesting mildness will reign for months and months or as if they're suggesting it's a definite outcome rather than a possibility.

Actually that looks better than yesterday in turns of cold, only one run went negative on that chart is looks like there flipping to a negative so I don't think that you can through that away just yet out of the 3 months of winter it has time to change as it just goes out to a 14 day period.

Edited November 7, 2012 by SN0WM4N

[Gibby]

Good evening. Here is the evening review of the 12z output of the big three tonight.

The pattern remains agreed upon between the models on where the weather goes between now and Monday of next week. A weak cold front crosses ESE over the UK tonight and tomorrow helping to lift some of the grey cloud in the current moist Westerly flow. The front itself will carry very little rain and will be followed by a WNW flow later tomorrow with dry and breezy conditions maintained in the North and West while the South and East sees a colder and clearer night on Thursday with maybe a touch of frost here and there. Friday sees a more active front move SE over the UK with all models showing a colder and clearer spell over the early part of the weekend though with plenty of showers in the North and West, heavy and thundery in places. By Sunday these will ease with a bright and dry day later on Sunday as improvements transfer West to East over Britain. On Monday a warm front moves steadily NE over the UK bringing a return to milder nd strong SW winds with rain for many, heaviest in the North and West.

GFS shows a couple of milder days early next week with rain and strong winds at times for all. Later in the week colder conditions develop as Low pressure drifts to the North Sea and much of Britain lies under a cold trough for a day or two with showers, perhaps wintry on Northern hills. In FI tonight mild weather returns with rain and strong winds at times over the UK as Low pressure persists close to NW Britain. Later on though this same Low pressure makes it's way over to the NE and East of us with a cold and wintry spell of weather possible for many Northern and Eastern areas as winds turn towards the NNW with showers or longer periods of rain, sleet or snow should it verify.

The GFS Ensembles maintain a flat pattern tonight with surface temperature likely to be near the seasonal normal throughout the next few weeks. The operational was a cold outlier at the end with the vast majority of members going for average uppers or even slightly above normal the most likely outcome. With rainfall scattered about throughout the run from the 12th in the South and Atlantic influenced pattern is more or less guaranteed.

The Jet Stream flows reasonably slowly across the Atlantic currently but strengthens greatly over the coming days as it ridges over the Atlantic before toppling South over the West of Britain late this weekend. The flow then looks set to stay in a basic West to East flow across Britain for some time thereafter.

UKMO for midday on Tuesday shows a deep depression West of Norway with a broad trough SW from it's centre to the Eastern Atlantic. The UK lies in a strong SW flow with sunshine and showers, these chiefly in the West. The polar trough will lie somewhere close to Southern Britain and the pattern looks favoured for ripples to run along this and give Southern areas some more prolonged rain at times. Temperatures would be near to normal generally.

ECM shows a similar setup to UKMO with the mild SW flow bringing rain in the South and showers in the North in more average temperatures here. Later in the run a small Low enhances rainfall from the SW whilst winds fall lighter as it moves North into Southern Britain. it then becomes absorbed by a reinvigorated SW flow around a major depression in the Iceland area bringing mild and wet conditions to the UK once more.

In Summary the weather continues the fairly flat pattern over the UK for the next few weeks with Low pressure to the North and higher pressure well to the South. Fronts crossing East will bring occasional periods of rain mixed with slightly cooler and showery spells. The GFS Ensembles show little or no respite from this pattern other than the operational which does introduce a NNW Arctic blast at the end of the run. It has no support though and is at 300+ hrs. ECM too tries to disrupt the pattern somewhat in it's later stages but on this occasion the power of the Atlantic train rolls back in.

[Frosty.]

The gfs is good at picking up on arctic blasts in deep FI that then eventually gets dropped by gfs and picked up by other models like ecm, it could gather support and in any case, it seems a cold end to the month and early dec is more likely than not.

[snowking]

Yup: as on the pressure anomaly output I'm looking at now. Strong signal. We shall see. Anyway I'm sure it's all been gawped at on here before so apols for any duplication!

Ive got access to this but I cant quite make out whether the version I can access is the full EPS mean or whether its just the control run (it certainly suggests as much as its titled ECMWF Monthly Forecast System - Individual Control Run) so certainly looks like just the control from the suite

Anyway, this on its own is suggestive of blocking being scandinavian based, with some pretty cold 850's being advected westward to our shores via undercutting lows.

Ive got access for the next 30 days so i'll keep an eye on this one and see how well it matches up with the full EPS suite details yourself and Matt Hugo are keeping us up to date on.

But scandinavian heights are certainly something being suggested in the latter parts of the current output which provides interest, albeit further east

SK

[Timmytour]

I love reading all the views on here, and I do get hopeful about the ones with a cold outlook and fearful about the ones with a mild outlook.

But I window shop only and don't buy anything more than ten days ahead.

Go back to the 16th April this year, and to this BBC headline about the drought

http://www.bbc.co.uk/news/uk-england-17690389

A month later we were wondering if the rain was ever going to end, four months later we were thinking it wasn't!

But not long before it broke, I don't think anyone interpreting the signals or the output of the models foresaw the extent to which it would.

There's some fantastic knowledge in here, used to produce different interpretations. But the one thing that we can be certain of is that no one can be certain what's going to be happen three weeks away.

[John Badrick]

I love reading all the views on here, and I do get hopeful about the ones with a cold outlook and fearful about the ones with a mild outlook.

But I window shop only and don't buy anything more than ten days ahead.

Go back to the 16th April this year, and to this BBC headline about the drought

http://www.bbc.co.uk/news/uk-england-17690389

A month later we were wondering if the rain was ever going to end, four months later we were thinking it wasn

But not long before it broke, I don't think anyone interpreting the signals or the output of the models foresaw the extent to which it would.

There's some fantastic knowledge in here, used to produce different interpretations. But the one thing that we can be certain of is that no one can be certain what's going to be happen three weeks away.

Very well said!!!!

Edited November 7, 2012 by John Badrick

[damianslaw]

Models are suggesting more of a traditional westerly pattern for the forseeable future, with temperatures very near average, nothing particularly mild on the horizon just quite normal for early-mid November which on average is still milder than March..

The weekend should bring a cooler interlude with the return of frost.

Next week looks generally unsettled with rain at times, but there are no signals of a vigorous jet taking hold or a particularly strong polar vortex setting up shop, it all looks rather benign and I wouldn't be surprised to see heights building out of Europe into scandi as we head towards the middle of the month forcing the rather weak atlantic to once again becom unstuck over the country with the trough languishing over the country with nowhere to go once again, and eventually being forced to retreat SW once again.. as heights build both to the NW and NE. There are a number of strong signals pointing to a cold end to the month.. but there is a while to go yet. The outlook is very different to the very mild SW dominated patterns of Nov 2009, and 2011.

[snowstorm445]

No, it would appear you're looking through cold-tinted glasses. The NAO forecast is not 'neutral at best', on the first graph* all members point to a moderately positive outcome for the next week, later trending towards neutral but with just four of them opting for varying degrees of -NAO.

And yet EML Network claimed it would be "very positive", as opposed to "moderately positive". Now, in my experience, I have seen much more positive NAOs than this predicted one, which from the looks of other NAO runs below won't last long (last Christmas saw a predicted NAO of nearly plus 4 or 5, not surprising given the extremely zonal weather with a very strong Jet).

He also claims it looks set to be positive "right through to the end of the period", which is incorrect as the NAO chart shows above. Fair enough if it turns out to be positive, but I don't know what he is basing this claim on if he is referring to the charts.

And I don't claim to solely seek cold weather, that would be cherry picking. But its important to define what is meant by the word "mild". Mild in meteorological terms means temperatures that are above the seasonal average. The models are currently predicting a coolish zonal flow for the next few days, and temperatures are set to be around the seasonal average. London, for example, is set to see temperatures around 9-11ºC, whilst the seasonal average high for London is 11.4ºC, so it looks likely to be even below average at times.

Further down the line, that can of course all change - EML isn't suggesting that November mildness (which earlier you were denying as being likely!) guarantees any sort of weather further down the line. It's rather the stratosphere's November weather, rather than the UK's weather, which is (strongly) indicative of the UK's weather further down the line, though of course still doesn't give anything close to definite.

*I've never paid attention to the three graphs below, no matter what they're showing. What exactly is the difference between them and the top graph, and why are they showing fairly different outcomes?

edit: I do think there's a tendency in this forum to jump on anyone who suggests/points out the possibility of mildness, as if they're suggesting mildness will reign for months and months or as if they're suggesting it's a definite outcome rather than a possibility.

Can you quote me on this?

He actually made no mention of the stratosphere in his post, rather to charts, and the High Pressure associated with it. He claims there is High pressure over southern Europe by the end of the run, whilst in actual fact, the high pressure systems (according to the GFS, which apparently has the best track record in FI) are located over the Azores, just extending into Iberia, and Eastern Europe. Regardless, these look to have no effect on the UK/Ireland as low pressure is centred over us bringing fairly mixed conditions.

Regarding your last part, that's usually the problem. There seems to be an almost phobic hatred of anything remotely mild, and should it show up in the charts, pessimism is often the order of the day. People seem to always buy into it and declare that the entire month ahead looks poor, as if this sole chart will inevitably come true, whereas colder charts are taken with a huge pinch of salt. I'm not buying into an overly cold November, but some of those who are even doubting a White Christmas at this stage need to bear in mind how unreliable weather forecasting becomes after even a week.

Edited November 7, 2012 by snowstorm445

[stewfox]

And I don't claim to solely seek cold weather, that would be cherry picking. But its important to define what is meant by the word "mild". Mild in meteorological terms means temperatures that are about the seasonal average.

Here 'mild' is 4c to 7c above average.

http://www.timeanddate.com/weather/glossary.html

Surely 'mild' cant mean average ? I think its important in a model sense ? Do we have a defintion ?

[davehsug]

_{Mild is of course temperatures above average. As for the} ECM _{32 dayer, how often were we told in the summer that it showed something better just around the corner?whatever's going on? I couldn't remove the underlining last night & now I can't change the font size. Is windows8 striking me?}

Edited November 7, 2012 by davehsug

[johnholmes]

Here 'mild' is 4c to 7c above average.

http://www.timeandda...r/glossary.html

Surely 'mild' cant mean average ? I think its important in a model sense ? Do we have a defintion ?

yep in the Guides, or at least the terms used by the Met O

[snowstorm445]

Here 'mild' is 4c to 7c above average.

http://www.timeandda...r/glossary.html

Surely 'mild' cant mean average ? I think its important in a model sense ? Do we have a defintion ?

Oops. I meant to say "above"!

My mistake.

[SnowObsessor90]

It's of no surprise to see the 18z not being commented on, it pretty much sums up the model output of late bar the very latter stages of the 12zs deep FI. Here's hoping that there's more in the way of proper eye candy for us to get our teeth into before too long even it literally is just that.

Edited November 7, 2012 by Anonymous21

[Rocheydub]

A21, I know exactly why you say that, it doesn't offer anything for coldies... However, the progress that just flattens that mid Atlantic high that was starting to get sucked up to Greenland near the end of the run, was a wee bit too progressive to me. Just didn't look right. Of course, it's FI, well into it, so it may look nothing like that in the build up!!!

[EML Network]

Ok just to clear some things up.

Yes I was wrong to use the term ''very positive'' when referring to the NAO forecast, doesn't mean that it's not forecast to go into a positive phase thought ! and in fact the ensemble ''mean'' will keep the NAO just ever so slightly above neutral through until the end of the run.

My point is that there does seem to be a trend over recent days to push the NAO forecast higher and higher into a more pronounced + value....who knows tomorrow it might trend the other way and you can all thrown rotten tomatoes at me :-)

So My bad on that one, will "hold my hands up" and admit I should have deleted the word "very" ....we'll see what the chart is showing in the next few days , hopefully it'll be a quick return into - values after a brief flirtation into the +

However, not once did I mention the word "Mild" nor did I say that High pressure was likely to build over Southern Europe and likewise I didn't once mention High pressure being over the UK, I didn't even mention December in my post and I certainly wasn't writing off Winter o the basis of one run.....Chinese whispers are clearly in effect !!

I am completely aware that it is November and that we shouldn't be expecting - 10 uppers and a bitterly easterly wind at this time of year, nor am I suggesting otherwise .

I was simply highlighting that fact that High Pressure looks set to be covering..and I quote " A great swathe of Europe" over the coming weeks and that it seems to be a fact that is overlooked.

I'm all for a cold and snowy outbreak, trust me..I'll be the first in the queue to lamp post watch, I just feel that sometimes this forum needs someone to act as devils advocate and give some members a bit of a reality check, I've spent too many years chasing FI only for it to never come to fruition.

There are a lot of positive trends as GP has presented quite elequently in his video , as we head into Winter, but we can't ignore the other trends that are saying something quite different, in fact if you look at the analog years at the end of that video, 2002, 2004 and 2005 are included along with 1977 , 1978 and 1953.

here's hoping we hit the jackpot and come Mid Winter we can all bask in the glory of 6 ft snow Drifts and build igloo's :-)

[bobbydog]

here's some pretty pictures for the doom-mongers to wake up to.....

Edited November 8, 2012 by bobbydog

[snow drift]

I Find the recent output encouraging and do see a change coming later in the month. I follow the output, example below, and a continuation of JS well to our south has been an indicator of cooler conditions in the main. If this trend continues and as time moves on I then start to look at other output in more detail. This to me is positive if you like cooler/ cold weather.

[bluearmy]

That's several gfs op runs with a late fi trending. We have seen that before in November. Still too erly to call but encouraging signs that if we have the right European pressure pattern, we could advent some pretty cold air last third November.

[IDO]

here's some pretty pictures for the doom-mongers to wake up to.....

That looks great, however a few runs to get support would be sensible. Look at the ensembles:

http://nwstatic.co.uk/viewimage.pbx?type=ens;date=20121108;time=00;file=t850Aberdeenshire;sess=848f79ee2f57698f3f137b366c8025b4

Very little support. Those last few frames of FI at the moment a cold outlier. Most members around the T850s mean of 0c, which has been the case for over a week.

But an improvement, as there have been a nominal amount of members showing even potential cold of late, so not a sea change but maybe signs of what the experts have been alluding to. Certainly there are strong heights over N.America on this run pushing the PV on a good axis for the UK:

http://cdn.nwstatic.co.uk/gfsimages/gfs.20121108/00/384/npsh500.png

I dont know if this is a strong lasting block, to keep the amplified trough over the UK?

[bluearmy]

The gefs 850's are currently useless for what's coming last third November. HLB continues to be pronged in the arctic. Where the balls fall is the question and the ensembles are not going to congregate around one solution for a while yet.