The introduction of a WMO RA II Research Development Project /19th Hangzhou Asian Games Research Development Project on Convective-scale Ensemble Prediction and Application (HangzhouRDP)

Abstract: The 19th Asian Games has been held in Hangzhou, China from 23 September to 8 October 2023 and 22 to 28 October 2023 for Asian Para Games. Heavy rainfall and strong gust wind during the Asian Games have high impact on relevant events, especially on those outdoor activities. How to combine forecast uncertainty and to provide more reliable forecast and early warning services was still one of the major scientific and social challenges. WMO RA II Focal Points on Research intend to initiate a WMO RA II Research Development Project / 19th Hangzhou Asian Games Research Development Project on Convective-scale Ensemble Prediction and Application (HangzhouRDP). The Scientific objectives were as follows:

1) Understand the impact of multi-scale initial errors and model errors on the prediction of high-resolution models and ehe forecast uncertainty of local severe convective weather.

2) Demonstrate the improvement of forecasting and early warning capabilities at sub-kilometer scale and minute scale by utilizing the uncertainty information from ensemble forecast.

3) Develop convective-scale ensemble prediction, postprocessing and verification method at sub-kilometer  meter and minute scale.

4) Share the experience gained with RA II members through training courses.

The project has conducted demonstration and application by developing convective-scale Ensemble Prediction System (EPS, including 1 km deterministic model and 3 km ensemble model) and using minute scale multi-source observations, gain a deep understanding toward the influence of multi-scale initial errors and model errors on high-resolution model forecasts, understand the forecast uncertainty of local severe weather event, demonstrate the improvement of forecast and early warning services of weather events at hundred-meters scale and minute scale brought by uncertainly information of ensemble forecast, and provide technical methods and references for RA II members on carrying out forecast and early warning services of high-impact weather at hundred-meters scale and minute scale.The project was designed to be jointly led by Zhejiang Meteorological Bureau (ZMB) and Centre for Earth System Modeling and Prediction of China Meteorological Administration (CEMC), along with the participation of National Meteorological Centre (NMC), CMA Huafeng Group, and WMO Regional Training Centre Beijing (CMA Training Centre, CMATC). The project expected to run for two years, including system development, data transmission test, ensemble prediction system construction in half a year, and case study and forecast evaluation of societal/economic impact in one and a half years. The project focused on improving 0-36 h forecast and early warning capabilities of local rainfall and wind using uncertainty information from ensemble forecast.