A real-time verification system for APCC participating single-model and multi-model predictions has been developed to assess the quality of the predictions in the APCC operational environment. This system is based on recommendations from the Commission for Basic Systems (CBS) of the World Meteorological Organization (WMO) Standardized Verification System for long-range forecasts (SVS-LRF) in terms of verification metrics and regions. The developed verification system for real-time forecast issues monthly three-month overlapping seasons for upcoming 3-month predictions (from a combination of 1-tier and 2-tier models) and 6-month predictions (from 1-tier models), with a 1-month lead time.

In addition, efforts have been made to improve the current version of the verification system for retrospective forecasts (hindcasts) operationally implemented at the APCC by considering the recent improvements of the prediction system (e.g., extended lead time, SST and ENSO prediction). This report provides a detailed explanation of the developed/improved verification system for real-time forecasts/hindcasts and preliminary documentation of the current status of the APCC operational multi-model performance, particularly focusing on real-time predictions of temperature and precipitation for the period of 2008JFM–2013/14DJF. Skill comparisons of other operational centers providing seasonal forecasts are also discussed.

1. INTRODUCTION

2. Data

a. Model Data

b. Observed Data

3. Research Results

a. APCC Operational Verification System

1) Real-Time Verification System

2) Hindcast Verification System

b. Preliminary Results of APCC Real-Time Forecasts

1) APCC Single-Model vs Multi-model Predictions

2) General Performance of APCC MME Prediction

3) Comparison of Other Operation Centers

4. Concluding Remarks

APPENDIX A : Verification Metrics

1. Deterministic Forecast

2. Probabilistic Forecast

REFERENCES

TABLES

APPENDIX TABLES

FIGURE CAPTIONS

APPENDIX FIGURE CAPTIONS

FIGURES