Corbyn - Winter Warning Of Exceptional Uk Cold And Snow

[UV-RAY]

none of the models has any bias built in. All synoptic models simply take the actual data and run from that.

none of the models has any bias built in. All synoptic models simply take the actual data and run from that.

But surely they must have some inbuilt bias into them John. The reason I ask is that the last thirty years we have seen a warming trend, no one can deny these facts, whatever caused the warming. So with this in mind, surely the models have an inbuilt warming trend that represents the last thirty years data. If this is the case, then maybe this is the sole reason as to why LRF by the Met Office has become such a hot potato?

But surely they must have some inbuilt bias into them John. The reason I ask is that the last thirty years we have seen a warming trend, no one can deny these facts, whatever caused the warming. So with this in mind, surely the models have an inbuilt warming trend that represents the last thirty years data. If this is the case, then maybe this is the sole reason as to why LRF by the Met Office has become such a hot potato?

But surely they must have some inbuilt bias built into them John. The reason I ask is that the last thirty years we have seen a warming trend, no one can deny these facts, whatever caused the warming. So with this in mind, surely the models have an inbuilt warming trend that represents the last thirty years data. If this is the case, then maybe this is the sole reason as to why LRF by the Met Office has become such a hot potato?

Why are my post replicating themselves when I try to edit them?

[VillagePlank]

The models do not have any bias. They may have characteristics that manifest themselves (which might mistakenly be attributed to bias) but that is an error in the programming, or data collection, not a bias based on trends. It might 'overcook' convection given high CAPE values, for instance - which is a 'mistake' (I say mistake, it's probably not enough resolution more than anything else)

Edited November 2, 2011 by Sparticle

[recklessabandon]

The models do not have any bias. They may have characteristics that manifest themselves (which might mistakenly be attributed to bias) but that is an error in the programming, or data collection, not a bias based on trends. It might 'overcook' convection given high CAPE values, for instance - which is a 'mistake' (I say mistake, it's probably not enough resolution more than anything else)

At the risk of getting caught up in semantics, we need to be clear. I think the argument is that the 'bias' is being referred to in the statistical sense rather than cognitive sense. Bias in the statistical sense is exactly what you have described above. I personally never suggested that there was bias in the cognitive sense in the models, because although they are under human control, they are objective numerical models. I suggested that statistical bias may be occurring because of the skew in available data and the way it is used (as per earlier comments) from different sources, which might suggest a skew, or bias, toward zonal type conditions.

[johnholmes]

I'll come back on this question of bias etc during tomorrow

[ZONE 51]

Would it not be a good thread on the Models bias discussion? i think it would be very interesting.

[recklessabandon]

Would it not be a good thread on the Models bias discussion? i think it would be very interesting.

I've started something now haven't I.....happy to be 'moved' if this conversation can be put somewhere more appropriate.

[Radiating Dendrite]

Model bias thread:

[Mark Neal.]

Piers Corbyn seems to be a character doesn't he, I do however hope he is right!

[Crocodile23]

While they might not affect the UK weather forecasts - NCEP don't agree with you.

http://www.hpc.ncep..../biastext.shtml

Just because the word bias is included in the page, it doesn't mean it's the same bias you were talking about in the first place.

[November13]

There is definately a pattern developing in all the forecast's. They keep getting it wrong and then keep moving the goalposts. We were originally expecting a cold September and that was way out. Then ice and snow in October hey that was way out as well. Now the posts have been moved to the end of November. I bet you I am sitting here on November 25th still waiting for the siberian weather. The weather forecasters will no doubt say "Cold Weather expected in December" One thing is clear their accuracy apart from a small few including the Met office has been rank so far!

[November13]

Remember this one? This guys got to be a berry counter or something. Think he just makes it up!

James Madden, of Exacta Weather, said: 'I expect to see the first signs of some moderate to heavy snowfalls as early as October or November in certain parts of the UK.

Well there was 2 days of heavy snow 3500ft up Glencoe and Cairngom does that count!

[Nights King]

There is definately a pattern developing in all the forecast's. They keep getting it wrong and then keep moving the goalposts. We were originally expecting a cold September and that was way out. Then ice and snow in October hey that was way out as well. Now the posts have been moved to the end of November. I bet you I am sitting here on November 25th still waiting for the siberian weather. The weather forecasters will no doubt say "Cold Weather expected in December" One thing is clear their accuracy apart from a small few including the Met office has been rank so far!

To be fair I don't think any forecasters ever said we were going to get real cold and snowy weather in october wasn't it just the media that misinterpreted a few forecasters over a small 'cool' spell which did come to fruition?

[Radiating Dendrite]

Remember this one? This guys got to be a berry counter or something. Think he just makes it up!

James Madden, of Exacta Weather, said: 'I expect to see the first signs of some moderate to heavy snowfalls as early as October or November in certain parts of the UK.

Well there was 2 days of heavy snow 3500ft up Glencoe and Cairngom does that count!

He would probably argue it does!

Indeed I think he does, cannot find the link now.

[Buzz]

Piers Corbyn seems to be a character doesn't he, I do however hope he is right!

He stands about as much chance of getting it right as I do from flipping a coin. Heads for mild, tails for very cold .............................

[ukpaul]

Remember this one? This guys got to be a berry counter or something. Think he just makes it up!

James Madden, of Exacta Weather, said: 'I expect to see the first signs of some moderate to heavy snowfalls as early as October or November in certain parts of the UK.

Well there was 2 days of heavy snow 3500ft up Glencoe and Cairngom does that count!

As far as I can see we haven't had November yet.

Who you are angry about is the Express/Mail, they did the same with an anodyne forecast from Brian Gaze on The Weather Outlook so direct you ire at them. They do it all the time, trying to scare people about health/weather/finance and so on. I doubt that there are many who get taken in by them anymore though.

[November13]

To be fair I don't think any forecasters ever said we were going to get real cold and snowy weather in october wasn't it just the media that misinterpreted a few forecasters over a small 'cool' spell which did come to fruition?

You are probably right but there did seem to be a general feeling of ...Hey it happened the last two years so we will predict it again type thing. The thing that I have noticed which is different to November 2010. The average October temperatures were much lower last year and then November 2010 the daily highs and averages even at the start of November were nowhere even near the crazy temps going about just now. It's funny how memory plays tricks ,as I would have said November 10 was similar to just now. It was only when I went back and checked the local weather the temps were roughly 3c colder even at the start of the month. The cold snap came on the back of averages about 3-4c then it dropped to -3c in the last week. The average today is 9c and at the moment it's 16c. We can safely say it will be roughly 12-14c for the next week at least.So the pattern is different this year.

[johnholmes]

Just because the word bias is included in the page, it doesn't mean it's the same bias you were talking about in the first place.

that is exactly the case, hopefully I'll be able to explain this more fully sometime today in the thread started about 'bias' of the models.

[Isolated Frost]

November13; only sensationalist forecasters went for a cold sep and icy october. Most did not.

[Coast]

Here is the full forecast with text for clarity:

http://www.youtube.com/watch?v=obLq_klpM1w

[Radiating Dendrite]

Here is the full forecast with text for clarity:

http://www.youtube.com/watch?v=obLq_klpM1w

His outstanding accuracy?? I lol'd at this!

[Summer Sun]

LOL what a way to start the video

"Those of you familiar with Piers forecasts will be aware of his astounding accuracy"

I'm afraid it's more luck than anything and when he gets it wrong he never seems to explain why, at least when Netweather got the summer forecast wrong this year they admitted it early and offered an explanation as to why which I can accept but the way Piers delivers his forecast's I have to say I'm not a fan 1 bit.

[greybing]

sometimes being on here reminds me of the schoolyard......thats all im going to say.

[johnholmes]

sorry I was only able to watch to his predictions of heavy snowfalls with dates.

Now, whatever one uses to predict the weather, it really is utterly impossible to do that sort of thing-utterly impossible. One could say that it would appear to be the coldest over a certain period up to a month ahead over a period of dates and that snowfall would seem probable sometime between those dates but to be as insistent as he sounded on actual dates is simply not possible to give that kind of detail.

IF it turns out correct, + or - a week he can and will claim a correct prediction, outside that time frame and his forecast will be flawed but I do not doubt if we get cold let along extreme cold (by the way what does he mean by extreme cold?) or no severe snowfalls (causing severe transport disruption over large areas) he will still claim he is right.

No professional organisation is going to get mixed up with pointing out his errors so he will get away with it again even if he is wrong. And so the saga of his forecasts and accuracy will continue.

I really should stop responding to these outputs from him. I've said it many times and its true, get the forecast right=keep quiet, get it wrong and be quick to apologise and explain what you think went wrong. To me that seems the honest way to go about being a forecaster, be it for 1 day ahead, 1 month ahead, or a season ahead.

end of another jh rant.

Edited November 7, 2011 by johnholmes

[greybing]

sorry I was only able to watch to his predictions of heavy snowfalls with dates.

Now, whatever one uses to predict the weather, it really is utterly impossible to do that sort of thing-utterly impossible. One could say that it would appear to be the coldest over a certain period up to a month ahead over a period of dates and that snowfall would seem probable sometime between those dates but to be as insistent as he sounded on actual dates is simply not possible to give that kind of detail.

IF it turns out correct, + or - a week he can and will claim a correct prediction, outside that time frame and his forecast will be flawed but I do not doubt if we get cold let along extreme cold (by the way what does he mean by extreme cold?) or no severe snowfalls (causing severe transport disruption over large areas) he will still claim he is right.

No professional organisation is going to get mixed up with pointing out his errors so he will get away with it again even if he is wrong. And so the saga of his forecasts and accuracy will continue.

I really should stop responding to these outputs from him. I've said it many times and its true, get the forecast right=keep quiet, get it wrong and be quick to apologise and explain what you think went wrong. To me that seems the honest way to go about being a forecaster, be it for 1 day ahead, 1 month ahead, or a season ahead.

end of another jh rant.

like you say man ,you should stop getting riled up by this ,its not worth it.

[Partholon]

sorry I was only able to watch to his predictions of heavy snowfalls with dates.

Now, whatever one uses to predict the weather, it really is utterly impossible to do that sort of thing-utterly impossible. One could say that it would appear to be the coldest over a certain period up to a month ahead over a period of dates and that snowfall would seem probable sometime between those dates but to be as insistent as he sounded on actual dates is simply not possible to give that kind of detail.

IF it turns out correct, + or - a week he can and will claim a correct prediction, outside that time frame and his forecast will be flawed but I do not doubt if we get cold let along extreme cold (by the way what does he mean by extreme cold?) or no severe snowfalls (causing severe transport disruption over large areas) he will still claim he is right.

No professional organisation is going to get mixed up with pointing out his errors so he will get away with it again even if he is wrong. And so the saga of his forecasts and accuracy will continue.

I really should stop responding to these outputs from him. I've said it many times and its true, get the forecast right=keep quiet, get it wrong and be quick to apologise and explain what you think went wrong. To me that seems the honest way to go about being a forecaster, be it for 1 day ahead, 1 month ahead, or a season ahead.

end of another jh rant.

not everyone is full of humility , these kinds of people will always be quick to self-praise if they get it right, but not forthcoming about when they get things wrong. you're wasting your time expecting them to change.

Edited November 7, 2011 by Partholon