NEWxSFC - Interim Summary…as of 07 JAN 2009

AVG SUMSQ

AVG STP

AVG Total Absolute

AVG Absolute

Mean RSQ

 

Previous Ranks

Rank

Forecaster

Class

Total STN 4casts

Error (")

Error Z

% MPRV over AVG

Rank

4cast (")

Error

Error Z

% MPRV over AVG

Rank

Error (")

Error Z

% MPRV over AVG

Rank

Error (")

Error Z

%MPRV over AVG

Rank

RSQ

RSQ Z

% MPRV over AVG

Rank

Forecaster

2

1

donsutherland1

Chief

49

60

-1.082

53%

2

61.6

8.1

-0.546

44%

5

19.67

-1.187

35%

2

1.21

-1.095

35%

2

79.0%

0.815

16%

4

donsutherland1

5

2

shanabe

Senior

46

78

-0.659

30%

5

55.8

14.7

0.010

2%

8

23.85

-0.591

20%

5

1.51

-0.598

18%

5

74.5%

0.456

10%

6

shanabe

3

3

dmcguriman

Senior

53

92

-0.492

24%

6

73.6

14.9

-0.006

3%

9

28.30

-0.291

7%

7

1.57

-0.514

17%

6

77.2%

0.633

13%

5

dmcguriman

4

4

herb @maws

Senior

50

96

-0.319

14%

7

66.4

13.3

-0.145

13%

8

27.38

-0.299

7%

7

1.66

-0.363

12%

7

71.2%

0.226

5%

8

herb @maws

6

5

TQ

Senior

51

135

-0.266

15%

7

74.3

16.3

0.256

-19%

9

33.40

-0.328

9%

6

1.99

0.024

2%

8

76.4%

0.271

5%

7

TQ

10

6

Donald Rosenfeld

Senior

60

138

-0.132

7%

8

96.6

15.2

0.346

-28%

5

39.33

0.264

-8%

9

1.91

-0.080

3%

7

70.4%

-0.179

-4%

8

Donald Rosenfeld

12

7

NYNJPAWeather

Rookie

52

174

-0.118

10%

8

89.0

8.5

-0.582

48%

7

38.18

-0.133

8%

7

2.20

-0.100

5%

8

69.0%

-0.159

-2%

9

NYNJPAWeather

11

8

ilibov

Senior

63

181

0.288

-12%

9

72.5

19.8

0.441

-34%

10

42.19

0.562

-16%

10

2.00

0.031

1%

9

73.3%

0.019

0%

8

ilibov

13

9

Don Rooney

Senior

48

165

0.826

-41%

13

85.5

26.9

1.082

-74%

14

36.05

0.701

-20%

12

2.32

0.691

-21%

12

71.4%

0.071

5%

8

Don Rooney

15

10

jackzig

Senior

56

270

1.203

-60%

12

76.3

11.3

-0.405

30%

7

56.58

1.489

-45%

14

2.95

1.270

-36%

13

35.3%

-2.248

-49%

14

jackzig

14

11

weatherT

Rookie

42

211

1.239

-55%

14

49.7

34.5

0.941

-103%

11

42.52

0.981

-30%

13

2.97

1.792

-62%

13

66.8%

-0.287

-2%

10

weatherT

 

 

There have been four (4) snowstorm forecasting Contests to date.  Under the ‘two-thirds’ rule…forecasters who have entered at least three (3) forecasts are included in this interim summary.

 

To qualify for ranking in the Interim and final ‘End-of-Season’ standings…a forecaster must enter at least two-thirds of all Contests.  If a forecaster has made more than enough forecasts to qualify for ranking…only the lowest SUMSQ Z-scores necessary to qualify are used in the computing the average.  IOW…if you made nine forecasts…only your six best SUMSQ Z-scores are used to evaluate your season-to-date performance.  You can think of it as dropping the worse quiz score before your final grade is determined.  The reason we have this rule is to 1) make it possible to miss entering a forecast or two throughout the season and still be eligible for Interim and ‘End-of Season’ ranking and 2) encourage forecasters to take on difficult and/or late-season storms without fear about how a bad forecast might degrade their overall 'season-to-date' performance score(s).

 

The mean normalized ‘SUMSQ error’ is the Contest/s primary measure of forecaster performance.  This metric measures how well the forecaster/s expected snowfall 'distribution and magnitude' for _all_ forecast stations captured the 'distribution and magnitude' of _all_ observed snowfall amounts.  A forecaster with a lower average SUMSQ Z Score has made more skillful forecasts than a forecaster with higher average SUMSQ Z Score.

 

The 'Storm Total Precipitation error’ statistic is the absolute arithmetic difference between a forecaster/s sum-total snowfall for all stations and the observed sum-total snowfall.  This metric…by itself…is not a meaningful measure of skill…but can provide additional insight of forecaster bias.

 

The 'Total Absolute error' statistic is the average of your forecast errors regardless of whether you over-forecast or under-forecast.  This metric measures the magnitude of your errors.

 

The 'Average Absolute Error' is the forecaster/s ‘Total Absolute Error’ divided by the number of stations where snow was forecast or observed.

 

The ‘RSQ error’ statistic is a measure of the how well the forecast captured the variability of the observed snowfall.  Combined with the SUMSQ error statistic…RSQ provides added information about how strong the forecaster/s ‘model’ performed.