Propagation of uncertainty from observing systems into NWP: COST‐731 Working Group 1

The COST‐731 Action is focused on uncertainty propagation in hydrometeorological forecasting chains. The goals and activities of the Action Working Group 1 can be subdivided by (1) describing and studying the impact of imperfect observations, mostly from radar, (2) exploiting radar data assimilation as a promising avenue for improved short‐range precipitation forecasts and (3) high‐resolution ensemble forecasting. Activities of Working Group 1 are presented along with their possible significance for hydrological applications.