1. Tutorial

2. Other post-processing approaches … 1) Bayesian Model Averaging (BMA) – Raftery et al (1997) 2) Analogue approaches – Hopson and Webster, J. Hydromet (2010) 3) Kalman Filter with analogues – Delle Monache et al (2010) 4) Quantile regression – Hopson and Hacker, MWR (under review) 5) quantile-to-quantile (quantile matching) approach – Hopson and Webster J. Hydromet (2010) … many other approaches …

3. Significance of Weather Forecast Uncertainty Bangladesh Discharge Forecasts 3 day 4 day Precipitation Forecasts 1 day4 day 7 day10 day 1 day4 day 7 day 10 day Discharge Forecasts Transformed into

5. Calculating the rank histogram … obs Forecast PDF Flow rate [m 3 /s] obs Forecast PDF Flow rate [m 3 /s] First occurrence Second occurrence => Count in bin 6 => Count in bin 3 Get data from shared disk: AfricaColloqData.txt Place in working directory (desktop will work) and read in spreadsheet … Generate histogram plot using spreadsheet Next, redo in R

6. Brier Score y = forecasted event occurence o = observed occurrence (0 or 1) i = sample # of total n samples => Note similarity to MSE Brier skill score -- Next, approximately determine 75 th quantile From the July observation data (let me know your answer before proceeding further) -- Then calculate the Brier score for probability of occurrence below this threshold. -- Then, using the climatology mean (using the July obs data – what is the value?), calculate The Brier skill score for this reference forecast (what’s your answer?). Is there a better reference forecast? Try this. Answer? -- Finally, using this same threshold, calculate The reliability diagram values (4 probabilities) And plot using spreadsheet (what are the Probabilities?) Note: for this exercise, we will use a more “discrete” form for the ensemble probability, in which you just count the # of ensemble members above or below the threshold to calculate the probability (arguably less exact then interpolating) Next steps … do both in spreadsheet and R

7. Reliability Diagram From Eumetcal module on forecast verification