Development and evaluation of convective scale data assimilation techniques for very short term high impact weather forecasting

Juanzhen Sun

National Center for Atmospheric Science

Convective-scale data assimilation has different data sources, requirements and challenges from the large-scale data assimilation. In this talk, several data assimilation techniques, such as nudging, 3DVAR, 4DVAR, and EnKF, that are designed for the assimilation of high-resolution data, particularly radar observations are reviewed. Performances of these data assimilation techniques are evaluated in multiple case studies and retrospective studies. The evaluation is based on their capabilities in improving the 0-12 hour prediction of convective precipitation using the Weather Research and Forecasting model.