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Offline ARTzeman  
#81 Posted : 23 June 2019 09:49:16(UTC)
ARTzeman

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Joined: 14/07/2012(UTC)
Posts: 25,576
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Location: Peasedown St John. N.E. Sommerset

Met Office Hadley          13.3c.       Anomaly       -0.6c. Provisional to 22nd.

Metcheck                       13.59c.     Anomaly       -0.56c

Netweather                    13.98c      Anomaly        -0.13c

Mean of my 10       13.95c      Difference      -1.38c.

Some people walk in the rain.

Others just get wet.

Offline Stormchaser  
#82 Posted : 24 June 2019 09:28:23(UTC)
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Location: West Hants

I don't think a surface wind chart has ever caused me so much angst outside of winter cold spells - just look at how the flow takes the longest feasible track across the North Sea before turning to cross the UK!

While there's plenty of dispute regarding the temps modelled by FV3 (most of all), ECM etc - there's no doubt that it won't be nearly as toasty as it could have been for the CET region, even with the western bias to the monitoring stations.

 

A markedly warmer than average final week was a factor in my estimation for this month, as the tropical cycle looked to be very supportive after factoring in the typical delay of a week or so.

Frustratingly, that cycle has actually played out pretty much as I expected, and the very warm setup has essentially manifested too, but for an unusually strong ridge that could easily have extended less or more east, leading to much less moderation of temps by the North Sea.

 

You see with the scientific approach, it's certainly possible to get the overall pattern sequence right for the remainder of the month, but the finer detail can still kick you into the gutter anyway.

If one instead uses a mathematical approach, then the best approach for a low average CET errror is actually to routinely estimate close to the LTA unless extreme anomalies are predicted with high confidence (by the NWP models) for the first week or so.

I gather that this mathematical approach is what GW's hoping to deter by withholding the LTA stats until after the deadline.

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If you have any problems or queries relating to TWO you can Email twomoderationteam@gmail.com :)

Homeland: Rural Mid-West Hants nearly 10 miles S of Salisbury (near Fordingbridge). Current location: Homeland

2018's Homeland Extremes:

T-Max: 30.9*C 8th July | T-Min: -7.7*C 28th Feb | Wettest Day: 19.2mm 14th October | Ice Days: 4 (28 Feb - 2 Mar & 18 Mar)

Keep Calm and Forecast On

Offline ARTzeman  
#83 Posted : 24 June 2019 09:37:15(UTC)
ARTzeman

Rank: Advanced Member

Joined: 14/07/2012(UTC)
Posts: 25,576
Man
Location: Peasedown St John. N.E. Sommerset

Met Office Hadley          13.5c.       Anomaly      -0.5c. Provisional to 23rd.

Metcheck                       13.74c      Anomaly      -0.41c

Netweather                    14.1c        Anomaly      0.0c

Mean of my 10 stations   14.07c. Difference    -1.26c.      

Some people walk in the rain.

Others just get wet.

Offline Caz  
#84 Posted : 24 June 2019 11:08:02(UTC)
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Location: Market Warsop, Nottinghamshire, East Midlands

Originally Posted by: Stormchaser Go to Quoted Post

I don't think a surface wind chart has ever caused me so much angst outside of winter cold spells - just look at how the flow takes the longest feasible track across the North Sea before turning to cross the UK!

While there's plenty of dispute regarding the temps modelled by FV3 (most of all), ECM etc - there's no doubt that it won't be nearly as toasty as it could have been for the CET region, even with the western bias to the monitoring stations.

 

A markedly warmer than average final week was a factor in my estimation for this month, as the tropical cycle looked to be very supportive after factoring in the typical delay of a week or so.

Frustratingly, that cycle has actually played out pretty much as I expected, and the very warm setup has essentially manifested too, but for an unusually strong ridge that could easily have extended less or more east, leading to much less moderation of temps by the North Sea.

 

You see with the scientific approach, it's certainly possible to get the overall pattern sequence right for the remainder of the month, but the finer detail can still kick you into the gutter anyway.

If one instead uses a mathematical approach, then the best approach for a low average CET errror is actually to routinely estimate close to the LTA unless extreme anomalies are predicted with high confidence (by the NWP models) for the first week or so.

I gather that this mathematical approach is what GW's hoping to deter by withholding the LTA stats until after the deadline.

Well, it’s like this SC!  This IS the British weather we’re talking about and it’s its job to baffle the best of us!  

I don’t think GW is talking about withholding LTA stats or anything that is already publicly available.  I think it’s his own MO analysis that he’s delaying until after prediction close.  At least that’s how I read it!  

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Edited by user 24 June 2019 11:09:21(UTC)  | Reason: Not specified

Market Warsop, North Nottinghamshire.

Join the fun of the monthly CET competition. Last chance to join in the yearly comp is 2nd March. Discuss monthly temperatures and records.

Offline Stormchaser  
#85 Posted : 24 June 2019 15:54:45(UTC)
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Originally Posted by: Caz Go to Quoted Post

Well, it’s like this SC!  This IS the British weather we’re talking about and it’s its job to baffle the best of us!  

I don’t think GW is talking about withholding LTA stats or anything that is already publicly available.  I think it’s his own MO analysis that he’s delaying until after prediction close.  At least that’s how I read it!  

So very true Caz 

Whoops, you're right - missed that last sentence in his announcement post!

So the mathematical approach will still be readily achievable. Hmm... 


Not sure whether to give in and go with that, or keep trying to fly the sodden flag of science .

If you have any problems or queries relating to TWO you can Email twomoderationteam@gmail.com :)

Homeland: Rural Mid-West Hants nearly 10 miles S of Salisbury (near Fordingbridge). Current location: Homeland

2018's Homeland Extremes:

T-Max: 30.9*C 8th July | T-Min: -7.7*C 28th Feb | Wettest Day: 19.2mm 14th October | Ice Days: 4 (28 Feb - 2 Mar & 18 Mar)

Keep Calm and Forecast On

Offline Caz  
#86 Posted : 24 June 2019 16:34:40(UTC)
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Originally Posted by: Stormchaser Go to Quoted Post

 

So very true Caz 

Whoops, you're right - missed that last sentence in his announcement post!

So the mathematical approach will still be readily achievable. Hmm... 


Not sure whether to give in and go with that, or keep trying to fly the sodden flag of science .

Well my biological approach (gut feeling) isn’t working this year!  

A month is a long time in terms of weather forecasting and as we know only too well, even models struggle to get it right beyond about five days.  So I think sticking your finger in the air to see which way the wind’s blowing is as good a method as any.  Actually, there’s an element of science in that too!   

Market Warsop, North Nottinghamshire.

Join the fun of the monthly CET competition. Last chance to join in the yearly comp is 2nd March. Discuss monthly temperatures and records.

Offline Global Warming  
#87 Posted : 24 June 2019 19:13:43(UTC)
Global Warming

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Joined: 07/10/2006(UTC)
Posts: 6,107

Originally Posted by: Stormchaser Go to Quoted Post

So the mathematical approach will still be readily achievable. Hmm... 

One thing I am toying with for next year is whether to award bonus points (i.e. a reduction in the calculated error) for close predictions when the CET is significantly different to the LTA. Effectively it would work in the opposite way to a penalty for a late prediction or missed prediction.

I don’t want to overcomplicate it. The current system is very simple and has the benefit of just considering actual deviations from the final CET. But as you say there is a potential incentive to just predict something close to the LTA as often that will avoid large errors. 

We should not discourage people from predicting the LTA because sometimes that is the correct answer. But to my mind there is a greater level of skill in correctly predicting the CET when it is say 2C above or below the LTA. So perhaps that should be recognised in the scoring system? If the CET came in close to average in every month of the year then there would be no bonus points. 

If anyone has any thoughts on the above do let me know. We have plenty of time to ponder any potential changes for next year. Happy to stick with the status quo if that is the consensus. 

Chineham, Basingstoke, Hampshire, 86m asl
Offline Caz  
#88 Posted : 24 June 2019 19:54:28(UTC)
Caz

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Joined: 28/10/2008(UTC)
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Location: Market Warsop, Nottinghamshire, East Midlands

Originally Posted by: Global Warming Go to Quoted Post

One thing I am toying with for next year is whether to award bonus points (i.e. a reduction in the calculated error) for close predictions when the CET is significantly different to the LTA. Effectively it would work in the opposite way to a penalty for a late prediction or missed prediction.

I don’t want to overcomplicate it. The current system is very simple and has the benefit of just considering actual deviations from the final CET. But as you say there is a potential incentive to just predict something close to the LTA as often that will avoid large errors. 

We should not discourage people from predicting the LTA because sometimes that is the correct answer. But to my mind there is a greater level of skill in correctly predicting the CET when it is say 2C above or below the LTA. So perhaps that should be recognised in the scoring system? If the CET came in close to average in every month of the year then there would be no bonus points. 

If anyone has any thoughts on the above do let me know. We have plenty of time to ponder any potential changes for next year. Happy to stick with the status quo if that is the consensus. 

I quite like that idea but would it make more work for you?  If we just award marks for the person closest to an anomalous CET, they might win by a fluke guess.  I can see the reason to reward as you suggest but I think you’d have to do it incrementally.  Twenty extra marks for correctly guessing 2c above/below LTA, 19 marks for 1.9c above/below, 18 for 1.8c etc.  Oo-er!  Gets a bit complicated doesn’t it?  Much more work for you too!  

I’m just as happy with the way it is now though.  I think it works well but if you think it needs to be spread out a bit more, you could ask for all predictions to be to two decimal places.  I’ll go with whatever you decide!  

 

Market Warsop, North Nottinghamshire.

Join the fun of the monthly CET competition. Last chance to join in the yearly comp is 2nd March. Discuss monthly temperatures and records.

Offline ARTzeman  
#89 Posted : 25 June 2019 10:54:14(UTC)
ARTzeman

Rank: Advanced Member

Joined: 14/07/2012(UTC)
Posts: 25,576
Man
Location: Peasedown St John. N.E. Sommerset

Met Office Hadley        13.7c.       Anomaly       -0.3c. Provisional to 24th.

Metcheck                     13.97c       Anomaly       -0.18c

Netweather                  14.31c       Anomaly       -0.22c

Mean of My 10 Stations 14.38c.  The Difference ~ 0.95c.   

Some people walk in the rain.

Others just get wet.

Offline Stormchaser  
#90 Posted : 25 June 2019 12:29:33(UTC)
Stormchaser

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Posts: 11,734
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That idea is one I've sometimes wondered about too GW  - but each time, I've decided not to put it forward because of the inherent complexity that Caz has highlighted very nicely.

Maybe a threshold approach would be manageable though - e.g. if both estimate and observed are differences to LTA (having turned negatives to positives) of >=1.0*C < 1.5*C, bonus reduction of 0.1*C, if both are >=1.5*C < 2.0*C, reduction 0.2*C, if both >=2.0*C < 2.5*C, reduction 0.3*C... and so on.

Depends on how you feel about the extra workings really. I suppose, once implemented in Excel, it would all calculate from same input CET estimates to save effort?

If you have any problems or queries relating to TWO you can Email twomoderationteam@gmail.com :)

Homeland: Rural Mid-West Hants nearly 10 miles S of Salisbury (near Fordingbridge). Current location: Homeland

2018's Homeland Extremes:

T-Max: 30.9*C 8th July | T-Min: -7.7*C 28th Feb | Wettest Day: 19.2mm 14th October | Ice Days: 4 (28 Feb - 2 Mar & 18 Mar)

Keep Calm and Forecast On

Offline Caz  
#91 Posted : 25 June 2019 13:57:20(UTC)
Caz

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Originally Posted by: Stormchaser Go to Quoted Post

That idea is one I've sometimes wondered about too GW  - but each time, I've decided not to put it forward because of the inherent complexity that Caz has highlighted very nicely.

Maybe a threshold approach would be manageable though - e.g. if both estimate and observed are differences to LTA (having turned negatives to positives) of >=1.0*C < 1.5*C, bonus reduction of 0.1*C, if both are >=1.5*C < 2.0*C, reduction 0.2*C, if both >=2.0*C < 2.5*C, reduction 0.3*C... and so on.

Depends on how you feel about the extra workings really. I suppose, once implemented in Excel, it would all calculate from same input CET estimates to save effort?

Oooh!  I vaguely remember Excel formulae from the distant past!  It would only require the same input once the formula has been changed.   

And yes, of course, I forgot to turn the figures to negative and they’d need to be right of decimal rather than whole figures. eg with a 2c LTA anomaly the awarded points would be -0.20, for 1.9c the awarded points would be -0.19 etc. 

That would work!  I’m still happy with it as it is but it does make sense to reward accuracy with greater anomalies.

Market Warsop, North Nottinghamshire.

Join the fun of the monthly CET competition. Last chance to join in the yearly comp is 2nd March. Discuss monthly temperatures and records.

Offline Global Warming  
#92 Posted : 25 June 2019 18:39:35(UTC)
Global Warming

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Joined: 07/10/2006(UTC)
Posts: 6,107

Originally Posted by: Stormchaser Go to Quoted Post

Maybe a threshold approach would be manageable though - e.g. if both estimate and observed are differences to LTA (having turned negatives to positives) of >=1.0*C < 1.5*C, bonus reduction of 0.1*C, if both are >=1.5*C < 2.0*C, reduction 0.2*C, if both >=2.0*C < 2.5*C, reduction 0.3*C... and so on.

That is exactly what I have in mind. Should be relatively simple to implement and manage.

Chineham, Basingstoke, Hampshire, 86m asl
Offline Caz  
#93 Posted : 25 June 2019 18:53:05(UTC)
Caz

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Originally Posted by: Global Warming Go to Quoted Post

 

That is exactly what I have in mind. Should be relatively simple to implement and manage.

 That’s it then!  If the two technical brains of the thread agree, it has to be a good idea!  

Erm, I did put my simple two pen’orth in as well!  

Market Warsop, North Nottinghamshire.

Join the fun of the monthly CET competition. Last chance to join in the yearly comp is 2nd March. Discuss monthly temperatures and records.

Offline Stormchaser  
#94 Posted : 25 June 2019 19:26:35(UTC)
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& Nice one Caz 

If you have any problems or queries relating to TWO you can Email twomoderationteam@gmail.com :)

Homeland: Rural Mid-West Hants nearly 10 miles S of Salisbury (near Fordingbridge). Current location: Homeland

2018's Homeland Extremes:

T-Max: 30.9*C 8th July | T-Min: -7.7*C 28th Feb | Wettest Day: 19.2mm 14th October | Ice Days: 4 (28 Feb - 2 Mar & 18 Mar)

Keep Calm and Forecast On

Offline Caz  
#95 Posted : 25 June 2019 20:21:24(UTC)
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Originally Posted by: Stormchaser Go to Quoted Post

& Nice one Caz 

Hmm!  I’m not sure I made my point very clear. I was thinking:  

If the LTA is 15 but the actual figure is 17 and someone correctly predicts it, they get a -0.2 bonus award.  Then if the person coming second predicts 16.9c, they get a -0.19 bonus.  The person coming third guessed 16.6c and gets a 0.16 bonus etc.  each person getting a bonus down to LTA at a rate of 10% of the anomaly.  Of course someone predicting 17.1c also gets a -0.19 bonus etc.  Hope that makes sense!

But if someone predicts 16.65 they'd get a -0.165 bonus!  3 decimal places!  Is that a step too far?  It’s only a teeny tiny digit but am I complicating matters?  Bed time for me!  

Market Warsop, North Nottinghamshire.

Join the fun of the monthly CET competition. Last chance to join in the yearly comp is 2nd March. Discuss monthly temperatures and records.

Offline lanky  
#96 Posted : 26 June 2019 08:42:00(UTC)
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Originally Posted by: Global Warming Go to Quoted Post

 

That is exactly what I have in mind. Should be relatively simple to implement and manage.

I think you Stormchaser and Caz are all pretty much in agreement on how it could work

From how I read them I think you are proposing something like this as a logical extension to the current rules

 

Definitions

CET Anomaly = absolute difference between this months CET and the LTA (Using 1961-90 for easy Met Office referral)
CET Estimate = the exact guess of the competitor for this month's CET to up to 2 decimal places expressed as an estimated anomaly
CET = The final value of the Met Office CET (to 1 decimal place as in the "official" version)
CET Error = The absolute value of the difference betwen the CET Estimate and the "Offical" CET as defined above

IF CET Anomaly < 2 then no bonus calcs this month (average month)
IF CET Error >= 1 Then no bonus for this player (not close enough for a bonus)

=Bonus for exceptional months and close guesses

Bonus Adjustment  = -(CET Anomaly-CET Error)/10

This will give a bonus correction in the range of about -0.5 to -0.1 to add to the straight estimating error

If the CET Anomaly is 5C and the estimate is spot on it would be (5-0)/10
If the CET Anomaly is 2C and the estimate is 1C out it would be (2-1)/10

These parameters can easily be tweaked but it is worth noting that negative anomalies over 2C are much more rare than positive ones and this formula does not reflect that fact/

Taking the period Jan 2010 to May 2019 (113 months) there have been 19 positve anomalies of 2C or more but only 3 negative ones


Edited by user 26 June 2019 08:58:43(UTC)  | Reason: Not specified

Martin

Richmond, Surrey

Offline Caz  
#97 Posted : 26 June 2019 11:18:03(UTC)
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Hmm.  Just a few minor details to think about.  How significant the difference needs to be for the bonus system to kick in?  Do you set it at a specific figure such as anything greater than 1c, 2c or something else?  Do you award it to just one person or incrementally to those predicting between the LTA and actual?  I think incrementally is the fairer option and it stops anyone getting too far in front.

Do you NOT start it at a specific difference and instead start it at ANY difference, bearing in mind the greater the difference, the greater the bonus.  I think that could work and incremental bonuses could be added right to the point of the LTA, decreasing the closer they get. 

Only thoughts.  I just love these threads, so I’m absolutely sure I’ll be happy however it’s done and I’ll still be happy to prop up the table from the bottom!  

 

Market Warsop, North Nottinghamshire.

Join the fun of the monthly CET competition. Last chance to join in the yearly comp is 2nd March. Discuss monthly temperatures and records.

Offline Col  
#98 Posted : 26 June 2019 11:30:40(UTC)
Col

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Joined: 12/01/2013(UTC)
Posts: 857
Location: Bolton 160m asl

All this talk of over-complicated systems is doin' my head in!
It's a CET prediction competion. Whoever gets closest to the value wins. There shouldn't be layer upon layer of compexity about it. KISS!

Edited by user 26 June 2019 11:31:51(UTC)  | Reason: Not specified

Col

Bolton, Lancashire

160m asl

Snow videos:

http://www.youtube.com/c...UC3QvmL4UWBmHFMKWiwYm_gg

Offline ARTzeman  
#99 Posted : 26 June 2019 11:31:12(UTC)
ARTzeman

Rank: Advanced Member

Joined: 14/07/2012(UTC)
Posts: 25,576
Man
Location: Peasedown St John. N.E. Sommerset

Met Office Hadley          13.9c.      Anomaly     -0.2c. Provisional to 25th.

Metcheck                       14.02c     Anomaly     -0.13c

Netweather                    14.41c     Anomaly     0.32c.

Mean Of my 10 stations   14.37c.   Difference   -0.96c.

Some people walk in the rain.

Others just get wet.

Offline Col  
#100 Posted : 26 June 2019 11:35:32(UTC)
Col

Rank: Advanced Member

Joined: 12/01/2013(UTC)
Posts: 857
Location: Bolton 160m asl

Originally Posted by: ARTzeman Go to Quoted Post

Met Office Hadley          13.9c.      Anomaly     -0.2c. Provisional to 25th.

Metcheck                       14.02c     Anomaly     -0.13c

Netweather                    14.41c     Anomaly     0.32c.

Mean Of my 10 stations   14.37c.   Difference   -0.96c.

Looking good for my prediction of 14.4C but are we expecting a downgrade this month?

Edited by user 26 June 2019 11:46:40(UTC)  | Reason: Not specified

Col

Bolton, Lancashire

160m asl

Snow videos:

http://www.youtube.com/c...UC3QvmL4UWBmHFMKWiwYm_gg

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