Real-time ensemble RTFDDA forecasting system combines real-time WRF-based FDDA technologies and a probabilistic forecast calibration technology for producing reliable real-time probabilistic wind/weather data assimilation and forecasting. The probabilistic mesoscale weather forecasting of this real-time system can provide more accurate forecasts of various weather variables and weather phenomena (lightning, severe winds, torrential rain, blizzard, icing, etc.) that threaten electric-power grid safety and generate important information of flow-dependent uncertainties of these weather variables and phenomena. The NCAR real-time ensemble FDDA systems have been deployed and used to support routine tests at the U.S. Army test ranges, Xcel Energy for wind-power integration, and also in northwestern China for wind-power forecast by SGCC.