Model Output Discussion:

[Frosty.]

Icant fathom this out. The met o outlook says cold in the east for next 15 days. Yet the faxs show Southwesterlies and

the beginnings of a bartlett forming just off the coast of SE France. Someones got it wrong..

Someone underestimated the force of the cold block to the east more like. 12z will be crucial but those experts at the meto plus BFTP have eased my concerns, well done guys

[Duane S.]

Indeed the GFS always seems to underplay the return of the Atlantic. I'm convinved the cold will return but not

until the end of Feb, but it could well last through the entire month of March. We need a mild reload to clear the atmosphere so that the cold can have another shot. At the moment we are stuck in southerly nothingness.. Sometimes rather cold othertimes a little milder.

Nope, I'd disagree with that. A milder reload doesn't mean we would end up with any more chance of cold than if we were sat in 'no mans land' for 10 days.

If we end up with too much energy in the Northern arm then even with a deeply -AO (which could paradoxically make it worse, especially without the aid of a -NAO) we could be stuck for a while in a westerly regime for a long time.

Personally I really don't think that will be the case though.

[Blizzard_of_Oz]

Hi Nick - I think your final sentence says it all.

Id add that having seen a section of my blog cited above on this thread, it must be stressed that it is, obviously, a very moveable feast (that blog entry was written based directly on detailed UKMO guidance from early yesterday, and we've since seen further briefings - part of which also cited above on this thread - albeit the general theme remains very much as you summarise above).

I tend to stick within the bounds of the nowcast/ short-range / NAE window on my blog; I'd urge any of you on this thread with technical interests in the longer-range output to visit my colleague Paul Hudson's blog instead - see http://bbc.co.uk/paulhudson

Best wishes to you all -

Ian

Thankyou Ian for giving us a bit of relief, it was me who posted your blog on the forum. In my first post with your blog I said 'belief' and some member commented about me believeing in God etc. and to be more realistic. This was a typo error it was supposed to read 'relief', you have now explained yourself and gave me a lot more belief now.

[Snowyowl9]

This day is where I`ve noticed some changes with the low NE which brings in some colder air back in.

http://91.121.93.17/pics/Rtavn781.png

http://www.wzkarten.de/pics/Recm721.gif

http://www.wzkarten.de/pics/brack2a.gif

All reasonable good agreement upto then at least.

[Guest North Sea Snow Convection]

The further outlook does suggest a nice cold outlook BUT it does not suggest winter armageddon - which I think is the interpretation that many members are going to take

Or want to take.

And as nick s very rightly says it is NOT a guarantee that it will happen either. It does suggest that the UKMO model might move away from its overt atlantic stance but it also suggests (to me) that the very coldest air that has been seen on the GFS fantasy charts that some members believe are going to verify, could well be to the east of us. Suggestions of a more south easterly flow (rather than the convective biting deep upper cold ENE type flow) are interpretive to me of the UK being towards the end of the line of the continental airstream and as such may well be high pressure based and more stable once an initial potential skirmish with atlantic fronts has passed. One that clearly suggests snow potential for that time.

However, again as nick s says, the UKMO model still has to change its pattern suggestion. It has now rolled out three consecutive charts with more atlantic jet energy and the METO outlook could easily change tomorrow (as it often does based on model changes) if the model doesn't budge.

The METO model might not be right, but it can't be ignored either because it sometimes is in these situations. This isn't a done deal by any stretch. Yet.

Edited January 30, 2010 by North Sea Snow Convection

[SnowBallz]

Someone underestimated the force of the cold block to the east more like. 12z will be crucial but those experts at the meto plus BFTP have eased my concerns, well done guys

Why "well done," when none of this has verified yet?

If we've learnt anything, is it not that the chances are that by tomorrow, it'll be a completely different picture?

I don't get this whole need to congratulate, when there's nothing to actually congratulate.

Obviously it'd be nice if we had an Easterly - because that's a bit more exciting than our usual run-of-the-mill Atlantic rubbish. But, until we experience otherwise, then I think it's healthy if all model watchers remember what's the dominant feature to us. It just sounds like people are so desperate for something exciting to be within the models, yet why look for the extraordinary when, 9 times out of 10, it never verifies? That's gotta be incredibly depressing.

Oh and, BFTP, I said of the last cold spell that it was incredibly stupid for people to suggest that the "UK would shutdown." Which it is, because it didn't. It's called exaggeration, which - ironically enough - is exactly what some of the models tend to do when they find something odd; it gets amplified out of all proportion. However, are these ridiculous, stupid charts ever dismissed? No, instead people weirdly save them to their hard drives. I mean, WTF??!!

And no BFTP, a 2c mean doesn't signal - to me - anything extraordinary at all. What it suggests - to me - is that there is quite obviously rather large discrepancy between peak and trough values, across the runs. It's cold - I'll grant you that - but it does not signal 'End of Days' scenarios which I read some try to continually push.

But we shall see, won't we - that's the beauty of the weather. However - as I said - I fully expect 8th Feb (or anywhere either side of it) to pass without any note whatsoever, and yet - as sure as night follows day - they'll be charts posted up dated 22Feb10, promising - yup you guessed it - Easterlies.

As I've always maintained, I'd love to be proven wrong - but I just feel that a healthy dose of realism is needed here. Let's make an informed, educated critique of the models, not slavishly follow whichever path they meander down. If something moronic is being suggested, then let us proclaim that it's moronic - not try and build a case for it, only for it to be blown out of the water, as resolution tidies it up. Because, for me, isn't good meteorology as much about disproving a scenario, as it is building a case for the unimaginable? I see a lot of the latter, but when someone tends to favour the former, they are dismissed as mere pessimists. Well, they could easily counter by accusing their 'adversaries' of being fantasists, couldn't they?

[Stu_London]

Massive scatter on the 06z ensembles = FI starts very early. probably +96 at the latest

Important 24 hours of output coming up

[yamkin]

once again there is low confidence in these model outputs ,hence the dissagreement ,bu that is to be expected in a blocking situation as in the past when these situation occured the bbc would simply say it like it is and not forecast any further ahead than they were certain of , but with the advent of these models the companies are obliged to give a forecast even if they know its likely to be wrong,the truths in there somewhere.

at the moment i would not bet against the UKMO at 144 ,but even then they have made mistakes in the past but i think the other models will have to come on board with UKMO or the UKMO does a quick turn around with either solution still possible and still the cold air could come back later in fi.

Going on past experiences if ever you see huge forecasting errors it is usually in these blocked situations ,so i would say hang fire and see if the UKMO sticks to its GUNS tonight , and another thing of note is the BBC have never made any mention of easterlies returning at least not yet but thet ar3e obviously keeping a close eye on things without commiting themselves

Incorrect, BBC forecasters Ian Fergusson and Paul Hudson have both indicated a possible flow from the East

Edited January 30, 2010 by yamkin

[cold snap]

The facts are this morning and i suppoes it sum up the whole week

We have never got this in to a reliable timeframe.i know ecm gave us a hint we might.but that had been dismissed by all other models then ECM decided to put it in the bin..

So the standoff between East and West contiunes within the reliable timeframe.a battle then has took up a few weeks .

The Pure cold to the East of us has been there for weeks.it would be hard to take if we could not tap into maybe for the final time.

This standoff has become very frustating and infact a bit boring when you see the Easterly put back another day.

ECM and GFS have struggled with the block.but in fairness to either model imo.i think we have to grin and bear it that the UK as a whole is and always will be the line in the sand between The mild West and the Cold East.breaches are always possible.

With all this being said we are in cold snap now.But hand on heart are experience tell us you just cant beat the beast from the East

[swilliam]

Concerning the UKMO 144 chart people are concentrating on the energy going into the N jet but I think more attention should be paid to the size, intensity and position of the block to the NE. Looking at the UK first you can see that the block is small, 'only' 1045 and quite a way east. The result is that the Atlantic LP just drifts and expands across the UK with a poor SW/NE alignment. It is difficult to get the Easterly from this position (although people should remember that 8th Feb is till over 70 hours away from this chart - small changes could still allow an Easterly of some description by then)

Looking at the ECMF the block is bigger, more intense (1050) and crucially further N and a bit further W. It is now less easy for the Atlantic lows to move over us and they are further W and S. The alignment is now N/S and the easterly is easier to achieve although it takes till the famed 8th Feb at 216 to get there

For the 06Z GFS the block is much bigger (even extending to Greenland), more intense again (1055) and well North and West. The result is that the Atlantic LPs are even further S and link up the LPs further East over Europe. The result is the troiugh is now aligned SE/NW and from here it is easyt o get an Easterly occurring within the next couple of days.

It is interesting to see why the differences occur. Looking the GFS there is WAA from Russia towards the pole. This then links up with WA already near the pole and this then grows into the large block shown previously.

Compare this to the UKMO there is the same WAA from Russia and the pool of warm air near the pole. However by +96 they fail to link up. The result at 120 is a much smaller, less intense block further S and E

So I think we need to pay attention to how the block develops to our N&E

[Guest North Sea Snow Convection]

Concerning the UKMO 144 chart people are concentrating on the energy going into the N jet but I think more attention should be paid to the size, intensity and position of the block to the NE.

So I think we need to pay attention to how the block develops to our N&E

Good analysis

I was always under the impression that a fault of UKMO model was to overplay high pressure blocking. That certainly doesn't seem to apply atm!

Edited January 30, 2010 by North Sea Snow Convection

[pyrotech]

Why "well done," when none of this has verified yet?

If we've learnt anything, is it not that the chances are that by tomorrow, it'll be a completely different picture?

I don't get this whole need to congratulate, when there's nothing to actually congratulate.

Obviously it'd be nice if we had an Easterly - because that's a bit more exciting than our usual run-of-the-mill Atlantic rubbish. But, until we experience otherwise, then I think it's healthy if all model watchers remember what's the dominant feature to us. It just sounds like people are so desperate for something exciting to be within the models, yet why look for the extraordinary when, 9 times out of 10, it never verifies? That's gotta be incredibly depressing.

Oh and, BFTP, I said of the last cold spell that it was incredibly stupid for people to suggest that the "UK would shutdown." Which it is, because it didn't. It's called exaggeration, which - ironically enough - is exactly what some of the models tend to do when they find something odd; it gets amplified out of all proportion. However, are these ridiculous, stupid charts ever dismissed? No, instead people weirdly save them to their hard drives. I mean, WTF??!!

And no BFTP, a 2c mean doesn't signal - to me - anything extraordinary at all. What it suggests - to me - is that there is quite obviously rather large discrepancy between peak and trough values, across the runs. It's cold - I'll grant you that - but it does not signal 'End of Days' scenarios which I read some try to continually push.

But we shall see, won't we - that's the beauty of the weather. However - as I said - I fully expect 8th Feb (or anywhere either side of it) to pass without any note whatsoever, and yet - as sure as night follows day - they'll be charts posted up dated 22Feb10, promising - yup you guessed it - Easterlies.

As I've always maintained, I'd love to be proven wrong - but I just feel that a healthy dose of realism is needed here. Let's make an informed, educated critique of the models, not slavishly follow whichever path they meander down. If something moronic is being suggested, then let us proclaim that it's moronic - not try and build a case for it, only for it to be blown out of the water, as resolution tidies it up. Because, for me, isn't good meteorology as much about disproving a scenario, as it is building a case for the unimaginable? I see a lot of the latter, but when someone tends to favour the former, they are dismissed as mere pessimists. Well, they could easily counter by accusing their 'adversaries' of being fantasists, couldn't they?

I actually save charts on hard drive for short term to watch changes from run to run, ie 12z changes over last few days etc, then delete them.

Now i do see where your coming from on unverified situations and congradulating people prior to event happening but BFTP contruibutes greatly to analysis on here and although like anyone else is not 100% accurate he does give a good analysis of what is shown and give explanations of why he thinks things will change.

With all due respect your post does not show any reasons why 8th feb will not be cold and you do not back up any comments about the models and what you see in them. Right or wrong BFTP and others do at least explain why they think things will occur or not by explaining the trends or limitations of each of the models.

I think your comments would be more beneficial if you could explain your reasons for Atlantic domination during the period.

Please take this a constructive critism and not as a personnal attack at your post.

[Duane S.]

Why "well done," when none of this has verified yet?

If we've learnt anything, is it not that the chances are that by tomorrow, it'll be a completely different picture?

I don't get this whole need to congratulate, when there's nothing to actually congratulate.

Obviously it'd be nice if we had an Easterly - because that's a bit more exciting than our usual run-of-the-mill Atlantic rubbish. But, until we experience otherwise, then I think it's healthy if all model watchers remember what's the dominant feature to us. It just sounds like people are so desperate for something exciting to be within the models, yet why look for the extraordinary when, 9 times out of 10, it never verifies? That's gotta be incredibly depressing.

Oh and, BFTP, I said of the last cold spell that it was incredibly stupid for people to suggest that the "UK would shutdown." Which it is, because it didn't. It's called exaggeration, which - ironically enough - is exactly what some of the models tend to do when they find something odd; it gets amplified out of all proportion. However, are these ridiculous, stupid charts ever dismissed? No, instead people weirdly save them to their hard drives. I mean, WTF??!!

And no BFTP, a 2c mean doesn't signal - to me - anything extraordinary at all. What it suggests - to me - is that there is quite obviously rather large discrepancy between peak and trough values, across the runs. It's cold - I'll grant you that - but it does not signal 'End of Days' scenarios which I read some try to continually push.

But we shall see, won't we - that's the beauty of the weather. However - as I said - I fully expect 8th Feb (or anywhere either side of it) to pass without any note whatsoever, and yet - as sure as night follows day - they'll be charts posted up dated 22Feb10, promising - yup you guessed it - Easterlies.

As I've always maintained, I'd love to be proven wrong - but I just feel that a healthy dose of realism is needed here. Let's make an informed, educated critique of the models, not slavishly follow whichever path they meander down. If something moronic is being suggested, then let us proclaim that it's moronic - not try and build a case for it, only for it to be blown out of the water, as resolution tidies it up. Because, for me, isn't good meteorology as much about disproving a scenario, as it is building a case for the unimaginable? I see a lot of the latter, but when someone tends to favour the former, they are dismissed as mere pessimists. Well, they could easily counter by accusing their 'adversaries' of being fantasists, couldn't they?

You are of course entitled to your opinion but maybe you would like to back it up with specific reasons as to 'why' you think what you do as opposed to 'it just will be'. Playing the devil's advocate will get you zilch respect on this forum I'm afraid Snowballz.

Those who save it to their hard drives (speaking for myself and I'm sure others) do so not under the belief that it will occur, contary to your extremely presumptious reasoning but because it looks rather nice. I have seen NOBODY talk in a way that they believe such a run (aka the GFS 18z) WILL come off but that it could (albeit unlikely). Perhaps you would like to show me exactly why it couldn't?

I have posted plenty of charts etc over the past 7 days explaining why I think we could be in for a very cold/snowy spell of weather. I have also explaining my thoughts more recently about why it may go wrong.

We are no worse off than were this time yesterday IMO, still heading towards a continental feed.

Edited January 30, 2010 by s4lancia

[swilliam]

Good analysis

I was always under the impression that a fault of UKMO model was to overplay high pressure blocking. That certainly doesn't seem to apply atm!

Thanks NSSC - I just thought that it takes 2 to Tango and that the details of the block are just as important as what is happening in the Atlantic

[andymusic]

Why "well done," when none of this has verified yet?

If we've learnt anything, is it not that the chances are that by tomorrow, it'll be a completely different picture?

I don't get this whole need to congratulate, when there's nothing to actually congratulate.

Obviously it'd be nice if we had an Easterly - because that's a bit more exciting than our usual run-of-the-mill Atlantic rubbish. But, until we experience otherwise, then I think it's healthy if all model watchers remember what's the dominant feature to us. It just sounds like people are so desperate for something exciting to be within the models, yet why look for the extraordinary when, 9 times out of 10, it never verifies? That's gotta be incredibly depressing.

Oh and, BFTP, I said of the last cold spell that it was incredibly stupid for people to suggest that the "UK would shutdown." Which it is, because it didn't. It's called exaggeration, which - ironically enough - is exactly what some of the models tend to do when they find something odd; it gets amplified out of all proportion. However, are these ridiculous, stupid charts ever dismissed? No, instead people weirdly save them to their hard drives. I mean, WTF??!!

And no BFTP, a 2c mean doesn't signal - to me - anything extraordinary at all. What it suggests - to me - is that there is quite obviously rather large discrepancy between peak and trough values, across the runs. It's cold - I'll grant you that - but it does not signal 'End of Days' scenarios which I read some try to continually push.

But we shall see, won't we - that's the beauty of the weather. However - as I said - I fully expect 8th Feb (or anywhere either side of it) to pass without any note whatsoever, and yet - as sure as night follows day - they'll be charts posted up dated 22Feb10, promising - yup you guessed it - Easterlies.

As I've always maintained, I'd love to be proven wrong - but I just feel that a healthy dose of realism is needed here. Let's make an informed, educated critique of the models, not slavishly follow whichever path they meander down. If something moronic is being suggested, then let us proclaim that it's moronic - not try and build a case for it, only for it to be blown out of the water, as resolution tidies it up. Because, for me, isn't good meteorology as much about disproving a scenario, as it is building a case for the unimaginable? I see a lot of the latter, but when someone tends to favour the former, they are dismissed as mere pessimists. Well, they could easily counter by accusing their 'adversaries' of being fantasists, couldn't they?

That last cold spell - you refer to did cause a lot of accidents cars /pedestrians with fractures/ airports to shut/ snowed in situations where if supplies were not gotten in, things could have become difficult - admittedly it wasn't "the day after tomorrow" scenario - but it was pretty severe - and the general population did suffer - and it's quite possible this could happen again this Feb 2010 - seems we may even have more snow than Vancouver (home of this years 2010 Olympics 13th Feb) in Canada - they've got none cause the jet stream is holidaying in hawaii!!!!!!!!!

Edited January 30, 2010 by andymusic

[nick sussex]

Quite an interesting difference of opinion between the EPO forecasts from NCEP and the physical sciences division of NOAA.

http://www.esrl.noaa.gov/psd/forecasts/teleconn/images/compare.we.png

For those newer members the EPO is the Eastern Pacific Oscillation, in a nutshell when this is negative it promotes an eastern USA trough and west coast ridge, this is an amplified upstream pattern and is generally more condusive to colder conditions in Europe, we can get a positive EPO and be cold but normally in these situations we would need a block with the flat jet running underneath. Interestingly NCEP flattens the jet out around the 4th February thats why its crucial that the block is far enough west to deflect jet energy underneath it. The ESRL/PSD measure keeps a more amplified upstream pattern, this would also draw the pattern further west pulling the block with it and also probably allowing some pressure rises over Greenland.

Interestingly the EPO and PNA are normally closely correlated, the PNA Pacific North American pattern when positive implies a similar west coast ridge eastern USA trough scenario and this correlates with a negative EPO. I wonder whether GP is about, does he ever use the PSD readings or generally sticks to the NCEP.

[BLAST FROM THE PAST]

Oh and, BFTP, I said of the last cold spell that it was incredibly stupid for people to suggest that the "UK would shutdown." Which it is, because it didn't. It's called exaggeration, which - ironically enough - is exactly what some of the models tend to do when they find something odd; it gets amplified out of all proportion. However, are these ridiculous, stupid charts ever dismissed? No, instead people weirdly save them to their hard drives. I mean, WTF??!! :blink:

And no BFTP, a 2c mean doesn't signal - to me - anything extraordinary at all. What it suggests - to me - is that there is quite obviously rather large discrepancy between peak and trough values, across the runs. It's cold - I'll grant you that - but it does not signal 'End of Days' scenarios which I read some try to continually push.

Please enlighten me...I haven't a clue what you are going on about.

BFTP

[Bobby]

Confidence on any outcome at the moment is low, just look at the model and ensemble scatter, anyone who claims to know what's going to happen is just decieving themselves, including the experts. The potential is certainly there for something great but realising that potential is something else isn't it?

The models will slowly work things out over the coming days, we just have to cross our fingers and hope for the best.

Edited January 30, 2010 by Barb-

[Rob]

Nice to see the cold coming back after the "milder interlude" mid week, still hints of a very cold snap mid feb :blink:

[SnowBallz]

Please enlighten me...I haven't a clue what you are going on about.

BFTP

Whoops, sorry I meant TITIS or whatever his moniker is.

Everyone uses acronyms on here, can get very confusing at times.

[Duane S.]

Concerning the UKMO 144 chart people are concentrating on the energy going into the N jet but I think more attention should be paid to the size, intensity and position of the block to the NE. Looking at the UK first you can see that the block is small, 'only' 1045 and quite a way east. The result is that the Atlantic LP just drifts and expands across the UK with a poor SW/NE alignment. It is difficult to get the Easterly from this position (although people should remember that 8th Feb is till over 70 hours away from this chart - small changes could still allow an Easterly of some description by then)

An excellent and very relevant post. The crucial alignment of the trough to the west will be primarily driven by the intensity and location of the block to our east

[TEITS]

Obviously it'd be nice if we had an Easterly - because that's a bit more exciting than our usual run-of-the-mill Atlantic rubbish. But, until we experience otherwise, then I think it's healthy if all model watchers remember what's the dominant feature to us. It just sounds like people are so desperate for something exciting to be within the models, yet why look for the extraordinary when, 9 times out of 10, it never verifies? That's gotta be incredibly depressing.

Oh and, BFTP, I said of the last cold spell that it was incredibly stupid for people to suggest that the "UK would shutdown." Which it is, because it didn't. It's called exaggeration, which - ironically enough - is exactly what some of the models tend to do when they find something odd; it gets amplified out of all proportion. However, are these ridiculous, stupid charts ever dismissed? No, instead people weirdly save them to their hard drives. I mean, WTF??!! :blink:

And no BFTP, a 2c mean doesn't signal - to me - anything extraordinary at all. What it suggests - to me - is that there is quite obviously rather large discrepancy between peak and trough values, across the runs. It's cold - I'll grant you that - but it does not signal 'End of Days' scenarios which I read some try to continually push.

But we shall see, won't we - that's the beauty of the weather. However - as I said - I fully expect 8th Feb (or anywhere either side of it) to pass without any note whatsoever, and yet - as sure as night follows day - they'll be charts posted up dated 22Feb10, promising - yup you guessed it - Easterlies.

For starters let me say you would be much better off posting about the models rather than members themselves. Back in January you complained about members ramping up snow potential because you thought the models looked dry. As we know the cold spell produced plenty of snow.

Finally as im short of time let me remind you this is the model discussion thread. What members have been discussing is only what has been shown consistently on the GFS and also at times the ECM. Very few have assumed the E,ly is on its way but merely discussing the potential. Until we have model agreement at +72 then nothing is yet certain.

So please post about the models on this thread rather than about members. I cannnot think of one post you have made about the models. You didn't even notice the 06Z was showing an E,ly at +144!!

[January Snowstorm]

Whoops, sorry I meant TITIS or whatever his moniker is.

Everyone uses acronyms on here, can get very confusing at times.

I think you mean 'teits' :blink:

[Guest North Sea Snow Convection]

Thanks NSSC - I just thought that it takes 2 to Tango and that the details of the block are just as important as what is happening in the Atlantic

I mentioned about trough alignment this morning in terms of a potential -NAO setting up - wrt the west based variety that GP has spoken about. At the boundary between the HP to the NE and any LP to the west, the alignment of these lows can make the difference between atlantic and continental air (or a blend of the two)

These NE 'ern blocks are never modelled especially well. However we saw how strong the Siberian block was a week or so back and it didn't make inroads for the BI. However that is not to say it won't in the future.

[Tim Bland]

Whoops, sorry I meant TITIS or whatever his moniker is.

Everyone uses acronyms on here, can get very confusing at times.

I think you mean Dave - TEITS lol!

Back to the models after all this is what we are to discuss isn't it? I dont see anything that would shut the UK down just a possible wintery spell. I don't think the outcome will be sorted by tonights output, there will be lots of choping and changing over the next few days. We could see a cool SE breeze by next weekend and be looking at models for the end of Feb showing the 'Beast From the East".