Recommended Prerequisite
This training complements the lessons that are presented in the module, Introduction to Verification of Hydrologic Forecasts. You should complete that module if you are not familiar with the scores and graphic displays associated with hydrologic forecast verification.

http://www.meted.ucar.edu/hydro/verification/intro/
You can use this summary table from that module as a quick refresher. It shows the numerical ranges and optimal values of statistical measures as well as the ideal plot for graphical measures.

http://www.meted.ucar.edu/hydro/verification/intro/VerifSummaryPage/